Predictive role of molecular subtypes in response to neoadjuvant chemotherapy in breast cancer patients in Northeast China

Introduction: Breast cancer is increasingly regarded as a heterogeneous disease which can be classified into distinct molecular subtypes with prognostic significance. Materials and methods: ER, PR, HER2 and ki-67 were used to divided 102 breast cancers treated with neoadjuvant chemotherapy ( NCT ) into 4 subtypes: luminal A (ER+,PR+,HER2-, and ki-67 ≤14%), luminal B (ER+, PR+,HER2- and ki-67>14% ; ER+ and/or PR+, HER2+), HER2-overexpression (ER-, PR- and HER2+) and triple-negative (ER-, PR-,and HER2-). Results: Among 102 patients, a pCR was seen in 16 (15.7%) patients. The pathologic complete remission (pC) rates according to different subtypes are as follows: luminal A, 0 of 20 (0.0%), luminal B, 2 of 23 (8.7%), HER2-overexpressio,n 4 of 18 (22.2%), and triple-negative, 10 of 41 (24.4%) (p=0.041). In triple-negative subtype patients, the rates of pCR differed significantly among the 3 chemotherapy regimens with 5.6% (1/18) for CEF (cyclophosphamide, epirubicin and flurouracil), 20.0% (1/5) for TE (docetaxel and epirubicin) and 44.4% (8/18) for TCb (docetaxel and carboplatin) (p=0.024). In locally advanced breast cancer patients, the rates of pCR seem to differ among the 3 chemotherapy regimens with 6.7% (2/30) for CEF, 0.0% (0/8) for TE and 23.1% (6/26) for TCb, but this did not attain statistical significance (p>0.05). Conclusions: Molecular subtypes are good predictors for response to NCT in breast cancer patients in Northeast China. Compared with luminal A tumors, HER2-overexpression and triple-negative subtypes are more sensitive to NCT. For triple-negative breast cancer, we concluded that the TCb combination is a promising NCT regimen. Our results also indicated that the TCb combination is promising for the treatment of locally advanced breast cancer.     

A case–control study of reproductive factors associated with subtypes of breast cancer in Northeast China

Based on the expression of estrogen receptor (ER), progesterone receptor (PR) and HER2/neu (HER2), breast cancer is classified into several subtypes: luminal A (ER+ and/or PR+, HER2?), luminal B (ER+ and/or PR+, HER2+), HER2-overexpressing (ER?, PR?, and HER2+) and triple-negative (ER?, PR?, and HER2?). The aim of this case–control study is to determine reproductive factors associated with breast cancer subtypes in Chinese women. A total of 1,417 patients diagnosed with breast cancer in the First Affiliated Hospital, China Medical University, Shenyang, China between 2001 and 2009 and 1,587 matched controls without a prior breast cancer were enrolled. Personal interviews were conducted to obtain information on reproductive characteristics and clinical history. Relationships between the factors and the subtypes of breast cancer were examined using logistic regression to compute odds ratios (OR) and 95% confidence intervals (CI). Notably, luminal A (50.0%) was the most prevalent subtype relative to luminal B (15.10%), HER2-overexpressing (10.87%) and triple-negative (23.08%). Menarche at an early age was associated with a reduced risk of luminal A (OR, 2.35; 95% CI, 1.45–3.81). Breastfeeding protected parous women from any subtype of breast cancer. Postmenopause and spontaneous abortion were inversely associated with the risk of luminal tumors. By contrast, multiparity, family history of breast cancer and induced abortion increased the risk of breast cancer. Collectively, our findings suggest that reproductive factors such as age at menarche, parity, breastfeeding, menopausal status and abortion history have different effects on the subtypes of breast cancer in Chinese women.     

Immunohistochemical surrogate markers of breast cancer molecular classes predicts response to neoadjuvant chemotherapy

BACKGROUND:

Complete pathologic response to neoadjuvant chemotherapy (NACT) is predominantly seen in “ERBB2” and “basal‐like” tumors using expression profiling. We hypothesize that a similar response could be predicted using semiquantitative immunohistochemistry for estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2).

METHODS:

ER, PR, and HER2 were used to classify 359 tumors treated with NACT into 6 groups: luminal A (strong ER+, HER2 negative), luminal B (weak to moderate ER+, HER2 negative), triple negative (negative for ER, PR, and HER2), ERBB2 (negative for ER and PR, but HER2+), luminal A‐HER2 hybrid (strong ER+ and HER2+), and luminal B‐HER2 hybrid (weak to moderate ER+ and HER2+). Complete pathologic response was defined as absence of invasive carcinoma in the breast and regional lymph nodes.

RESULTS:

Thirteen percent (48 of 359) demonstrated complete pathologic response. The highest rate of complete pathologic response was seen in ERBB2 (33%; 19 of 57) and triple negative (30%; 24 of 79) tumor classes. Among the ER+ “molecular” group, the highest rate of complete pathologic response was seen among luminal B‐HER2 hybrid tumors, 8% (2 of 24). Remainder of ER+ tumors demonstrated a very low rate of complete pathologic response, 1.5% (3 of 198). The 5‐year survival for patients achieving complete pathologic response was 96% compared with 75% in patients that failed to achieve complete pathologic response. The overall survival was worse in the ER‐negative group (ERBB2 and triple negative) compared with the ER‐positive group.

CONCLUSIONS:

We confirm the recently defined “triple negative paradox,” or rather “hormone receptor negative paradox,” that despite the best response to NACT, ERBB2 and triple negative tumors show the worst overall survival because of higher relapse among those with residual disease. Cancer 2010. © 2010 American Cancer Society.     

Pathologic features and molecular phenotype by patient age in a large cohort of young women with breast cancer

Prior studies have suggested a higher prevalence of high grade, ER-negative, HER2-positive, and basal-like carcinomas in young women with breast cancer. However, the precise distribution of poor prognostic features in this population remains unclear. We examined the pathologic features and distribution of molecular phenotype in relation to patient age in a large group of young women (≤40?years) with invasive breast cancer. Medical records were reviewed for clinical characteristics, tumor stage, and receptor status. Pathologic features, including those features associated with basal-like carcinomas, were examined by central review. Using tumor grade and biomarker expression, cancers were categorized as luminal A (ER+ and/or PR+ and HER2-, histologic grade 1 or 2); luminal B (ER+ and/or PR+ and HER2+, or ER and/or PR+, HER2- and grade 3); HER2 (ER and PR- and HER2+); and triple negative (ER-, PR-, and HER2-). Among 399 women?of ≤40?years, 33% had luminal A tumors, 35% luminal B, 11% HER2 (ER-negative), and 21% triple negative. Compared to published results for all breast cancers, a greater proportion of young women had luminal B tumors, and a lesser proportion had luminal A. There were no significant differences in molecular phenotype, tumor stage or grade among the different age groups of young women. However, this population of young women presented with a different distribution of molecular phenotypes compared to the general population of women with breast cancer. These findings may have implications with regard to the etiology and prognosis of breast cancer in young women.     

Pattern of recurrence of early breast cancer is different according to intrinsic subtype and proliferation index

Introduction

Recurrence risk in breast cancer varies throughout the follow-up time. We examined if these changes are related to the level of expression of the proliferation pathway and intrinsic subtypes.

Methods

Expression of estrogen and progesterone receptor, Ki-67, human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR) and cytokeratin 5/6 (CK 5/6) was performed on tissue-microarrays constructed from a large and uniformly managed series of early breast cancer patients (N = 1,249). Subtype definitions by four biomarkers were as follows: luminal A (ER + and/or PR+, HER2-, Ki-67 <14), luminal B (ER + and/or PR+, HER2-, Ki-67 ≥14), HER2-enriched (any ER, any PR, HER2+, any Ki-67), triple-negative (ER-, PR-, HER2-, any Ki-67). Subtype definitions by six biomarkers were as follows: luminal A (ER + and/or PR+, HER2-, Ki-67 <14, any CK 5/6, any EGFR), luminal B (ER + and/or PR+, HER2-, Ki-67 ≥14, any CK 5/6, any EGFR), HER2-enriched (ER-, PR-, HER2+, any Ki-67, any CK 5/6, any EGFR), Luminal-HER2 (ER + and/or PR+, HER2+, any Ki-67, any CK 5/6, any EGFR), Basal-like (ER-, PR-, HER2-, any Ki-67, CK5/6+ and/or EGFR+), triple-negative nonbasal (ER-, PR-, HER2-, any Ki-67, CK 5/6-, EGFR-). Each four- or six-marker defined intrinsic subtype was divided in two groups, with Ki-67 <14% or with Ki-67 ≥14%. Recurrence hazard rate function was determined for each intrinsic subtype as a whole and according to Ki-67 value.

Results

Luminal A displayed a slow risk increase, reaching its maximum after three years and then remained steady. Luminal B presented most of its relapses during the first five years. HER2-enriched tumors show a peak of recurrence nearly twenty months post-surgery, with a greater risk in Ki-67 ≥14%. However a second peak occurred at 72 months but the risk magnitude was greater in Ki-67 <14%. Triple negative tumors with low proliferation rate display a smooth risk curve, but with Ki-67 ≥14% show sharp peak at nearly 18 months.

Conclusions

Each intrinsic subtype has a particular pattern of relapses over time which change depending on the level of activation of the proliferation pathway assessed by Ki-67. These findings could have clinical implications both on adjuvant treatment trial design and on the recommendations concerning the surveillance of patients.     

Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios are Not Different among Breast Cancer Subtypes

Background: Breast cancer is a heterogeneous complex of diseases comprising different subtypes that have different treatment responses and clinical outcomes. Systemic inflammation is known to be associated with poor prognosis in many types of cancer. The neutrophil / lymphocyte ratio (NLR) and platelet / lymphocyte ratio (PLR) are factors used as indicators of inflammation. In this study, we evaluated NLR and PLR ratios in breast cancer subtypes. Methods: A total of 255 breast cancer patients were evaluated retrospectively. Patients were classified into three subtypes: estrogen receptor (ER)- or progesterone receptor (PR)-positive tumors were classified as luminal tumors; human epidermal growth factor receptor-2 (HER2)-overexpressed and ER-negative tumors were classified as HER2-positive tumors; and ER, PR, and HER2-negative tumors were classified as triple-negative tumors. The NLR and PLR were calculated. Results: The median NLR and PLR were 3 (0.37–37,1) and 137 (37.1–421.3), respectively. 66.7% of the patients were luminal type, 19.2% were HER2 positive, and 14.1% were triple negative. NLR was not associated with grade (p: 0.412), lymphovascular invasion (p: 0.326), tumor size (p: 0.232) and metastatic lymph node involvement (p: 0.406). PLR was higher in the patients with lymph node metastasis than in those without lymph node metastasis (p: 0.03). The NLR was 2 in the luminal group, 1.8 in the HER2-positive group, and 1.9 in the triple-negative group, but the differences were not significant(p: 0.051). PLR was 141 in the luminal group, 136 in the HER2-positive group, and 130 in the triple-negative group, but the differences were not significant. Conclusion: We could not find any significant differences for NLR and PLR according to breast cancer subtypes.     

Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size

Objective: Breast carcinoma (BC) is a heterogeneous disease that exhibits variation in biological behaviour, prognosis and response to therapy. Molecular classification is generally into Luminal A, Luminal B, HER2+ and triple negative/basal-like, depending on receptor characteristics. Clinical factors that determined the BC prognosis are age and tumor size. Since information on molecular subtypes of Indonesian BCs is limited, the present study was conducted, with attention to subtypes in relation to age and tumor size. Methods: A retrospective cross-sectional study of 247 paraffin-embedded samples of invasive BC from Dr. Sardjito General Hospital Yogyakarta in the year 2012- 2015 was performed. Immunohistochemical staining using anti- ER, PR, HER2, Ki-67 and CK 5/6 antibodies was applied to classify molecular subtypes. Associations with age and tumor size were analyzed using the Chi Square Test. Results: The Luminal A was the most common subtype of Indonesian BC (41.3%), followed by triple negative (25.5%), HER2 (19.4%) and luminal B (13.8%). Among the triple negative lesions, the basal-like subtype was more frequent than the non basal-like (58.8 % vs 41.2%). Luminal B accounted for the highest percentage of younger age cases (< 40 years old) while HER2+ was most common in older age (> 50 years old) patients. Triple negative/basal-like were commonly large in size. Age (p = 0.080) and tumor size (p = 0.462) were not significantly associated with molecular subtypes of BC. Conclusion: The most common molecular subtype of Indonesian BC is luminal A, followed by triple-negative, HER2+ and luminal B. The majority of triple-negative lesions are basal-like. There are no association between age and tumor size with molecular subtypes of Indonesian BCs.     

Triple negative breast cancer in Korea-distinct biology with different impact of prognostic factors on survival

We analyzed breast cancer subtypes using Korean Breast Cancer Society Registration Program data to compare clinical features and prognosis for triple-negative breast cancer (TNBC). A cohort of 26,767 breast cancer patients were divided in four groups: luminal A (ER+ and/or PR+, HER2−), luminal B (ER+ and/or PR+ HER2+), HER2+ (ER−, PR−, HER2+), and triple-negative (ER−, PR−, HER2−). Clinicopathologic factors were evaluated. The luminal A (14,437 patients, 53.9%) subtype was the largest in our study. Compared with luminal A subtype, TNBC correlated with younger age, more aggressive characteristics and poor overall survival and breast cancer-specific survival. The hazard rate showed a peak at 24 months for the TNBC subtype, but after 60 months, risk was similar to that of the luminal A subtype. Higher T, N stage and histologic grade, and lymphatic and vascular invasion showed poor prognosis in TNBC patients, but on multivariate analysis only histologic grade and ki-67 status were related. Young age was related to poor prognosis in the luminal A subtype, however, age was not related to prognosis in the TNBC subtype. Of the 5,586 TNBC patients, 282 patients (7.11%) expired within 3 years of diagnosis. T and N stage and grade were significantly associated with prognosis on multivariate analysis. TNBC subtype is characterized by younger age with poorer outcome. However, younger age is not related to prognosis, and mortality risk decreases to that of the luminal A subtype, which is known to have the best prognosis after a few years.     

Immunohistochemistry Subtypes (ER/PR/HER) of Breast Cancer: Where Do We Stand in the West of Saudi Arabia?

In Saudi Arabia, cancer of breast is ranked the most frequent neoplasm and second source of cancer deathin the female population. Breast cancer (BC) fast diagnosis, prognosis and medication management necessitate,these days, immunohistochemistry (IHC) assessment of hormone receptors and HER2 expression profile. Thepresent report defines the IHC profile of ER, PR and HER2 in Saudi female breast neoplasms of ductal andlobular types and associations ER, PR and HER2 expression patterns with various clinicopathological factors(age, type of tumor, size, laterality, histological grade, and involvement of axillaries lymph nodes). Ninety ninecases of breast tumors were recruited from the pathology department archive of King Abdulaziz UniversityHospital, Kingdom of Saudi Arabia. ER, PR and HER2 expression was assessed using IHC staining. Ductalcarcinomas with a variety of histological grades constituted 88 (88.8%) of total cases. Seventy four (77.8%), 59(62.1%), and 35 (36.8%) of ductal carcinomas showed positive staining for ER, PR and HER2, in that order.Remaining breast cancer cases were four (4%) lobular carcinomas and two (2%) mixed form of ductal andlobular types, which were ER+, PR+, and HER2-. Breast cancer expression pattern of ER, PR and HER2 inSaudi female is different from that of Tunisian and Jordanian female populations and closer to the expressionpattern of Egyptian, Lebanese, Iraqi and western country females. Furthermore, the present study found twoIHC patterns of breast cancer ER+/PR-/HER2+ (5%) and ER+/PR-/HER2- (11.1%), which had not been reportedin other Arabic studies. Thus the rates of IHC expression patterns in breast cancer show some variation amongArabic female populations.     

Differences in subtype distribution between screen-detected and symptomatic invasive breast cancer and their impact on survival

Purpose

Stage shift is considered a major reason for more favorable outcomes in patients with screen-detected breast cancer. However, even after adjusting for clinical stage, unresolved issues concerning the reasons for a survival benefit associated with screening programs remain. This study aims to evaluate differences in subtype distribution and outcomes among patients with screen-detected and symptomatic invasive breast cancer and assess whether variations in subtype distribution could explain differences in prognosis.

Methods

Survival analysis was performed to estimate the likelihood of distant recurrence and death in 1132 patients. Subtypes were defined as luminal A [estrogen receptor (ER)+ and/or progesterone receptor (PR)+, human epidermal growth factor receptor 2 (HER2)?, and Ki67 low], luminal B (HER2?) (ER+ and/or PR+, HER2?, and Ki67 high), luminal B (HER2+) (ER+ and/or PR+ and HER2+), HER2 overexpressing (ER?, PR?, and HER2+), and triple negative (ER?, PR?, and HER2?).

Results

Screen-detected cancers had favorable clinicopathological characteristics, such as smaller tumor size and a lower frequency of lymph node involvement. Women with screen-detected cancers had a survival advantage. Subtype distribution differed significantly among women with screen-detected and symptomatic cancer. Screen-detected cancers were more likely to be luminal A and less likely to be HER2 overexpressing or triple negative cancer compared with symptomatic cancers (luminal A 61.3 vs. 44.2%, HER2 overexpressing 4.0 vs. 8.0%, triple negative 8.0 vs. 15.9%). Node status, mode of detection, and subtype were independent prognostic factors in the multivariate analysis.

Conclusions

Differences in subtype distribution between screen-detected and symptomatic cancer could partially explain differences in outcomes.

     

Association between mammographic density and basal-like and luminal A breast cancer subtypes

Introduction

Mammographic density is a strong risk factor for breast cancer overall, but few studies have examined the association between mammographic density and specific subtypes of breast cancer, especially aggressive basal-like breast cancers. Because basal-like breast cancers are less frequently screen-detected, it is important to understand how mammographic density relates to risk of basal-like breast cancer.

Methods

We estimated associations between mammographic density and breast cancer risk according to breast cancer subtype. Cases and controls were participants in the Carolina Breast Cancer Study (CBCS) who also had mammograms recorded in the Carolina Mammography Registry (CMR). A total of 491 cases had mammograms within five years prior to and one year after diagnosis and 528 controls had screening or diagnostic mammograms close to the dates of selection into CBCS. Mammographic density was reported to the CMR using Breast Imaging Reporting and Data System categories. The expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 1 and 2 (HER1 and HER2), and cytokeratin 5/6 (CK5/6) were assessed by immunohistochemistry and dichotomized as positive or negative, with ER+ and/or PR+, and HER2- tumors classified as luminal A and ER-, PR-, HER2-, HER1+ and/or CK5/6+ tumors classified as basal-like breast cancer. Triple negative tumors were defined as negative for ER, PR and HER2. Of the 491 cases 175 were missing information on subtypes; the remaining cases included 181 luminal A, 17 luminal B, 48 basal-like, 29 ER-/PR-/HER2+, and 41 unclassified subtypes. Odds ratios comparing each subtype to all controls and case-case odds ratios comparing mammographic density distributions in basal-like to luminal A breast cancers were estimated using logistic regression.

Results

Mammographic density was associated with increased risk of both luminal A and basal-like breast cancers, although estimates were imprecise. The magnitude of the odds ratio associated with mammographic density was not substantially different between basal-like and luminal A cancers in case–control analyses and case-case analyses (case-case OR = 1.08 (95% confidence interval: 0.30, 3.84)).

Conclusions

These results suggest that risk estimates associated with mammographic density are not distinct for separate breast cancer subtypes (basal-like/triple negative vs. luminal A breast cancers). Studies with a larger number of basal-like breast cancers are needed to confirm our findings.     

Breast cancer-specific survival by clinical subtype after 7 years follow-up of young and elderly women in a nationwide cohort

Age and tumor subtype are prognostic factors for breast cancer survival, but it is unclear which matters the most. We used population-based data to address this question. We identified 21,384 women diagnosed with breast cancer at ages 20–89 between 2005 and 2015 in the Cancer Registry of Norway. Subtype was defined using estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (HER2) status as luminal A-like (ER+PR+HER2-), luminal B-like HER2-negative (ER+PR-HER2-), luminal B-like HER2-positive (ER+PR+/-HER2+), HER2-positive (ER-PR-HER2+) and triple-negative (TNBC) (ER-PR-HER2-). Cox regression estimated hazard ratios (HR) for breast cancer-specific 7-year survival by age and subtype, while adjusting for year, grade, TNM stage and treatment. Young women more often had HER2-positive and TNBC tumors, while elderly women (70–89) more often had luminal A-like tumors. Compared to age 50–59, young women had doubled breast cancer-specific mortality rate (HR = 2.26, 95% CI 1.81–2.82), while elderly had two to five times higher mortality rate (70–79: HR = 2.25, 1.87–2.71; 80–89: HR = 5.19, 4.21–6.41). After adjustments, the association was non-significant among young women but remained high among elderly. Young age was associated with increased breast cancer-specific mortality among luminal A-like subtype, while old age was associated with increased mortality in all subtypes. Age and subtype were strong independent prognostic factors. The elderly always did worse, also after adjustment for subtype. Tumor-associated factors (subtype, grade and stage) largely explained the higher breast cancer-specific mortality among young. Future studies should address why luminal A-like subtype is associated with a higher mortality rate in young women.     

Locoregional recurrence after breast cancer surgery: a systematic review by receptor phenotype

Molecular subtyping confirms that breast cancer comprises at least four genetically distinct entities based on the expression of specific genes including estrogen receptor (ER), progesterone receptor (PR), and HER2/neu receptor. The quantitative influence of subtype on ipsilateral locoregional recurrence (LRR) is unknown. The aim of this study was to systematically appraise the influence of breast cancer subtype on LRR following breast conserving therapy (BCT) and mastectomy. A comprehensive search for studies examining outcomes after BCT and/or mastectomy according to breast cancer subtype was performed using Medline and cross-referencing available data. Reviews of each study were conducted and data extracted to perform meta-analysis. Primary outcome was LRR related to breast cancer subtype. A total of 12,592 breast cancer patients who underwent either BCT (n = 7,174) or mastectomy (n = 5,418) were identified from 15 studies. Patients with luminal subtype tumors (ER/PR +ve) had a lower risk of LRR than both triple-negative (RR 0.38; 95% CI 0.23-0.61); and HER2/neu-overexpressing (RR 0.34; 95% CI 0.26-0.45) tumors following BCT. Luminal tumors were also less likely to develop LRR than HER2/neu-overexpressing (OR 0.69; 95% CI 0.54-0.89) or triple-negative tumors (OR 0.61; 95% CI 0.46-0.79) after mastectomy. HER2/neu-overexpressing tumors have increased risk of LRR compared to triple-negative tumors (RR 1.44; 95% CI 1.06-1.95) following BCT but there was no difference in LRR between HER2/neu-overexpressing and triple-negative tumors following mastectomy (RR 0.91; 95% CI 0.68-1.22). Luminal tumors exhibit the lowest rates of LRR. Patients with triple-negative and HER2/neu-overexpressing breast tumors are at increased risk of developing LRR following BCT or mastectomy. Breast cancer subtype should be taken into account when considering local control and identifies those at increased risk of LRR, who may benefit from more aggressive local treatment.     

Breast cancer subtypes and survival in patients with brain metastases

Introduction

Brain metastases (BM) occur in up to one third of patients with metastatic breast cancer (MBC), whose incidences and prognoses by breast cancer subtypes in BM have not been well delineated.

Methods

Retrospective survival analyses were performed in 126 BM patients from 805 MBC patients treated at the National Cancer Center between August 2001 and April 2006, according to clinical characteristics, breast cancer subtypes, and receipt of trastuzumab. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth receptor-2 (HER2) statuses were tested by immunohistochemical (IHC) staining, and HER2 FISH analysis conducted for IHC 2+.

Results

The proportion of HER2+/ER- (29% vs 16%) and triple-negative (37% vs 25%) tumors was higher in the 126 BM patients than those without BM. While median survival after recurrence was longer in patients with luminal A disease (median survival of luminal A vs luminal B vs HER2+/ER- vs triple-negative: p = 0.0246; 39.6 vs 27.4 vs 20.9 vs 15.5 months), survival was shorter from BM to death in luminal A and triple negatives (median survival: p = 0.0113; 4.0 vs 9.2 vs 5.0 vs 3.4 months). Receipt of trastuzumab after BM was a significant variable for survival in HER2+ patients. Multivariate analyses identified ER-negative, HER2-negative, or triple-negative, as well as older age, presence of leptomeningeal disease, and three or more extracranial disease sites, as poor prognostic factors for survival after BM.

Conclusion

MBC patients who developed BM had higher proportions of triple-negative and HER2+/ER- tumor status. Triple receptor status is a useful prognostic marker for predicting survival after BM in metastatic breast cancer patients.     

Incidence and risk factors for breast cancer subtypes in three distinct South-East Asian ethnic groups: Chinese,Malay and natives of Sarawak,Malaysia

We determined the incidences of the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) subtypes among breast cancer cases in Sarawak, Malaysia and their correlation with various risk factors in the three ethnic groups: Chinese, Malay and native. Subtype status was ascertained for 1,034 cases of female breast cancer (93% of all cases diagnosed since 2003), and the age-standardized incidence rates (ASRs) of each subtype were inferred. Case–case comparisons across subtypes were performed for reproductive risk factors. We found 48% luminal A (ER+/PR+/HER2−), 29% triple-negative (ER−/PR−/HER2−), 12% triple-positive (ER+/PR+/HER2+) and 11% HER2-overexpressing (ER−/PR−/HER2+) subtypes, with ASRs of 10.6, 6.0, 2.8 and 2.8 per 100,000, respectively. The proportions of subtypes and ASRs differed significantly by ethnic groups: HER2-positive cases were more frequent in Malays (29%; 95% CI [23;35]) than Chinese (22%; [19;26] and natives (21%; [16;26]); triple-negative cases were less frequent among Chinese (23%; [20;27]) than Malays (33%; [27;39]) and natives (37%; [31;43]). The results of the case–case comparison were in accordance with those observed in western case series. Some uncommon associations, such as between triple-negative subtype and older age at menopause (OR, 1.59; p < 0.05), were found. The triple-negative and HER2+ subtypes predominate in our region, with significant differences among ethnic groups. Our results support the idea that the risk factors for different subtypes vary markedly. Westernized populations are more likely to have factors that increase the risk for the luminal A type, while risk factors for the triple-negative type are more frequent in local populations.     

Tumor phenotype and breast density in distinct categories of interval cancer: results of population-based mammography screening in Spain

Introduction

Interval cancers are tumors arising after a negative screening episode and before the next screening invitation. They can be classified into true interval cancers, false-negatives, minimal-sign cancers, and occult tumors based on mammographic findings in screening and diagnostic mammograms. This study aimed to describe tumor-related characteristics and the association of breast density and tumor phenotype within four interval cancer categories.

Methods

We included 2,245 invasive tumors (1,297 screening-detected and 948 interval cancers) diagnosed from 2000 to 2009 among 645,764 women aged 45 to 69 who underwent biennial screening in Spain. Interval cancers were classified by a semi-informed retrospective review into true interval cancers (n = 455), false-negatives (n = 224), minimal-sign (n = 166), and occult tumors (n = 103). Breast density was evaluated using Boyd’s scale and was conflated into: <25%; 25 to 50%; 50 to 75%; >75%. Tumor-related information was obtained from cancer registries and clinical records. Tumor phenotype was defined as follows: luminal A: ER+/HER2- or PR+/HER2-; luminal B: ER+/HER2+ or PR+/HER2+; HER2: ER-/PR-/HER2+; triple-negative: ER-/PR-/HER2-. The association of tumor phenotype and breast density was assessed using a multinomial logistic regression model. Adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. All statistical tests were two-sided.

Results

Forty-eight percent of interval cancers were true interval cancers and 23.6% false-negatives. True interval cancers were associated with HER2 and triple-negative phenotypes (OR = 1.91 (95% CI:1.22-2.96), OR = 2.07 (95% CI:1.42-3.01), respectively) and extremely dense breasts (>75%) (OR = 1.67 (95% CI:1.08-2.56)). However, among true interval cancers a higher proportion of triple-negative tumors was observed in predominantly fatty breasts (<25%) than in denser breasts (28.7%, 21.4%, 11.3% and 14.3%, respectively; <0.001). False-negatives and occult tumors had similar phenotypic characteristics to screening-detected cancers, extreme breast density being strongly associated with occult tumors (OR = 6.23 (95% CI:2.65-14.66)). Minimal-sign cancers were biologically close to true interval cancers but showed no association with breast density.

Conclusions

Our findings revealed that both the distribution of tumor phenotype and breast density play specific and independent roles in each category of interval cancer. Further research is needed to understand the biological basis of the overrepresentation of triple-negative phenotype among predominantly fatty breasts in true interval cancers.     

乳腺浸润性导管癌免疫组化分层法的预后价值(英文)

Objective:Gene expression profiling of breast cancer has identified five molecularly distinct subtypes of breast cancer that have different biological behavior and clinical outcomes. These subtypes are termed luminal A, luminal B, luminal HER2, HER2-enriched and triple negative breast cancers (TNBC). We aimed at identification of breast cancer subtypes among Egyptian population and their clinicopathologic features using ER, PR and HER2, Ki-67 and CK5/6. Methods:Tumors from 100 patients with invasive duct carcinoma were subtyped by immunohistochemistry using ER, PR, HER2, Ki-67 and CK5/6. The prognostic value of the immunohistochemical assignment for breast cancer disease-specific survival was investigated by using Kaplan-Meier curves. Results:Immunohistochemical profiling classified 22 cases as luminal A, 33 cases as luminal B, 9 cases as luminal HER2, 26 cases as HER2-enriched and 10 cases as TNBC. Tumors that measured more than 3.5 cm, showed predominance of HER2-enriched subtype. HER2-enriched and luminal B subtypes dominated the node positive cases (35.4% and 33.8%; respectively). Large tumor size (> 3.5 cm), hormone receptor negative state and HER2 positive state were associated with poor prognosis. Disease free survivals (DFSs) were significantly different (P<0.0001) among different breast subtypes with worst 2-year DFS for HER2-enriched subtype (40.77%) followed by luminal A (63.56%). DFS was almost similar in the remaining other subtypes, and luminal B, luminal HER2 and TNBC which were 86.85%, 87.5% and 88.89%; respectively. Conclusion:ER, PR, HER2 and Ki-67 constituted a strong surrogate for molecular breast cancer subtypes and can be easily applied. HER2-enriched subtype carries worse features being associated with large tumor size, nodal metastasis and is associated with poor outcome. Luminal A is a heterogeneous subtype with underlying several factors that can turn its prognosis adversely. TNBC subtype may behave unexpected in a favorable way.     

Immunohistochemical and molecular subtypes of breast cancer in Nigeria

OBJECTIVE: Previous studies suggest that the majority of breast cancer in Africans are hormone receptor negative and thus differ from breast cancer in other populations. We decided to evaluate the hormone receptor status of patients seen in our practice to see if they indeed differ from that of other populations. METHODS: We prospectively collected and analyzed tumors from consecutive patients presenting to our clinic over an 18 months period from July 2004. During the period, we saw 192 patients without previous histological diagnosis and conducted routine histological and immunohistochemical analysis of their tumors for hormone receptor status. RESULTS: Most, 65.1% of tumors were ER+, 54.7% were PR+ and 79.7% were HER2 negative. Majority of the tumors, 77.6% were luminal type A, 2.6% were luminal type B, 15.8% were basal type and the remaining 4.0% (6/152) were HER2+/ER- subtype. We found an association between hormone receptor status and tumor grade but not with stage at presentation. CONCLUSION: We conclude that there is no difference in the pattern of hormone receptors in breast cancer patients of African origin compared to other populations and urge more use of hormone manipulation for management of breast cancer in this population.     

不同病理亚型乳腺癌脑转移患者预后分析

目的:了解不同病理亚型乳腺癌脑转移患者的预后特点。方法:根据肿瘤组织免疫组化ER、PR、HER-2 的表达情况将89例患者分为4 组:Luminal A型（ER+ 和/或PR+ ,HER-2-）17例、Luminal B型（ER+ 和/或PR+ ,HER-2 +）15例、HER-2 + 型（ER- ,PR- ,HER-2 +）24例和Basal-like型（ER- ,PR- ,HER-2-）33例。主要观察4 组患者分布比例、发病年龄、月经状态、病理类型、病理分级、肿瘤大小、淋巴结状态及脑转移发生距手术时间及部位等。使用SPSS15.0 统计软件进行数据分析,定量资料采用t检验,计数资料比较采用卡方检验,生存率计算采用Kaplan-Meier 法并用Log-rank 检验,P<0.05为差异有统计学意义。结果:所有患者当中Basal-like型所占比例最高（37.1%）,其次为HER-2 +（27%）,Luminal A型（19.1%）,Luminal B型最少（16.9%）。 Basal-like 型患者预后最差,其病理分级Ⅲ级的患者比例达到了73% 。在其他部位出现转移情况上,Luminal型患者表现出较高的骨转移倾向。全组患者的中位生存期为47个月,无病生存期为20个月,确诊脑转移后的生存期为9 个月。ER（-）且PR（-）较ER/PR（+）（45个月vs.52个月,P=0.006）、HER-2（+）较HER-2（-）（45个月vs.51.5 个月,P=0.04）、Basal-like亚型的患者预后较其他亚型差（33个月vs.52个月,P=0.000）。 结论:病理亚型是判断乳腺癌脑转移患者预后不同的良好指标,ER（-）且PR（-）、HER-2（+）、Basal-like亚型患者容易出现脑转移且预后较差。      

Reproductive history and risk of three breast cancer subtypes defined by three biomarkers

Breast cancer subtypes defined by estrogen receptor (ER), progesterone receptor (PR), and HER2 expression are biologically distinct and thus, may have distinct etiologies. In particular, it is plausible that risk factors operating through hormonal mechanisms are differentially related to risk of such tumor subtypes. Using data from the Breast Cancer Surveillance Consortium, we explored associations between reproductive history and three breast cancer subtypes. Data on parity and age at first birth were collected from 743,623 women, 10,896 of whom were subsequently diagnosed with breast cancer. Cases were classified into three subtypes based on tumor maker expression: (1) ER positive (ER+, N = 8,203), (2) ER negative/PR negative/HER2 positive (ER−/PR−/HER2+, N = 288), or (3) ER-, PR-, and HER2-negative (triple-negative, N = 645). Associations with reproductive history, evaluated using Cox regression, differed significantly across tumor subtypes. Nulliparity was most strongly associated with risk of ER+ breast cancer [hazard ratio (HR) = 1.31, 95% confidence interval (CI): 1.23–1.39]; late age at first birth was most strongly associated with risk of ER-/PR-/HER2+ disease (HR = 1.83, 95% CI: 1.31–2.56). Neither parity nor age at first birth was associated with triple-negative breast cancer. In contrast to ER+ and ER−/PR−/HER2+ subtypes, reproductive history does not appear to be a risk factor for triple-negative breast cancer.