Predictive value of breast cancer molecular subtypes in Chinese patients with four or more positive nodes after postmastectomy radiotherapy

The molecular subtypes of breast cancer based on status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2) expression are associated with markedly different clinical outcomes. We retrospectively analyzed 774 breast cancer patients with four or more positive nodes, who underwent mastectomy between March 1999 and December 2007. Treatment with postmastectomy radiotherapy (PMRT) reduced the rates of locoregional recurrence-free survival (LRFS; 6.7% vs. 26.6%), distant metastasis-free survival (DMFS; 26.9% vs. 50.0%), and mortality (24.4% vs. 45.3%) for luminal-A subtypes (ER+ or PR+, Her2-) and reduced LRFS (12.1% vs. 27.5%) for the luminal-B subtype (ER+ or PR+, Her2+) compared with patients not receiving PMRT. However, PMRT did not affect the endpoints for the Her2-enriched or basal subtypes. Thus, understanding the differences in patterns of relapse between the different subtypes of breast cancer may enable targeted adjuvant therapy and improved surveillance decisions.     

Breast Cancer Subtypes as Defined by the Estrogen Receptor (ER), Progesterone Receptor (PR), and the Human Epidermal Growth Factor Receptor 2 (HER2) among Women with Invasive Breast Cancer in California, 1999–2004

Abstract: Breast cancer research examining either molecular profiles or biomarker subtypes has focused on the estrogen receptor negative/progesterone receptor negative/human epidermal growth factor receptor 2 negative (ER−/PR−/HER2−) and ER−/PR−/HER2+ subtypes. Less is known about the epidemiology or clinical outcome of the other subtypes. This study examines the eight combinations of ER/PR/HER2 in patients with invasive breast cancer. The 5‐year relative survival and the distribution among demographic, socioeconomic, and tumor characteristics of each of the subtypes are examined. Using the California Cancer Registry, 61,309 women with primary invasive breast cancer were classified according to ER/PR/HER2 status. Five‐year relative survival was computed for the eight subtypes. Bivariate analyses were used to assess the distribution of cases across all subtypes. Multivariate logistic regression was used to compute the adjusted odds of having one of the five subtypes with the best and worst survival. Survival varied from 96% (ER+/PR+/HER2−) to 76% (ER−/PR−/HER2+ and ER−/PR−/HER2−). The four subtypes with the poorest survival were all ER negative. Women who were younger than age 50, non‐Hispanic black or Hispanic, of the lowest SES groups, and had stage IV tumors that were undifferentiated were overrepresented in ER−/PR−/HER2+ and triple negative (ER−/PR−/HER2−) subtypes. Asian Pacific Islanders had increased odds (OR = 1.41; 95% confidence interval [CI] = 1.26–1.57) of having the ER−/PR−/HER2+ subtype. Stage III tumors (OR = 1.25; 95% CI = 1.08–1.44) and stage IV tumors (OR = 1.58; 95% CI = 1.27–1.98) had higher odds than stage I tumors of being ER−/PR−/HER2+. Stage IV tumors (OR = 0.54; 95% CI = 0.44–0.67) strongly decreased the odds of the ER−/PR−/HER2− subtype. Poorly differentiated and undifferentiated tumors were over 20 times as likely as well‐differentiated tumors of being ER−/PR−/HER2− or ER−/PR−/HER2+. There are considerable differences in survival, demographics, and tumor characteristics among the eight subtypes. We recommend reporting breast cancer as an ER/PR/HER2 subtype and precisely documenting demographic and tumor characteristics.     

Hormone Receptors and Her2 Expression in Breast Cancer in Sub‐Saharan Africa. A Comparative Study of Biopsies from Ghana and Norway

Hormonal treatment of breast cancer is effective only in patients whose tumors express estrogen and/or progesterone receptors (ER, PR). Receptor assessment is often not available in low‐resource areas, and the choice may be to apply endocrine therapy to all or none of breast cancer patients, depending on the proportion of patients that can be expected to respond. Fifty‐one invasive breast cancers from Ghana and 100 from Norway diagnosed in the same laboratory during the same time period were reexamined in a blinded slide review. Of Ghanaian tumors, 76% were ER+ (≥1% ER+ tumor cells). Of Norwegian tumors, 85% were ER+. Triple‐negative tumors were seen in 22% of Ghanaian patients and in 7% of Norwegian patients. A review of previous similar studies in sub‐Saharan patients shows very discrepant results. Standardization and quality control of receptor assessment and well‐designed clinical trials in sub‐Saharan African breast cancer patients are needed to give a sound basis for endocrine treatment in this area.     

Roles of hormone replacement therapy and iron in proliferation of breast epithelial cells with different estrogen and progesterone receptor status

Estrogen and iron play critical roles in a female body development and were investigated in the present study in relation to in vitro cell proliferation. Prempro, a hormone replacement therapy drug, and 17beta-estradiol (E2) were shown to increase cell proliferations in estrogen receptor positive (ER+) cells independent of progesterone receptor (PR) status. For example, increased cell proliferation was observed in ER+/PR+ human breast cancer MCF-7, its matching non-cancerous human breast epithelial MCF-12A, and ER+/PR+ murine mammary cancer MXT+ cells, but not in ER-/PR- MDA-MB-231, its matching non-cancerous MCF-10A, and MXT- (ER-/PR+) cells. By mimicking post-menopausal conditions of high estrogen in local breast tissue and increased iron levels due to cessation of menstrual periods, E2 and iron were shown to exert synergistic effects on proliferation of MCF-7 cells and significantly increased Ki67 and proliferating cell nuclear antigen. Western blotting of E2-treated ER+ but not ER- cells showed that E2 also increased transferrin receptor (TfR). Further studies are needed to assess the mitogenic effects of iron and estrogen in normal post-menopausal breast.     

Clinical characteristics and survival outcome of patients with estrogen receptor low positive breast cancer

BackgroundThe benefit of endocrine therapy for patients with estrogen receptor (ER)-low (1%–10%) positive breast cancer is a matter for debate. We aimed to compare the clinical characteristics and survival outcome of ER-low patients with ER-high (＞10%) positive patients and ER-negative patients.MethodsFrom the breast cancer database of our institution, we identified 5466 patients with known ER status who were diagnosed with early-stage breast cancer between January 2008 and December 2016. Variables associated with initiation of endocrine therapy were identified using multivariate logistic regression model. According to ER status, all patients were classified into ER-low (1%–10%), ER-high (>10%) and ER-negative subgroups. Fine and Gray competing risks regression was performed to compare the survival outcome of three subgroups.ResultsAge at diagnosis, ER status and progesterone receptor (PR) status were identified as correlates of initiation of endocrine therapy. ER-low patients were more likely to have advanced, PR-negative, human epidermal growth factor receptor 2 (HER2)-positive or grade Ⅲ disease compared to ER-high patients. Similar to ER-negative patients, ER-low patients presented increased rate of locoregional recurrence (LRR), distant recurrence (DR) and breast cancer mortality (BCM) than ER-high patients. Endocrine therapy showed nonsignificant trends toward lower LRR, DR and BCM in ER-low patients.ConclusionSimilar to ER-negative patients, ER-low patients had more aggressive clinical characteristics and worse survival outcome than ER-high patients. ER-low patients appeared to benefit less from endocrine therapy. Randomized studies are needed to further explore the endocrine responsiveness of ER-low patients.     

Adjuvant therapy for older women with breast cancer

The major risk factor for breast cancer is increasing age and more than half of all breast cancers in affluent nations occur in women 65 years and older. Co-morbidity is a key consideration in offering systemic adjuvant treatment to older women since significant co-morbidity minimizes the potential value of any adjuvant therapy. Tamoxifen has clearly been shown to significantly decrease the risk of recurrence and improve survival in women of all ages who have estrogen (ER) or progesterone receptor (PR) positive invasive breast cancer, including those 70 years and older. Chemotherapy in older patients can improve survival but adds little to tamoxifen in women with node-negative, ER+ or PR+ tumors: it should be reserved for older women who have reasonable life-expectancy and larger node-negative tumors, or node-positive tumors. Ageism is still a barrier to clinical trials participation and clinical trials focusing on older women are needed.     

Estrogen and Progesterone Receptors in Primary Breast Cancer

Abstract: The purpose of this study was to determine biological variable profiles and survival experiences associated with different combinations of estrogen receptor (ER) and progesterone receptor (PR) status (ER+PR+, ER+PR-, ER-PR+, ER-PR-). Data were collected and provided by the State Health Registry (SHR) of Iowa, part of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Significant associations were determined for individual prognostic variables with each ER/PR categories, and overall survival was compared between each ER/PR category. Multiple logistic regression analyses were conducted to determine all significant prognostic variables associated with each ER/ PR category. All women diagnosed with primary breast cancer in Iowa from 1990 through 1992 were included in this study (N = 6, 178). In unadjusted analyses, Caucasian woman and older women were significantly more likely to be ER + PR+, while African American women and younger women were significantly more likely to be ER-PR-. In multivariate analyses, each ER/PR category was associated with distinct profile of age, menopausal status, histologic grade, and histology. Survival was best for women in the ER+PR+ group, followed, in decreasing order, by ER+PR-, ER-PR+, and ER-PR-. In this population-based study of primary breast cancer, combined hormone receptor status was a significant prognostic determinant for primary breast cancer, and was associated with distinct biological variables and survival experiences. In combination with other variables such as age, menopausal status, tumor histologic grade, and tumor histology, combined hormone receptor status can provide important prognostic information to the clinician.?     

Progesterone receptor status provides predictive value for adjuvant endocrine therapy in older estrogen receptor-positive breast cancer patients

Estrogen receptor (ER) status can predict the efficacy of endocrine therapy. However, the predictive significance of the progesterone receptor (PgR) is controversial in an adjuvant setting. Records of 758 ER+ breast cancer patients who received adjuvant tamoxifen (TAM) for 3-5 years were reviewed to evaluate the predictive value of PgR for TAM treatment in ER+/PgR+ and ER+/PgR- groups. By a median of 40 months' follow-up, there was no significant difference between the two groups with regard to disease-free-survival (DFS). On the basis of STEPP analysis showing the tendency of age effect on DFS in both the ER+/PgR- and ER+/PgR+ groups, we classified the ER+ patients into three strata by age (<45, 45-60, and >or=60 years). There was no significant difference in DFS and overall survival (OS) between the two groups in the <45 stratum and the 45-60 stratum. In contrast, the ER+/PgR- group had a worse prognosis in the >or=60 stratum with regard to both DFS (P=0.0484) and OS (P=0.0009). The results suggest that PgR status might be a predictive factor of benefit to be gained from adjuvant TAM for older ER+ patients with regard to DFS and OS. This should take into account older ER+/PgR- patients who tend to be resistant to TAM.     

Neoadjuvant Chemotherapy of Breast Cancer: Tumor Markers as Predictors of Pathologic Response,Recurrence, and Survival

Abstract: This study reports the value of the tumor markers estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in predicting the response of breast cancer to neoadjuvant chemotherapy. A community cancer center prospectively maintained breast cancer database containing over 8,000 patient records was used. Since 1989, 464 patients were treated with neoadjuvant chemotherapy followed by surgical resection and were tested for ER and PR. Estrogen receptor and/or PR positive patients were considered hormone receptor (HR) positive. Human epidermal growth factor receptor 2 status was available on 368 patients. Total, breast, and nodal pathologic complete response (pCR) rates, recurrence, and overall survival were assessed. Total and breast pCR rates were higher in HR negative (HR?) patients (26% and 32%, respectively) than in HR positive (HR+) patients (4% and 7%, respectively; p < 0.001). Compared to HR+ patients, HR? patients had higher recurrence rates (38% versus 22%; p < 0.001), a shorter time to recurrence (1.28 versus 2.14 years; p < 0.001), and decreased overall survival (67% versus 81%; p < 0.001). Human epidermal growth factor receptor 2 positive patients treated with neoadjuvant trastuzumab (NAT) demonstrated higher total pCR (34% versus 13%; p = 0.008), breast pCR (37% versus 17%; p = 0.02), and nodal pCR rates (47% versus 23%; p = 0.05) compared to HER2+ patients not treated with NAT. Furthermore, HER2+ patients who received NAT had lower recurrence rates (5% versus 42%; p < 0.001) and increased overall survival (97% versus 68%; p < 0.001). In conclusion, breast cancer HR status is predictive of total and breast pCR rates after neoadjuvant chemotherapy. Although HR? patients derive greater benefit from neoadjuvant chemotherapy in terms of pathologic response, they have worse outcomes in terms of recurrence and survival. Hormone receptor positive patients demonstrate significantly less response to neoadjuvant chemotherapy, but significantly better overall outcome. For both HR? and HR+, addition of NAT for HER2+ tumors results in both a superior response and outcome.     

The Challenging Estrogen Receptor‐Negative/ Progesterone Receptor‐Negative/HER‐2‐Negative Patient: A Promising Candidate for Epidermal Growth Factor Receptor‐Targeted Therapy?

While epidermal growth factor receptor (EGFR)-targeted therapy has been very promising in a number of human malignancies, to date these targeted biologic agents have not proven effective in breast cancer. However, the EGFR tyrosinase inhibitors have been used indiscriminately against all types of breast tumors, perhaps missing a subpopulation of patients who may be prime candidates for EGFR-targeted therapy. In this communication we propose that patients with estrogen receptor (ER)-negative/progesterone receptor (PR)-negative/HER-2-negative tumors, which currently present a therapeutic challenge for the oncologist, may be the subgroup of breast cancer patients that might benefit from specific EGFR-targeted therapies.     

Breast hormonal receptors test should be repeated on excisional biopsy after negative core needle biopsy

Therapeutic decision-making for women diagnosed with breast cancer requires accurate determination of the estrogen receptor (ER) and progesterone receptor (PR). Decisions about adjuvant therapy are often based on the immunohistochemical (IHC) profile of the core needle biopsy sample (CNB) because the staining is not repeated on the final excisional biopsy (EB). The purpose of this study was to assess the concordance of breast cancer IHC receptor assays on CNB and EB. We identified 176 patients with matching breast CNB and EB that had available ER and PR. While the CNBs were processed and stained in different laboratories, the EB were processed and stained in our institution. The following antibodies were used 1D5, 6F11 and SP1 for ER, and PgR636, 16 and 1E2 for PR, from Dako, Leica and Ventana respectively. Correlation of scores of CNBs with matching EB was analyzed using Spearman correlation coefficients. Sensitivity, specificity, overall agreement and the kappa statistic were used to measure the concordance between CNB and EB. For CNB, there were 141 (80.1%) cases positive for ER and 118 (67%) cases positive for PR. For EB, there were 143 (81.3%) cases positive for ER and 130 (73.9%) cases positive for PR. Overall agreement for ER and PR was seen in 93% (95% CI = 0.88, 0.96) and 90% (95% CI = 0.84, 0.94) respectively. Overall, ER- CNB/ER+ EB was seen in seven (4%) cases and PR- CNB/PR+ EB in 15 (8.5%) cases. ER+ CNB/ER- EB was seen in five (2.8%) cases and PR+ CNB/PR- EB in three (1.7%) cases. To avoid erroneous omission of life-saving endocrine therapy ER and PR should be repeated on the EB for patients whose CNB has negative hormonal receptors.     

新辅助化疗后ER、PR阳性表达乳腺癌患者的内分泌治疗

目的 探讨乳腺癌新辅助化疗后ER、PR阳性表达的乳腺癌患者内分泌治疗的疗效.方法 将97例术前ER、PR阴性表达经新辅助化疗后转变为阳性表达的乳腺癌患者分为两组(内分泌治疗组和对照组)进行治疗,并随访15～60个月,对其生存率和总生存率进行比较.结果 内分泌治疗组3年和5年无病生存率分别为74.5%(38/51)、60.7%(31/51),其3年和5年总生存率为80.0%(41/51)、74.5%(38/51).对照组的3年和5年无病生存率分别为54.2%(26/46)及41.7%(20/46),3年和5年的总生存率为60.9%(28/46)、50%(23/46).内分泌治疗组无病生存率及总生存率均高于对照组(P＜0.05).结论 新辅助化疗后ER、PR变为阳性表达的患者应用内分泌治疗可提高此类患者的生存率.     

Outcome of small invasive breast cancer with no axillary lymph node involvement

Abstract: The prognosis and need or not for adjuvant therapy in patients with small breast tumors (≤1 cm N0) is the subject of controversy as regards the clinical benefit obtained, toxicity, and the economical costs generated. A retrospective analysis was made of 238 patients with early‐stage breast cancer (pT1 ≤ 1 cm N0M0) diagnosed between January 1993 and May 2008. As regards the systemic adjuvant treatments provided, (a) 122 (51%) received no treatment, (b) 102 (43%) received hormone therapy, (c) 9 (4%) chemotherapy, and (d) 5 (2%) received both hormone therapy and chemotherapy. An analysis was made of disease‐free survival (DFS) and breast cancer‐specific survival in our series of patients, and of their correlation to clinicopathological factors (age, tumor size, histological grade, estrogen receptor (ER) expression, HER‐2 overexpression, and systemic adjuvant therapy). The median follow‐up of this cohort was 63 months (range 5–145). Some type of relapse was recorded in 4.2% of the patients (six patients presented local recurrence in all cases subjected to rescue treatment with surgery and/or radiotherapy, three patients developed distant metastases, and one patient presented a resected local recurrence followed by systemic relapse). The 5 year DFS was 96%, and the 5 year breast cancer‐specific survival was 99.6%. A univariate analysis was made of the clinicopathological variables and their association to DFS. None of the variables was seen to be significantly correlated to shorter DSF except for an association between HER‐2 overexpression and poor outcome borderline significance (p = 0.07). The prognosis of our pT1 ≤ 1 cm N0M0 tumors was excellent, although the absence of systemic adjuvant therapy in one‐half of the patients.     

Prognosis of Japanese Breast Cancer Based on Hormone Receptor and HER2 Expression Determined by Immunohistochemical Staining

BACKGROUND: We classified Japanese breast cancer patients based on estrogen receptor (ER), progesterone receptor (PR), and HER2 protein expression and compared their prognoses. METHODS: We compared the background and prognostic factors of 600 patients with breast cancer who were assigned to the following groups: luminal A (ER + and/or PR + and HER2-; n = 431; 71.8%), luminal B (ER + and/or PR + and HER2 + ; n = 27; 4.5%), HER2 (ER-, PR-, and HER2 + ; n = 39; 6.5%) and basal-like (BBC; ER-, PR-, and HER2-; n = 103; 17.2%). RESULTS: Background factors did not significantly differ among the groups. Disease-free survival rates were significantly lower for the luminal B, HER2, and BBC subtypes than for the luminal A subtype. Cancer tended to recur earlier and overall survival was significantly lower for the BBC than for the luminal A and HER2 subtypes. Overall survival rates for the luminal B, HER2, and luminal A subtypes were comparable. CONCLUSIONS: The subtype distribution for Japanese and Caucasian patients was comparable. The prognosis for the BBC subtype was poorest among all subtypes. Breast cancer tended to recur earlier for the luminal B and HER2 subtypes than for the luminal A subtype; however, overall survival did not significantly differ among them.     

Prognostic and predictive value of TFF1 for adjuvant endocrine therapy in Chinese women with early ER positive breast cancer: Comparing aromatase inhibitors with tamoxifen

Factors that predict in favor of an aromatase inhibitors (AIs) over tamoxifen (TAM) in estrogen receptor (ER) breast cancer remains to be identified. We compared progesterone receptor (PR) and trefoil factor 1 (TTF1) status (+ve versus −ve) as predictive of superior effect of AI’s over tamoxifen among a total of 1973 Chinese women with early ER+ breast cancer. The expression of TFF1 was independently associated with ER and PR. However, there was no correlation with TFF1 and HER-2 expression. Treatment effect was more pronounced in the ER+/TFF1+ postmenopausal patients with a hazard ratio favoring AIs (HR = 0.397, 95%CI 0.183-0.860), but not in the PR positive cohorts (HR = 0.466, 95%CI 0.186-1.164). We suggested that AIs was better than TAM especially in the postmenopausal patients with ER+/TFF1+ breast cancer; however the clinical application of this observation still requires further prospective studies.     

Steroid Hormone Receptor Profile of Normal, Benign, and Malignant Female Breast Epithelium: An Immunohistochemical Analysis of 325 Biopsies

Abstract: The steroid hormone receptor (SR) profile was determined for both the estrogen receptor (ER) and progesterone receptor (PR) in 55 fibroadenomas, 69 fibrocystic changes, 38 ordinary, and 14 atypical intraductal hyperplasias as well as 149 breast carcinomas obtained from 325 female patients by diagnostic surgical biopsy. Normal breast tissue adjacent to the lesions under study was simultaneously evaluated in 234 cases. SR were proven immunohistochemically in cryostat sections using an immunohistochemical assay with rat monoclonal antibodies against human ER or PR. The findings were scored and summarized into the phenotypes ER+PR+,ER?PR+, ER+PR? and ER?PR?. The ER+PR+ status was most often found in fibroadenomas (67%) and normal breast tissue (64%) as well as in fibrocystic changes (63%) and breast carcinomas (58%). ER?PR? was inversely rare in fibroadenomas (4%), normal breast tissue (15%), fibrocystic changes (23%), and breast carcinomas (29%). The simultaneous SR analysis in breast disease and its surrounding normal tissue showed in fibroadenomas in 90% and in fibrocystic changes in 80%, a ER/PR phenotype expression similar to adjacent normal tissue; whereas in breast carcinomas the SR status corresponded with the preexisting normal tissue only in 36%. The comparative SR analysis of normal and pathological breast tissue showed a gradually inverse biological correlation between the decrease of ER+PR+ and the increase of ER?PR? frequency from benign breast changes to noninvasive and invasive breast carcinomas. In benign breast epithelium, ER?PR+ might be regarded as low-risk phenotype, whereas ER+PR? could be estimated as high-risk phenotype in view of a later dedifferentiation and possible malignization. The more frequent discordance of SR expression between breast carcinomas and their adjacent normal breast tissue suggests that the neoplastic growth may become more and more independent from normal endocrine influences.     

Evaluation of the pathologic and prognostic correlates of estrogen receptors in primary breast cancer.

The presence of estrogen receptors in breast cancer tissue has been reported to correlate with improved prognosis in women after mastectomy. The prognostic value (if any) of the presence or absence of estrogen receptors (ER) in malignant breast tissue was evaluated 104 women who were treated for primary breast cancer, whose pathology was re-examined, and whose records were subjected to multifactorial analysis. Sixty patients were ER positive, and 44 were ER negative, and a total of 94 who had curative resections were available for follow-up (mean follow-up time 20 months). The presence of estrogen receptors showed significant positive correlations with age, lobular cancer, and a variant of infiltrating duct cancer that is prevalent in the elderly and characterized by the presence of cells showing granular eosinophilic cytoplasm. Of 26 cases identified as infiltrating duct cancer showing granular eosinophilic cytoplasm, 22 were ER positive, one was ER negative, and three had borderline values. There was no significant difference between the groups with regard to family history of breast cancer or hysterectomy. A striking observation was noted in the ER positive group in which there were seven cases of second primary breast cancers, whereas no such cases occurred in the ER negative patients (p=0.05). There was a higher percentage of nodal metastases in the patients who were ER positive compared with those who were ER negative; 27 of 53 (51%) of the ER positive patients has positive nodes compared with four of 40 (32%) who were ER negative, p = 0.08. There was no significant correlation of disease free survival nor time to recurrence in either the overall group nor according to stage. In patients whose tumors had been reviewed and graded, there was no prognostic relationship of ER status in high grade tumors, but in patients with low-grade tumors, improved disease-free survival was demonstrated in patients who were ER negative. Although the estrogen receptor assay is a highly useful tumor marker and guide for therapy of advanced breast cancer, its relationship to the prognostic variables of primary breast cancer is complex and controversial and merits continued study.     

Relationship of estrogen and progesterone receptors to prognosis in breast cancer.

To ascertain the role of estrogen (ER) and progesterone (PR) receptors as prognostic indicators of resectable breast cancer, the records of 204 patients were analyzed whose receptor studies were done at the Maimonides Medical Center from 1975 to 1983. All patients had radical or modified radical mastectomies and did not show any evidence of distant metastases at the time of operation. Median follow-up was 37 months. An additional 117 patients received some form of adjuvant therapy, mainly chemotherapy, and were analyzed separately. Life table analysis using the log rank test for measuring significance, and a Cox multivariate analysis was performed. At 48 months, 22% of the ER positive (ER+) group versus 33% of the ER negative (ER-) group had recurred as compared to 16% and 35% for the PR+ versus PR- groups, respectively. Life table analysis of the disease free interval (DFI) showed that the difference between the ER+ and ER- groups was not significant (p greater than 0.1), while the difference in DFI between the PR+ and PR- groups was significant (p less than 0.05). Multivariate analysis revealed that the most important factors in predicting the DFI were nodal status (p less than 0.001), tumor size (p less than 0.025), and progesterone receptor status (p less than 0.05). Estrogen receptor status was not found to be significant. In conclusion, PR- patients have a shorter DFI than PR+ patients and that PR status is a more valuable predictor of DFI than ER status.