Insulin-like growth factors in human breast cancer

Several protooncogenes and suppressor genes and a variety of growth factors and their receptors have been shown to be mutated, deleted, or activated in human breast cancer. These changes may account for the unregulated growth of breast carcinoma cells. Insulin-like growth factors I and II (IGF-I, IGF-II) belong to a family of polypeptides with growth promoting properties and structural homology to insulin. They exert their mitogenic effects by binding to the IGF-I receptor and activating its tyrosine protein kinase. Other proteins that specifically bind the IGFs include the plasma membrane IGF-II receptor, which also binds lysosomal hydrolases, and several IGF-binding proteins which may serve to modulate IGF interactions with receptors.     

Clinical significance of angiogenic factors in breast cancer

Growth, progression, and metastasis of breast cancer, as well as of most of the other tumors, are angiogenesis-dependent processes.Several pro-angiogenic growth factors and endogenous inhibitors of angiogenesis have been identified and sequenced, and experimental studies suggest that angiogenic activity of a tumor may result from down-regulation of inhibitors of angiogenesis or up-regulation of endothelial growth factors. The mechanisms leading to the alteration of the balance between positive and negative modulators of angiogenesis are only partially known.We are at the beginning of research to identify the more active angiogenic factors in human breast cancer, and little information is presently available on their clinical significance. Preliminary results suggest that among the known angiogenic peptides, both vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor / thymidine phosphorylase (PD-ECGF/TP) have promising prognostic and, perhaps, predictive value.No data are available on the clinical value of co-determination of positive and negative regulators of angiogenesis to look at the angiogenic balance of each single tumor. Only a few studies have assessed the role of endogenous inhibitors of angiogenesis in human breast cancer, with results available only on thrombospondin-1 and -2 (TSP-1, -2).Finally, the determination of some integrins such as 6 and v3 and of some other endothelial-adhesion molecules seems to be of potential prognostic value.Recognizing which are the more biologically active positive and negative angiogenic factors is the key for the identification not only of new prognostic markers but also of targets for antiangiogenic therapy in human breast cancer.     

Insulin-like growth factors in human breast cancer

IGF1 and IGF2 are circulating peptide hormones and locally-acting growth factors with both paracrine and autocrine functions. IGF1 and IGF2 signal through a common tyrosine kinase receptor, the insulin- like growth factor 1 receptor (IGF1R), and have mitogenic, cell survival, and insulin-like actions that are essential for embryogenesis, post-natal growth physiology, and breast development. The activities of IGF1 and 2 are tightly-regulated by a network of binding proteins and targeted degradation mechanisms. This complex regulatory system is disrupted in breast cancer, leading to excess IGF1R signaling. Evidence for this statement includes: a) breast cancers are infiltrated with IGF2 expressing stromal cells; b) mannose 6-phosphate/IGF2 receptor (M6P/IGF2R) is mutated in breast cancer, leading to loss of IGF2 degradation; c) IGF1R is overexpressed by malignant breast epithelial cells, and in some cases IGF1R is amplified; and d) complex changes in IGF binding protein expression occur during breast cancer progression which most likely also affect IGF1 and 2 signaling. The clinical importance of these epigenetic and genetic changes has recently been stressed by the finding that IGF1R signaling alters the apoptotic response of breast cancer cells to genotoxic stress and, in addition, IGF1R activation sensitizes cells to estrogen by inducing phosphorylation of the estrogen receptor. As a consequence of these findings, we propose that IGF analysis of breast cancer samples should shift from prognostic studies to an evaluation of IGF ligands, receptors, and binding proteins as resistance/sensitivity markers for radiation, chemotherapy, and endocrine therapy.     

Multimodal approach in the therapy of stage III female breast cancers

One thousand thirty-seven female breast cancers were treated at the Cancer Institute (WIA), Madras, between 1965 and 1978. Five hundred twenty-one of them (ie, just over 50%) were in stage III, with extensive local disease, unsuitable for surgery ab initio. Four hundred twelve of them (group A) received radiation therapy (RT) initially and 109 (group B) a combination of radiation and chemotherapy (CT). In 68% of the former and 77% of the latter the tumours became resectable after this preliminary treatment. Radical mastectomy in group A and Patey's mastectomy in group B were performed. The material in these two groups was similar. The five-year survival NED in group A was 45%, and in group B 64.61%. Adequate surgery following RT and CT seemed essential to improve survival. The impact of added chemotherapy (CT) was mainly felt in the node-positive cases.     

Novel antagonists of growth hormone-releasing hormone inhibit growth and vascularization of human experimental ovarian cancers

BACKGROUND:

Antagonists of growth hormone‐releasing hormone (GHRH) inhibit the proliferation of various human cancer cell lines and experimental tumors by mechanisms that include direct action on GHRH receptors in cancer cells.

METHODS:

In this study, the effects of newly synthesized GHRH antagonists, MIA‐313, MIA‐602, MIA‐604, and MIA‐610, were investigated in 2 human ovarian epithelial adenocarcinoma cell lines, OVCAR‐3 and SKOV‐3, in vitro and in vivo. The expression of receptors for GHRH was demonstrated by Western blot analysis and ligand competition methods in the OVCAR‐3 and SKOV‐3 cell lines and in tumors from those cells grown in athymic nude mice. The effects of GHRH antagonists on the secretion of vascular endothelial growth factor (VEGF) by OVCAR‐3 cells and on the vascularization of OVCAR‐3 xenografts also were evaluated.

RESULTS:

Both the pituitary and the splice variant type 1 (SV1) GHRH receptors were detected in the 2 cell lines and in tumor xenografts, and SV1 was expressed at higher levels. Cell viability assays revealed the antiproliferative effect of all GHRH antagonists that were. Maximal tumor growth inhibition was approximately 75% in both models. MIA‐313 and MIA‐602 decreased VEGF secretion of OVCAR‐3 cells, as measured by enzyme‐linked immunosorbent assay, and reduced tumor vascularization in a Matrigel plug assay, but caused no change in the expression of VEGF or VEGF receptor in the terminal ileum of mice with OVCAR‐3 tumors.

CONCLUSIONS:

Results from the current study indicated that a he novel approach based on GHRH antagonists may offer more effective therapeutic alternatives for patients with advanced ovarian cancer and who do not tolerate conventional anti‐VEGF therapy. Cancer 2012;. © 2011 American Cancer Society.     

Histoculture of human breast cancers

Breast cancers from 53 patients were explanted in culture, and 39 with two-year or more follow-up and documentable tissue forms of cancer in culture (histoculture) are the subject of this report. Clinicopathologic findings have been correlated with dynamic aspects of the cancers in short-term histocultures, including cell cohesiveness, yield and survival time of the cancer cells in culture, emigration of macrophages from the explants, and the occurrence of special interactions of lymphocytes with cancer cells. The outstanding finding was the association of special lymphocyte-cancer cell interactions with a more favorable prognosis; six of seven patients (86%) with infiltrating ductal cancer showing lymphocyte congregation, emperiopolesis, or other special activity were tumor-free survivors. Additional findings were: 1) patients having four or fewer lymph nodes positive for cancer had a survival rate of 50%, but this fell to 20% when emigrating macrophages were not present in the cancer cultures; 2) eight of the 12 patients (67%) having discoid histoculture survival time of less than one week were tumor-free, as opposed to three of eight patients (27%) where tumor survival in vitro was greater than one week. The reverse was true for nondiscoid, poorly cohesive colonies of cancer; 3) the combination of tumor-negative lymph nodes and low in vitro cancer yield was associated with the best patient survival rate, 64%. However, the combination of negative nodes and high in vitro yield was linked to the worst patient survival (20%). Although the overall study does not permit definitive conclusions, there is an undeniable potential for the use of histocultures in the evaluation of human cancers. Expanded studies are warranted, including larger numbers of tumors and cultures, and longer patient follow-up periods.     

Second cancers after adjuvant tamoxifen therapy for breast cancer in Japan

Background:Women treated with tamoxifen for breast cancer are atincreased risk of endometrial cancer. We conducted a retrospective cohortstudy to evaluate the risk of second primary cancers after adjuvant tamoxifentherapy for breast cancer in Japan. Patients and methods:The subjects of the study were 6148 womenwho had been diagnosed with stage I, II, or IIIA unilateral primary breastcancer and had received surgical treatment during the period from January 1982through December 1990 at nine institutions in Japan. The information on eachpatient was obtained from medical records or a prospectively compiled computerdatabase at each institution. Results:Of the 6148 women, 3588 (58.4%) were administeredtamoxifen as an adjuvant treatment and 2560 (41.6%) were notadministered. Median follow-up periods were 7.64 years for tamoxifen-treatedpatients and 8.10 years for non-tamoxifen-treated patients, respectively. Theduration of tamoxifen treatment was mostly two years or less (80.7%),and few patients received tamoxifen for more than five years. The cumulativeincidence rates of all second cancers at 10 years were 4.61% and4.09% among tamoxifen-treated and non-tamoxifen-treated patients(P = 0.62), respectively, and the incidence rate ratio (IRR) forall second cancers was 1.06 (95% confidence interval (CI):0.77–1.47) after adjustment of several covariates. The numbers ofendometrial cancers was 9 and 3 among tamoxifen-treated andnon-tamoxifen-treated patients, respectively, and the IRR was 2.37 (95%CI: 0.64–8.77, P = 0.20). Of the 12 patients who developedendometrial cancer, 4 died of cancer (for 3 of them, the cause of death wasbreast cancer), and the other 8 patients were alive as of March 1996. Stomachcancer was the most frequent second cancer and the IRR was 1.34 (95%CI: 0.76–2.38, P = 0.31). There was no substantialincrease in any other type of gastrointestinal cancer such as colorectal andliver cancers among tamoxifen-treated patients. Conclusions:The incidence and risk of second primary cancersassociated with tamoxifen therapy is low. The potential benefit of adjuvanttamoxifen therapy in breast cancer patients outweighs the risk of secondprimary cancers for Japanese breast cancer patients.     

Circulating endothelial cells and angiogenic serum factors during neoadjuvant chemotherapy of primary breast cancer

Circulating endothelial cells (CECs) as well as bone-marrow-derived endothelial precursor cells (EPC) play an important role in neovascularisation and tumour growth. To study the impact of neoadjuvant chemotherapy on the amounts of CEC and their precursor cells, mature CEC and their progenitors were quantified by flow cytometry in peripheral blood of breast cancer patients during anthracycline and/or taxane based neoadjuvant chemotherapy and subsequent surgery in comparison to age-matched healthy controls. Cell numbers were tested for correlation with serum levels of angiopoietin-2, erythropoietin, endostatin, endoglin, VEGF and sVCAM-1 as well as clinical and pathological features of breast cancer disease. Circulating endothelial cells were significantly elevated in breast cancer patients and decreased during chemotherapy, whereas EPC (CD34+/VEGFR-2+) as well as their progenitor cell population CD133+/CD34+ and the population of CD34+ stem cells increased. Concomitantly with the increase of progenitor cells an increase of VEGF, erythropoietin and angiopoietin-2 was observed. These data suggest that chemotherapy can only reduce the amounts of mature CEC, probably reflecting detached cells from tumour vessels, whereas the EPC and their progenitors are mobilised by chemotherapy. Since this mobilisation of EPC may contribute to tumour neovascularisation an early antiangiogenic therapy in combination with chemotherapy could be beneficial for the success of cancer therapy.     

Prognostic factors for patients with breast cancers 1cm and smaller

The widespread use of mammography has resulted in the detection of an increasing number of small invasive breast cancers,i.e. those that are 1cm and smaller. Patients with these small cancers generally have a low incidence of axillary lymph node metastases, and this has led to some to question the routine use of axillary dissection in these patients. In addition, the prognosis of these patients is generally favorable, and the routine use of adjuvant systemic therapy is difficult to justify. Nonetheless, some patients with these small invasive cancers will have axillary nodal involvement and/or develop metastatic disease. The identification of this prognostically unfavorable subset of patients within this otherwise favorable group is an important goal of clinical research. In this article, we review the available literature on prognostic factors for patients with breast cancers 1cm and smaller to help determine which of these features might be of value in the identification of patients at risk for axillary lymph node involvement and/or metastatic disease.     

Relationship between breast cancer risk factors and mammographic breast density in the Fernald Community Cohort

Background:

We investigated associations of known breast cancer risk factors with breast density, a well-established and very strong predictor of breast cancer risk.

Methods:

This nested case–control study included breast cancer-free women, 265 with high and 860 with low breast density. Women were required to be 40–80 years old and should have a body mass index (BMI) <35 at the time of the index mammogram. Information on covariates was obtained from annual questionnaires.

Results:

In the overall analysis, breast density was inversely associated with BMI at mammogram (P for trend<0.001), and parity (P for trend=0.02) and positively associated with alcohol consumption (ever vs never: odds ratio 2.0, 95% confidence interval 1.4–2.8). Alcohol consumption was positively associated with density, and the association was stronger in women with a family history of breast cancer (P<0.001) and in women with hormone replacement therapy (HRT) history (P<0.001). Parity was inversely associated with density in all subsets, except premenopausal women and women without a family history. The association of parity with density was stronger in women with HRT history (P<0.001).

Conclusion:

The associations of alcohol and parity with breast density appear to be in reverse direction, but stronger in women with a family history of breast cancer and women who ever used HRT.     

VIP receptor antagonists and chemotherapeutic drugs inhibit the growth of breast cancer cells

The effects of vasoactive intestinal peptide (VIP) antagonists on breast cancer cells were investigated. (N-stearyl, norleucine¹⁷)VIP hybrid ((SN)VIPhyb) inhibited specific ¹²⁵I-VIP binding to MCF7, SKBR3, T47D ZR75-1 and MDA-MB231 cells with high affinity (IC₅₀ values of 0.03–0.06M). (SN)VIPhyb,1M, inhibited the ability of 10nM VIP to cause elevation of cAMP and to increase c-fos mRNA. Micromolar concentrations of (SN)VIPhyb inhibited the proliferation of MDA-MB231 or MCF7 cells using a MTT and clonogenic assay. Using a MTT assay, (SN)VIPhyb enhanced the ability of taxol and doxorubicin to inhibit breast cancer growth. Using nude mice bearing MDA-MB231 xenografts, VIPhyb potentiated the ability of taxol to inhibit proliferation. The results indicate that VIP receptor antagonists increase the ability of chemotherapeutic drugs to kill breast cancer cells.     

Prognostic factors for patients with liver metastases from breast cancer

Summary Background The prognosis of patients with liver metastases from breast cancer is commonly poor. After initial diagnosis of hepatic metastases, a median survival time of 1–20 months can be expected. The definition of prognostic factors for such patients may influence therapeutic decisions. In particular, the characterization of patients who can expect long-term survival could assist in optimizing treatment. Methods We retrospectively studied n=350 patients with liver metastases from breast cancer. All patients were stratified following their survival after occurrence of liver metastases. Kaplan–Meier studies were performed, as well as univariate and multivariate analyses of several clinical, histopathological and therapeutic factors. Results Median survival time was 14 months. N=66 (18.9%) patients survived longer than 36 months after the primary diagnosis. Multivariate analysis showed prognostic relevance for the time interval between the primary diagnosis of breast cancer and the initial diagnosis of hepatic metastases (p<0.05). Furthermore, prognostic relevance was found for the pattern of metastasization (p<0.05) and for signs of hepatic dysfunction (ascites, jaundice, p<0.005). Univariate analysis showed a prognostic benefit for patients with an expression of Ki-67<20%, p53<50% and a positive hormonal receptor status. Patients who received a regional therapy survived on average longer than patients who were only treated systemically (33 versus 11 months, p<0.001). Conclusions Consideration of prognostic implications of the described parameters may help to find the most appropriate treatment for patients with liver metastases from breast cancer. The possibility of local therapeutic interventions should be considered in a defined subgroup.     

Familial association of histology specific breast cancers with cancers at other sites

Breast cancer histologies show important differences in their incidence pattern, method of detection and management. Aggregation of breast cancer occurs also in families diagnosed for cancer at sites different from the breast. Therefore, the familial association of histology specific breast cancers with cancers at other sites is of great interest. The nationwide Swedish Family-Cancer Database was used to calculate standardised incidence ratios (SIRs) for breast cancer when parents or sibling were diagnosed with cancer at the most common sites. Significant SIRs were found when parents had breast, ovarian, laryngeal, endometrial, prostate, lung and colon cancers. If women were diagnosed before the age of 50 years, the SIRs were significant when parents were diagnosed with breast, ovarian, and prostate cancers, and leukaemia, and when siblings were diagnosed with squamous cell skin, pancreatic, breast and endometrial cancers. If mothers were diagnosed with breast cancer, histology-specific SIRs were ranked as comedo > tubular > ductal > lobular; SIR for medullary carcinoma was not significant but it was high when mothers presented with ovarian cancer. Other associations were between the upper aerodigestive tract and lobular, colon and comedo, larynx and ductal cancer. Moreover, cervical cancer was associated with comedo and endometrial cancer with the medullary histology. In conclusion, histology-specific breast cancers were associated with specific cancer sites and the strength of the association varied among histologies.     

The biguanides metformin and phenformin inhibit angiogenesis,local and metastatic growth of breast cancer by targeting both neoplastic and microenvironment cells

The human white adipose tissue (WAT) contains progenitors with cooperative roles in breast cancer (BC) angiogenesis, local and metastatic progression. The biguanide Metformin (Met), commonly used for Type 2 diabetes, might have activity against BC and was found to inhibit angiogenesis in vivo. We studied Met and another biguanide, phenformin (Phe), in vitro and in vivo in BC models. In vitro, biguanides activated AMPK, inhibited Complex 1 of the respiratory chain and induced apoptosis of BC and WAT endothelial cells. In coculture, biguanides inhibited the production of several angiogenic proteins. In vivo, biguanides inhibited local and metastatic growth of triple negative and HER2+ BC in immune‐competent and immune‐deficient mice orthotopically injected with BC. Biguanides inhibited local and metastatic BC growth in a genetically engineered murine model model of HER2+ BC. In vivo, biguanides increased pimonidazole binding (but not HIF‐1 expression) of WAT progenitors, reduced tumor microvessel density and altered the vascular pericyte/endothelial cell ratio, so that cancer vessels displayed a dysplastic phenotype. Phe was significantly more active than Met both in vitro and in vivo. Considering their safety profile, biguanides deserve to be further investigated for BC prevention in high‐risk subjects, in combination with chemo and/or targeted therapy and/or as post‐therapy consolidation or maintenance therapy for the prevention of BC recurrence.     

Pathologic characteristics of second breast cancers after breast conservation for ductal carcinoma in situ

BACKGROUND:

The number of women diagnosed with ductal carcinoma in situ (DCIS) is increasing. Although many eventually develop a second breast cancer (SBC), little is known about the characteristics of SBCs. The authors described the characteristics of SBC and examined associations between the pathologic features of SBC and index DCIS cases.

METHODS:

Women were identified in the National Comprehensive Cancer Network Outcomes Database who were diagnosed with DCIS from 1997 to 2008 and underwent lumpectomy and who subsequently developed SBC (including DCIS or invasive disease that occurred in the ipsilateral or contralateral breast). The Fisher exact test and the Spearman test were used to examine associations between the pathologic characteristics of SBC and index DCIS cases.

RESULTS:

Among 2636 women who underwent lumpectomy for DCIS, 150 (5.7%) experienced an SBC after a median of 55.5 months of follow‐up. Of these 150 women, 105 (70%) received adjuvant radiotherapy, and 50 (33.3%) received tamoxifen for their index DCIS. SBCs were ipsilateral in 54.7% of women and invasive in 50.7% of women. Among the index DCIS cases, 60.6% were estrogen receptor (ER)‐positive, and 54% were high grade, whereas 77.5% of SBCs were ER‐positive, and 48.2% were high grade. Tumor grade (P = .003) and ER status (P = .02) were associated significantly between index DCIS and SBC, whereas tumor size was not (P = .87).

CONCLUSIONS:

After breast conservation for DCIS, SBC in either breast exhibited pathologic characteristics similar to the index DCIS, suggesting that women with DCIS may be at risk for developing subsequent breast cancers of a similar phenotype. Cancer 2012. © 2012 American Cancer Society.     

Clinical results of breast conserving therapy for stage I and II breast cancers: Assessment of local recurrences in relation to surgical margins

Background Because of previously reported shortened follow-up periods, breast conserving therapy is still not prevalent for patients with breast cancer in Japan. This is a report of clinical trial results. Methods Between November 1987 and October 1995, breast carcinomas in 462 patients were treated with breast conserving therapy (BCT). Three hundred and sixty-four patients with follow-up periods of longer than 1 year, excluding simultaneous bilateral breast carcinomas, were analyzed. There were 19 stage 0,211 stage I, 132 stage II, and 2 stage III tumors according to the 1987 UICC classification. A total dose of 50 Gy was delivered over 5 weeks to the preserved breast using⁶⁰Co γrays. The primary site was boosted with a total dose of 10 Gy in 5 fractions in 40 of the 83 patients whose tumor margins were either positive or close. Results In a follow-up period of 12 to 96 months with a median of 35 months, 8 patients developed a breast recurrence. The actuarial overall, relapse-free, and breast-recurrence-free survival at 5 years were 99.0%, 92.3%, and 97.8%, respectively. The difference in the local control rate was significant between patients with negative margins and those with positive margins (P<0.0001), and between the patients with negative margins and those with close margins (P=0.0284). Conclusions The 5-year results of our trial were similar to those of other reported series. Positive and close margins are risk factors for breast recurrence. Improvements in optimal methods of radiation therapy including boost irradiation are needed.     

Case-control study of risk factors for breast cancer in Nigerian women

This study evaluated the potential risk factors for breast cancer in Nigerian women using a case-control design of 250 women with breast cancer and their age-matched female controls. Both cases and controls were recruited from 4 University Teaching Hospitals in Midwestern and Southeastern Nigeria. Data on the clinical and epidemiological characteristics were collected using interviewer-administered structured questionnaires. The mean age of the cases and controls were 46.1 and 47.1 years, respectively. Fifty-seven percent of the cases were premenopausal while 43% were postmenopausal. The association of risk factors with breast cancer was assessed using conditional logistic regression. Positive family history of breast cancer in first- and second-degree relatives (Odds ratio [OR] = 8.07, 95% confidence interval [CI], 1.003, 64.95, p = 0.04), education of high school level and above (OR = 1.35, 95% CI 1.04, 1.74, p = 0.0205), age at first fullterm pregnancy (FFTP) greater than 20 years (OR = 1.32 95% CI 1.01, 1.71, p = 0.0413) and waist/hip ratio (WHR) (OR = 1.98, 95% CI 1.27, 3.10, p = 0.0026) were associated with increased risk of breast cancer in the final multiple conditional logistic regression model. The findings from this study have shown that sociodemographic characteristics, reproductive variables and anthropometric measures are significant predictors of breast cancer risk in Nigerian women.     

Prognostic factors for node-negative breast cancers: Results of a study program by the Japanese breast cancer society

Background  Prognostic factors for predicting the recurrence of node-negative breast cancers have been controversial. The present study was performed to elucidate practically useful prognostic factors using formalin-fixed paraffin sections. Methods  This was a case-controlled multi-institutional study that composed 40 patients with recurrent node-negative breast cancer and 80 patients with node-negative breast cancer but without recurrence after radical surgery. Tumors were smaller than 3 cm in diameter and were treated surgically between January 1, 1985 and December 31, 1990. The recurrent and non-recurrent cases were matched with regard to their age, adjuvant chemotherapy and the year in which surgery was performed. Fourteen immunohistochemical factors and 8 histological factors of the primary tumor were studied on formalin-fixed, paraffin-embedded sections by immunohistochemical and histochemical analyses. Results  According to univariate analysis, factors such as progesterone receptor (PgR), MIB-1, CD44_v6, CD44_v9 and platelet-derived endothelial cell growth factor (PDECGF) were significantly different between the recurrent and non-recurrent groups (p>0.1; Wilcoxon-Mann-Whitney analysis). Chisquared test showed significant differences in MIB-1, cdc2 and stromal plasminogen activator receptor (suPAR). Histologically, mitotic count was also significantly different between the two groups (p>0.005). Multivariate analysis revealed that positivity for cdc2 (p=0.01), high mitotic count (p=0.04) and negativity for CD44_v9 (p=0.02) were independent prognostic factors among variables selected by univariate analysis, and that positivity for MIB-1 (p=0.03) and cdc2 (p=0.01), and negativity for CD44_v9 (p=0.03) were independent prognostic factors among the immunohistochemical markers examined. Conclusion  Our results indicated that positivity for MIB-1 and cdc2, high mitotic count and negativity for CD44_v9 could serve as independent factors for predicting the recurrence of node-negative breast cancer.