Relationships of DNA ploidy, S-phase fraction and hormone receptor status to tumor stage in breast cancers detected by population screening. The South-East Sweden Breast Cancer Group

Apoptosis and Bcl-2 Expression in Relation to Age, Tumor Characteristics and Prognosis in Breast Cancer

The extent of apoptosis and the expression of Bcl-2 was investigated in tumor samples from 165 women who underwent surgery for primary breast carcinoma between 1989 and 1990 in South-East Sweden. Apoptosis was assessed by a DNA fragmentation assay for flow cytometry. Bcl-2 protein expression was analyzed with immunocytochemistry Bcl-2 immunoreactivity correlated with estrogen receptor (ER) and progesterone receptor (PgR) positivity and was inversely correlated with p53 accumulation. Apoptosis increased with patient age and a high degree of apoptosis was negatively associated with Bcl-2 immunostaining. Apoptosis showed no significant correlation with any of the other variables studied, including prognosis. The group with Bcl-2-positive tumors tended to have a lower risk of distant recurrence than others, but the association of Bcl-2 with recurrence was different in groups divided by ER and PgR status. Whereas Bcl-2 positivity indicated a low recurrence rate among PgR-negative patients, in the PgR-positive group, those with Bcl-2-positive tumors showed a non significantly higher recurrence rate than Bcl-2-negative cases. In the PgR-positive group, Bcl-2-positive tumors also appeared more frequently to be lymph node positive and DNA aneuploid. The results suggest that hormone receptor status is of importance for the prognostic role of Bcl-2. Likewise, patient age merits consideration when apoptosis is studied in human cancer.

No association between the progesterone receptor gene polymorphism (+331G/a) and the risk of breast cancer: an updated meta-analysis

BACKGROUND

Many published studies have estimated the association between the +331G/A (rs10895068) polymorphism in the progesterone receptor (PgR) gene and breast cancer risk. However, the results remain inconsistent and controversial. To address this inconsistency, we systematically interrogated the aforementioned association via a meta-analysis.

METHODS

Through a literature search, we identified 13 case-control studies, including 12,453 cases and 14,056 case-free controls. The strengths of reported associations were evaluated using odds ratios (ORs) with 95% confidence intervals (95%CIs).

RESULTS

An association was found between +331G/A polymorphism and +331G/A risk in the dominant model (p = 0.027). Via subgroup analysis, we found no association between +331G/A and breast cancer risk in Caucasians, Asians or mixed racial groups.

CONCLUSIONS

Through meta-analysis, we were able to gain insight into previously reported associations between +331G/A polymorphism and breast cancer risk. However, further studies are still needed to provide more evidence.

Hormone Use is Associated with Lymphovascular Invasion in Breast Cancer

BACKGROUND

Risk of developing breast cancer increases with short breastfeeding and the use of hormones. The prognosis of breast cancer is better if the tumours are hormone receptor positive. Since breast feeding affects estrogen and progesterone receptors, we wanted to investigate how such reproductive factors as breastfeeding and the use of hormones interact with known prognostic markers and specific tumour characteristics in women with breast cancer.

MATERIALS AND METHODS

A total of 250 women treated for breast cancer from a larger cohort completed a questionnaire on breastfeeding, number and age at births and use of hormones. A logistic regression analysis was made to search for connections between known prognostic markers on the one hand (type of cancer, grade, tumor size, estrogen receptor and progesterone receptor, lymphovascular invasion and DNA-ploidy) and reproductive data, breastfeeding, and hormone use on the other.

RESULTS AND CONCLUSIONS

Hormone use, but not breastfeeding, was significantly associated, also on multivariate analysis, with the prognostic variable lymphovascular invasion, connected to a worse prognosis. No other hormone use or breast feeding correlations with prognostic variables were found.

Survival after treatment for breast cancer in a geographically defined population

Background

South East Sweden with 976 000 inhabitants is served by nine hospitals with specialized breast surgeons. Population-based mammographic screening was introduced in 1986 for women aged 40–74 years. Patients with primary breast cancer were treated according to a joint management programme.

Methods

All patients were reported to a regional cancer registry from which breast cancer incidence, treatment and survival in this defined population were reported.

Results

A total of 7892 women had their first invasive breast cancer diagnosed between 1986 and 1999. The median tumour size was 17 mm and 29·9 per cent had axillary metastases. Some 49·8 per cent of these women had a modified radical mastectomy and 31·9 per cent had a segmental resection with axillary clearance. Postoperative radiotherapy was given to 40·3 per cent of the women after mastectomy and to 87·1 per cent after breast-conserving surgery. Tamoxifen and chemotherapy were used as adjuvant treatment except in low-risk patients. Breast cancer-specific survival rate for all stages was 83·5 per cent at 5 years and 74·0 per cent at 10 years. Respective values were 95·8 and 90·9 per cent for patients with stage T1 N0 M0 tumours, and 77·7 and 62·4 per cent for those with T1–2 N1 M0 tumours.

Conclusion

Breast specialists treating women with breast cancer according to a joint management programme have achieved very good survival rates.

Flow cytometry and quantitative immunohistochemical study of cell cycle regulation proteins in invasive breast carcinoma: prognostic significance

BACKGROUND

Between January 11, 1991 and January 8, 1992, 104 patients with previously untreated, invasive, primitive breast carcinoma were admitted to the authors' hospital.

METHODS

For each patient, flow cytometry DNA analyses on frozen samples and on immunohistochemical staining were performed, including Ki-67, cyclin A, p53, and p21(waf1) (p21), with assessment of the percentages of positive nuclei were assessed. Correlations with classic clinicopathologic data and survival (overall, metastasis free, or recurrence free) and a multivariate analysis were performed.

RESULTS

After a multivariate analysis according to a Cox model that was stratified by age, tumor size, tumor grade, lymph node status, and receptor status, among the factors studied, the presence of p21 was the unique remaining prognostic factor for patients with invasive breast carcinoma. Because of the lack of a correlation between p21 and proliferative factors (Ki-67, S-phase, and cyclin A), the authors combined p21 with those markers and found that, for the different combinations, after statistical analysis, only p21 combined with S-phase or with cyclin A and lymph node status were salient survival prognostic factors.

CONCLUSIONS

Immunohistochemical study of proteins involved in the cell cycle and assessment of proliferative activity using flow cytometric DNA analysis aided the authors in singling out correlations of cyclin A and S-phase, along with p21, with metastasis free survival and overall survival in patients with invasive breast carcinoma. These promising results will require confirmation in a larger series of patients.

Human progesterone receptor gene polymorphism PROGINS and risk for breast cancer in Austrian women

A germline TaqI restriction fragment length polymorphism in the intron G of the progesterone receptor (PR) gene designated PROGINS was described to be associated with an increased risk for ovarian carcinoma. It was supposed that the PR isoform A protein associated with PROGINS has an increased stability and therefore, a higher transcriptional activity. This may cause an inadequate control of estrogen receptor (ER) and PR B isoform and lead to the increased risk of tumor development. On the other hand, loss of heterozygosity (LOH) of the chromosomal region 11q22-23, where the PR gene is located, was frequently observed in breast cancer, suggesting the presence of a tumor suppressor gene in this region. Recently, it was reported that PROGINS is associated with a decreased risk for breast cancer. In order to examine if PROGINS is associated with an alteration of the risk for breast cancer, we examined PROGINS in 155 sporadic breast cancer patients in Austrian women and in a control group of 106 healthy volunteers. LOH affecting the PR gene was also analyzed in the tumor patients. No statistically significant difference was found for the frequencies of the PROGINS carriers (23.2%) in the Austrian breast cancer patients and in the healthy control group (26.4%), indicating that PROGINS is not associated with either an increased or a decreased risk for breast cancer. Furthermore, no associations between the PROGINS status and the protein levels of ER and PR, clinical data like tumor type, differentiation grade, tumor size, and the nodal status as well as the age of the patients were found. There was also no significant difference in the frequency of LOH affecting the PR gene in the PROGINS carriers and non carriers, demonstrating that LOH at PR gene is not associated with the PROGINS status.

Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients

Akt/PKB is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin beta 1 and Bcl-2 was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged <50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P=0.001) and the presence of heregulin beta 1-expressing stromal cells (P=0.017). Neither Akt-1 nor pAkt was related with other factors. Tumour cells-derived heregulin beta 1 was found mainly in oestrogen receptor negative (P=0.026) and node negative (P=0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P=0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer.

DNA ploidy analyses in 218 consecutive Pakistani breast cancer patients: does it add anything?

An analysis was made to evaluate the significance of DNA ploidy in the biology and prognosis of breast carcinoma. This was done by estimating the correlation of DNA ploidy with other established prognostic markers of breast cancer, namely tumor size, tumor grade, lymph node metastasis and S-phase fraction. From 1995 up to year 2000 ploidy analysis was performed on 218 consecutive cases of infiltrating breast carcinoma by flow cytometry using formalin fixed paraffin embedded material. From the laboratory record, data regarding other pathological variables was retrieved. No correlation could be found between DNA ploidy and tumor grade, nor could there be found a correlation with tumor size. For lymph node metastasis there was a significant difference between the proportion of aneuploids and diploids having metastasis in more than 4 lymph nodes. However, no significant difference was found in axillary lymph node positive and negative groups when number of positive lymph nodes was not taken into account. The mean value of S-phase fraction for the aneuploids and the diploids was also insignificantly different. In conclusion DNA ploidy alone did not add much to predict tumor behaviour in terms of known pathologic variables.

A comparison between flow cytometric assessment of S-phase fraction and Nottingham histologic grade as prognostic instruments in breast cancer

Flow cytometric DNA analysis with assessment of S-phase fraction and DNA ploidy was compared to Nottingham histologic grade. The study population consisted of 654 patients who presented between 1987 and 1996 with primary operable breast cancer and whose tumours had been analysed for S-phase fraction and DNA ploidy at the time of surgery. Grade, tumour size, node status, steroid receptor status, age, S-phase fraction and DNA ploidy were analysed univariately and multi-variately in a Cox proportional hazard analysis. In the univariate analyses all parameters were statistically significantly associated with breast cancer mortality during the follow-up period of 2-11 years. The most powerful predictor of death from breast cancer in the multiple regression analysis was grade. Patients with grade 1 tumours have excellent prognosis. We conclude that tumour grade is a strong prognostic indicator applicable to all breast cancer patients, regardless of size and nodal status, and advocate its general use.

Flow cytometry in primary breast carcinomas. Prognostic impact of proliferative activity

From 1990 to 1996, 607 previously untreated, node-negative, invasive breast carcinomas were sampled by a pathologist for flow-cytometric DNA analysis. The aim of the present work was to study the correlations between flow cytometric results obtained thanks to the American Consensus (AC) guidelines of 1993 and the established clinico-pathological prognostic factors (T, grade, receptors), and despite a short global follow-up (mean of 4 years), to correlate flow cytometry with the outcome of the patients. In this study S-phase fraction (SPF) correlated strongly with tumor size, histological grade, lack of steroid receptors, histological type and was together with the mitotic activity a paramount prognostic factor even after multivariate analysis. This study compared also the technical criteria proposed by the AC with our own more stringent ones and concluded that the criteria of the AC are relevant and allow, thanks to the use of tertiles in the reporting of SPF values, a comparison of values obtained by different teams. Our review of the literature, focused on series using fresh material, enabled us to show that there is a rather wide agreement concerning the relationship between SPF and prognosis most often after multivariate analysis. This despite the lack of standardization in the design of the studies (implementation of the technical steps or reporting of results). When estimated from fresh or frozen material following AC's guidelines. SPF along with mitotic activity should become a prognostic factor used in the daily practice by oncologists in the management of breast carcinomas.

Association of in vitro invasiveness and gene expression of estrogen receptor, progesterone receptor, pS2 and plasminogen activator inhibitor-1 in human breast cancer cell lines

The invasive potential of tumor cells is usually tested either by in vitro invasion assays which evaluate cell spreading ability in basement membrane-like matrices or by in vivo invasion assays in nude mice. Both methods are laborious and time-consuming. Tumor invasiveness is accompanied by the changes in expression of various genes. The invasive behavior of cells is therefore represented by certain gene expression patterns. The purpose of this study was to investigate whether expression patterns of several genes are characteristic for the invasiveness of cultured cells. We examined the mRNA levels of estrogen receptor (ER), progesterone receptor (PR), estrogen inducible pS2 and plasminogen activator inhibitor-1 (PAI-1) in 23 cell lines derived from benign and malignant breast tissues using a competitive reverse transcription-polymerase chain reaction (cRT-PCR) system. We also evaluated the invasiveness of these cell lines by their ability to penetrate into a collagen-fibroblast matrix. We demonstrate that the gene expression pattern of breast cell lines is clearly associated with their in vitro invasiveness. In general, cells with ER, PR, pS2 but no PAI-1 expression showed a non-invasive phenotype, while cells expressing PAI-1 mRNA but not ER mRNA are invasive. Our study indicates that the invasiveness of breast cancer cell lines is characterized by PAI-1 gene expression and the lack of ER mRNA. This suggests that PAI-1 may participate in the invasive process.

S-phase fraction and breast cancer--a decade of experience

During the past decade, more than 300 articles, abstracts, and book chapters have been published about S-phase fraction (SPF) determined by DNA flow cytometry and its clinical utility for patients with breast cancer. However, the use of SPF for making treatment decisions for breast cancer patients remains controversial. After reviewing 273 published articles, we conclude: 1) Despite different techniques and cutpoints, correlations between SPF and other prognostic markers are relatively consistent across studies; higher SPF is generally associated with worse tumor grade, absence of steroid receptors, larger tumors, and positive axillary lymph nodes. 2) Higher SPF is generally associated with worse disease-free and overall survival in both univariate and multivariate analyses; SPF values from laboratories that have conducted validation studies can be used, in combination with other factors, to estimate the prognosis of patients with primary breast cancer. 3) There is considerable variability among laboratories regarding assay methodology, cell-cycle analysis techniques, and cutpoints for classifying and interpreting SPF; use of SPF values from different laboratories is problematic, and there remains a need for standardization of these processes and well-designed confirmation studies. We conclude that measurement of SPF does have clinical utility for patients with breast cancer, but standardization and quality control must be improved before it can be routinely used in community settings.

Estrogen receptor status of breast cancer: a marker of different stages of tumor or different entities of the disease?

Breast cancer can be divided into two types according to the estrogen receptor (ER) level of the tumor: ER-positive and ER-negative. Two hypotheses have been raised about the relationship between ER-positive and ER-negative breast tumors. One hypothesis considers ER status as an indicator of a different stage of the disease. The other regards ER-positive and ER-negative tumors as different entities. For both etiological and biological studies of breast cancer it is important to know which hypothesis is correct. In this paper, we review evidence for and against each hypothesis and suggest issues to be addressed in future studies.

Image analysis evaluation of ploidy, S-phase fraction and nuclear area in canine mammary tumours

Image analysis was used on cytocentrifuge preparations of Feulgen-stained nuclei extracted from formalin-fixed, paraffin wax-embedded tissues to determine ploidy (assessed by integrated optical density), S-phase fraction, and nuclear area of 90 canine mammary tumours (30 benign and 60 malignant). Only two lesions identified histologically as benign were aneuploid, suggesting potential malignancy. Of malignant tumours, 37% were aneuploid. No distinction based on ploidy could be made within benign or malignant groups, except for tubular adenocarcinomas of complex type, all of which were diploid. Mean S-phase fraction of malignant lesions (15.60%) was twice that of benign lesions (7.87%; P < 0.0001). The mean nuclear surface was significantly smaller in malignant lesions (70.62 microns2) than in benign counterparts (77.45 microns2; P < 0.05). No relation was found between a given tumour type and S-phase fraction or nuclear area within histologically malignant or benign tumour groups. Infiltration of lymphatics by neoplastic cells, known to indicate a poor prognosis, was associated with aneuploid lesions (mean DNA index > 1.25) and high S-phase fraction. The presence of necrosis and of a high number of mitoses was significantly associated with high S-phase fraction lesions.

Pathological and biological features of mammographically detected invasive breast carcinomas

The pathological and biological features of a consecutive series of impalpable invasive breast carcinoma, detected by mammography in the prevalent round of the breast screening programme, have been compared with a clinically presenting group of carcinomas in age-matched patients. There was a significantly higher prevalence of tubular carcinomas as well-differentiated infiltrating ductal carcinomas in the mammographically detected group, and a lower prevalence of poorly differentiated infiltrating ductal carcinomas. Lymph node metastasis was found in 6.5% of the impalpable group compared with 53% of the clinical group. The prevalence of oestrogen receptor was much higher in the impalpable group (96%) than in the control group (67%), although there were no significant differences for progesterone receptor. The prevalence of pS2 was also much higher in the impalpable group, as was cathepsin D. This finding is surprising in view of the reported relationship between cathepsin D and poorer survival. p53 and c-erb-2 proteins were detectable in fewer impalpable carcinomas. The mean MIBI (Ki-67) index was lower in the impalpable group (11.6) than in the clinical group (15.25). Within the mammographically detected group there was a significant difference in the MIBI index between tubular carcinomas and the different grades of infiltrating ductal carcinomas, with a wide range in each category but no association with size. The impalpable carcinomas detected by mammography differ from clinically presenting carcinomas in many ways, raising the question of whether a proportion or all would progress (dedifferentiate) with time.

Simultaneous analysis of c-erbB-2 expression and DNA content in breast cancer using flow cytometry

The c-erbB-2 oncogene is frequently amplified and overexpressed in human breast cancer. We have studied the c-erbB-2 protein in conjunction with DNA content in frozen samples from breast cancers using flow cytometry. The cell suspensions were obtained by mechanical disaggregation followed by a short fixation in 1% paraformaldehyde. The level of c-erbB-2 expression was calculated as a fluorescence index, taking into account the relative amount of total cellular fluorescence compared to nonspecific fluorescence. The flow cytometric value correlated with immunohistochemical results obtained with the same monoclonal antibody (c-neu, clone 9G6). Overexpression of c-erbB-2 was significantly more frequent in DNA aneuploid tumors than in DNA diploid ones and correlated with increasing S-phase fraction and estrogen receptor negativity. In 10 DNA multiploid tumors, the different aneuploid stemlines uniformly expressed c-erbB-2, supporting the hypothesis that overexpression is an early event in breast cancer. Of the 172 tumors, the 37 (22%) judged as positive with immunohistochemistry showed a somewhat higher rate of distant recurrence than others (P = 0.14). The fluorescence index was significantly associated with prognosis (P = 0.0012), as it was also among the immunohistochemically positive cases. If the degree of overexpression is important, then flow cytometry could be a feasible technique for classification.

Prospective study correlating P120 antigen expression with established prognostic factors in breast cancer

P120 is a nucleolar proliferation antigen found in rapidly dividing cells and a variety of malignancies. Previous retrospective studies have demonstrated that, when detected in human breast cancer, P120 is associated with a poorer prognosis. To determine whether P120 expression correlates with other prognostic factors in breast cancer, we prospectively analysed pathologic and clinical data from 61 patients. P120 was detected in 40 of the 61 specimens (66%). No significant correlation existed between P120 expression and either tumour size or hormone receptors. A significant correlation was found between P120 expression and histological grade, degree of aneuploidy, S-phase fraction, degree of nodal involvement, and stage of disease. P120 is a biological marker indicative of tumour aggressiveness and may play an important role in determining which patients would most benefit from adjuvant therapy.

Prediction of axillary lymph node metastases in a screened breast cancer population. South-East Sweden Breast Cancer Group

To define a subgroup of patients, in whom axillary dissection could be omitted, we analysed the frequency of pathologically confirmed lymph node metastases depending on tumour size, hormonal receptors, DNA ploidy, S-phase fraction (SPF), and clinical nodal status among 1,145 patients with stage I-II breast cancer from an area with ongoing screening. Clinical nodal status and tumour size were strongly correlated to pathological nodal status. Also SPF > 10% was strongly correlated to node positivity in univariate analysis. In multivariate analysis there was still a significant correlation among cases with tumour size < or = 20 mm. In conclusion, patients with clinically negative nodal status, and tumour size < or = 20 mm and < or = 10 mm had pathologically positive nodes in 25% and 15% of cases respectively. The addition of SPF did not lower these figures significantly since small tumours with high SPF are few.

Cellular accumulation of p53 protein: an independent prognostic factor in stage II breast cancer

The p53 gene product is a tumour suppressor protein, and alterations of the protein are common in human cancer. Previous studies have focused on nuclear accumulation of p53. To investigate if cytoplasmic accumulation of p53 strengthens the relationships to different pathobiological variables and distant recurrence-free survival in breast cancer, tumours from 164 stage II patients were examined with the monoclonal antibody PAb1801. Nine per cent of the tumours were nuclear positive and 21% were cytoplasmic positive. Cellular p53 accumulation, related to the nucleus or the cytoplasm or both, showed stronger associations with pathobiological variables than nuclear accumulation alone. Accumulation of p53 was significantly correlated to tumour size over 20 mm, negative oestrogen receptor (ER) status, DNA aneuploidy, high S-phase fraction and positive erbB-2 status. Cytoplasmic p53 was significantly correlated to distance recurrence-free survival in patients negative for nuclear p53 (P < 0.0001). Cellular p53 accumulation was an independent prognostic factor, in addition to lymph node status and ER content. We conclude that consideration of cytoplasmic staining enhances the clinical importance of p53.

Prognostic studies in breast cancer. Multivariate combination of nodal status, proliferation index, tumor size, and DNA ploidy

We studied histological samples and clinical data from 111 breast carcinoma patients originally treated in 1975-1977 who did not have distant metastases at the time of diagnosis. A multivariate survival analysis using the Cox model selected the studied variables in the following order according to their prognostic association (breast cancer deaths, or deaths from any cause): axillary lymph node status, tumor size, mitotic index, and DNA ploidy status. The association of the different variables to the prognosis in respect to breast cancer deaths was evaluated 1-10 years after treatment by stepwise logistic regression. Lymph node status, tumor size, mitotic index, and DNA ploidy all showed significant relation to the prognosis but this association varied considerably with time of observation.