Interrelations between cellular DNA content, S-phase fraction, hormone receptor status and age in primary breast cancer. A series of 1,342 consecutively detected tumors. South-East Sweden Breast Cancer Group

Flow cytometry in primary breast carcinomas: prognostic impact of multiploidy and hypoploidy

BACKGROUND

The aims of the present work were to study the prognostic impact of multiploidy and/or hypoploidy in breast cancers and their relation to other classic clinicopathologic prognostic factors (T, grade, receptors, and lymph node status).

METHODS

From 3 January 1990 to 7 January 1999, 1984 previously untreated, invasive breast carcinoma samples were snap frozen for flow-cytometry.

RESULTS

Multiploid tumors had the same prognosis as the aneuploid ones, and those with one hypoploid peak had a better prognosis than did the other aneuploid tumors. However, the presence of both multiploid and hypoploid peaks was correlated with a poor outcome, even after multivariate analysis. In this series after quality control, 93.4% of the histograms could be evaluated concerning ploidy; of these 81.6% could be assessed concerning S-phase fraction (SPF) in the entire population and 77.1% in the multiploid population. In the entire population, we performed a multivariate analysis including all relevant prognostic factors remaining after monovariate analysis by using a compound factor (proliferative activity) regrouping SPF and mitotic activity. This analysis showed that lymph node status and proliferative activity correlates with every type of survival, whereas receptor status correlates with all types of survival except recurrence free survival size, correlated with non-metastasis and overall survival. Grade and age correlated only with overall survival and vascular permeations only with disease-free survival.

CONCLUSIONS

SPF is a valuable predictor of survival, can be confidently assessed in multiploid histograms, and thus improves the yield of flow cytometry. When combined with mitotic activity, the prognostic impact of SPF is the same as that of lymph node status. Tumors that are hypoploid and multiploid have a significantly worse prognosis.

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.

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.

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.

DNA aneuploidy in early breast cancer

High-resolution flow cytometric (FCM) DNA analysis was performed on 148 unfixed, frozen tissue samples from four groups of early breast cancers: invasive carcinomas (ICs) with predominance of carcinoma in situ (DCIS) (group I), small clinical cancers < or = 15 mm (group II), node-negative, clinical cancers (group III) and small screening-detected cancers < or = 15 mm (group IV). The median tumour size was 12 mm. The aim of the study was to support, with a larger sample, our recent findings with respect to DNA ploidy pattern in the selected group of ICs with predominance of DCIS (group I). Similar results to this group were found for both the small clinical cancers and the node-negative cancers, with respect to frequency of DNA aneuploidy (79% and 90%), DNA index (DI) distribution, intratumoral DNA heterogeneity and S-phase fraction. A high frequency of DNA hyperdiploid clones was found, in particular related to highly differentiated tumours. A significant difference was found compared with the screening-detected cancers, which were characterised by a much lower frequency of DNA aneuploid samples (49%) and may represent a biologically specific group of low-malignant, slowly growing tumours. Associations were shown between histological grade and DI subclasses, and between lymph node status and DNA diploidy/aneuploidy, whereas DI was not correlated with tumour size. The DNA ploidy findings in this series of early cancers are concordant to our own results from preinvasive lesions as well as those reported from series of more advanced cancers.

Flow cytometric DNA ploidy defines patients with poor prognosis in node-negative breast cancer

Flow cytometric DNA analysis was performed on fine-needle aspirates from frozen tumour biopsies from 421 node-negative, non-adjuvantly-treated breast-cancer patients with a median observation time of 6.75 years. Among premenopausal patients (n = 175), those having at least one DNA "hypoploid" subpopulation defined as DNA index (DI) < 0.96 or 1.44 < or = 1.92 (n = 81) were characterized by early recurrences (log-rank p = 0.05), Wilcoxon p = 0.007), poor overall survival (OS) (p < 0.001) and poor survival after recurrence (p < 0.001). In the postmenopausal group (n = 246), there were no significant difference among 7 different DI classes regarding either recurrence-free survival (RFS) or OS. S-phase fraction (SPF), divided into quartiles, predicted OS in premenopausal patients only (p = 0.02). Conventional multivariate Cox analysis of OS in the premenopausal group revealed hypoploidy to be the only independent prognostic factor involving a relative risk (RR) of 22.8. Age < or = 40 years was of marginal significance, whereas SPF, histological grade (WHO), oestrogen and progesterone receptor (PgR) content, tumour size and number of lymph nodes removed were excluded from the model. Application of the conventional Cox model to the premenopausal group regarding RFS was found inappropriate due to lack of proportionality of the hazards of hypoploidy due to lack of proportionately of the hazards of hypoploidy, SPF and histological grade. However, introduction of time-dependent co-variates using 2 years as cut-off level showed hypoploidy with a RR of 3.52 and age < or = 40 years with a RR of 3.28 to be independent prognostic factors. In the postmenopausal group, the conventional Cox model identified the number of lymph nodes removed to be the only independent prognostic factor regarding RFS as well as OS, whereas SPF < 9% (lowest quartile) was of marginal significance in RFS analysis. Hypoploidy was correlated to high SPF, low PgR content and low differentiation, indicating that hypoploid tumours proliferate rapidly and hormone-independently. These patients may therefore benefit from adjuvant chemotherapy administered while tumour burden and risk of drug resistance are still low.

Significance of S-phase fraction and hormone receptor content in the management of young breast cancer patients

Tumours from 336 breast cancer patients under the age of 50 were analysed for hormone receptor content and by DNA flow cytometry. Sixty-six percent of the tumours were positive for estrogen receptors (ER), 60% were progesterone receptor (PR) positive and 42% showed DNA diploid profiles. DNA hypodiploid tumours were relatively frequent (7%), especially in patients aged 40 years or less (11%). S-phase fraction (SPF), with a mean of 10%, correlated significantly with receptor status, DNA ploidy, lymph node status, tumour size and age. With a median follow-up period of 34 months, the distant recurrence-free interval was independently predicted by lymph node status, tumour size, SPF and PR content. Amongst the 212 patients who had not received adjuvant systemic treatment, receptor status was, in addition to lymph node status and SPF, independently related to distant recurrence rate. A high SPF identified a subgroup with high recurrence rate, comprising approximately one third of the node-negative patients. Similarly, the one third of node-positive patients who had PR-positive tumours with a low S-phase fraction formed a subgroup with low recurrence rate. We conclude that hormone receptor assays and DNA flow cytometry should be useful tools in the management of breast cancer patients less than 50 years of age.