The DNA labelling index: a prognostic factor in node-negative breast cancer

Feasibility of a Cell Kinetic-Based Adjuvant Chemotherapy Trial in Axillary Node-Negative Breast Cancer

Aims and background

Accumulated information on biologic prognostic indicators and predictors of response to different types of treatment in patients with different tumor characteristics has made it possible to design clinical protocols on biologic bases. Among cell proliferation indices, the thymidine labelling index (TLI) has proved to be an independent and consistent prognostic indicator over time. Moreover, experimental and retrospective analyses of clinical studies have revealed a direct relation between TLI and response to chemotherapy. On the basis of the results, a prospective clinical protocol on axillary node-negative breast cancer was activated in Italy in 1989.

Methods

Patients with low TLI tumors were treated with local-regional therapy alone, whereas patients with high TLI tumors were randomized to receive local-regional therapy followed or not by adjuvant chemotherapy consisting of 6 cycles of CMF.

Results and Conclusions

The present paper reports on the feasibility of a prospective clinical protocol based on a subgroup of patients with specific pathologic (node negative) and biologic (rapidly proliferating) breast cancers. However, patient eligibility was only 11%.

Cell Kinetics and Tumor-Associated Antigen Expression in Human Mammary Carcinomas

Twenty-six primary breast carcinomas were studied to evaluate cell proliferation as assessed by thymidine labeling index (TLI), and antigenic phenotype, as defined by immunohistochemistry using eight monoclonal antibodies (MAbs) to tumor-associated antigens (TAAs). The majority of tumors had low TLI values. Reactivity to MAbs B72.3, CC49, CC83 (anti TAG 72), COL-12 (anti CEA) and MOv2 (against a tumor-associated mucoprotein) was restricted to < 50% of the tumors studied, while MAbs B1.1 (anti CEA), MBrl and MBr8 (to tumor-associated carbohydrates) reacted with > 50% of the cases. Correlations between expression of TAAs and proliferative activity showed that the tumors could be divided into three groups, two characterized by either high proliferative activity and absence of antigenic expression or low proliferative activity and strong antigenic expression, and the third showing no relation between these two biological features. We defined two antigenic phenotypes associated with specific cellular kinetics: one characterized by negative immunoreaction with MAbs, CC49, CC83 and COL-12 and high proliferative activity; the other characterized by intense immunoreactivity with these antibodies and low proliferative activity. The data suggest that cell proliferation and antigenic phenotype may define biologic subsets of breast carcinomas

Epidermal Growth Factor Receptor in Human Breast Cancer: Comparison with Steroid Receptors and other Prognostic Factors

The relationship between epidermal growth factor receptor (EGFR) status and various prognostic factors was investigated in 70 human breast cancer specimens. Epidermal growth factor receptor was determined by radioligand binding assay, standardized by the EORTC Receptor Study Group, using hydroxyapatite to separate receptor-bound and free ligand. The percentage of EGFR positivity was 80% when the cutoff was set at 5 fmol/mg of membrane protein; this percentage was among the highest hitherto reported. Regression analysis of EGFR versus ER and PR levels confirmed an inverse relationship between EGFR and ER (p = 0.022) as well as between EGFR and PR (p = 0.024). Univariate analysis of the EGFR data stratified according to steroid hormone receptor status showed EGFR to be negatively associated with ER and PR. No association was found between EGFR and menopausal status, axillary lymph node involvement, tumor size, and differentiation grade. A direct association between EGFR status and Ki-67 positive cell rate could be demonstrated.

Prognostic and predictive indicators in operable breast cancer

Because of its biological heterogeneity and wide spectrum of responsiveness to different treatments, breast cancer is a complex disease of difficult clinical management. Over the past several years, knowledge of the molecular mechanisms regulating normal and aberrant cell growth leading to cancer has been enhanced. These advances have enabled the identification of an increasing number of surrogate biomarkers, which have been correlated with prognosis or used as predictors of response to specific treatments. Axillary nodal status, age, tumor size, pathologic grade, and hormone receptor status are the established prognostic and/or predictive factors for selection of adjuvant treatments. The role of new biomarkers, such as p53, HER2/neu, angiogenesis, and the proliferation index value, is promising; however, the clinical value of their determination must be provided by prospective clinical studies.

Relationship between the thymidine labeling and Ki-67 proliferative indices in 126 breast cancer patients

Proliferative activity has been proposed as a prognostic and predictive marker for breast cancer; Ki-67 is one of the most frequently used markers to assess proliferative activity. In the current study, Ki-67 immunoreactivity was comparatively assessed, even in terms prognostic relevance, with 3H-thymidine labeling index as a reference standard for proliferation in 126 patients with stage I and II breast cancer. There was a significant but weak correlation between Ki-67 values and the 3H-thymidine labeling index (r = 0.19, P = 0.03). Analysis of variance showed that the mean 3H-thymidine labeling index values were not statistically different in terms of pathologic size (T1, T2. T3, T4), number of pathologically positive axillary nodes (neg, pos 1-3, pos > 3), and grading classes (1, 2, 3), but significantly and inversely correlated with estrogen receptor status (P = 0.033) and progesterone receptor status (P = 0.08). The Ki-67 values significantly correlated with N status (P = 0.041), estrogen receptor status (P < 0.001), progesterone receptor status (P < 0.001), and grading (P < 0.001). The median follow-up was 37 months. In terms of prognosis, Ki-67 was associated significantly with overall survival (P = 0.01) and marginally with disease-free survival (P = 0.095). A significant difference in prognosis was found for both disease-free survival (P = 0.024) and overall survival (P = 0.040) when a 3H-thymidine labeling index cut-off of 6.5% was used (P = 0.024). The results suggest that, although both are indicators of proliferative activity, 3H-thymidine labeling index and Ki-67 seem to identify breast cancers with different phenotypes.

Natural history of node-negative breast cancer: are conventional prognostic factors predictors of time to relapse?

The purpose of this study was to determine a subpopulation of node-negative breast cancer patients at high risk of metastases and to analyse the relationship between conventional prognostic factors and the onset of metastatic disease. Patients with node-negative breast cancer, who were not receiving systemic adjuvant therapy, were prospectively enrolled into a multicentre study. We studied the onset of metastatic disease in relation to family history, age, and tumour characteristics of 2683 registered patients, 2213 were available for analysis. Median follow-up was 100 months. Metastatic disease-free survival was 88% at 5 years and 80% at 10 years. The two strongest prognostic factors in a multivariate analysis tumour Scraff, Bloom and Richardson (SBR) grade (P<0.0001) and size (P<0.02), were used to classify patients into three groups with different risks of relapse at 10 years: (1) lowest (8.4%) risk: SBR I and < or =1 cm; (2) intermediate (20%) risk: SBR I and >1 cm or SBR II or SBR III and < or =2 cm; (3) highest (32%) risk: SBR II or SBR III and >2 cm. A peak in the incidence of metastases was noted between 2 and 4 years, and a nadir between 6 and 8 years, after surgery. SBR grade is a highly predictive factor in node-negative breast cancer. The time course of the appearance of metastases is not linear. Prognostic factors are related to the height of an early peak in the occurrence of metastases rather than to the timing of this peak.

Comparison between different cell kinetic variables in human breast cancer

Cell kinetics holds a prominent role among biological factors in predicting clinical outcome and response to treatment in neoplastic patients. Different cell kinetic variables are often considered as valid alternatives to each other, but the limited size of case series analysed in several studies and the lack of simultaneous determinations of all the variables on the same tumours do not justify this conclusion. In the present study, the correlation between [3H]thymidine labelling index ([3H]dT LI), flow cytometric S phase cell fraction (FCM-S) and Ki-67 immunoreactivity (Ki-67/MIB-1) was verified and the type of correlation with the most important clinical, pathological and biological patient and tumour characteristics was investigated in a very large series of breast cancer patients. Ki-67/MIB-1, FCM-S and [3H]dT LI were determined in 609, 526 and 485 patients, respectively, and all three cell proliferation indices were evaluated in parallel on the same tumour in a series of 330 breast cancer patients. All the cell kinetic determinations were performed within the context of National Quality Control Programmes. Very poor correlation coefficients (ranging from 0.37 to 0.18) were observed between the different cell kinetic variables determined in parallel on the same series of breast cancers. Moreover, Ki-67/MIB-1 and FCM-S showed a significant relationship with histological type, grade and tumour size, whereas statistically significant correlations were not observed for [3H]dT LI. In conclusion, the results show that the different cell kinetic variables provide different biological information and cannot be considered as alternatives to each other.

Prognostic significance of biologic markers in node-negative breast cancer patients: a prospective study

It is generally thought that future advances in the treatment and cure of breast cancer patients will be made possible through a deeper understanding of tumor biology and an improved capability to define the prognosis of each single patient. This will lead to the formulation of new, more selective, and patient-tailored therapies. It is therefore important, when studying potential prognostic factors, to follow methodologic requirements and guidelines which involve the carrying out of prospective studies as confirmatory steps. Repeatedly or recently investigated prognostic markers (tumor size, menopausal status, ER, PgR, 3H thymidine labeling index, c-erbB-2 and p27 expression) were evaluated on a series of 286 prospectively recruited node negative breast cancer patients who underwent loco-regional treatment alone and were closely followed. The individual and relative prognostic contribution of each variable with respect to other factors, as well as their ability to identify node negative patients at risk, were assessed by univariate and multivariate analysis. At a five-year follow-up, only tumor size (p = 0.021) and TLI (p = 0.016) individually proved to be significant prognostic indicators of relapse-free survival. Conversely, p27 expression was not related to RFS and c-erbB-2 expression appeared to have only a short-term effect on patient prognosis. TLI and tumor size, tested in multivariate analysis along with ER and menopausal status, maintained their independent prognostic relevance. The study, performed on a large series of node-negative patients given loco-regional treatment alone, for the first time prospectively recruited, showed the prognostic relevance of TLI and its independence from other clinico-pathologic and biologic factors over a five-year period.

Prognostic and predictive value of thymidine labelling index in breast cancer

In the last few decades, much effort has been directed towards identifying the phenotypic or functional aspect of tumor cells which can contribute to a biofunctional staging for improving the accuracy of pathologic staging used for identifying patients at different risk. Among known biologic factors, the proliferative capacity of the tumor cell population, a feature common to all tumors, has been widely investigated. Several approaches have been used to measure different aspects of the cell cycle. Among these, the thymidine labeling index (TLI) represents the fraction of cells in S-phase cell fraction and is based on the active incorporation of labelled thymidine into DNA. From basic studies conducted on several thousands of patients, the TLI of primary breast cancers appears closely related to steroid receptor status and generally unrelated to pathologic stage. Retrospective analyses performed on large series of patients treated with local regional therapy alone have consistently shown the relevance of TLI value to clinical aggressiveness in terms of relapse-free survival and overall survival. Moreover, TLI is a prognostic indicator which is independent of tumor size, steroid receptors, and p53 and bc12 protein expression, and which, together with patient age and tumor size, is able to identify patients at different risk of loco-regional or distant metastases. Recently, a direct relationship between TLI and response to polychemotherapy has been shown in patients with operable and advanced breast cancers. This finding, derived from retrospective and recently confirmed in prospective clinical studies, has led to the activation of cell kinetics based therapeutic protocols for patients with node-negative and one to three node-positive operable breast cancers.

Prognostic and Therapeutic Implications of the MIB-1 Labeling Index in Breast Cancer

BACKGROUND: Assessment of tumor proliferative activity is considered to be the most powerful prognostic factor aside from axillary lymph node status. The purpose of this study is to assess the clinical value of measurement of proliferative activity using the MIB-1 labeling index in patients with breast cancer. METHODS: Surgical specimens from 36 patients with benign breast disorders and146 patients with breast cancer were investigated. The MIB-1 labeling index wasdetermined on the specimens stained by immunohistochemical methods as much as possible. Clinical factors associated with the MIB-1 labeling index were reviewed. RESULTS: The MIB-1 labeling index for non-proliferative disorders, proliferative disorders, and breast cancer was 3.4 +/-1.9%, 8.9 +/-6.2% and 20+/-12%, respectively. The MIB-1 labeling index and tumor size, lymph node metastasis status, and clinical stage according to the TNM classification correlated significantly. Survival rate was inversely correlated with the MIB-1 labeling index. No patientwith an MIB-1 labeling index of less than 10% had lymph node metastases, and all are alive without recurrence. Patients with an MIB-1 labeling index of over 30% had an extremely poor prognosis. CONCLUSION: The MIB-1 labeling index is very useful for predicting both either extremely good or extremely poor prognosis, and axillary lymph node metastasis

Fatty acids and breast cancer cell proliferation

We and others have shown that fatty acids are important regulators of breast cancer cell proliferation. In particular individual fatty acids specifically alter EGF-induced cell proliferation in very different ways. This regulation is mediated by an EGFR/G-protein signaling pathway. Understanding the molecular mechanisms of how this signaling pathway functions and how fatty acids regulate it will provide important information on the cellular and molecular basis for the association of dietary fat and cancer. Furthermore these in vitro studies may explain data previously obtained from in vivo animal studies and identify "good" as well as "bad" fatty acids with respect to the development of cancer.

Cell proliferation in 3,800 node-negative breast cancers: consistency over time of biological and clinical information provided by 3H-thymidine labelling index

For breast cancer, many prognostic markers that initially appeared promising have failed to maintain their clinical predictive value. Few reports have analyzed the consistency over time of biological and clinical information provided by biomarkers. Tumour cell proliferation has acquired relevance as an indicator of prognosis and of response to treatment. Since its clinical role has been investigated for some decades, cell proliferation represents an ideal marker for an over-time validation. In 3,800 node-negative breast cancers recruited between 1972 and 1991, the consistency of information provided by the 3H-thymidine labelling index (TLI), in terms of basic relations with other clinico-pathological and biological variables and clinical predictivity, was evaluated using a combined analysis of results previously published by our group for distinct series of patients. Clinical predictivity was analyzed on a subset of 2,067 patients given local-regional therapy until relapse and followed for a median time from 6 to 10 years. Over the entire period TLI maintained a weak direct relation with tumour size and an inverse strong relation with steroid receptors. An increase in TLI was observed for tumours in post-menopausal patients up to the mid 1980s. During 3 different accrual periods (1972-1983; 1984-1987; 1988-1991), TLI was a consistent and independent predictor of relapse-free time, distant metastasis and overall survival, regardless of its consideration as a continuous variable or with a cutoff value of 3%. The reproducibility of our results over time provides support to the consistency of the methodology used and of the biological and clinical information obtained when using TLI as an indicator of breast cancer cell proliferation.

Heterogeneity of intratumour proliferative activity in primary breast cancer: biological and clinical aspects

The present retrospective study was undertaken to verify whether the extent of intratumour proliferative activity variation or the method of quantifying tumour proliferative activity is related to biological characteristics and clinical outcome in a series of operable node-negative breast cancer patients. For tumour proliferative activity evaluation, the 3H-thymidine autoradiographic assay was used. After incubation of 3-8 samples from different areas of the equatorial section of each tumour for 1 h at 37 degrees C with 3H-thymidine, the following methods were used for evaluation of tumour cell labelling: mean tumour labelling index (LI), the highest labelling value from a specific area (LI-max), and the extent of intratumour labelling variation from several samples (LI-CV). LI-max was related to ER and PgR status, and linearly correlated with LI (c.c. = 0.92, P < 10(-6)) whereas LI-CV was independent of tumour size, grade ER and PgR status, but dependent on the number of tumour samples analysed for each tumour. After 5 years of median follow-up, disease-free survival was only related to tumour size (T1 versus T2: 84 versus 64%, P < 0.04 by log rank analysis) and different LI values (low versus high 3H-Tdr-LI:86 versus 61%, P < 0.03 by log rank analysis). LI-max and LI-CV values were not significantly related to clinical outcome. Cox multivariate analysis confirmed the independent prognostic value of LI and tumour size on disease-free survival.

Expression of proliferating cell nuclear antigen, Ki-67 antigen, estrogen receptor protein, and tumor suppressor p53 gene in cytologic samples of breast cancer: an immunochemical study with clinical, pathobiological, and histologic correlations

Sixty-six unselected breast cancers were analyzed in cytologic smears and histologic sections for the expression of Ki-67, proliferating cell nuclear antigen (PCNA), estrogen receptor protein (ERP), and p53 protein using a standard immunochemical method. The results, expressed as both positive cases and labelling index (LI), were compared with clinical and pathobiological variables. Ki-67 and PCNA immunostaining was seen in all cases, whereas ERP was detectable in 46/63 cases and p53 protein in 20/66 cases. The expression of these markers was generally lower in cytology than in histology, though the differences were not statistically significant. PCNA-LI and Ki-67-LI were closely correlated (P < 0.001), the mean PCNA:Ki-67 ratio being 0.92 +/- 0.57. Occasional discrepancies, however, were found. PCNA and Ki-67 expression was associated with an increase in histologic grade and a decrease in ERP content of tumors, whereas p53 was statistically associated with no clinical or pathobiological variables. The data suggest that proliferative activity and oncogene overexpression may be reliably evaluated in breast cancer by FNA cytology, though PCNA is not a suitable indicator for cell proliferation. The results do not resolve the issue as to whether immunostaining for p53 protein constitutes a dedifferentiation product of the tumor, or is a fundamental aspect of the malignant progression. Survival studies in a larger series of tumors are thus needed to elucidate this point.

High proliferative rates demonstrated by bromodeoxyuridine labeling index in breast carcinomas with p53 overexpression

The protein p53 is a product of a suppressor oncogene. Mutations occurring in 13-15% of breast carcinomas are associated with p53 stainability within nuclei and progression of the tumor. We determined the extent to which p53 abnormality was associated with proliferation by measuring p53 immunohistochemically with a polyclonal antibody and monoclonal PAb1801 in invasive carcinomas of known S-phase fraction (SPF) assessed histologically by bromodeoxyuridine incorporation. Results with the two antibodies always agreed. One of 20 low, 2/18 midrange, and 9/17 high SPF carcinomas were positive for p53. P53 positivity was also related to other indicators of aggressiveness including size of primary tumor, nuclear and nucleolar size, and estrogen and progesterone receptor content, but relationships between p53 and vascular invasion and lymph node metastasis were not found. We conclude that nuclear p53 accumulation is more closely related to proliferation than to invasion and metastasis, and that it identifies some but not all breast carcinomas with high proliferative indices.

New approaches to cell kinetics in human tumors

Both clinical and laboratory evidence indicate that local control rates for many experimental and clinical human tumors decrease with protraction of the overall duration of radiation therapy. A likely basis for this is tumor cell repopulation during treatment. Such observations have stimulated interest in tumor kinetics, and a number of techniques have evolved to increase the potential for meaningful clinical study of the proliferative behavior of tumors. This review discusses the clinical and experimental evidence for proliferation during treatment, describes two potential approaches--accelerated fractionation and inhibition of proliferation--that could be employed in attempting to overcome such intratreatment proliferation, explores both past and newer, evolving methods available for measuring tumor cytokinetics, and discusses how such kinetic information could be used in the future to tailor therapy to a tumor's individual characteristics.

EGF-R and steroid receptors in breast cancer: a comparison with tumor grading, tumor size, lymph node involvement, and age

In this study epidermal growth factor receptor (EGF-R), estrogen receptor (ER), and progesterone receptor (PR) status was evaluated in 326 primary breast carcinomas. Nineteen percent of samples were EGF-R positive, 63% were positive for ER, and 54% for PR. In 46% of the tumors both ER and PR were positive. These data are presented together, with grading, size of tumor, lymph node involvement, histological subtype, and age. Sixty-nine percent of EGF-R negative tumors were ER-positive and 51% were positive for ER as well as PR. In particular, negative correlation between EGF-R and steroid receptor status was found. A quantitative correlation was also shown. A combination of negative steroid receptor and positive EGF-R was found more often in the population of poorly differentiated tumors. Tumors bigger than 5 cm were related to a positive EGF-R status. No correlation between nodal status and any receptor status was found. Intraductal carcinomas were more often EGF-R positive than infiltrating ductal (NOS) or infiltrating lobular lesions. The age of patients correlated with the concentration of ER only. In our study we reaffirmed the negative correlation between steroid receptor status and the overexpression of EGF-R; furthermore the combination of EGF-R+ and ER- tumors was observed more often in histological high-risk tumors. Patient outcome did not show statistically significant differences concerning the EGF-R status, but was associated with the steroid receptor status.

Prognostic indicators in early breast cancer

Approximately 115,000 new cases of axillary node negative breast cancer were diagnosed in this country last year. Since about 20-30% of these patients will ultimately relapse and die of their disease, adjuvant systemic therapy has been advocated for this group to decrease the relapse rate and prolong survival. However, although most clinical trials have demonstrated a modest impact on disease recurrence, the available data have failed to show consistent improvements in overall survival and does not justify the generalized use of systemic treatment in this patient subgroup. For this reason, a plethora of prognostic factors have been described to identify those patients with a higher risk of recurrence to concentrate therapeutic options in this specific group. Of all the disease prognosticators studied, tumor size, nuclear grade, and proliferative indexes appear to correlate well with tumor recurrence. In addition, biologic characteristics of primary tumors such as the presence of hormone and growth factor receptors, secretion of specific polypeptides and proteases, expression of proto-oncogenes, and abnormalities in tumor suppressor genes have been shown to be potentially useful as prognostic indicators in patients with early breast cancer. Despite these provocative data, larger clinical trials are necessary before incorporating these parameters in the routine evaluation of patients with axillary node negative breast cancer.

Prognostic significance of proliferative activity and ploidy in node-negative breast cancers

BACKGROUND

Cell kinetics and DNA ploidy have provided relevant information on the natural history of breast cancer. We assessed the prognostic role of proliferative activity and ploidy, alone and in association with tumor size, estrogen (ER) and progesterone (PgR) receptors.

PATIENTS AND METHODS

In a series of 340 women with resectable node-negative breast cancers given local-regional therapy alone until relapse, proliferative activity was determined as the 3H-thymidine labeling index (3H-dT LI) and flow-cytometric S-phase cell fraction (FCM-S), as quantified by using different modeling systems. DNA ploidy, ER and PgR content were determined on frozen samples by FCM and by the dextran-coated charcoal absorption technique, respectively.

RESULTS

FCM-S estimates obtained by the different models were weakly associated with one another and to the corresponding 3H-dT LIs. Four-year relapse-free survival was significantly predicted by 3H-dT LI, ploidy and tumor size but not by FCM-S. Multiple regression analysis showed that 3H-dT LI, ploidy and tumor size retained their prognostic significance and that 3H-dT LI was the most significant indicator of relapse (p = 0.009).

CONCLUSIONS

The finding that 3H-dT LI and ploidy are weakly related and provide independent prognostic information could allow a more accurate identification of patients at different risk of relapse.

Randomised clinical trial of adjuvant chemotherapy in patients with node-negative, fast-proliferating breast cancer

A prospective randomised clinical trial in patients with node-negative, fast-proliferating breast cancer was initiated in January 1990 to verify the feasibility and reliability of a 3H-thymidine (3H-Tdr) autoradiographic assay in a prospective and consecutive series of node-negative patients and the therapeutic effect of adjuvant chemotherapy in patients with node-negative breast cancer and high tumour proliferative activity. Node-negative patients with a high 3H-Tdr Labelling Index (3H-Tdr-LI) were randomised to receive either no further treatment or combination chemotherapy consisting of fluorouracil, epirubicin plus cyclophosphamide (FEC) for 6 cycles. The autoradiographic assay was performed in 307 of 317 patients (97%) and was evaluable in 291 of 317 patients (92%). A total of 176 patients with a high 3H-Tdr-LI entered the clinical randomised study: 91 in the FEC arm and 85 in the control arm. Patient groups were fairly well balanced regarding the most important clinical and pathological characteristics. In total, 530 FEC cycles have been administered with an actual dose intensity of 90%. Patients receiving FEC demonstrated leucopenia in 35% of cases, alopecia in 70%, and loss of menses in premenopausal patients in an age-dependent manner. Patients are still being entered into the study.

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.

Prognostic factors and natural history in lymph node-negative breast cancer patients

The prognostic significance of clinical and histological factors as well as hormone receptors was analyzed in a population of 3,064 lymph node-negative breast cancer patients operated in the Stockholm region between 1976 and 1988. None of these patients received systemic adjuvant treatment. Multivariate analysis showed that only histological tumor size, number of examined axillary lymph nodes, and progesterone receptors were independent prognostic factors in terms of recurrence-free interval. An individual risk of recurrence was calculated taking into account these three factors to discriminate between three groups of patients with a risk of less than 15%, 15-25%, and more than 25% of recurrence at 5 years. Similar results were obtained taking into account only the first two factors. The prognostic information added by the knowledge of progesterone receptors only changed the recurrence rate in approximately 3%. This study showed that conventional prognostic factors permit the identification of high risk lymph node-negative breast cancer patients. Results obtained by the use of new more sophisticated factors should be compared with those obtained analyzing strong conventional prognostic factors.

Prognostic potential of flow cytometric S-phase and ploidy prospectively determined in primary breast carcinomas

In a prospective study of a consecutive breast cancer series accumulated in the period 1978-82, the S-phase fraction (SPF) and ploidy status were determined by flow cytometry performed on cell nuclei derived from samples of 580 primary tumors. Sixty percent of the tumors were non-diploid. After correction for debris the median SPF values were 7.3% overall, 12% for non-diploid tumors, and 2.9% for diploid tumors (2.6% when nodal subsets N2 and N3 and cases with metastases at presentation were excluded). The SPF values correlated both to tumor size (p = 0.008) and to the number of positive axillary lymph nodes (p = 0.03). At clinical follow-up in 1986, 467 unilateral breast cancer patients who had undergone radical treatment for cure could be evaluated with respect to the prognostic value of both the SPF value and ploidy status. The median duration of follow-up was then 59 months (range 2-90), and the median time-to-recurrence 24 months (range 2-69, n = 137). At follow-up in 1991, 201/467 of the patients had died, the median duration of follow-up being 50 months (range 2-126) for the decreased, and 119 (range 6-148) for the survivors. In multivariate analysis (Cox's proportional hazards models), the strongest independent predictors of distant recurrence-free survival (DRFS) were the number of positive axillary lymph nodes (p less than 0.0001), the debris-corrected SPF value alone (p = 0.003, versus p = 0.05 for uncorrected value), and ploidy status combined with the corrected SPF value (p = 0.0002). When age was taken into account, both the corrected SPF value and the ploidy-SPF combination were predictors of crude survival (p = 0.006 and p = 0.002, respectively). In univariate life-table analysis, the 5-year DRFS rate was 93% in node-negative (N0) cases with an SPF less than 7.3%, as compared to 80% in those with an SPF greater than or equal to 7.3% (p = 0.005). Among node-positive cases, the prognostic value of the SPF was confined to those with 1-3 positive nodes, the 5-year DRFS rate being 68% in cases with an SPF less than 7.3%, as compared to 40% in cases with an SPF greater than or equal to 7.3% (p = 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Pathologic correlates of survival in 378 lymph node-negative infiltrating ductal breast carcinomas. Mitotic count is the best single predictor

Pathologic features of 378 breast carcinomas without axillary lymph node metastases were correlated with long-term prognosis. Mitotic count, the feature best predicting prognosis, was most useful at lower mitotic count levels than usually studied. Cases with less than 4.5 mitotic figures per ten high-power fields had a 20-year tumor-related survival of 73% versus 48% for those with higher mitotic counts. Low and high mitotic count groups had significantly different prognoses for T1c, T2, and T3 tumors. Multivariate analysis showed that the best combination of features predicting tumor-related death were high mitotic count (relative risk, x 2.8), large tumor size (relative risk, x 1.7), lymphatic invasion (relative risk, x 1.7), and skin or subjacent muscle or chest wall invasion (relative risk, x 2.5). Nuclear grade, Bloom-Richardson grade, modified Scarff-Bloom-Richardson grade, Fisher's grade, and necrosis correlated well with survival but had no significant additional predictive value when adjusted for the mitotic count.

Feasibility and reproducibility of the [3H]-thymidine labelling index in breast cancer. The SICCAB Group for Quality Control of Cell Kinetic Determination

For several malignancies, autoradiographic evaluation of the S phase cell fraction by means of [3H]-thymidine ([3H]dT) has proved a valid prognostic tool which should be included in a 'risk factor profile system' to estimate prognosis in individual patients. However, its clinical implementation requires a methodological standardization, a high feasibility and an assessment of the reproducibility of results, within and between different laboratories. The recent availability of a kit for in vitro incubation with [3H]dT and histological fixation of solid tumour specimens has contributed to the methodological simplification and standardization of the technical procedure, increasing its feasibility in several institutions. For breast cancer, preliminary results from a quality control study promoted by the Italian Society of Basic and Applied Cell Kinetics (SICCAB) showed a high inter-observer reproducibility within (r = 0.96) and between different laboratories (r = 0.93). Moreover, on a series of 20 autoradiographic samples sent to 15 different institutions, only 2% of tumours shifted from one of the cell kinetic subgroups, defined using the median [3H]dT labelling index (LI) of 2.8% as a cutoff, to the other. In addition, a marked consistency of results was observed among the different Italian institutions involved in cell kinetic studies on breast cancers, both in terms of median [3H]dT LI values and basic correlations. Periodic assessment of the reproducibility of [3H]dT LI evaluation among different laboratories is needed, especially for institutions involved in multicentre clinical protocols based on cell kinetic characteristics.

Breast cancer proliferation measured on cytological samples: a study by flow cytometry of S-phase fractions and BrdU incorporation

Cell kinetics have been shown to be an important predictor of clinical evolution of operated breast cancer. We established a method for the estimation of the proliferative activity of tumour cells obtained by fine needle sampling without aspiration (FNS), using simultaneously S-phase fractions (SPF) measured on DNA histograms and 5-bromodeoxyuridine (BrdU) labelling index (BLI) measured by flow cytometry. Biparametric BrdU/DNA flow cytometry could be performed in 122 of 189 (65%) consecutive patients. The mean BLI of the cytologically malignant FNS (118) was of 3.0 and the median of 2.2%. One hundred and forty-eight DNA histograms (78%) were suitable for SPF analysis, of which 141 presented malignant cells, showing a mean of 4.5 and a median of 3.5%, comparable to BLIs. These results were obtained from fluorescence peak area histograms with doublet discrimination and background subtraction allowing the measurements of SPFs as low as 0.4%. An excellent correlation was thus observed between BLIs and SPFs, for the 94 cases for which both results were available (r = 0.85). Infrequent discordances (9%) were noted with SPFs considerably higher than BLIs. Seven patients had three consecutive FNS of their tumour at weekly intervals before treatment. Some variability in the proportions of multiple subpopulations of tumour cells was observed on the DNA histograms. In contrast, proliferation indices (SPF or BLI) were reproducible, suggesting homogeneous growth rates. We conclude that an estimation of the proliferative activity of breast tumours at any stage of the disease is possible routinely by SPF and/or BLI analysis of FNS. At least one quantitative proliferation index could be obtained for 91% of patients.

Cell kinetics and hormonal features in relation to pathological stage in breast cancer

Proliferative activity (expressed as 3H-thymidine labeling index, 3H-TdR LI) was evaluated on a series of 281 primary tumors recruited in two years in 6 different institutions from central Italy. 3H-TdR LI proved to be low in intraductal, or well and moderately differentiated, or hormone receptor positive tumors. Conversely, no relation was observed between 3H-TdR LI and menopause, tumor size, or lymph node involvement. An inverse relation was observed between 3H-TdR LI and hormone receptor content. Specific patterns of 3H-TdR LI value and ER content association were observed as a function of menopause, lymph nodal status, and degree of lymph nodal involvement.

Regional heterogeneity in breast carcinoma: thymidine labelling index, steroid hormone receptors, DNA ploidy

We examined multiple samples of 65 primary breast carcinomas larger than 1 cm in diameter for thymidine labelling index (TLI), DNA index (DNAI, a measure of cellular DNA content by flow cytometry), and estrogen (ER) and progesterone (PgR) receptors by radioligand-binding. One or more axillary metastases were also assayed in 11 patients. Two to 15 samples were successfully assayed for TLI from 59 tumors, 2-31 samples for DNAI from 61 tumors, and 2-15 samples from 55 tumors for ER and PgR. Criteria for heterogeneity were excess inter-sample variance in comparison with intrasample variance at the p less than 0.05 level for TLI and DNAI, and variation of clinically significant magnitude in assay results for ER and PgR. Sixty-one percent of tumors were heterogeneous for TLI, 26% for DNAI, 24% for ER and 40% for PgR. High TLI disposed toward heterogeneity for TLI itself (p = 0.06), for ER (p = 0.04), and for PgR (p = 0.007). Young age favored heterogeneity for TLI (p = 0.12), ER (p = 0.002), and PgR (p = 0.04). Heterogeneity for DNAI was not related to age and TLI status but was more common in larger tumors (p = 0.08). After consideration of relationships between TLI, age, size, ER and PgR, TLI rather than age appears to be the more important determinant of heterogeneity for receptors. High TLI could lead to heterogeneity through increased numbers of cell divisions that favor emergence of variant stemlines, or by causing local vascular and humoral disparities through rapid growth. Regional heterogeneity can explain erroneous prognostic predictions in approximately 10% to 20% of breast carcinoma patients. We recommend multiple sampling of large breast carcinomas and analysis of axillary metastases for study of tumor markers.

Mitotic rate, DNA distribution, and chromatin in situ sensitivity to heparin in breast cancer

The purpose of this study was to characterize breast carcinomas by cell kinetic parameters. Mitotic rate (MR) and flow cytometrically (FCM) measured cell cycle distribution as well as chromatin testing in situ employing heparin for determination of activated chromatin, provided the following results: MR counted in 73 unselected carcinomas showed an increase up to a tumor size of 4.2 cm (p less than 0.05); beyond this diameter, the MR was found to decrease. In T1-T2 carcinomas, cell cycle stage analysis yielded higher percentages of cells in S and G2M phase for ductal (13% and 12%, N = 22) than for lobular (8% and 7%, N = 8) node-negative carcinomas (p less than 0.002). In ductal carcinomas, lymph node involvement was reflected by higher % G2M values (15%, N = 26) compared with negative cases (12%, N = 22) (p less than 0.05). Ductal node-positive T3-T4 carcinomas (N = 10) revealed a higher % S value (16%) than their T1-T2 counterparts. A correlation between MR and % G2M was established only up to a tumor size of 4.2 cm (r = 0.39, p less than 0.05). A highly sensitive ('H') and a poorly sensitive ('P') subgroup of carcinomas with respect to heparin-induced changes in fluorescence intensity of the G1/0 peak of the DNA aneuploid cell line were identified, as previously shown. These subgroups were here updated with a larger number of carcinomas and were limited to T1-T2 cancers (N = 57). Group 'H' included more younger patients (p less than 0.005), less cases with nodal involvement in ductal carcinomas (p less than 0.05), and lower % G2M values in lobular node-negative cases (p less than 0.05), than group 'P'. DNA diploid cells always existing in DNA aneuploid carcinomas are more sensitive than their aneuploid counterparts (p less than 0.01); however, they strengthen the stratification to 'H' and 'P'. We suggest 'H' carcinomas to be less aggressive than 'P' carcinomas. Small breast carcinomas are recommended to cell kinetic investigations for individualizing adjuvant therapy.

Pathologic findings from the National Surgical Adjuvant Breast and Bowel Projects (NSABP). Prognostic discriminants for 8-year survival for node-negative invasive breast cancer patients

Twenty-two pathologic features (including estrogen and progesterone receptors) and four clinical features observed in 950 women with node-negative Stage I invasive breast cancer who enrolled in the National Surgical Adjuvant Breast and Bowel Projects (NSABP) protocol B-06 were evaluated for their possible prognostic significance. Preliminary univariate analysis revealed ten characteristics that were significant in this regard at the 1% level. Their assessment in a Cox regression model demonstrated only three to be prognostically important; notable among these were nuclear grade, histologic tumor type, and race. Life-table plots revealed that 86% of patients whose cancers exhibited good nuclear grade survived for 8 years as opposed to 64% in whom the nuclear grade was scored as poor. Analyses demonstrated three prognostic categories for histologic tumor type. Patients with either mucinous, tubular, or papillary cancers fared significantly better than those having not otherwise specific (NOS) or atypical medullary tumors. Survival for those with typical medullary, NOS combinations, or lobular invasive cancers was intermediate. Blacks fared worse than whites. Survival was correspondingly better or worse when two favorable or unfavorable characteristics were detected. The number of black women in this cohort was considered too small for further subset analysis although generally the pattern of findings suggested that survival was worse for blacks than for whites in all subsets. A review, as well as our own experience, suggested that nuclear grade is as good if not better as a predictor of survival in node negative patients as information derived from DNA analyses, immunohistochemical demonstration of erb-B2 overexpression, and, possibly, the tumor labeling index at predicting survival in node-negative patients.

Cytometric and histopathologic features of tumors detected in a randomized mammography screening program: correlation and relative prognostic influence

Cytometric determination of S-phase fraction and ploidy type was performed on 430 tumors detected within a randomized trial of mammographic screening. The results were compared to several histopathologic features. A high S-phase fraction was estimated in tumors with a high grade of malignancy and other histopathologic findings related to rapid tumor progression, including lack of tubule formation, a high mitotic index, marked nuclear pleomorphism, multifocal cancer growth, tumor emboli in lymphatic and blood vessels, tumor necrosis, and inflammatory reaction. DNA aneuploidy was correlated with a high malignancy grade, frequent mitoses, a high degree of nuclear pleomorphism, vascular invasion, necrosis, and the presence of noninvasive ductal carcinoma. Both cytometric variables were inversely related to the degree of elastosis. Positive nodes, large tumor size, DNA aneuploidy, a high S-phase fraction, high grade of malignancy, lack of tubule formation, as well as high mitotic index and pleomorphism, presence of multifocal cancer, and vascular invasion, predicted a significantly shorter distant recurrence-free interval after a median follow-up time of 46.6 months. Elastosis and the presence of estrogen and progesterone receptors indicated favorable prognosis. In the multivariate analysis, only lymph node status, tumor size, S-phase fraction, and multifocal growth pattern had independent prognostic value.

Indicators of prognosis in node-negative breast cancer

Measures of the proliferative activity of tumor cells have prognostic value in patients with node-negative breast cancer. We studied 367 women in southern Sweden who had undergone surgical resection for such cancer. Tumor specimens were analyzed with DNA flow cytometry in order to estimate both the DNA content (ploidy) and the fraction of cells in the synthetic phase of the cell cycle (S phase). The median duration of follow-up was four years; 28 percent of the patients received adjuvant therapy, usually with tamoxifen (n = 83). A multivariate analysis based on complete data on 250 patients included the following covariates: age (greater than or equal to 75, 50 to 74, and less than or equal to 49 years), tumor size (less than or equal to 20 vs. greater than 20 mm), concentration of estrogen and progesterone receptors (less than 10 vs. greater than or equal to 10 fmol per milligram of protein), ploidy (diploid vs. nondiploid), and S-phase category (fraction of cells in S phase: less than 7.0 percent, 7.0 to 11.9 percent, and greater than or equal to 12 percent). The S-phase fraction yielded the most prognostic information, followed by progesterone-receptor status and tumor size. A prognostic model based on these three variables identified 37 percent of the patients as constituting a high-risk group with a fourfold increased risk of distant recurrence. In the remaining 63 percent of the patients, the five-year overall survival rate (92 +/- 4 [+/- SE] percent) did not differ from the expected age-adjusted rate for Swedish women. We conclude that a prognostic index that includes indicators of the proliferative activity of tumor cells may be able to identify women with node-negative breast cancer in whom the risk of recurrence is sufficiently low that adjuvant chemotherapy can be avoided.

Ploidy, proliferative activity and prognosis. DNA flow cytometry of solid tumors

Flow cytometric study has been used to measure the cellular DNA content of solid tumors for the last decade, and of paraffin-embedded tumor specimens for the last 5 years. Ploidy and proliferative activity are the two properties commonly measured by DNA content flow cytometric study. The ability to study archival, paraffin-embedded tumors has hastened an appreciation of the prognostic utility of this assay. Either abnormal ploidy or elevated proliferative activity predict a worsened disease-free or overall survival in most common adult malignancies. Both abnormalities are associated with poor outcome in locoregional breast, non-small cell lung, and colorectal cancers, and in all stages of ovarian cancer. Abnormal ploidy is also a dire prognostic indicator for cancers arising from the kidney, bladder, prostate, and endometrium. Clinical management of patients with these diseases may be aided by studying their tumors for these objective markers of biological aggressiveness.

Influence of S-phase fraction on metastatic pattern and post-recurrence survival in a randomized mammography screening trial

Using static cytofluorometry, S-phase was determined on the primary tumors of 421 patients with breast carcinomas in stages I-III diagnosed 1981-85 during the second and third screening rounds of a randomized trial evaluating the effect of mammographic screening. Through December 1988, 82 patients had developed local and/or distant recurrence, 51 of whom had died of cancer during the same period. The distribution among sites of recurrence differed between patients with tumors detected by mammography screening and cancers diagnosed due to clinical symptoms. The mean S-phase fraction was highest in patients with liver or brain metastases and lowest in patients with metastases in subcutaneous and cutaneous tissue and lymph nodes only. In univariate analysis, survival after first recurrence was significantly associated with the site of primary recurrence, the disease-free interval, and node status and tumor size at diagnosis, as well as the S-phase level. The median survival period was 31.3. months for patients with a S-phase fraction below 6%, and 10.7 months in cases with S-phase exceeding 10%. Neither ploidy nor the estrogen receptor content had significant influence on post-recurrence survival. In Cox's multiple regression analysis, only metastatic site, disease-free interval, and S-phase fraction showed significantly independent prognostic value.

Inflammatory symptoms in breast cancer. Correlations with growth rate, clinicopathologic variables, and evolution

Based on two pretreatment evaluations, doubling time (DT) was calculated in 75 cases of invasive breast cancer (BC). The cases studied were more or less equally distributed between three DT groups: fast-growing tumors (DT less than 90 days), intermediate cases (DT between 90 and 180 days), and slow-growing tumors (DT greater than 180 days. A correlation was found to exist between DT and patient age and, to an even greater extent, between DT and pathologic prognostic indicators such as histologic grading and nuclear grade. Inflammatory symptoms were not associated with DT, but were closely related to the size of the tumor and regional lymph node involvement. The date of detection of distant metastases depended heavily on the DT of the BC:BC with shorter DT = earlier metastatic spread. The presence of inflammatory signs was also decisive: within each DT category, inflammatory BC metastases were both more frequent and precocious.

Prognostic value of histologic grade nuclear components of Scarff-Bloom-Richardson (SBR). An improved score modification based on a multivariate analysis of 1262 invasive ductal breast carcinomas

We did a multivariate analysis of 1262 patients with operable, invasive ductal breast carcinoma to assess the prognostic value of the Scarff-Bloom-Richardson (SBR) histologic grading system. Nodal metastasis and SBR were the two most important factors for metastasis-free survival (MFS), P = 10-9 and P = 10-5, respectively, for total study time. In patients who were node negative, the SBR and International Union Against Cancer (UICC) stages were the most important for MFS (P = 4 X 10-4 and P = 0.03). In order to try to improve the SBR prognostic value, we first studied the three components of the SBR separately: ductoglandular differentiation proved the least predictive and nuclear pleomorphism and mitotic index the most predictive. A rearrangement of the two nuclear scores alone produced higher risk values and better risk separation of patient subpopulations than SBR, and eliminated the SBR from the multivariate model. This rearrangement, modified SBR (MSBR), defined five new risk subgroups with statistically different risk ratios for MFS (P = 3 X 10-8). SBR grade II (55% of patients) was separated into three MSBR groups significantly different according to MFS (P = 0.008). In the patients who were node negative, MSBR replaced the SBR and was the most important factor for prediction of relapse of MFS (P less than 0.00001). The MSBR is more accurate and predictive than the standard SBR grade and is particularly useful when the nodal status of the patient is negative or unknown.