DNA flow cytometry and prognostic factors in 1331 frozen breast cancer specimens

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

Estrogen and progesterone receptors were assessed by an immuno-biochemical method and DNA content was analysed by flow cytometry in a consecutive series of 1,342 frozen breast cancer samples. Forty-six percent of the ER-positive tumors were DNA diploid compared to 23% among ER-negative cases. The proportion of ER-/PR- cases was highest among hypertetraploid tumors (45%) and lowest among DNA diploids (13%). While receptor positivity and DNA ploidy were strongly related, no differences in mean receptor levels were detected when comparing DNA diploid and aneuploid cases of receptor positive tumors. In receptor positive tumors ER content--but not PR content--increased with age. S-phase fraction (SPF) was estimated in 1,165 cases (87%) with an overall mean of 8.6%. Tumors with high S-phase levels and DNA hypodiploid tumors were significantly more often found in younger than in older patients. The frequency of DNA hypodiploidy was less than 1% among women older than 75 years, while it was 8% among those aged 40 years or younger. S-phase fraction was inversely related to ER and PR status. However, while mean SPF gradually decreased with increasing levels of PR, no significant difference in S-phase fraction was seen for ER concentrations just above the cut-off level for receptor positivity. Tumors positive for both receptors showed the same pattern of DNA ploidy as ER+/PR- tumors while differences in S-phase fraction were observed between the groups. These results support that PR status better than ER status reflects hormone dependent growth in breast cancer.

Clinical application of flow cytometry for DNA analysis of solid tumors

Recent developments of flow cytometry (FCM) technology which make multiple correlative biological measurements on normal and neoplastic cells is affecting areas of diagnostic pathology as well as research fields, and a general understanding of FCM techniques is essential for pathologists. Today, FCM DNA measurements of tumors also becomes routine in the clinical and/or pathological laboratory for aid in cancer diagnosis and cancer treatment. It can also contribute to diagnosis of tumors as a supplemental method to conventional histopathology, and DNA ploidy and the percentage of S-phase fraction are considered as complementary prognostic parameters independent of the stage of disease. This article reviews clinical applications of flow cytometry focusing on the DNA measurements of solid tumors, and related practical issues, such as the methodology for nuclear DNA measurement, interpretation of DNA histograms and the relationship of DNA ploidy and S-phase fraction to clinical and pathological features of human solid tumors.

Flow cytometric DNA index and S-phase fraction in breast cancer in relation to other prognostic variables and to clinical outcome

One frequently used classification of flow cytometric DNA ploidy status (diploid versus nondiploid) was compared with a division into seven ploidy classes based on DNA index (DI) and number of cell populations (hypodiploid, diploid, near-hyperdiploid, hyperdiploid, tetraploid, hypertetraploid, and multiploid). The latter ploidy classification showed a better correlation with prognosis and other prognostic factors (i.e., lymph node involvement, estrogen and progesterone receptor status, and S-phase fraction). The improvement in correlation was mainly due to the identification of near-hyperdiploid cases (DI 1.00-1.14) which could be combined with the diploid cases to form a group with favourable prognosis. In contrast to cases with a small increase in DNA content (near-hyperdiploid), those with a small decrease of DNA content (hypodiploid) manifested a more aggressive disease. In multivariate analysis, S-phase fraction (SPF) was a more important prognostic factor than both the improved or the conventional ploidy classification.

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)

The prognostic significance of ploidy analysis in operable breast cancer

The nuclear DNA content of 98 operable breast cancers was determined by flow cytometric analysis using paraffin-embedded tissue. All patients were on follow-up and failure of treatment or recurrences were identified. DNA ploidy data in the form of ploidy status and DNA index (DI) has been correlated with various clinical and histopathologic factors. The only significant correlation using univariate analysis exists between the histologic grade and DI (P less than 0.025), recurrence of the disease and ploidy status (P less than 0.005), and recurrence of the disease and DI (P less than 0.005). The absence of correlation of ploidy status with other tumor derived factors indicates the independent nature of ploidy as a prognostic factor. Multivariate analysis showed that in the whole-group ploidy (P less than 0.01), tumor margin (P less than 0.01), and menopausal status (P less than 0.01) were significant factors in the order mentioned. DI with a cut of at 1.29 is not found to be a significant factor in the multivariate analysis. The maximum prognostic value of ploidy status was observed in the postmenopausal group (P less than 0.0005). In the node-negative group ploidy status (P less than 0.05) is the only independent significant factor predicting for early relapse. It is concluded that ploidy status is an independent prognostic factor predicting for recurrence of the disease. In the node-negative subgroup this could be used to identify the subset of patients who may benefit from adjuvant treatment.

A meta-analysis of reported correlations between prognostic factors in breast cancer: does axillary lymph node metastasis represent biology or chronology?

A statistical overview of published results on correlations between various prognostic factors in breast cancer was undertaken. A distinction was made between clinical (or anatomical) prognostic factors--namely, axillary lymph node status and tumour size--and eight different biological prognostic factors. The latter included: tumour grade, oestrogen and progesterone receptor status, thymidine labelling index, DNA ploidy, S-phase fraction, epidermal growth factor receptor expression and c-erbB-2 gene amplification (or overexpression). 139 articles were eligible for review which reported a total of 432 individual correlations. A simple form of meta-analysis was employed: the counting method, in which the number of studies achieving a statistically significant correlation or not were counted. For each possible correlation examined, the proportion of studies showing a statistically significant correlation was calculated and an exact binomial 99% confidence interval determined for that proportion. If the 99% confidence interval included 5% (the proportion of correlations that would be expected to be statistically significant if the null hypothesis was true), it was taken as failing to exclude the null hypothesis of a zero correlation, while if it excluded 5% it was taken as rejecting the null hypothesis of a zero correlation. A broad agreement was found among published reports on the existence of a statistically significant correlation between the various biological prognostic factors in breast cancer. Of the 20 correlations examined, 18 had a 99% confidence interval excluding 5%, thus rejecting the null hypothesis of a zero correlation. On the other hand, a completely different result was obtained when reports on possible correlations between lymph node status and tumour size on the one hand and the eight biological prognostic factors on the other were analysed. Of the 16 correlations examined, 13 had a 99% confidence interval including 5%, failing to reject the null hypothesis of a zero correlation. These observations suggest the hypothesis that the prognostic influence of node status and tumour size cannot be explained by an analysis of the biology of breast cancer; and is compatible with the contention that axillary node status is merely a reflection of the relative chronological age of breast cancer.

3H-thymidine labeling index, hormone receptors, and ploidy in breast cancers from elderly patients

Breast cancers from 476 elderly patients, 70 years and older, operated on since 1972, were analyzed for proliferative activity, hormone receptors, and DNA content. Tumor proliferative activity, expressed as 3H-thymidine labeling index (3H-TdR LI), had a median value of 3.4%, which progressively increased from 1972 to 1990. Estrogen and progesterone receptors were present respectively in 83% and 61% of the cases; the positivity for estrogen receptors slightly increased with time. Aneuploid clones were detected in 74% of the cases, and this incidence was relatively stable during the time of observation. 3H-TdR LI, hormone receptors, and ploidy were generally unrelated to the local-regional extension of the disease in these elderly patients, in agreement with observations on cancer from younger patients. However, the absence of hormone receptors and the presence of aneuploidy were markedly indicative of fast cell proliferation. As in younger patients, these biologic findings in elderly patients could be considered as a complement to clinico-pathologic features in a 'risk-factor profile system' for treatment planning.

Cytologic assessment of tumor cell kinetics: applications of monoclonal antibody Ki-67 to fine-needle aspiration smears

Rates of tumor-cell proliferation often provide prognostic information about a given neoplasm. Previously available methods for accessing cell kinetics are time consuming and expensive, and often require special equipment or radioactive reagents. Monoclonal antibody Ki-67 binds a nuclear antigen expressed in proliferating but not in resting cells. We studied Ki-67 immunostaining of fine-needle aspiration smears from 40 benign and malignant masses. Labeling indices ranged from 0 (thyroid follicular adenoma) to 75 percent (pulmonary oat-cell carcinoma). Frozen section immunostaining (11 cases) and flow cytometric assessment of cell proliferation (8 cases) were in good agreement with Ki-67 labeling indices on smear material. We suggest that this method provides a rapid, inexpensive, and dependable means of assessing tumor-cell kinetics in cytologic preparations.

Should all patients with node-negative breast cancer receive adjuvant therapy? Identifying additional subsets of low-risk patients who are highly curable by surgery alone

This study, which used combined first-generation prognostic factors (tumor size, histologic differentiation, and age) on 408 patients with axillary node-negative (ANN) breast cancer treated by surgery alone without systemic adjuvant therapy between 1976 and 1987 at the Roswell Park Cancer Institute, discerned four subsets of low-risk patients with a 7-year relapse rate of 6% or better. The first subset consisted of 48 patients (12% of the population) with tumors 1 cm or less in diameter that were well or moderately differentiated. These patients had a disease-free rate (DFR) of 100% (95% confidence interval [CI], 94% to 100%). The second subset consisted of 35 patients (9% of the population) with tumors less than or equal to 1 cm that were poorly differentiated or anaplastic. These patients older than 50 years of age had a DFR of 97% (95% CI, 91% to 100%). The third subset consisted of 36 patients (9% of the population) with tumors 1.1 to 2 cm that were well or moderately differentiated. These patients were older than 50 years of age and had a DFR of 94% (95% CI, 85% to 100%). The fourth subset consisted of 36 patients with ductal carcinoma in situ with microscopic invasion. These patients had a DFR of 100% (95% CI, 87% to 100%). Twenty-two of these patients, not in the other subsets mentioned, comprised 5% of the total population. These patients at low risk of recurrence, who comprise one third of the entire node-negative population, are highly curable by local therapy alone and may be spared the risks and costs of routine adjuvant systemic therapy (AST). Patients with tumors larger than 2 cm (152 patients; 37% of the population) are at high risk of recurrence (26% with a DFR of 74% [95% CI, 64% to 84%]) and should routinely receive systemic adjuvant therapy. Patients with tumors up to 2 cm who are not in the low-risk groups fall in a gray area (recurrence, 15% to 21%; DFR, 79% to 85%). For these groups, combining second-generation prognostic factors such as DNA ploidy, S-phase fraction, or cathepsin D should give the physician additional information to aid in making decisions regarding adjuvant therapy.

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.

Breast biopsy nuclear pellets are a convenient source of DNA for routine determination of Her-2/neu gene amplification

Cell nuclei from breast biopsies are a byproduct of routine hormone receptor determination and are usually discarded. We report here that DNA purified from this source is suitable for use in conventional Southern blot or Polymerase Chain Reaction (PCR) techniques to screen for Her-2/neu amplification, enabling efficient use of limited biopsy material.

Flow cytometric DNA measurement and cytomorphometric analysis of formalin fixed rat mammary tumours

Archival paraffin embedded material was used to examine whether additional quantitative criteria would be helpful to discriminate between histologically benign and malignant rat mammary tumours. To this end nuclear DNA content expressed as DNA ploidy index (DI) was measured using flow cytometry (FCM). A total of 63 benign and malignant mammary tumours were investigated. Thirteen out of 38 (34%) mammary carcinomas were DNA aneuploid against 0 out of 25 benign mammary tumours. Aneuploidy was not significantly increased in tumours showing histological signs of greater malignancy such as cribriform-comedo type or invasive growth. In addition to DI other quantitative criteria indicative for malignancy, such as mitotic count and nuclear morphometric characteristics, were estimated in 24 benign and malignant tubulopapillary tumours, a category where the histological classification may be difficult. It appeared that five out of nine noninvasive tubulopapillary carcinomas and six out of seven invasive carcinomas had abnormal values for either DI, mitotic count or nuclear area or for a combination of these parameters. Each single parameter however was abnormal only in a minority of the malignant tumours. In this respect our data are in accordance with the fact that rat mammary carcinomas are clinically and histologically less malignant than their human counterparts.

Sequential determination of immunocytochemical estrogen receptor and nuclear DNA content in fine needle biopsies from breast carcinoma

The application of fine needle biopsy as a tool for early detection of breast cancer is becoming extensive, therefore parameters reported to be associated with prognosis should be standardized in this material. We propose the sequential determination of estrogen receptor (ER) status and DNA ploidy on the same smear obtained from a fine needle biopsy of a breast carcinoma, since both parameters seem to reflect properties associated with tumor behaviour and biological aggressiveness. Fifty fine-needle biopsies were investigated for presence of ER by the monoclonal antibody D75 followed by DNA content quantification using Feulgen-DNA cytophotometry. Overall, 66% of the tumors showed immunoreactivity for ER and 66% were classified as aneuploid. Forty-one percent of the aneuploid tumors were negative for ER, while only 7% of the diploid tumors showed no immunoreaction (p less than 0.05). The significant association between absence of immunocytochemical ER and DNA aneuploidy on the same fine-needle smear is consistent with data obtained through other methods previously reported using much larger tissue samples.

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.

Adjuvant systemic therapy of stage I and II breast cancer

The value of adjuvant systemic therapy has been clearly demonstrated in both node-positive and node-negative patients. However, there are many women with favorable prognoses whose breast cancer recurs. It has been possible only recently to identify subsets of patients who are at definite risk for recurrence. Advances both in selection and treatment of patients with early-stage breast cancer are being made as critical research questions are delineated and examined in prospective randomized trials.

Medical management of early-stage breast cancer

With improved screening and education, a greater proportion of breast cancer is detected at an early stage. Although the prognosis for many of these patients is excellent following definitive local therapy alone, some subsets of node-negative patients have a 30% chance of eventually developing metastatic disease that will be incurable with current therapy. Thus, an increasing proportion of early-stage patients are being offered some form of adjuvant therapy, with the expectation of improved relapse-free survival, and possibly improved overall survival. Efforts have been made to base the selection of patients for adjuvant therapy on specific prognostic factors. Meanwhile, the scope and complexity of putative prognostic factors continues to widen, and now includes such items as the presence of occult microscopic metastases, DNA ploidy and proliferative fraction, cytogenetic abnormalities, oncogene expression, growth factor receptors, and expression of hormonally regulated proteins. In addition, there is now a considerable range of options with regard to the composition, dose intensity, and sequence of multimodality therapy. Data regarding the classification, significance, and interpretation of prognostic factors is reviewed together with the development, current status, and recommendations regarding adjuvant therapy for patients with early-stage breast cancer. For 1991, the National Cancer Institute (NCI) has estimated that 175,000 new cases of breast cancer will be diagnosed in American women. It is also estimated that 44,500 women will die of breast cancer. Unfortunately, the age-adjusted death rate from breast cancer has shown no overall change from 1930 through 1987. However, effective screening techniques continue to identify an increasing percentage of early-stage tumors, which should exceed 50% of all new tumors in 1991. Ultimately, our understanding of environmental and genetic risk factors may identify new ways to reduce the impact of this disease. In the interim, development and application of effective systemic adjuvant chemotherapy and hormonal therapy has become increasingly important. There is no question that a greater proportion of patients with less extensive disease are now being offered some form of adjuvant therapy. Meanwhile, selection of patients for adjuvant therapy, and choice among specific adjuvant regimens, has remained controversial. Analysis of multiple prognostic factors is performed not only in the context of cooperative investigational trials, but more often in the offices of individual physicians caring for individual patients. Tumor biopsies can now be routinely sent to specialized laboratories for performance of complex assays with potential prognostic information, although interpretation of these results with reference to a specific patient is often uncertain.(ABSTRACT TRUNCATED AT 400 WORDS)

Node negative breast cancer: the prognostic value of DNA ploidy for long-term survival

The DNA content of breast tumours from 170 patients who presented between 1978 and 1980 was measured by flow cytometry. The relationship between tumour ploidy and disease outcome was assessed and its association with other prognostic factors evaluated. Compared with those with diploid tumours, patients with aneuploid tumours had significantly earlier relapse and shorter survival (P less than 0.0001). Tumour ploidy was strongly related to grade (P less than 0.001), but there was no significant association between DNA ploidy and c-erb-B-2 expression, lymph node status or tumour size. In lymph node negative and c-erb-B-2 negative patients, aneuploid tumours were associated with a poorer prognosis (P less than 0.001) than diploid tumours. Multivariate analysis showed that tumour ploidy gave independent information on disease free and overall survival. Tumour ploidy may be used as an independent prognostic variable in patients with breast cancer and it may be helpful in defining patients within the node negative or c-erb-B-2 negative groups likely to have a poor outcome who might benefit from adjuvant treatment.

Effects of primary chemotherapy in conservative treatment of breast cancer patients with operable tumors larger than 3 cm. Results of a randomized trial in a single centre

272 women with operable breast adenocarcinomas larger than 3 cm were included in a randomized trial. The patients in group A (n = 138) with histological nodal involvement (N+) or a lack of estrogen and progesterone receptors (EPR-) were treated by initial mastectomy and axillary node dissection + adjuvant chemotherapy. Those in group B (n = 134) were treated by initial chemotherapy (the same as in group A) followed by loco-regional treatment, adjusted according to their response to chemotherapy. Prognostic factors were identical in the two groups. In group A, 32 patients received no adjuvant treatment (N- and EPR+), while 104 were given adjuvant chemotherapy (N+ and/or EPR-). Two patients were lost to follow-up. In group B, all patients received initial chemotherapy; 44 were in complete clinical remission and were treated with radiotherapy only; 40 with residual tumor (less than 20 mm) were treated with tumorectomy + axillary node dissection + radiotherapy; 49 with residual tumors (greater than 20 mm) had mastectomies. Conservative treatment was administered to 84 patients in group B (62.6%). EPR-tumors responded better to chemotherapy than did EPR+ ones (p = .003). After a median follow-up of 34 months, isolated local recurrences were more frequent in the group with initial chemotherapy, which, however, experienced a better overall survival (p = 0.04).

Adjuvant therapy for node-negative breast cancer. The use of prognostic factors in selecting patients

Patients with invasive breast cancer and pathologically negative lymph nodes (NO) have a favorable 10-year survival rate, particularly with small (less than 1 cm) primary tumors. Overall, however, 20% to 35% will experience recurrence with local therapy only. Adjuvant chemotherapy or tamoxifen have prolonged disease-free survival (DFS), but not overall survival (OS). Unanswered questions of optimal end point (DFS or OS) and the risk of treating many to benefit few have prompted clinicians to use prognostic indicators to facilitate treatment recommendations. Currently, the most readily available and accurate information comes from TNM staging, pathologic features, and hormone receptors. Ploidy, S-phase fraction, HER-2-neu amplification or over-expression, and cathepsin-D may be useful prognostic indices. Until a more precise system of weighing several prognostic variables is developed, the decision to recommend adjuvant systemic therapy in this generally good prognosis group will have to be thoughtfully considered by patient and physician. Whenever possible, patients should be encouraged to enter clinical trials.

Hormones and breast cancer

The study of steroid hormone receptors in human breast cancer provides insight into tumor biology and forms the rationale for many therapeutic modalities. Clinical assays for estrogen and progesterone receptors improve the selection of patients who may benefit from hormonal therapy. In addition, receptor content in breast cancer tissue is useful for determining prognosis. Together with other new prognostic factors, hormone receptors help to distinguish among patients with primary breast cancer who are at risk for early recurrence.

Cutaneous and subcutaneous leiomyosarcoma: a clinicopathological review of 14 cases with reference to antidesmin staining and nuclear DNA patterns studied by flow cytometry

Among 14 patients (11 female and three male) with cutaneous and subcutaneous leiomyosarcomas, metastatic spread occurred in six of the 13 patients with adequate follow-up. The tumours were classified with regard to tumour grade, number of mitotic figures per 10 high-power fields, reactivity to antidesmin antibodies, and DNA pattern as assessed by flow cytometry. Antidesmin antibody staining was present in only six cases and seemed to be less common in the higher-grade tumours. The DNA pattern was aneuploid in five cases and non-classifiable in one case; all of these cases had metastatic spread. None of the eight remaining diploid cases had metastatic spread. DNA content was a strong predictor of metastatic potential.

Correlation between nuclear DNA content and steroid receptor status in ovarian cancer

The nuclear DNA content of 47 malignant epithelial ovarian tumours and five ovarian tumours of borderline malignancy was correlated with estrogen (ER), progesterone (PR) and androgen receptor (AR) status. Aneuploidy was observed in 60% of the malignant tumours. The DNA index of poorly differentiated tumours was higher than that of well differentiated tumours (P less than 0.05). Ploidy did not correlate with histological type, stage of disease and ER content. Of the diploid tumours, 74% was PR-positive, in contrast to 36% of the aneuploid tumours (P less than 0.05). In addition, 89% of the diploid tumours had high AR levels (greater than or equal to 30 fmol/mg cytosol protein), in contrast to only 54% of the aneuploid tumours (P less than 0.05). These observations strengthen our previous findings on the prognostic importance of PR and also suggest that androgens may have a role in ovarian cancer.

Comparison of image analysis and flow cytometric determination of cellular DNA content

A good correlation (r = 0.94) was obtained between the DNA indices (DI) using flow cytometry and image analysis of nuclei cytospins extracted from paraffin wax embedded tumour sections. Some of the limitations and problems associated with image analysis which came to light included an unacceptably high coefficient of variation (CV) and a "left-shift" in the DI in most DNA histograms obtained when using image analysis of 5 microns sections. In contrast, the DNA histograms generated using image analysis of cytospun nuclei from paraffin wax blocks were of good quality and similar to those obtained using flow cytometry. Variability in Feulgen staining was common and an important source of error despite rigorous control of the staining technique. This could be overcome by using internal controls such as fibroblasts rather than external controls (rat hepatocytes) to determine the diploid DI with image analysis. A thorough understanding and appreciation of the methodological problems associated with image analysis and flow cytometric determination of DNA content is required before these methods find widespread clinical application.

Flow cytometric analysis of DNA stemline heterogeneity in primary and metastatic breast cancer

Flow cytometric DNA-ploidy analysis was used to investigate intratumor DNA stemline heterogeneity in primary breast carcinomas and lymph node metastases (LNM). The study was done in tumor specimens from 44 patients 35 of whom had LNM. In all, measurements were done in 214 different samples of primary tumors and 211 lymph nodes. Sixty-one percent (27/44) of the primary tumors were found to have multiple DNA aneuploid stemlines when the data of the separate samples per tumor (mean 4.9) were compared. Only five of 44 (11%) primary tumors were DNA diploid; two of these had DNA aneuploid metastases. Statistical analysis of these results indicated that, on average, four samples are needed for reliable determination of the DNA ploidy status of primary tumors by flow cytometry. In the majority of the cases (26/35), distinct tumor DNA stemlines found in LNM were also present in the primary tumor, which suggests that the generation of DNA ploidy diversity may have taken place prior to metastasis. Multiploidy was not related to tumor size but, particularly for LNM, was significantly correlated with age (r = 0.40, P = 0.02). The results of this study support the view that breast cancer is an extremely heterogeneous disease and that underestimation of this factor might account for the disagreement in literature about the prognostic value of DNA ploidy determinations.

DNA ploidy and cell-cycle analysis: tools for assessment of cancer prognosis

DNA ploidy and cell cycle analysis as measured by flow cytometry (FC) and image analysis (IA) have moved out of the realm of the research laboratory to become valid clinical tests used in the assessment of prognosis of the cancer patient. Although much information on the relationship of DNA ploidy/%S-phase analysis to patient prognosis is available in the literature, the data are not presented in such a way as to be helpful in clinical decision making. Because predictive values and confidence intervals, which measure the likelihood that a given clinical test will rule in or rule out a clinical outcome, were not calculated in previous reviews, conclusions about the clinical utility of these analyses were not possible. Using the available raw data on DNA ploidy and %S-phase analysis from previously published papers, predictive values and confidence limits were calculated for specific clinical presentations. In several such clinical situations (tumor type, stage, etc.), predictive value of greater than 90% was derived. We conclude that in these situations DNA ploidy and %S-phase analysis can be used to predict clinical outcome, to design treatment, and to guide patient management. The evaluation of the clinical utility of these tests must ultimately rest on prospective trials which show that randomized arms respond to treatment regimens dependent upon the DNA ploidy and %S-phase status.

Prognostic indicators in invasive breast cancer

Tumor size and axillary lymph node involvement are the primary determinants of clinical course for most patients. Receptors for estrogen and progesterone are important additional prognostic factors for disease-free survival, overall survival, survival time after initial disease recurrence, and the likelihood of response to hormonal therapy. Histologic grading has merit as a prognostic factor, although poor reproducibility limits its broad application. Promising data have been emerging from the use of flow cytometry to analyze DNA content and proliferative rate. Patients with aneuploid tumors are more likely to have a shorter survival time than patients with diploid tumors. A high S-phase fraction also identifies a subset of patients at increased risk for early relapse. A combined index of ploidy and S-phase may be a more useful guide; together, diploidy and low S-phase identify a subgroup of node-negative patients at very low risk for disease recurrence. A number of oncogenes have been identified in breast cancer; amplification of the HER-2/neu gene or overexpression of the gene product may be an important prognostic indicator for node-positive patients.

Medical and legal implications of screening and follow-up procedures for breast cancer

Grievances result from false expectations on the part of both practitioners and patients when a disease treatment problem is unsolved because of biological variations in the disease itself. Widely publicized screening and follow-up recommendations are often the source of the grievances. Even when recommendations are followed exactly, bad outcomes are still associated with incurable cancer even though a fatal outcome is inevitable. Patients must be told about treatment prospects including limitations of efficacy, so that patient expectations will be realistic. Otherwise, practitioners may find themselves involved in lawsuits alleging deviation from case standards for an adverse outcome actually attributable to the nature of the cancer. Because screening and follow-up techniques continue to control treatment of breast cancer, such lawsuits are common. When ineffective treatment exists, there often are adverse harm/benefit considerations and high costs, particularly when screening or follow-up are practiced defensively, without hard data proving the value of a strategy. This article will review these problems, placing specific emphases on screening and follow-up procedures and on strategies for breast cancer. Factors that limit efficacy and increase both cost and diagnosis-associated morbidity will also be explored.

DNA ploidy level and S-phase fraction as prognostic factors in breast cancer

Imprint smears from sixty cases of breast cancer made after mastectomy were stained by the Feulgen method and the nuclear DNA content measured by a cytofluorometer equipped with an incident illumination system. After logarithmic transformation of the fluorescence intensity, the ploidy level and S-phase fraction (SPF) were calculated with a microcomputer and the correlation between the ploidy level or SPF and the clinicopathological prognostic factors studied. Patients with tumors of a larger diameter and more extensive lymph node involvement had higher levels of ploidy and SPF and the ploidy level in the metastatic lymph nodes was higher than that in the primary lesion. Moreover, a significant increase in SPF was observed in the metastatic lymph nodes and a high ploidy level found to be associated with tumors having a negative estrogen receptor. When the tumors were divided into a diploid group and an aneuploid group, the diploid group showed a significantly better prognosis than the aneuploid group, in 6-year survival. Similarly, the groups in which SPF was less than 20.0 per cent had significantly better prognoses than the group in which SPF was 20.1 per cent or more. These prognostic factors were evaluated with Cox's proportional hazard model and a significant correlation observed in lymph node status, ER status, ploidy level and S-phase fraction. It was thus concluded that ploidy level and SPF are important and independent prognostic factors for predicting the postoperative course of breast cancer patients.

Assessment of nucleolar organizer regions by automatic image analysis in breast cancer: correlation with DNA content, proliferation rate, receptor status and histopathological grading

The value of automatic image analysis in the investigation of nucleolus regions (AgNOR) has been examined in tissue sections of 52 malignant and 30 benign breast lesions. Determination of the AgNOR number per cell alone revealed a considerable overlap between benign (range 1.2-3.8) and malignant specimens (range 1.5-16.2). They differed however, highly significantly (P less than 0.001) in their AgNOR sizes. In benign breast disorders the mean AgNOR area per tumour ranged from 0.22 microns2 to 1.07 microns2 (mean 0.39 microns2), whereas in carcinomas AgNOR sites ranged from 0.05 microns2 to 0.22 microns2 (mean 0.09 microns2). AgNOR counts showed a good correlation with histopathological grade (P less than 0.05), aneuploidy (P less than 0.01), proliferation rate as determined by Ki67 immunostaining (P less than 0.01), as well as oestrogen and progesterone receptor content (P less than 0.01). Image analysis proved to be advantageous over AgNOR counting alone as it facilitated the standardization of the AgNOR technique itself and thus, significantly improved its diagnostic specifity.

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.

Prognostic significance of flow cytometric DNA analysis in node-negative breast cancer patients

Flow cytometric DNA analysis using paraffin-embedded tumor blocks was done retrospectively on 155 node-negative breast cancers. The median duration of follow-up in patients still alive at the time of analysis was 10 years. Tumor aneuploidy was correlated significantly with increased tumor size (P = 0.003) and higher tumor grade (P less than 0.001). No significant correlation between tumor ploidy and patient age was found. Patients with diploid tumors had a significantly improved relapse-free and overall survival compared with patients with aneuploid tumors (P = 0.0001). In a Cox multivariate model with parameters including ploidy, histologic grade, tumor size, and patient age, ploidy (P = 0.02) and tumor size (P = 0.05) emerged as significant independent predictors of overall survival. Only ploidy was independently significant in the analysis of relapse-free survival. In conclusion, the current study indicates that flow cytometric measurement of DNA ploidy is a powerful prognostic indicator in node-negative breast cancer patients.

An immunohistological study of breast cancer--with special reference to the expression of carbohydrate antigens and estrogen receptor status

An investigation carried out on 100 cases of primary breast cancer, both clinicopathologically and immunohistologically, revealed estrogen receptor (ER)-positive cases to be found significantly more often in early stage cancer than advanced stage cancer. On the other hand, ER negative cases were found to have a greater incidence of high-grade lymph node metastasis and were seen significantly more frequently in large tumors. Span-1, CA19-9, and SLEX antigens were detected in 33 per cent, 38 per cent, and 64 per cent of the total cases, respectively and the ratio of ER negative cases was significantly higher in each antigen positive group. Irrespective of the presence or absence of lymph node metastasis, ER negative cases were found significantly more often in antigen-positive groups than in their counterparts and tumor size tended to be greater in the antigen-positive cases. The results of this study thus indicated that the disease progression in breast cancer appears to be correlated with ER status and carbohydrate antigen expression.

DNA index, S-phase fraction, histological grade and prognosis in breast cancer

DNA index and S-phase fraction (SPF) were measured by flow cytometry on paraffin embedded tissue from 140 primary breast tumours. The results of DNA analysis were compared with the size, degree of axillary node involvement, histological grade and steroid receptor content of the tumours, as well as with the patients' subsequent clinical course. Forty-four (31.4%) of the 140 tumours were diploid. S-phase fraction was evaluable for 134 (95.7%). The median SPF of the whole population was 7.1%, with diploid tumours having a significantly lower median SPF (3.2%) than aneuploid (10.1%, P less than 0.001). Both aneuploidy (P = 0.002) and high SPF (P less than 0.001) were strongly associated with high histological grade. There was no significant association between either DNA ploidy or SPF and tumour size, nodal status or steroid receptor content. An SPF below the median was strongly associated with better relapse-free survival (P = 0.008), overall survival (P = 0.004) and survival after relapse (P less than 0.001). Ploidy did not correlate significantly with clinical course. Multivariate analysis using the Cox model suggested that, while SPF gave prognostic information independent of tumour size or nodal status, this independent significance was lost when histological grade was included in the analysis.

Is DNA ploidy an independent prognostic indicator in infiltrative node-negative breast adenocarcinoma?

To evaluate DNA content as an independent, long-term prognostic indicator in infiltrative, node-negative adenocarcinoma of the breast, flow cytometric DNA analyses were performed retrospectively in 165 patients. The exclusive use of paraffin-embedded tissue permitted the study of patients for whom 3 to 15 years' follow-up was available. Other investigators have shown a relationship between DNA nuclear content and well-known prognostic indicators of breast carcinoma, such as estrogen receptors, age, menopausal status, and stage of tumor. However, very few of these studies were based on patients with long-term clinical follow-up and investigated the independent prognostic value of DNA nuclear content. The frequency of aneuploidy in the patients in this study was 57%, with DNA indices ranging from 0.73 to 2.59. Survival in patients with localized breast carcinoma with DNA aneuploid tumors was 84.1% at 5 years and 75.5% at 10 years. Those with diploid tumors showed survival of 87.8% at 5 years and 73.4% at 10 years. These data show no independent prognostic value for DNA nuclear content. The relationship between DNA content, tumor histologic type, and age was also investigated. High-grade tumors were more often aneuploid. There was no association between DNA content and age. Of 165 patients, information regarding estrogen receptor status was available in only 77; 45% of those with aneuploid tumors and 35% with diploid tumors were estrogen receptor-negative. This difference was not significant. The authors conclude that simple determination of DNA ploidy fails to indicate prognosis for infiltrative, node-negative breast carcinoma.

The prognostic significance of tumor ploidy and pathology in adenocarcinoma of the esophagogastric junction

Tumor DNA content has been advocated to be an important prognostic indicator in human malignancies. Paraffin-embedded specimens of 75 resected adenocarcinomas (AC) of the esophagogastric junction were studied by flow cytometric DNA analysis to determine whether tumor ploidy was a significant prognostic variable independent of stage and histologic grade of the tumor. Eighty-one percent of the tumors were aneuploid. More patients with aneuploid tumors had lymph node metastases than patients with diploid tumors (P = 0.007). Patients with aneuploid tumors had poorer 18-month disease-free and overall survival than patients with diploid tumors. Cox regression analysis demonstrated that the most important prognostic variables for predicting overall survival were lymph node status, depth of wall invasion, and tumor differentiation. Tumor ploidy was not an independent prognostic variable in predicting recurrent disease or death from AC of the esophagogastric junction. Tumor DNA content is valuable, however, as a marker for patients at increased risk of lymph node metastases, early recurrence, and poorer survival.

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.

New diagnostic, staging, and therapeutic aspects of early breast cancer

Many advances have occurred in breast cancer through research and clinical trials. More confidence in new biological consumptions about invasive breast cancer indicate that: (1) details of the primary breast cancer do not control survival; (2) breast-only failures after local excision do not bias against survival; and (3) cancer cell dissemination occurs at the same time via both lymphatic and hematogenous routes. Early detection with mammographic screening has indicated a greater number of smaller breast cancers, including sharp increases in ductal carcinoma in situ (DCIS). With proper analysis and control, DCIS of limited extent can be treated by local excision with or without radiation. Invasive breast cancer of limited extent can frequently be managed by lumpectomy and radiation therapy with survival rates equivalent to the more traditional mastectomy. Patient desires regarding breast preservation and quality of life are paramount. Risk: benefit analyses for individual patients need to be emphasized in issues of breast preservation and in selecting adjuvant therapy, both regional (radiotherapy) and systemic (chemotherapy) and hormonal therapy). We are entering an era of highly selective therapy based on more sophisticated analysis of the primary cancer. In the future, not only statistical predictions of outcome as achieved by flow cytometry, for example, will be more widely used, but individual prognostic factors may be developed such as with oncogene expression. Such individual prognostic factors will enable more selective therapy.

Cathepsin D and prognosis in breast cancer

We investigated the possibility that cathepsin D, an estrogen-induced lysosomal protease, might have value as a prognostic factor in breast cancer by studying frozen tissue specimens from 397 patients. We measured the 34-kd mature form of the enzyme by Western blot assay and densitometry. Among 199 patients with node-negative disease, but not among 198 with node-positive disease, high levels of cathepsin D proved to be a significant predictor of reduced disease-free survival (median follow-up, 64 months), either as a continuous variable (log cathepsin D; P = 0.018) or as a dichotomous variable with an optimized cutoff point (P = 0.0001). Results were similar for overall survival (P = 0.009 and 0.0001, respectively). Relating the level of cathepsin D to other prognostic factors in the patients with node-negative disease, we found an association with aneuploidy but none with estrogen or progesterone receptors, tumor size, or the age of the patient. In multivariate analyses, a high level of cathepsin D was the most important independent factor in predicting shorter disease-free and overall survival in patients with node-negative disease. As compared with the risk in women with low levels of cathepsin D, the relative risk of tumor recurrence was 2.6 (95 percent confidence interval, 1.6 to 4.4) and the relative risk of death was 3.9 (95 percent confidence interval, 2.1 to 7.3) among those with high levels of cathepsin D. For disease-free survival, cathepsin D status was predictive of outcome primarily among those with aneuploid tumors; the actuarial five-year recurrence rates of aneuploid tumors were 60 percent among women with high levels of cathepsin D and 29 percent among those with low levels, as compared with 22 percent for all diploid tumors. We conclude that cathepsin D may be an independent predictor of early recurrence and death in node-negative breast cancer.

Estrogen receptor gene amplification is found in some estrogen receptor-positive human breast tumors

The genomic organization of the estrogen receptor (ER) gene has been analyzed in 21 primary human breast cancers and 1 axillary metastasis. No evidence of rearrangements of the ER gene was found in the analyzed tumors. In 6/14 ER-positive tumors a certain degree of amplification of the ER gene, ranging from 1.6 to 3-fold, was detected. No correlation was observed between the level of gene amplification and the amount of ER in the tumors. In the 8 ER-negative tumors analyzed no amplification could be detected. It is concluded that ER gene amplification may be one of the mechanisms underlying the increased ER expression in some breast tumors.

Prognostic value of S-phase fraction and DNA ploidy studied with in vivo administration of bromodeoxyuridine on human gastric cancers

The authors studied the prognostic values of DNA ploidy pattern and proliferative activity with in vivo administration of bromodeoxyuridine in human gastric cancers. Fresh specimens surgically removed from 117 patients with gastric cancer were investigated by flow cytometric study using a monoclonal antibody to bromodeoxyuridine. DNA ploidy patterns were classified into four types according to the bivariate BrdUrd/DNA distribution: D1, tumors with single diploid population; D2, tumors which showed mosaic of diploid and aneuploid population; A1, tumors with single aneuploid population; and A2, several aneuploid populations without diploid population. The numbers of cases of each ploidy pattern were as follows: D1, 36 cases (30.8%); D2, 38 cases (32.5%); A1, 15 cases (12.8%); and A2, 27 cases (23.1%). DNA ploidy pattern and S-phase fraction (SPF) showed no relation with clinicopathologic findings, except for type A2. In type A2, lymph node metastasis and lymphatic vessel invasion were observed more often than type D1. The SPF calculated from the bivariate BrdUrd/DNA distribution was higher in aneuploidy (D2, A1, and A2) than in diploidy (D1) (P less than 0.01). Also, A2 exhibited a higher SPF than A1 (P less than 0.01). Furthermore, SPF correlated with DNA index significantly (P less than 0.01). Patients who showed aneuploid tumors, DNA ploidy type A2, or SPF of more than 10% survived 3 years less than those with diploid tumors, DNA ploidy type D1, or SPF of less than 10%, respectively (P less than 0.05). By analyzing with the Cox's proportional hazard's model, it is revealed that DNA ploidy and SPF are one of the independent factors of prognostic significance. The results indicated that the patients with aneuploid tumors or highly proliferative tumors had a poor prognosis and that DNA ploidy pattern and SPF were useful prognostic factors for gastric cancers.

Flow cytometric analysis of DNA content and keratins by using CK7, CK8, CK18, CK19, and KL1 monoclonal antibodies in benign and malignant human breast tumors

We have used a double-labelling flow cytometry analysis of keratin (CK) and DNA in breast cancer. Five monoclonal anti-keratin antibodies were tested: KL1 recognizing Mr 55,000-57,000 keratins, and "anti-glandular epithelia," LE41, RGE-53, and LP2K specific for CK n. 7, 8, 18, and 19 of Moll's classification, respectively. Flow cytometric (DNA-CK) analysis was performed on 10 benign and 19 malignant human breast tumors. All the benign tumors were diploid and 63% of the malignant tumors were aneuploid. This technique permits the analysis of DNA in the epithelial fraction alone. In aneuploid tumors, gating the DNA-keratin-positive population allowed accurate DNA analysis without interference due to debris background and non-epithelial cells. Moreover, double-labelling using the CK19 antibody gave a better identification of near-diploid tumors. An enhancement of keratin expression in malignant tumors was observed with CK 19 (P less than 0.001), KL1 (P less than 0.01), CK 8 (P less than 0.05), and CK18 (n.s.) compared to benign tumors. The comparison of keratin expression in aneuploid and diploid malignant tumors revealed reduced CK8, CK18, and CK19 in the former.

Season of tumour detection influences factors predicting survival of patients with breast cancer

The rate of initial detection of breast tumours varies during the year in a seasonal fashion, more tumours being discovered in late spring/early summer than at other times of the year. This phenomenon is particularly pronounced in young women (less than 50 years) with progesterone receptor positive tumours. The present study investigates whether season of tumour detection influences the predictive capacity of several recognised prognostic and risk factors in patients with breast cancer. Axillary nodal status, tumour progesterone receptor status, and season of tumour detection significantly influenced survival in both older (greater than 50 yrs) and younger (less than 50 yrs) patients. Parity, lactational history, body mass index, tumour oestrogen receptor status, and patient age also influenced survival, but these effects were significant only in age groups less than 50 or greater than 50 yrs. Season of detection of tumour did not effect the prognostic significance of axillary nodal status. However, the effect of oestrogen receptor status on survival was more significant in patients who detected their tumours in the spring/summer compared with winter (odds ratio 0.52 and 0.73 respectively). Negative progesterone receptor status was associated with significant poorer survival only in patients with tumours found in the winter. There was a significant survival disadvantage for nulliparous compared with parous women with breast cancer who were greater than or equal to 50 years at diagnosis, and for women who had never lactated compared with those who had lactated, but this disadvantage was restricted to those who found their tumours in the summer. An increased body mass index (greater than or equal to 28) was associated with decreased survival, but this was significant only for those detecting tumours in winter. The increased incidence of detection of breast cancer in spring/summer may reflect cyclic influences on tumour growth. Such influences may be hormonal in nature and may underlie the effect of season of tumour detection on the prognostic influence of lactation, parity, body mass index, and oestrogen and progesterone receptor status in patients with breast cancer.

Correlation of growth fraction by Ki-67 immunohistochemistry with histologic factors and hormone receptors in operable breast carcinoma

Breast cancer tissue samples obtained from 147 Stage I and II patients were tested with the monoclonal antibody Ki-67 and avidin-biotin-peroxidase complex in frozen sections. The percentage of cells with nuclear staining ranged from 5% to 65%. The frequency of Ki-67 positivity was classified in five groups: 0% (45/147 = 31%); 5-9% (38/147 = 26%); 10-19% (15/147 = 10%); 20-39% (24/147 = 16%) and greater than or equal to 40% (25/147 = 17%). The mean value was 20%, median 18% with standard deviation of 14.5%. A significant positive correlation was observed between the presence of high Ki-67 nuclear staining rate with pathological tumor size (p = 0.003), histologic grading (p = 0.04), and axillary lymph node metastases (p = 0.009). An inverse significant correlation was found between Ki-67 and estrogen receptor expression (p less than 0.001). No correlation was observed with progesterone receptor expression or menopausal status. The overall picture is of an inverse relationship between high growth fraction determined with Ki-67 antibody and tumor differentiation parameters. These correlations confirm those already reported by thymidine labeling index and flow cytometry methods. The proliferative rate determined with Ki-67 antibody may provide information regarding cell kinetics of breast carcinoma, potentially useful in identifying patients with a different clinical course in order to improve the therapeutic approach, by a rapid, practical and easily performed immunohistochemical method.

The prognostic significance of nuclear DNA content in invasive breast cancer--a study with long-term follow-up

The nuclear DNA content of 351 breast carcinomas was determined by flow cytometry from paraffin-embedded tissue to assess the prognostic significance of DNA ploidy, the DNA index (DI) and the S-phase fraction (SPF). The minimum follow-up of the patients was 22 years, and they were all from a defined urban population. DNA ploidy correlated with histological type and grade, mitotic count and nuclear pleomorphism (P less than 0.0001), and also with axillary nodal status (P = 0.0005), tumour necrosis (P = 0.001), primary tumour size (P = 0.03), menopausal status (P = 0.004) and the presence of distant metastases at the time of the diagnosis (P = 0.04). Survival corrected for intercurrent deaths of the patients with a diploid tumour was better than that of the patients with a non-diploid tumour (P = 0.0001, 48% vs 28% at 25 years). SPF had prognostic significance in both axillary node positive and negative patients, but ploidy and DI only in the node negative group, and their significance was greater in post-menopausal than in premenopausal patients. Axillary nodal status, primary tumour size, histological grade and the type of tumour margin circumscription were the most important independent prognostic factors in Cox's multivariate analysis, and SPF had independent prognostic value, whereas ploidy and DI did not. It is concluded that DNA ploidy, DI and SPF have long-term prognostic significance in breast cancer.

A simple and rapid method for determining the linearity of a flow cytometer amplification system

We describe a simple and rapid method for determining the linearity of a flow cytometer amplification system. The method is based on a fundamental characteristic of linear amplifiers: The difference between two amplified signals increases linearly with increasing amplifier gain. Two populations of beads or cells, differing slightly in fluorescence intensity, are analyzed by the flow cytometer at increasing photomultiplier tube high-voltage settings. The distribution of the populations' mean difference versus mean position is a straight line intersecting the origin for linear amplifiers. Although some types of nonlinearities cannot be detected with this technique, deviations from linearity indicate nonlinear components in the flow cytometer amplification system. The correlation coefficient is used to quantify degree of nonlinearity. We also describe a method for amplifier nonlinearity compensation.