Grade and flow cytometric analysis of ploidy for infiltrating ductal carcinomas

Performance of a novel spectroscopy-based tool for adjuvant therapy decision-making in hormone receptor-positive breast cancer: a validation study

PURPOSE

Digistain Index (DI), measured using an inexpensive mid-infrared spectrometer, reflects the level of aneuploidy in unstained tissue sections and correlates with tumor grade. We investigated whether incorporating DI with other clinicopathological variables could predict outcomes in patients with early breast cancer.

METHODS

DI was calculated in 801 patients with hormone receptor-positive, HER2-negative primary breast cancer and ≤ 3 positive lymph nodes. All patients were treated with systemic endocrine therapy and no chemotherapy. Multivariable proportional hazards modeling was used to incorporate DI with clinicopathological variables to generate the Digistain Prognostic Score (DPS). DPS was assessed for prediction of 5- and 10-year outcomes (recurrence, recurrence-free survival [RFS] and overall survival [OS]) using receiver operating characteristics and Cox proportional hazards regression models. Kaplan-Meier analysis evaluated the ability of DPS to stratify risk.

RESULTS

DPS was consistently highly accurate and had negative predictive values for all three outcomes, ranging from 0.96 to 0.99 at 5 years and 0.84 to 0.95 at 10 years. DPS demonstrated statistically significant prognostic ability with significant hazard ratios (95% CI) for low- versus high-risk classification for RFS, recurrence and OS (1.80 [CI 1.31-2.48], 1.83 [1.32-2.52] and 1.77 [1.28-2.43], respectively; all P < 0.001).

CONCLUSION

DPS showed high accuracy and predictive performance, was able to stratify patients into low or high-risk, and considering its cost and rapidity, has the potential to offer clinical utility.

Impact of intratumoral heterogeneity on the metabolic profiling of breast cancer tissue using high-resolution magic angle spinning magnetic resonance spectroscopy

High-resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) is a useful metabolic profiling technique for human tissue. However, the impact of intratumoral heterogeneity on the metabolite levels of breast cancers is not yet established. The purpose of this prospective study was to investigate whether the tumor cell fraction of core needle biopsy (CNB) specimens of breast cancers affect metabolic profiles assessed with HR-MAS MRS. From June 2015 to December 2016, 46 patients with 47 breast cancers were enrolled. HR-MAS MRS was used for the metabolic profiling of 285 CNB specimens from the 47 cancers. Multiple CNB samples (range 2-8) for the HR-MAS MRS experiment were obtained from surgical specimens under ultrasound guidance following surgical removal of the tumor. Tumor cell fraction was expressed as a percentage of the tumor cell volume relative to the total tumor volume contained in each CNB sample. Metabolite quantification levels were compared according to primary tumor characteristics using the t-test. Multivariate analyses were performed including primary tumor characteristics and tumor cell percentages as variables. Correlations between tumor cell percentage and metabolite levels in the CNB specimens were assessed according to the immunohistochemical status of the primary tumor. In univariate analysis, levels of choline-containing compounds, glutamate, glutamine, glycine, serine, and taurine were correlated with primary tumor characteristics. In multivariate analysis, most metabolite levels were not affected by tumor cell percentage. Tumor cell percentage showed poor correlation with metabolite levels in hormone receptor-positive cancer and triple-negative cancer, and poor to fair correlation with metabolite levels in HER2-positive cancer. This study showed that differences in the tumor cell fraction of CNB samples do not affect predictions on the primary cancer from which the samples are obtained.

A Direct Test of Selection in Cell Populations Using the Diversity in Gene Expression within Tumors

Although intratumor diversity driven by selection has been the prevailing view in cancer biology, recent population genetic analyses have been unable to reject the neutral interpretation. As the power to reject neutrality in tumors is often low, it will be desirable to have an alternative means to test selection directly. Here, we utilize gene expression data as a surrogate for functional significance in intra- and intertumor comparisons. The expression divergence between samples known to be driven by selection (e.g., between tumor and normal tissues) is always higher than the divergence between normal samples, which should be close to the neutral level of divergence. In contrast, the expression differentiation between regions of the same tumor, being lower than the neutral divergence, is incompatible with the hypothesis of selectively driven divergence. To further test the hypothesis of neutral evolution, we select a hepatocellular carcinoma tumor that has large intratumor SNV and CNV (single nucleotide variation and copy number variation, respectively) diversity. This tumor enables us to calibrate the level of expression divergence against that of genetic divergence. We observe that intratumor divergence in gene expression profile lags far behind genetic divergence, indicating insufficient phenotypic differences for selection to operate. All these expression analyses corroborate that natural selection does not operate effectively within tumors, supporting recent interpretations of within-tumor diversity. As the expected level of genetic diversity, hence the potential for drug resistance, would be much higher under neutrality than under selection, the issue is of both theoretical and clinical significance.

Clonal cooperativity in heterogenous cancers

Tumor heterogeneity is a major obstacle to the development of effective therapies and is thus an important focus of cancer research. Genetic and epigenetic alterations, as well as altered tumor microenvironments, result in tumors made up of diverse subclones with different genetic and phenotypic characteristics. Intratumor heterogeneity enables competition, but also supports clonal cooperation via cell-cell contact or secretion of factors, resulting in enhanced tumor progression. Here, we summarize recent findings related to interclonal interactions within a tumor and the therapeutic implications of such interactions, with an emphasis on how different subclones collaborate with each other to promote proliferation, metastasis and therapy-resistance. Furthermore, we propose that disruption of clonal cooperation by targeting key factors (such as Wnt and Hedgehog, amongst others) can be an alternative approach to improving clinical outcomes.

Prognostic relevance of DNA flow cytometry in breast cancer revisited: The 25-year experience of the Portuguese Institute of Oncology of Lisbon

The potential prognostic significance of DNA flow cytometric measurements (DNA ploidy and S-phase fraction) in breast cancer remains in dispute. Inconclusive data, primarily due to the lack of consistent standardization and quality control programs, have limited its translation into clinical practice. The aim of the present review, based on the 25-year experience of the Portuguese Institute of Oncology of Lisbon, is to assess the clinical relevance and application of DNA flow cytometry for the prognosis of breast cancer. Overall, data from Portuguese Institute of Oncology of Lisbon indicate that DNA flow cytometry provides significant prognostic information that is biologically relevant and clinically useful for the management of patients with breast cancer. Furthermore, this data has demonstrated the independent value of DNA aneuploidy as a prognostic indicator of poor clinical outcome in various subgroups of patients with early or locally advanced breast cancer at short- and long-term follow-up. Notably, aneuploidy identifies subsets of patients with grade (G)1 or G2 tumours who exhibit a poor clinical outcome. These patients may benefit from adjuvant chemotherapy, particularly those with luminal A and luminal B/human epidermal growth factor-2-negative endocrine-responsive breast cancer. In conclusion, data from Portuguese Institute of Oncology of Lisbon reinforces the clinical importance and utility of DNA flow cytometric analysis, particularly DNA ploidy, in the prognostic assessment and therapeutic planning for patients with breast cancer.

Prognostic Factors for Carcinoma of the Male Breast

Male mammary carcinoma (MMC) affects approximately 1000 men in the United States each year. Aside from the impact of estrogen-receptor positivity on the clinical course of this tumor, relatively little information exists in published form on the ability of special pathologic studies to predict its biologic behavior. The authors analyzed 26 cases of invasive ductal MMC, comparing overall survival with tumor size, histologic grade (Page and Anderson), immunohistologic estrogen receptor protein status, DNA ploidy, expression of S 100 and gross cystic disease fluid proteins, and immunohisto chemically-detected amplification of the c-erbB-2 (HER-2/neu) oncoprotein. Tumor size and amplification of c-erbB-2 oncoprotein emerged as the statistically significant predictors in this group; MMCs of <2 cm had a more favorable prognosis than large tumors. Estrogen receptor protein was seen in 80% of cases; c-erbB-2 amplification was present in 35%; 80% were DNA-aneuploid; and S 100 and gross cystic disease fluid were observed in 38% and 62% of cases, respectively. The latter data are virtually identical to those on histologically similar tumors in women, but all except c-erbB-2 failed to achieve statistical prognostic value in this study. Substrata of histologic grades among MMCs were numerically too small to subject to statistical assessment. These findings suggest that no substantive differences exist between the pathologic features of male and female breast cancers. They also indicate that adjunctive laboratory studies are currently unhelpful in the prognostication of MMC. Int J Surg Pathol 2(3):199-206, 1995

Clinical management of breast cancer heterogeneity

Traditionally, intertumour heterogeneity in breast cancer has been documented in terms of different histological subtypes, treatment sensitivity profiles, and clinical outcomes among different patients. Results of high-throughput molecular profiling studies have subsequently revealed the true extent of this heterogeneity. Further complicating this scenario, the heterogeneous expression of the oestrogen receptor (ER), progesterone receptor (PR), and HER2 has been reported in different areas of the same tumour. Furthermore, discordance, in terms of ER, PR and HER2 expression, has also been reported between primary tumours and their matched metastatic lesions. High-throughput molecular profiling studies have confirmed that spatial and temporal intratumour heterogeneity of breast cancers exist at a level beyond common expectations. We describe the different levels of tumour heterogeneity, and discuss the strategies that can be adopted by clinicians to tackle treatment response and resistance issues associated with such heterogeneity, including a rationally selected combination of agents that target driver mutations, the targeting of deleterious passenger mutations, identifying and eradicating the 'lethal' clone, targeting the tumour microenvironment, or using adaptive treatments and immunotherapy. The identification of the most-appropriate strategies and their implementation in the clinic will prove highly challenging and necessitate the adoption of radically new practices for the optimal clinical management of breast malignancies.

Aneuploidy identifies subsets of patients with poor clinical outcome in grade 1 and grade 2 breast cancer

OBJECTIVE

Histological grade is a well-established prognostic/predictive factor in breast cancer. However, mainly within intermediate categories, patients may have unpredictable outcome. We hypothesised whether ploidy status can distinguish different prognostic groups among breast cancer patients with similar tumour grade.

MATERIAL AND METHODS

The study involved 684 patients with invasive breast carcinoma, and median follow-up of 134.5 months. Pathological staging was evaluated according to WHO classification. Tumour differentiation was assessed using the Nottingham grading system. Ploidy was determined prospectively by DNA flow cytometry. Disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method.

RESULTS

There were 179 (26.2%) deaths and 239 (33.3%) disease recurrences. For grading, tumours were classified as follows: 163 (23.8%) G1, 356 (52.1%) G2 and 165 (24.1%) G3, while 389 (56.9%) tumours presented aneuploidy. Ploidy and grading are strongly associated (P < 0.001). Patients with aneuploid G2 tumours showed worse DFS (P = 0.001) and OS (P < 0.001), as well as those with aneuploid G1 tumours in relation to OS (P = 0.013). When a subset analysis was performed in early breast cancer patients (n = 451) with Stage I/IIA of disease, it remained the same significant associations of aneuploid G1 (to OS) and G2 tumours (to DFS and OS) with unfavourable prognosis.

CONCLUSIONS

Aneuploidy identifies subsets of breast cancer patients with G1 and G2 tumours who showed poor clinical outcome. The finding has therapeutic implications, as these patients are potential candidates to risk-adapted adjuvant therapy.

Intratumor heterogeneity: evolution through space and time

Recent technologic advances have permitted higher resolution and more rapid analysis of individual cancer genomes at the single-nucleotide level. Such advances have shown bewildering intertumor heterogeneity with limited somatic alterations shared between tumors of the same histopathologic subtype. Exacerbating such complexity, increasing evidence of intratumor genetic heterogeneity (ITH) is emerging, both within individual tumor biopsies and spatially separated between biopsies of the same tumor. Sequential analysis of tumors has also revealed evidence that ITH temporally evolves during the disease course. ITH has implications for predictive or prognostic biomarker strategies, where the tumor subclone that may ultimately influence therapeutic outcome may evade detection because of its absence or presence at low frequency at diagnosis or because of its regional separation from the tumor biopsy site. In this review, the implications of "trunk and branch" tumor evolution for drug discovery approaches and emerging evidence that low-frequency somatic events may drive tumor growth through paracrine signaling fostering a tumor ecologic niche are discussed. The concept of an "actionable mutation" is considered within a model of clonal dominance and heterogeneous tumor cell dependencies. Evidence that cancer therapeutics may augment ITH and the need to track the tumor subclonal architecture through treatment are defined as key research areas. Finally, if combination therapeutic approaches to limit the consequences of ITH prove challenging, identification of drivers or suppressors of ITH may provide attractive therapeutic targets to limit tumor evolutionary rates and adaptation.

Molecular evolutionary patterns in breast cancer

Geno-phenotypic patterns of pre-invasive and invasive lobular breast cancers and infiltrating ductal carcinomas of low, intermediate, and high grade are reviewed. One of the main differences between lobular breast cancers and ductal carcinomas is the presence of inactivating E-cadherin gene mutations in lobular breast cancers. In many other respects, lobular breast cancers and low-grade ductal carcinomas exhibit similar geno-phenotypic profiles. The development of p53 dysfunction may be a hallmark of infiltrating ductal cancers of intermediate and high grade. Sequential Her-2/neu and ras abnormalities define a subset of aggressive high-grade tumors, and the development of Rb dysfunction may define a separate subset of aggressive ductal cancers. Based on these observations, a branching molecular evolutionary model for the development and progression of breast cancer is proposed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Molecular markers in the diagnosis and staging of breast cancer

Considerable advances have been made in understanding the molecular events that accompany the development of breast cancer. Although our knowledge of these genetic alterations has greatly outpaced clinical applications, many new advances are beginning to have an impact on the diagnosis and staging of breast cancer. Clinical evaluation of estrogen and progesterone receptors and HER2/neu status has become routine. The increasing use of these and other molecular markers promises to help refine diagnoses, define disease subsets, and provide more accurate information about the probable biologic outcome of a given tumor. Studies of molecular markers are also likely to lead to the identification and development of new therapeutic targets. I review the molecular markers currently used in the clinical diagnosis and staging of breast cancer, and discuss other potentially useful markers and assays.

Two-color, cytokeratin-labeled dna flow cytometric analysis of 332 breast cancers: lack of prognostic value with 12-year follow-up

CONTEXT

DNA flow cytometry of breast cancer is a proposed tumor marker of prognostic significance that is of controversial clinical utility because of lack of standardization and confirmatory studies.

OBJECTIVE

To evaluate the prognostic significance of the more informative technique of multiparametric 2-color DNA flow cytometry as recommended by the 1992 DNA Cytometry Consensus Conference.

DESIGN

Three hundred thirty-two breast carcinomas with 7 to 12 years of follow-up were prospectively analyzed as fresh tumors that were mechanically dissociated into whole cell suspensions. These suspensions were dual fluorescence-labeled with propidium iodide (DNA) and antibodies to cytokeratin (epithelium) and leukocyte common antigen (internal leukocyte control) for gated analysis of subpopulations. Multicycle software with histogram-dependent algorithms employing background, aggregate, and debris correction were used in DNA and cell-cycle quantitation. Data were analyzed according to the DNA Flow Cytometry Consensus Conference recommendations.

RESULTS

DNA ploidy and proliferation stratified into 3 categories were not predictive of overall or disease-free survival. Sixty-five percent of tumors were nondiploid, and 35.4% were diploid. Two hundred six tumors were able to be evaluated for synthesis-phase fraction (SPF) analysis, with 74 of 206 cases in the low range (<13.4%), 36.4% in the intermediate range (>13.5 to <25.4%), and 27.6% in the high SPF (>25.5%) category. Aneuploid tumors tended to have a higher SPF. Univariate survival analysis showed prognostic significance of the following: tumor size, stage, TNM components, vascular invasion, nuclear grade, and histologic grade. Only T classification, presence of positive axillary lymph nodes, and distant metastases were significant independent predictors of survival in multivariate Cox regression models. Age and hormone receptor status showed no prognostic significance. Synthesis-phase fraction was significantly correlated with tumor size, stage, T classification, nuclear and histologic grade, presence of estrogen or progesterone receptors, and axillary lymph node status. None of the histologic parameters showed any significant association with DNA aneuploidy, except for high nuclear and histologic grade and the absence of estrogen receptors.

CONCLUSIONS

Despite the use of state-of-the-art processing and flow cytometry analytic techniques, DNA ploidy and proliferation measurements were not predictive of survival in any stage of breast cancer. However, select histopathologic parameters and TNM stage were significant predictors of survival in univariate and multivariate analyses. We conclude that DNA ploidy and proliferation measurements do not provide significant prognostic information for clinicians to integrate into therapeutic decision making for patients with breast cancer.

Evaluation of numerical abnormalities of chromosomes 1 and 17 in proliferative epithelial breast lesions using fluorescence in situ hybridization

Our aim was to investigate the putative role of chromosome abnormalities of chromosomes 1 and 17 in the process of breast carcinogenesis. Numerical abnormalities of chromosomes 1 and 17 were investigated using fluorescence in situ hybridisation (FISH) in a series of 16 primary invasive breast carcinomas associated with intraductal proliferative epithelial lesions. Chromosome 1 aneusomy was detected in 55.6% of ductal hyperplasia (DH), 81.8% of ductal carcinomas in situ (DCIS) and 87.5% of invasive ductal carcinomas (IDC). Chromosome 17 aneusomy was not detected in the cases of DH and was present in 90.9% of DCIS and in 87.5% of IDC. Simultaneous aneusomy of chromosome 1 and 17 was found in 81.8% of DCIS and in 75.0% of IDC. Our results showed that the number of chromosome 1 and 17 copies increases from normal epithelium to invasive cancer. The numerical abnormalities of chromosome 1 were already detected in DH, suggesting that a gain in the copy number of chromosome 1 may be involved early in breast carcinogenesis.

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

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

Short-term significance of DNA ploidy and cell proliferation in breast carcinoma: a multivariate analysis of prognostic markers in a series of 308 patients

AIM

To determine the importance of tumour DNA ploidy and cell proliferation, as measured by the S phase fraction (SPF), in relation to other established clinicopathological indicators of prognosis in breast cancer.

METHODS

A prospective study of 308 patients. Tumours were staged following the TNM system criteria and were classified according to the histological type and grade. DNA flow cytometry was performed on fresh/frozen samples stained with propidium iodide. Hormone receptors were analyzed by immunocytochemistry. A Cox proportional hazards regression model was used for statistical evaluation of the prognostic factors.

RESULTS

Median follow up time was 39.6 months (range 3 to 84). A DNA diploid pattern was found in 134 tumours (43.5%) and aneuploid in 174 (56.5%). Median SPF value was 6.1% (range 1% to 27.8%). DNA ploidy and SPF were strongly correlated (p < 0.001), and both were related to histological type (p < 0.001), grade of differentiation (p < 0.001), tumour size (p = 0.006 and p = 0.002), and hormone receptor activity (p < 0.001). DNA ploidy was also related to node status (p = 0.022), but SPF was not. In univariate analysis, there were significant correlations between disease-free survival and age, histological grade, tumour size, node status, DNA ploidy, SPF, and hormone receptor activity; age, tumour size, node status, DNA ploidy, and hormone receptors were predictors of overall survival. In multivariate analysis, only node status (p = 0.001) and DNA ploidy (p = 0.006) retained independent prognostic significance in relation with overall survival, while node status (p < 0.001) and SPF (p < 0.001) were predictors of disease-free survival. DNA ploidy and SPF continued to predict disease-free and overall survival in lymph node positive (pN1) patients but not in the lymph node negative (pN0) group.

CONCLUSIONS

DNA ploidy and SPF are strongly intercorrelated and have independent prognostic value for predicting the short term clinical outcome of breast carcinoma patients.

Breast carcinoma tumor characteristics in black and white women

BACKGROUND

A significant disparity in mortality rates exists between black and white patients with breast carcinoma. This study was designed to compare breast carcinoma tumor characteristics by race and to examine the possible reasons for these differences.

METHODS

Female patients with an initial diagnosis of breast carcinoma between January 1, 1985 and December 31, 1993 were selected from the Yale-New Haven Hospital Tumor Registry for this retrospective cohort study. All black patients were eligible and white patients were selected randomly and matched to each black patient by year of diagnosis. Data were gathered from multiple sources including the hospital, the Connecticut Tumor Registry, and the U. S. Census. All pathology specimens were reviewed at Yale-New Haven Hospital.

RESULTS

The final cohort had 100 black and 300 white patients. The black patients tended to be younger than white patients at the time of diagnosis (mean age 55 years vs. 60 years; P = 0.001). A significant racial difference was noted in eight tumor characteristics: stage, size of the tumor, lymph node status, presence of necrosis, vascular/lymphatic invasion, ductal carcinoma in situ, perineural invasion, and progesterone receptor status. Although income, medical insurance coverage, and method of tumor detection explained some pathology differences, black patients still were more likely to have necrosis and a larger tumor size, even after adjustment.

CONCLUSIONS

Black patients with breast carcinoma tend to be diagnosed at a younger age and in a few important respects have different tumor characteristics compared with white patients, even after controlling for income, medical insurance coverage, and method of tumor detection after screening mammography. These differences may have etiologic and clinical implications.

Ploidy level determination and quantitative chromatin pattern description in pregnancy-associated breast cancers

The present study deals with the characterization of hormone-sensitivity in pregnancy-associated breast cancers (PBCs). This characterization was carried out in 22 PBCs as opposed to 88 non-pregnancy-associated breast cancers (NPBCs). For this study, we used the digital cell image analysis of Feulgen-stained nuclei to assess the type of hormone-sensitivity. In a previous study it was demonstrated that the chromatin pattern in breast cancers is related to the amounts of estrogen receptors they contain. Our results demonstrated that the quantitative description of the chromatin pattern by means of 15 parameters (relating to morphometric, densitometric, and textural features) made it possible to identify typical cell nuclei populations in the PBC and NPBC groups. The use of specific statistical analyses (principal-components and discriminant) made it possible to quantify the proportion of each cell nucleus type in the PBCs. Furthermore, of the 22 PBCs under study, 13 contained a large majority of cell nuclei whose chromatin pattern was characteristic of hormone-sensitive cells, while 5 cases contained a large majority of typically hormone-insensitive ones. The remaining 4 cases contained a relatively similar proportion of typically hormone-sensitive and insensitive cell nuclei. The quantitative chromatin pattern description thus made it possible to characterize the hormone-sensitivity level in PBCs, whereas DNA ploidy level determination did not enable any such characterization to be carried out. The chromatin pattern assay described here, which enables hormone-sensitive pregnancy-associated breast cancers to be identified from hormone-insensitive ones independently from biochemical assays, should help the physician regarding therapy adaptation.

Histopathology grading in small breast cancers < or = 10 mm--results from an area with mammography screening

Histopathological malignancy grading using the Bloom-Richardson classification of ductal cancers was performed for 248 invasive ductal breast cancers < or = 10 mm operated 1978-1985. There were significantly more grade 1 lesions in the prevalence screening round. Grade 3 was correlated with aneuploidy, higher S-phase (SPF), and more receptor negative tumours. There were also significantly more positive lymph nodes in grade 3 lesions, 18% compared to 5% and 12% respectively for grades 1 and 2 (p < 0.05). In life table analysis for survival, when the high risk group of grade 3 lesions was compared to the grade 1 and 2 lesions combined, five-year disease-free survival was 84.6% vs. 99.1% (p < 0.001). With good training and care from the pathologist, malignancy grading seems useful for prognostication of eventual recurrence and death. In tumours 10 mm or smaller only grade 3 lesions need to be included in follow-up systems and should probably have adjuvant treatment. Malignancy grading is especially good in small ductal breast cancers where grading can always be performed while other prognostic determinations are hampered by shortage of material. Lymph node positivity is also low in this group.

Intratumoral heterogeneity in primary breast carcinoma: study of concurrent parameters

BACKGROUND AND OBJECTIVE

Intratumoral heterogeneity for prognostic factors (ploidy, proliferation, hormone receptor positivity) has been demonstrated in primary breast carcinoma by both flow cytometric and image analysis methods. Previously, heterogeneity in tumors had been demonstrated for only singular parameters. Our objective, using maps of tumors in which discrete regions can be analyzed simultaneously for DNA index (DI) and proliferative activity, was to demonstrate heterogeneity with respect to two parameters and to determine whether any interparametric relationships existed.

METHODS

We analyzed 25 cases of archived, paraffin-embedded breast carcinoma (ductal) for Feulgen stain DNA analysis and MIB-1 immunohistochemistry using the CAS 200 Image Cytometer. For each tumor, four discrete regions were analyzed including tumor-host tissue interface sectors.

RESULTS

Of 25 cases, 19 (76%) were homogeneously diploid or near-diploid aneuploid, and 6 (24%) were heterogeneous. Within the heterogeneous group, all cases had at least one diploid and one or more aneuploid populations from separate discrete regions. Five of six DI heterogeneous tumors displayed diploid values for the overall measurements of the respective tumors, based on analysis of 200 or more nuclei. Eight of 25 cases (32%) showed significant measurable variation for MIB-1 proliferative activity in various sectors of tumor. All the MIB-1 heterogeneous tumors, with one exception, were homogeneously diploid.

CONCLUSIONS

These findings demonstrate that (1) heterogeneity is present with respect to DI and proliferative activity in breast carcinoma and is relatively common, (2) tumors homogeneous for one parameter may be heterogeneous for another, and (3) heterogeneity for proliferative activity is more common in homogeneously diploid tumors than in heterogeneous/aneuploid tumors.

Quantitative image cytometry of infiltrating ductal carcinoma: comparison with prognostic parameters and reproducibility of histological grade

Quantitative image cytometry was used to compare 18 parameters relating to ploidy, nuclear area, and chromatin texture to axillary lymph node status, tumor size, and histological grade for 34 infiltrating ductal carcinomas, each of which had been graded independently by each of six surgical pathologists. Zinc formalin-fixed, paraffinembedded tumors were assessed using the Elston and Ellis modification of the Bloom and Richardson histological grading scheme. When axillary lymph node-negative tumors were compared with those involving four or more nodes, % 2 c (diploid) cells, nuclear area, and eight of 12 chromatin texture parameters showed statistically significant differences. Carcinomas < 2 cm had more % 2 c (diploid) cells and fewer % > 4 c (hypertetraploid) cells than larger neoplasms. For tumors having nuclear pleomorphism score two versus those with score three, nuclear area, four of five parameters related to ploidy level, each of five parameters related to run-length matrix features and one of four co-occurrence matrix features showed significant differences. Nearly all of these cytometric parameters also showed significant differences for histological grade and mitotic count, which was strongly correlated with nuclear pleomorphism. In examining the cytometric parameters in relation to the interobserver reproducibility of histological grade and its components, the largest number of statistically significant parameters related to the nonreproducibility of nuclear pleomorphism. The findings indicate that as the grade of infiltrating ductal carcinomas increases, there are fewer % 2 c (diploid) cells and more % > 4 c (hypertetraploid) and % > or = 5 c (polyploid) cells. In addition, the cells of high grade tumors have larger nuclear areas and more small and large dense chromatin clumps, which increase in such number that they tend to join together. When compared with the cytometric parameters, nuclear pleomorphism is the most sensitive component of grade to nonreproducibility.

Nuclear grading and flow cytometric DNA pattern in fine-needle aspirates of primary breast cancer

Fine-needle aspiration (FNA) biopsy is increasingly used in the diagnosis and biological characterization of breast carcinomas in patients who receive preoperative chemotherapy. In this context, nuclear cytologic grade supplemented by DNA content could play an important role in the morphologic assessment of breast cancer. In this study, DNA ploidy pattern, analyzed by flow cytometry on FNAs from 92 primary breast carcinomas, was related to cytologic nuclear grade. Twenty-seven samples were cytologic grade 1, 33 were grade 2, and 32 were grade 3. Ploidy correlated with cytologic nuclear grade (P = 0.0001). Thirty percent of grade 1, 55% of grade 2, and 84% of grade 3 tumors were DNA aneuploid. For 30 of the 92 FNAs, it was possible to compare nuclear cytologic grade with the corresponding histologic grade using the Scarff, Bloom, and Richardson system. A high concordance (80%) between nuclear grade on FNAs and histologic grade was found. DNA flow cytometry in combination with nuclear cytologic grade might represent additional information for the characterization of breast cancer diagnosed by FNA.

Tumorigenesis of rat mammary epithelial cells by N-nitroso-N-methylurea in an in vitro system: characterization of the microtumors

Chemical carcinogenesis is a lengthy process that involves the rather loosely defined stages of initiation, promotion, and progression. Several model systems of mammary carcinogenesis have been designed to elucidate the mechanisms of chemical carcinogenesis. Most of these systems have included animal models. While organ specific chemical carcinogenesis can be initiated in these systems, the subsequent stages of promotion and progression are difficult to study in detail. Investigations on in vitro carcinogenesis have shown transformation of mammalian cells in culture; the transformational event, however, is difficult to discern within the monolayer culture. We have recently reported the development of an in vitro carcinogenesis system that allows both the initiation as well as the progression of mammary cells in a collagen gel matrix culture system. The cells transformed by a chemical carcinogen develop into discernible microtumors within the three dimensions of a collagen gel culture. Isolation of these microtumors from the collagen gel and subsequent culture in monolayer has produced cells capable of colony formation in soft agar. The present study further characterizes these microtumors originated in vitro by analysis of cell growth kinetics versus parallel control cells. In addition, flow cytometric and cytogenetic studies have been performed to investigate the chromosomal stability of these cells. It was also observed that the microtumors, produced in vitro from mammary epithelial cells of an inbred strain of rats, show the ability to form tumors upon transplantation into the fat pad of syngeneic hosts.

New aspects in the histological diagnosis of breast carcinoma

The wide use of mammographic screening and breast conservation surgery, as well as the introduction of a variety of new morphological and immunohistological assessment methods, has markedly changed the practice of breast histopathology. These changes have led to the emergence of new macroscopic and microscopic interpretation demands and difficulties. It is hoped that in the future the role played by diagnostic histopathology in the management of breast cancer will continue to be refined, so that it can provide more detailed information about individual tumors that will help in deciding the most likely approach to obtain the best treatment results.

DNA flow cytometry of canine mammary tumours: the relationship of DNA ploidy and S-phase fraction to clinical and histological features

The DNA ploidy status and S-phase fraction (SPF) of benign proliferative lesions (BPL) and malignant tumours (MT) in the mammary glands of dogs were determined by flow cytometric analysis and the results were related to their clinical and histological features. Seven (14.3 per cent) of 49 BPL and 16 (48.5 per cent) of 33 primary MT had aneuploid G0,1 peaks (P < 0.001). Hypodiploid G0,1 peaks were found in one BPL and in five primary MT. The DNA ploidy status of primary MT was not found to be associated with their size, nodal status, grade of histological malignancy or nuclear grade. In several cases there was intra-tumour heterogeneity in ploidy status independent of histological heterogeneity. The SPF was significantly higher in 27 primary MT than in 45 BPL when diploid and aneploid cases were combined for comparison (P < 0.05), but not when only diploid cases were compared. Among the primary MT the SPF was higher in aneuploid than in diploid tumours (P < 0.05) and it was higher in five MT from five dogs with regional disease than in 22 MT from 19 dogs with local disease (P < 0.05). The SPF was positively correlated with the grade of histological malignancy (P < 0.05) but not with nuclear grade.

The histologic grading of cancer

BACKGROUND

The histologic grade of a tumor provides prognostic information in addition to that provided by stage of disease. Poorly differentiated tumors are known to pursue a more aggressive course than their well differentiated counterparts.

METHODS

The frequency of grading and the relationship of grade to outcome was investigated for 793,649 cases of cancer from 15 anatomic sites as recorded in the Surveillance, Epidemiology, and End Results Program.

RESULTS

For all cancers, the frequency of grading increased from 1973 to 1987 and varied by anatomic site and histologic type. Survival decreased with advancing grade, and within each stage, grading separated cases into at least three distinct prognostic subgroups. For some cancers, regional stage cases assigned Grade 1 or 2 had higher survival rates than did localized stage cases assigned Grade 3 or 4. Therefore, grading allowed the identification of high and low risk subgroups within each stage grouping.

CONCLUSIONS

The tumor grade was a strong prognostic indicator for cancers of the urinary bladder, endometrium, and prostate--sites most often graded by pathologists. The histologic grade was also an important determinant of outcome for cancers of the brain, soft tissue, and breast; however, only a small percentage of these tumors were graded. The results are important because no common criteria for grading were established among the many contributing pathologists. Therefore, observer variation did not alter the known relationship of histologic grade to outcome. This review demonstrates that the histologic grade is a strong predictor of outcome that refines the prognostic information provided by the stage of disease.