Gene expression profiling identifies responsive patients with cancer of unknown primary treated with carboplatin, paclitaxel, and everolimus: NCCTG N0871 (alliance).

BACKGROUND: Carboplatin (C) and paclitaxel (P) are standard treatments for carcinoma of unknown primary (CUP). Everolimus, an mTOR inhibitor, exhibits activity in diverse cancer types. We did a phase II trial combining everolimus with CP for CUP. We also evaluated whether a gene expression profiling (GEP) test that predicts tissue of origin (TOO) could identify responsive patients. PATIENTS AND METHODS: A tumor biopsy was required for central confirmation of CUP and GEP. Patients with metastatic, untreated CUP received everolimus (30 mg weekly) with P (200 mg/m(2)) and C (area under the curve 6) every 3 weeks. The primary end point was response rate (RR), with 22% needed for success. The GEP test categorized patients into two groups: those having a TOO where CP is versus is not considered standard therapy. RESULTS: Of 45 assessable patients, the RR was 36% (95% confidence interval 22% to 51%), which met criteria for success. Grade ≥3 toxicities were predominantly hematologic (80%). Adequate tissue for GEP was available in 38 patients and predicted 10 different TOOs. Patients with a TOO where platinum/taxane is a standard (n = 19) tended to have higher RR (53% versus 26%) and significantly longer PFS (6.4 versus 3.5 months) and OS (17.8 versus 8.3 months, P = 0.005), compared with patients (n = 19) with a TOO where platinum/taxane is not standard. CONCLUSIONS: Everolimus combined with CP demonstrated promising antitumor activity and an acceptable side-effect profile. A tumor biomarker identifying TOO may be useful to select CUP patients for specific antitumor regimens. CLINICALTRIALSGOV: NCT00936702.

Tamoxifen suppresses histologic progression to atypia and DCIS in MCFIOAT xenografts, a model of early human breast cancer.

We evaluated the effects of tamoxifen on the growth and progression of MCFIOAT xenografts, an estrogen responsive model of human breast tumor progression, in which cells are injected orthotopically into the mammary fat pad of female nude mice. At 10 weeks following implantation, histologic sections of each graft were evaluated microscopically for histologic lesions analogous to human breast tumor progression, graded as simple hyperplasia, complex hyperplasia, atypical hyperplasia, ductal carcinoma in situ and invasive carcinoma. Three out of five xenografts in (endocrine intact) control animals progressed to atypical hyperplasia, one progressed to ductal carcinoma in situ and one to invasive carcinoma. The latter two control grafts also contained foci of putative precursor lesions (i.e. atypical hyperplasia and in situ carcinoma, respectively). Tamoxifen supplemented xenografts (N= 17) were uniformly smaller than controls, but contained invasive carcinoma in a similar proportion (4/17, 24%). However, none of these grafts exhibited ductal carcinoma in situ and only one contained atypical hyperplasia. Most grafts in tamoxifen supplemented animals (10/17, including all four with carcinomas) showed complex hyperplasia, which typically dominated the graft. We conclude that tamoxifen selectively inhibits the appearance or growth of preinvasive index lesions. Development of malignancy in the absence of such precursors, though, implies selection for alternative histogenetic pathways as a result of endocrine manipulation.

Centrally necrotizing carcinomas of the breast: a distinct histologic subtype with aggressive clinical behavior.

Most breast carcinomas exhibit ductal differentiation. However, recognition of less common histologic patterns provides clinically useful data. This report describes a distinctive subtype of breast carcinoma that we have termed "centrally necrotizing carcinoma" (CNC; in this study, N = 34), which is characterized by an unusual and aggressive natural history. Centrally necrotizing carcinomas are composed of well-circumscribed, unicentric nodules with extensive central necrosis that are surrounded by a narrow rim of viable high-grade tumor cells. These tumor cells show minimal ductal differentiation (i.e., tubule formation), but are usually associated with focal ductal carcinoma in situ. The mean age of the patients in this study was 57.5 +/- 11.6 years, and the mean tumor size was 2.5 +/- 1.2 cm. Twenty-eight percent of the patients had positive axillary lymph nodes (mean number of lymph nodes involved, 2.1 +/- 1.2). Ninety-four percent of cases were negative for estrogen and progesterone receptors. In 21 patients (62%), local and/or distant recurrences developed (median time to recurrence, 16.2 months), and, to date, 20 have died from breast cancer (median time to death, 22.5 months). Progression of disease (defined as the development of either a recurrence or death resulting from disease) occurred in 24 patients (71%). Comparison with a set of 26 poorly differentiated ductal carcinomas with (nonextensive, patchy) necrosis matched for age, tumor size, and lymph node status showed a significantly worse progression-free survival rate for the CNC group (p < 0.004). We conclude that CNC is an uncommon but readily identifiable subtype of breast carcinoma and is characterized by early systemic metastasis and an accelerated clinical course.

Determination of Her-2/Neu status in breast carcinoma: comparative analysis of immunohistochemistry and fluorescent in situ hybridization.

Her-2/neu (H2N) status in breast carcinoma has been considered a prognostic factor that may have therapeutic implications; however, the correlation between H2N overexpression and gene amplification has not been completely defined. A consecutive series of ductal carcinomas (34 invasive and 7 in situ) were analyzed by fluorescent in situ hybridization for H2N gene and chromosome 17 copy number using touch preps of intact cells and by immunohistochemistry, using three different commercial antibodies to H2N protein (Zymed, clone 31G7; Ventana, clone CB11; and Dako, polyclonal) in corresponding formalin-fixed, paraffin-embedded tissue sections. Gene amplification was classified as unequivocal if more than five signals were present in more than 80% of the counted nuclei and absent if more than 80% of the nuclei counted contained two or fewer gene copies. Cases that did not fulfill the above criteria were considered equivocal for amplification. Immunostaining was classified as follows: 0 = no staining; 1+ = faint, incomplete membranous pattern; 2+ = moderate, complete membranous pattern; 3+ = strong membranous pattern. Of the 34 invasive tumors, 10 (29%) had unequivocal gene amplification. Furthermore, all had more than 10 copies of the gene in more than 60% of the counted nuclei. An additional nine cases (26%) had equivocal amplification, which was usually the result of chromosome 17 aneuploidy (seven of nine) or heterogeneity. With the Zymed and Dako antibodies, all tumors with 3+ staining had unequivocal gene amplification and all cases with 2+, 1+, or 0 staining were negative or equivocal for gene amplification. With the Ventana antibody, all cases with 3+ staining had unequivocal gene amplification, but two cases with unequivocal amplification by fluorescent in situ hybridization exhibited 1+ staining. Moderate (2+) H2N staining was observed in one case, three cases, and five cases with the Ventana, Dako, and Zymed reagents, respectively, and did not correlate with H2N gene copy number. Discordance between H2N and chromosome 17 copy number was not a useful means of defining amplification. Two cases of ductal carcinoma in situ with the Zymed antibody and two with the Dako antibody showed 3+ staining despite lack of unequivocal gene amplification. We conclude that (1) strong H2N immunostaining is highly associated with gene amplification, although there is minor variation in sensitivity between different antibodies; (2) a subset of breast carcinomas (3 to 15%) demonstrate moderate H2N staining without evidence of amplification, and it is unclear whether they represent highly sensitive staining or are a subset of cases that show overexpression without amplification; (3) gene amplification, as detected by fluorescent in situ hybridization, is associated with at least 10 gene copies per nucleus, and lower gene copy duplication (3 to 4/nucleus) is frequent, usually the result of chromosome 17 polysomy, and not associated with high-level overexpression; (5) overexpression of H2N without amplification may be more frequent in ductal carcinoma in situ, implying a different role in the biology of preinvasive versus invasive neoplasm.

Clinicopathologic significance of ductal carcinoma in situ in breast core needle biopsies with invasive cancer.

To assess whether the presence and amount of intraductal component (IC) in diagnostic needle core biopsies (NCB) is predictive of an extensive IC (EIC), the authors evaluated 50 invasive ductal carcinomas diagnosed with NCB, and then excised via lumpectomy, with regard to the extent of IC in both the NCB and subsequent lumpectomy specimen. These parameters were compared with each other and with the lumpectomy margin status. Extent of IC in the NCB was evaluated by dividing the number of ducts that contained IC by the total number of tissue cores. A ratio of more than 0.5 was considered EIC (EICc). IC extent in the lumpectomy was established by estimating the percentage of the tumor corresponding to IC and was considered extensive (EIC(L)) if more than 25% and if there was presence of IC away from the invasive tumor. The mean size of resected tumors was 1.6 +/- 0.7 cm. In 29 cases (58%) there was no IC in the NCB (NegICc), 11 cases (22%) exhibited nonextensive IC (NEICc), and 10 cases (20%) demonstrated EICc. A total of 7%, 36%, and 70% of the NegICc, NEICc, and EICc cases respectively had EIC(L)(p < 0.0001). The presence of EIC(L) correlated significantly with close or positive margin status for in situ disease (EIC(L) positive, 12 of 13 [92%] vs EIC(L) negative, 11 of 37 [30%]; p = 0.004). None of the NegICc, 27% of NEICc, and 40% of EICc had a positive margin for in situ neoplasm in the lumpectomy specimen (p = 0.004), and 24%, 18%, and 50% had positive margins for invasive neoplasm (p = not significant). The authors conclude that EICc predicts EIC(L) and constitutes a risk factor for positive lumpectomy margin status-particularly for in situ tumor. EICc may thus be of clinical value in identifying a subset of patients that requires a wider local excision.

Analysis of chromosome aneuploidy in breast carcinoma progression by using fluorescence in situ hybridization.

Nonisotopic fluorescence in situ hybridization by using alpha satellite centromeric probes was performed on intact tissue sections of 12 breast carcinomas to compare the pattern of aneuploidy for chromosomes 7, 8, 16, and 17 between foci of residual in situ carcinoma (DCIS) and a representative area of coexisting invasive neoplasm. Most hybridization pairs (58%) showed a gain in chromosomal copy number between the in situ and corresponding invasive area, whereas 29% showed no apparent change and 13% showed loss in copy number. Hybridizations from areas of invasive carcinoma, thus, were more frequently characterized by tumor cells with trisomy/polysomy (78%) than neoplastic cells from residual DCIS (50%) and less frequently characterized by cells with monosomy (10% versus 16%, p = 0.01). Even when DCIS cells exhibited chromosome trisomy, 65% of hybridizations demonstrated a significantly greater proportion of trisomic cells in the corresponding invasive population. The hybridization pairs (n = 7) initially showing apparent loss in chromosome copy number from in situ to invasive growth were all from two cases that demonstrated morphologic heterogeneity. Enumeration of cells from histologically distinct areas of these cases revealed different patterns of aneusomy, in keeping with karyotypic diversity. However, comparison of histologically similar areas of DCIS and invasive neoplasm demonstrated a pattern of chromosome copy gain with invasive growth, similar to morphologically homogeneous tumors. We conclude that invading cells in breast carcinomas differ from residual in situ populations with respect to degree of chromosome aneuploidy and that tumor progression from preinvasive to an invasive phenotype in human breast carcinoma is characterized by a significant increase in the degree of genetic instability. The observed pattern of chromosome copy number gain, moreover, is consistent with a common cellular level genetic mechanism underlying early breast tumor progression.

Clinicopathologic analysis of microscopically invasive breast carcinoma.

Breast biopsy or mastectomy cases having diagnoses of carcinoma in situ with "microinvasion," "minimal invasion," "focal invasion," or "suggestive of invasion" were reviewed and all histologically identified foci of invasive disease from each case were measured using an ocular micrometer. Cases in which any single focus of invasion was greater than 5 mm or the added size of separate invasive foci exceeded 10 mm were excluded, resulting in a study group of 75 patients. Invasive neoplasm was present in the initial biopsy in 69 of 75 cases (92%); however, residual invasive neoplasm was found in the subsequent lumpectomy/mastectomy from 14 of these (20%). In 59% of cases, two or more histologically separate foci of invasion were identified. Invasive foci consisted of isolated cells or cell clusters, each less than 1 mm (microfocal invasion), in 33% of cases. In 12 cases, the sum of individual invasive foci was 5 to 10 mm. Axillary lymph nodes (LN) from 5 of 69 patients (7%) contained metastatic carcinoma (four cases, one LN positive; one case, two LN positive). The cumulative sizes of all invasive foci in the LN-positive group were microfocal invasion (one case), 0.6 mm (one case), 1.1 mm, 2.5 mm, and 5.8 mm. The difference in frequency of axillary node metastasis between tumors with microfocal and measurable invasion (4.3% v 8.6%) was not statistically significant. Follow-up data were available on 55 cases (mean interval, 66.1 months). One (node-negative) patient had duct carcinoma in situ recurrence in the same breast 4 years after initial treatment. Another (with unknown node status) developed an axillary lymph node metastasis 13 months after initial treatment (96% disease-free survival). We conclude that microscopic stromal invasion in breast carcinoma, at least in the setting of significant in situ component, is often initiated from multiple foci. Patients with microscopically invasive breast carcinoma have a small but significant risk of axillary metastases, although a highly favorable survival.

Galectin-3 and L1 retrotransposons in human breast carcinomas.

Galectin-3 is a galactoside binding protein found at elevated levels in a wide variety of neoplastic cells and thought to be involved in cognitive cellular interactions during transformation and metastasis. Previously, we have shown that introduction of human galectin-3 (Mr 31,000) cDNA into the human breast cancer cells BT-549 which are galectin-3 null and non-tumorigenic in nude mice resulted in the establishment of four galectin-3 expressing clones. Three of them acquired tumorigenicity when inoculated in the mammary fat pad of nude mice. Here, we questioned what is the molecular difference between the nude mouse tumorigenic and non-tumorigenic galectin-3 expressing BT-549 cell clones. Differential display analysis and Northern blotting revealed that, unlike the tumorigenic clones, neither the parental cells nor the non-tumorigenic clone expressed a 6.5 Kb transcript. A 607 bp PCR (polymerase chain reaction) product from the differentially displayed mRNA revealed a 93% sequence homology with the human L1 retrotransposon previously suggested to play a role in the pathobiology of some breast cancers. In addition, we show that the two gene products, i.e., galectin-3 and L1, are co-expressed in breast carcinoma specimens and in other nude mouse tumorigenic cell lines.

Direct action of estrogen on sequence of progression of human preneoplastic breast disease.

We have used the MCF10AT xenograft model of human proliferative breast disease to examine the early effects of estradiol exposure on morphological progression of preneoplastic lesions and to define the step(s) in the morphological sequence at which estrogen may act. The effects of estradiol on neoplastic progression of estrogen-receptor-positive MCF10AT cells in the orthotopic site were examined in ovariectomized female nude mice that received subcutaneous administration of implants of 17beta-estradiol or placebo pellets. At 10 weeks, histological analysis of the lesions derived from the estrogen-supplemented group revealed that 92% of lesions displayed histological features of atypical hyperplasia, carcinoma in situ, or invasive carcinoma, and the remaining 8% exhibited histological features of moderate hyperplasia. These highly proliferative lesions are in marked contrast to the control group in which 60% of samples displayed no evidence of hyperplasia. In contrast with control xenografts, estrogen-exposed xenografts demonstrated extensive areas of papillary growth, adenosis-like areas, prominent host inflammatory infiltration, and angiogenesis. Our results suggest that estrogen exerts a growth-promoting effect on benign or premalignant ductal epithelium by enhancing 1) the frequency of lesion formation, 2) the size of lesions, 3) the speed of transformation from normal/mild hyperplasia to those with atypia, 4) the degree of dysplasia, and 5) angiogenesis.

Histopathologic and flow-cytometric analysis of neoplastic and benign "background" tissue in breast carcinoma resections.

Two-color, multiparametric synthesis phase fraction (SPF) analysis of cytokeratin-labeled epithelial cells was flow cytometrically performed on both benign (SPFb) and malignant tissue samples (if available, SPFt) from 132 mastectomy/lumpectomy specimens. These data were then correlated with clinicopathologic features, including (1) tumor differentiation, (2) the proportion of tumor comprised of duct carcinoma-in situ (DCIS), and (3) the histology of accompanying benign breast tissue, classified by predominant microscopic pattern as intact, normal terminal duct lobular units (NTDLU, 34% of cases), atrophic (AT, 33% of cases), proliferative fibrocystic (PFC, 26% of cases), and non-proliferative fibrocystic (NPFC, 7% of cases). SPFt was inversely correlated with extent of DCIS (DCIS = 0-20% tumor volume - 12.7% mean SPFt, vs. DCIS >20% tumor volume - 6.4% mean SPFt, p = 0.001). SPFt also correlated with the histology of background benign breast tissue (NTDLU - 14.8% mean SPFt vs. AT - 6.9% mean SPFt vs. PFC - 12.7% mean SPFt, p = 0.05) but it did not correlate with patient age or SPFb (overall mean = 0.73%). SPFb was correlated with patient age (>56 yr - 0.59% mean SPFb vs. <56 yr - 0.84% mean SPFb, p = 0.02), with background histology (NTDLU - 1.1% mean SPFb vs. AT - 0.43% mean SPFb vs. PFC - 0.70% mean SPFb, p < 0.02) and with the grade of the neoplasm (well/moderate - 0.58% mean vs. poorly differentiated - 0.85% mean, p = 0.04). Patients having a background of PFC were significantly older than patients with a background of NTDLU (45.2 yr vs. 60.2 yr, p = 0.01). We conclude: (1) breast carcinomas arising from a background of more actively cycling pre-involutional or proliferative fibrocystic epithelium have a greater proliferative fraction than tumors arising from atrophic epithelium, implying that the differentiation status of target cells may impact the effect(s) of tumorigenic events; (2) PFC may represent delayed, abnormal or interrupted involution rather than a hyperproliferative state relative to NTDLU, suggesting that it facilitates neoplasia by extending the period of exposure to promoter agents such as endogenous hormones, and (3) lower SPFt in breast neoplasia with more abundant "residual" DCIS may reflect a lengthier pre-invasive disease interval due to intrinsically less aggressive phenotype.

Clinicopathologic and interphase cytogenetic analysis of papillary (chromophilic) renal cell carcinoma.

Trisomy 7 and 17 with deletion of Y is typical of papillary renal cell adenoma (PRCA), and additional alterations occur in the putative genetic progression toward papillary renal cell carcinoma (PRCC). Our study correlated aneuploidy with clinicopathologic features in PRCCs. We used fluorescence in situ hybridization to assess copy number for chromosomes 7, 8, 10, 12, 16, 17, and Y in 16 PRCCs and surrounding benign tubular parenchyma from 15 patients by use of alpha satellite (centromere) probes on deparaffinized tissue sections. We then compared the pattern of monosomy/nullisomy or trisomy/polysomy/hemidisomy to clinicopathologic parameters. Nine tumors (58% Group 1) showed the numeric aberrations typical of PRCAs and PRCCs, with gains of 7 and 17 and loss of Y. We also identified four trisomies of 12 and 16 and one of 8 in Group 1. The remaining seven cases (Group 2) were cytogenetically atypical. Two displayed borderline loss of chromosome 7, although trisomy 17 was present in both. Five had trisomy 7, but none exhibited chromosome 17 alterations, and two exhibited a gain of Y. Neoplasms in Group 2 were less often multicentric than were Group 1 tumors, and they contained foamy macrophage infiltrates less often. One chromophilic carcinoma with abundant clear cells and another with oncocytic features exhibited Group 2 chromosomal profiles. One patient (nuclear grade 4) died from disease, and 14 had no evidence of carcinoma at the last follow-up. We concluded that PRCCs represent a histologically and genotypically heterogeneous group of tumors. If PRCAs consistently exhibit +7, +17, and -Y, it is uncertain whether PRCCs always evolve directly from such lesions. The presence of genotypic heterogeneity might reflect histologic variants of PRCCs, which overlap with other types of RCC. PRCC is generally an indolent neoplasm, despite a high frequency of chromosomal aneuploidy.

Clinicopathologic analysis of amphiregulin and heregulin immunostaining in breast neoplasia.

We observed no association between neoplastic epithelial immunostaining for either amphiregulin (AR) or heregulin (HRG) and presence of ER, EGFR/ERBB-2 overexpression, nodal status, or disease recurrence in 34 breast carcinomas. However, stromal cell staining for both correlated with outcome; 29% of stromal cell AR - cases recurred vs. 85% for AR + cases (p = 0.001), and 41% of stromal cell HRG - cases recurred vs. 82% of HRG + cases (p = 0.01). We conclude that both HRG and AR have significant biologic roles in breast carcinoma growth or progression via mediation of host-tumor interactions which favor aggressive tumor behavior.

Clinicopathologic analysis of k-ras, p53, and ERBB-2 gene alterations in pulmonary adenocarcinoma.

We compared PCR-SSCP detected mutations of k-ras (codon 12) and p53 (exons 5-8) to ERBB-2 immunostaining and clinicopathologic features in 31 pulmonary adenocarcinomas. There were nine tumors (29%) with mutations of ras, 13 tumors (42%) with mutations of p53, and three tumors (10%) with mutations of both. Neither k-ras nor p53 mutation alone was significantly correlated with stage, grade, or survival. However, tumors with k-ras mutation were more frequently associated with an invasive growth pattern, defined as > 30% tumor volume composed of infiltrative nests of cells within desmoplastic, scar-like stroma [< 30% volume invasive--1/13 (8%) with k-ras mutation vs. > 30% volume invasive--8/18 (44%) with k-ras mutation, p = 0.02]. Accordingly, k-ras mutations were observed in only 1/9 (15%) predominantly bronchoalveolar or papillary tumors versus 6/22 (28%) acinar or scar carcinoma tumors. All three patients with combined k-ras/p53 mutation had advanced stage (III/IV) at presentation and died of the disease. In contrast to k-ras, staining for ERBB-2 was more frequently observed in tumors exhibiting < 30% invasive growth pattern (12/13, 92%) than in tumors with > 30% invasive growth pattern (10/18, 56%, p = 0.03). ERBB-2 immunoreactivity was more frequent in Stage I (14/15, 93%) versus Stage II-IV (8/16, 50%) cases, but it did not correlate with survival. There was a reciprocal relationship between k-ras mutation and ERBB-2 staining; only 4/9 (44%) k-ras mutated cases were ERBB-2 positive versus 18/22 (82%) cases without k-ras mutation (p = 0.005). In contrast, 8/13 cases with p53 mutation were ERBB-2 positive. We conclude that well-differentiated and less invasive papillary and bronchoalveolar tumors are more often ERBB-2 positive/k-ras negative (i.e. at codon 12), whereas less well differentiated acinar or scar carcinomas are more often ERBB-2 negative/k-ras mutated at codon 12. These findings imply that the divergent histogenesis of pulmonary adenocarcinoma may reflect specific differences in genetic pathology.

Haploid transcripts persist in mature human spermatozoa.

Mammalian spermiogenesis is marked by the morphological and functional differentiation of round haploid spermatids into mature spermatozoa. A molecular restructuring of the chromatin accompanies this process facilitated by the transition proteins and protamines which compact and condense the genetic material within the developing spermatid. Previous studies from this laboratory have demonstrated that human protamines PRM1, PRM2 and transition protein TNP2 transcripts are associated with round and elongating spermatids. Extending this investigation, we examined the occurrence of these transcripts in mature spermatozoa by in-situ hybridization analysis using [35S]-labelled cRNA probes. These results demonstrate that PRM1, PRM2 and TNP2 haploid-specific transcripts are present in mature spermatozoa. Quantitative analysis of the localized signal also indicates that the PRM1, PRM2 and TNP2 transcripts persist at a similar ratio to that previously described for these transcripts in human testes, i.e. PRM2 > PRM1 approximately equal to TNP2. The persistence of these transcripts in mature spermatozoa warrants further investigation.

Evaluation of MYC and chromosome 8 copy number in breast carcinoma by interphase cytogenetics.

We used fluorescence in situ hybridization (FISH) to determine MYC and chromosome 8 copy number on whole nuclear imprint preparations of 24 breast carcinomas, seven benign breast samples, and two phyllodes tumors. None of the benign tissues and neither of the phyllodes tumors demonstrated an increased copy number for MYC or chromosome 8, which was defined as greater than two signals in > 10% of nuclei. In contrast, 22 of 24 carcinomas demonstrated an increased MYC copy number. The modal numbers of MYC copies/nucleus were 0-2 in seven cases (29%), 3-5 in seven cases (29%), 6-9 in five cases (21%), and > 9 in five cases (21%). An increased chromosome 8 copy number was observed in 21 of 22 carcinomas with MYC gain, and the modal number of signals/nucleus was either identical to (n = 14; 64%) or less than (n = 8; 36%) the number of MYC copies. The number of MYC copies correlated with cellular DNA content, as determined by using flow cytometry. In peridiploid tumors (DNA index 0.9-1.2; n = 7), the MYC copy numbers/nucleus were 0-2 in five cases and 3-5 in two cases. In contrast, the modal MYC copy numbers/nucleus among the 11 hyperdiploid tumors (DNA index 1.3-1.9) were 0-2 in one case, 3-5 in four cases, 6-9 in five cases, and > 9 in one case. All three tetraploid/hypertetraploid carcinomas exhibited > 9 MYC copies/nucleus. We conclude that an increased MYC copy number, as detected by using interphase cytogenetics, is extremely frequent in human breast carcinomas. However, in most cases, MYC gene duplication is probably secondary to polysomy of chromosome 8 and/or genomic endoreduplication (i.e., DNA aneuploidy).

Cell cycle analysis of normal, atrophic, and hyperplastic breast epithelium using two-color multiparametric flow cytometry.

We performed two-color flow cytometric synthesis phase fraction (SPF) determinations on cytokeratin-labeled benign epithelial populations from 142 breast specimens (41 mastectomy, 70 diagnostic biopsy, 31 reduction mammoplasty). There was wide variability of SPF, ranging from 0.1 to 3.5%, with a frequency distribution skewed to higher values (mean 0.75%, median 0.5%). The mean SPE for women less than 29 years was 0.91%, vs. 0.89% for 30-42 years, 0.66% for 43-49 years, and 0.56% for > or = 50 years (P = 0.05). Histologically atrophic tissue samples exhibited a mean SPF approximately half that of morphologically normal tissue from premenopausal age women (0.79% vs. 0.36%, P = 0.02). Tissues showing histologically proliferative fibrocystic features had a greater mean SPF than non-proliferative fibrocystic tissues (0.59% vs. 0.92%); however, due to the wide spread of values within each of these categories, this difference was not statistically significant and neither group was significantly different from 'normal' tissue samples. Patients with histologically normal breast tissue, though, were significantly younger (mean = 34.6 years) than those with fibrocystic changes (non-proliferative mean = 53.4 years vs. proliferative mean = 42.8 years, P = 0.005). Synchronous right- and left-sided specimens obtained from reduction mammoplasty demonstrated significantly correlated SPF determinations (R = 0.77). We conclude that selective analysis of epithelial populations using two-color flow cytometry provides cell cycle information in benign breast tissue which is analogous to that obtained by labor-intensive nucleotide labeling studies. This study also confirms the biologic variability and age-dependence of breast epithelial proliferation. Finally, the data imply that derangements of cell proliferation in fibrocystic conditions are heterogeneous, complex and incompletely correlated with histologic parameters such as hyperplasia.

Correlation between p53 immunostaining patterns and gene sequence mutations in breast carcinoma.

We performed p53 immunostaining in 82 invasive breast carcinomas by using two commercially available antibodies, one of which (DO7) was employed in formalin-fixed paraffin-embedded sections. The other antibody (PAb1801) was evaluated in corresponding acetone-fixed cryostat sections. A greater percent of cases were immunostained with DO7 compared to PAb1801 (52% vs 33%); however, the staining was more often heterogeneous (6-50% cells positive) or focal (< or = 5% cells positive) with DO7 (9% vs 31%). To investigate the genetic relevance of p53 immunostaining, single-strand conformational polymorphism (SSCP) analysis and DNA sequencing were performed on exons 2-11 by using archival tissue samples of 18 cases that were selected on the basis of certain immunostaining patterns. Two (33%) of six tumors with negative staining for DO7 had gene sequence mutations; however, one of these mutations was a base-pair deletion that caused a reading-frame shift and the other was a base-pair insertion that resulted in a stop codon. Both of these tumors exhibited immunostaining with PAb1801, although it was weak and cytoplasmic in one case. Conversely, three (30%) of 10 tumors showing immunoreactivity in 6-100% of cells with both reagents lacked a gene sequence mutation. Of the remaining seven tumors that were positive by SSCP, six contained a point mutation resulting in a base-pair substitution. Despite repeat analyses, one of the cases positive by SSCP failed to demonstrate a mutation in the sequenced exons. Four (80%) of five cases with heterogeneous DO7 immunoreactivity (that is, 6-50% of nuclei positive) were positive for gene sequence mutation. Neither of two cases showing focal DO7 nuclear staining in < 5% of tumor cells contained a mutation in the sequenced exons, and neither of these cases was strongly positive with PAb1801. Staining for either antibody was significantly associated with adverse outcome, as determined by disease recurrence at 52 months median follow-up (DO7, p = 0.01; and PAb1801 p = 0.002, chi-squared test). We conclude that a variety of factors may account for discrepancies when immunohistology is used to evaluate p53 status. These include fixation artifacts, differing epitope specificities of monoclonal reagents, presence of immunohistologically "silent" mutations and, possibly, aberrant overexpression of wild-type protein.

Clinicopathologic analysis of bcl-2 immunostaining in breast carcinoma.

Tissue sections of 81 breast carcinomas and 19 benign breast tissues were immunostained with a monoclonal antibody to the bcl-2 gene product, a cytoplasmic protein that regulates apoptosis. The degree of immunoreactivity was then compared with clinicopathologic parameters and to immunostaining for mutated p53 gene product. Immunoreactivity for bcl-2 was present consistently in lymphocyte populations and in residual benign lobules. Apocrine metaplasia (n = 6) and lactating breast (n = 1) exhibited minimal bcl-2 expression, whereas duct hyperplasia (n = 10) showed staining of cells primarily at the periphery of the involved structure and adenosis (n = 7) displayed staining in a majority of cells. Neoplastic epithelial bcl-2 immunoreactivity was negative or minimally positive (staining in 1-5% of cells) in 42% of cases, heterogeneous (staining in 6-30% of cells) in 27% of cases, and diffuse (> 30% of cells) in 31% of cases. Immunostaining for bcl-2 correlated with the presence of estrogen receptor (bcl-2 negative, 16% estrogen receptor positive versus bcl-2 positive, 88% estrogen receptor-positive; P < 0.001), with differentiation (bcl-2 negative, 62% poorly differentiated versus bcl-2 positive, 8% poorly differentiated; P < 0.001) and with better disease-free survival (bcl-2 negative, 82% recurrence versus bcl-2 positive, 28% recurrence; P = 0.0001; 52-mo mean follow-up). Immunostaining for p53 in greater than 5% of tumor cells was observed in 39% of cases and was more frequent in bcl-2-negative tumors (18/35, 51%) as opposed to bcl-2-positive tumors (14/46, 30%); P = NS. Disease recurrence correlated with p53 staining, which was observed in 51% of tumors that relapsed versus only 22% of tumors that did not recur. We conclude that bcl-2 is expressed in benign breast tissues that retain proliferative capacity and partial differentiation. Moreover, in neoplastic breast tissue, it is better correlated with a differentiated, "hormonally responsive," prognostically favorable phenotype than with disabled p53 gene function.

Evaluation of chromosome aneuploidy in tissue sections of preinvasive breast carcinomas using interphase cytogenetics.

BACKGROUND: Little is known about cellular level genetic alterations in preinvasive breast lesions, particularly lobular carcinoma in situ. METHODS: We employed fluorescence in situ hybridization (FISH) using pericentromeric (alpha satellite) probes to assess numerical alterations of chromosomes 1, 7, 8, 16, 17, and X in deparaffinized archival tissue sections of 9 lobular carcinomas in situ (LCIS), 10 ductal carcinomas in situ (DCIS), and a spectrum of proliferative lesions (including 3 ductal hyperplasias, 1 adenosis, 1 radial scar, and 2 atypical hyperplasias). Three of the LCIS lesions and five of the DCIS lesions were from patients who had a concurrent invasive neoplasm as a component of the tumor. RESULTS: None of the proliferative lesions exhibited detectable chromosome gains, and only 1 showed evidence of signal loss consistent with monosomy (chromosome 7 in the adenosis lesion). Six LCIS patients (67%) displayed evidence of monosomy, with involvement of chromosome 17 in 6 of 6 patients, chromosome 8 in 2 of 6 patients, and chromosome 7 in 2 of 6 patients. Two LCIS patients, each of whom had a concurrent invasive neoplasm, exhibited signal gains consistent with trisomy for chromosomes 1 and 8 (1 patient each). Chromosome aneuploidies were observed in 7 of 10 (70%) DCIS patients, including 2 of 5 patients (40%) without concurrent invasive neoplasm and 5 of 5 patients (100%) with concurrent invasive neoplasm. The pattern of numerical chromosome alteration in DCIS included two patients with losses only, 2 patients with gains only, and 3 patients with both gains and losses (i.e., involving different chromosomes). Chromosome 17 aneuploidy was observed in all DCIS and all LCIS patients who exhibited abnormalities; however, DCIS patients showed more frequent aneuploidies for chromosomes X and 16 (0 LCIS patients vs. 4 DCIS patients with each). CONCLUSIONS: Distinctive pathologic subsets of preinvasive breast neoplasia have divergent patterns of genetic instability. Foci of residual in situ neoplasia that accompany invasive disease may have a greater degree of genetic instability than neoplasms that lack progression to invasive phenotype.