Mutation Profiling of Usual Ductal Hyperplasia of the Breast Reveals Activating Mutations Predominantly at Different Levels of the PI3K/AKT/mTOR Pathway.

Usual ductal hyperplasia (UDH) of the breast is generally regarded as a nonneoplastic proliferation, albeit loss of heterozygosity has long been reported in a part of these lesions. To gain deeper insights into the molecular drivers of these lesions, an extended mutation profiling was performed. The coding regions of 409 cancer-related genes were investigated by next-generation sequencing in 16 cases of UDH, nine unassociated with neoplasia (classic) and seven arising within papillomas. Phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) activation was investigated by phosphorylated AKT, mTOR, and S6 immunohistochemistry. Of 16 lesions, 10 (63%) were mutated; 56% of classic lesions were unassociated with neoplasia, and 71% of lesions arose in papillomas. Fourteen missense mutations were detected: PIK3CA [6 (43%) of 14], AKT1 [2 (14%) of 14], as well as GNAS, MTOR, PIK3R1, LPHN3, LRP1B, and IGF2R [each 1 (7%) of 14]. Phosphorylated mTOR was seen in 83% and phosphorylated S6 in 86% of evaluable lesions (phospho-AKT staining was technically uninterpretable). In conclusion, UDH displays mutations of the phosphatidylinositol 3-kinase/AKT/mTOR axis at different levels, with PIK3R1, MTOR, and GNAS mutations not previously described. Specifically, oncogenic G-protein activation represents a yet unrecognized route to proliferation in UDH. On the basis of evidence of activating mutations, loss of heterozygosity, and a mass forming proliferation, we propose that UDH is most appropriately viewed as an early neoplastic intraductal proliferation.

Quantitative assessment of the spatial heterogeneity of tumor-infiltrating lymphocytes in breast cancer.

BACKGROUND: Tumor-infiltrating lymphocyte (TIL) count in breast cancer carries prognostic information and represents a potential predictive marker for emerging immunotherapies. However, the distribution of the lymphocyte subpopulations is not well defined. The goals of this study were to examine intratumor heterogeneity in TIL subpopulation counts in different fields of view (FOV) within each section, in different sections from the same biopsy, and between biopsies from different regions of the same cancer using quantitative immunofluorescence (QIF). METHODS: We used multiplexed QIF to quantify cytokeratin-positive epithelial cells, and CD3-positive, CD8-positive and CD20-positive lymphocytes in tissue sections from multiple biopsies obtained from different areas of 31 surgically resected primary breast carcinomas (93 samples total). Log2-transformed QIF scores or concordance and variance component analyses with linear mixed-effects models were used. Cohen's kappa index [k] of high versus low scores, defined as above and below the median, was used to measure sample similarity between areas. RESULTS: We found a strong positive correlation between CD3 and CD8 levels across all patients (Pearson correlation coefficient [CC] = 0.827). CD3 and CD8 showed a weaker but significant association with CD20 (CC = 0.446 and 0.363, respectively). For each marker, the variation between different FOVs in the same section was higher than the variation between sections or between biopsies of the same cancer. The intraclass correlation coefficients (ICC) were 0.411 for CD3, 0.324 for CD8, and 0.252 for CD20. In component analysis, 66-69 % of the variance was attributable to differences between FOVs in the same section and 30-33 % was due to differences between biopsies from different areas of the same cancer. Section to section differences were negligible. Concordance for low versus high marker status assignment in single biopsies compared to all three biopsies combined yielded k = 0.705 for CD3, k = 0.655 for CD8, and k = 0.603 for CD20. CONCLUSIONS: T and B lymphocytes show more heterogeneity across the dimensions of a single section than between different sections or regions of a given breast tumor. This observation suggests that the average lymphocyte score from a single biopsy of a tumor is reasonably representative of the whole cancer.

Exploring chromosomal abnormalities and genetic changes in uterine smooth muscle tumors.

Smooth muscle tumors of the uterus are a diagnostically challenging group of tumors. Molecular surrogate markers reliably distinguishing between benign and malignant tumors are not available. Therefore, the diagnosis is based on morphologic criteria. The aim was to investigate a well-characterized group of challenging uterine smooth muscle tumors consisting of 20 leiomyomas, 13 leiomyomas with bizarre nuclei, and 14 leiomyosarcomas for copy number alterations, MED12 mutations and FH deletions to search for potential diagnostically useful surrogate markers. MED12 mutations were detected in 47, 15, and 25% of leiomyomas, leiomyomas with bizarre nuclei and leiomyosarcomas, respectively. MED12 mutations in leiomyomas with bizarre nuclei were detected outside the hotspot region. FH-deletions were seen in 27, 30.8, and 25% of leiomyomas, leiomyomas with bizarre nuclei and leiomyosarcomas, respectively. By using copy number alteration profiling a clear separation of leiomyomas, leiomyomas with bizarre nuclei and leiomyosarcomas could not be observed. Copy number alterations revealed clear genetic similarities between leiomyomas with bizarre nuclei and leiomyosarcomas. Leiomyosarcomas showed a similar pattern of gains and losses as leiomyomas with bizarre nuclei, with additional copy number alterations and more homozygous losses and high-level amplifications compared to leiomyomas with bizarre nuclei. In conclusion, this study demonstrates that known FH-deletions, a recurrent molecular change in leiomyomas, occur in morphologically challenging variants of leiomyomas, leiomyomas with bizarre nuclei and leiomyosarcomas. Although MED12 mutations are common in leiomyomas, they infrequently occur in leiomyomas with bizarre nuclei and leiomyosarcomas. The genetic similarities between leiomyomas with bizarre nuclei and leiomyosarcomas raise the intriguing possibility that uterine leiomyomas with bizarre nuclei and leiomyosarcomas are closely related and challenge the traditional concept that leiomyoma with bizarre nuclei is a tumor with just marked 'degenerative' cellular changes. These findings support the hypothesis that tumor progression within uterine smooth muscle tumors might occur.

Brain metastasis in breast cancer: a comprehensive literature review.

This comprehensive review provides information on epidemiology, size, grade, cerebral localization, clinical symptoms, treatments, and factors associated with longer survival in 14,599 patients with brain metastasis from breast cancer; the molecular features of breast cancers most likely to develop brain metastases and the potential use of these predictive molecular alterations for patient management and future therapeutic targets are also addressed. The review covers the data from 106 articles representing this subject in the era of modern neuroimaging (past 35 years). The incidence of brain metastasis from breast cancer (24 % in this review) is increasing due to advances in both imaging technologies leading to earlier detection of the brain metastases and introduction of novel therapies resulting in longer survival from the primary breast cancer. The mean age at the time of breast cancer and brain metastasis diagnoses was 50.3 and 48.8 years respectively. Axillary node metastasis was noted in 32.8 % of the patients who developed brain metastasis. The median time intervals between the diagnosis of breast cancer to identification of brain metastasis and from identification of brain metastasis to death were 34 and 15 months, respectively. The most common symptoms experienced in patients with brain metastasis consisted of headache (35 %), vomiting (26 %), nausea (23 %), hemiparesis (22 %), visual changes (13 %) and seizures (12 %). A majority of the patients had multiple metastases (54.2 %). Cerebellum and frontal lobes were the most common sites of metastasis (33 and 16 %, respectively). Of the primary tumors for which biomarkers were recorded, 37 % were estrogen receptor (ER)+, 41 % ER-, 36 % progesterone receptor (PR)+, 34 % PR-, 35 % human epithelial growth factor receptor 2 (HER2)+, 41 % HER2-, 27 % triple negative and 18 % triple positive (TP). Treatment in most patients consisted of a multimodality approach often with two or more of the following: whole brain radiation therapy (52 %), chemotherapy (51 %), stereotactic radiosurgery (20 %), surgical resection (14 %), trastuzumab (39 %) for HER2 positive tumors, and hormonal therapy (34 %) for ER and/or PR positive tumors. Factors that had an impact on prognosis included grade and size of the tumor, multiple metastases, presence of extra-cranial metastasis, triple negative or HER2+ biomarker status, and high Karnovsky score. Novel therapies such as application of agents to reduce tumor angiogenesis or alter permeability of the blood brain barrier are being explored with preliminary results suggesting a potential to improve survival after brain metastasis. Other potential therapies based on genetic alterations in the tumor and the microenvironment in the brain are being investigated; these are briefly discussed.

Reproducibility of current classifications of endometrial endometrioid glandular proliferations: further evidence supporting a simplified classification.

AIMS: To compare the reproducibility of the current (2003) World Health Organization (WHO), endometrial intraepithelial neoplasia (EIN) and European Working Group (EWG) classifications of endometrial endometrioid proliferations. METHODS AND RESULTS: Nine expert gynaecological pathologists from Europe and North America reviewed 198 endometrial biopsy/curettage specimens originally diagnosed as low-grade lesions. All observers were asked to classify the cases by using the categories described in each scheme: six for WHO, four for EIN, and three for EWG. The results were evaluated by kappa statistics for more than two observations. The analysis was repeated using only two major categories (benign versus atypical/carcinoma). Both the WHO and EIN classifications showed poor interobserver agreement (κ = 0.337 and κ = 0.419, respectively), whereas the EWG classification showed moderate agreement (κ = 0.530). Full agreement between pathologists occurred in only 28% for the WHO classification, 39% for the EIN classification, and 59% for the EWG classification. With only two diagnostic categories, kappa values increased in all classifications, but only the EWG classification reached a substantial level of agreement (κ = 0.621); similarly, full agreement among all pathologists increased to 70% for the WHO classification, 69% for the EIN classification, and 72% for the EWG classification. CONCLUSIONS: A two-tier classification of endometrial endometrioid proliferative lesions improves reproducibility, and should be considered for the diagnosis of endometrial biopsy/curettage specimens.

Brain metastasis from ovarian cancer: a systematic review.

To review the existing literature on brain metastasis (BM) from ovarian cancer and to assess the frequency, anatomical, clinical and paraclinical information and factors associated with prognosis. Ovarian cancer is a rare cause of brain metastasis with a recently reported increasing prevalence. Progressive neurologic disability and poor prognosis is common. A comprehensive review on this subject has not been published previously. This systematic literature search used the Pubmed and Yale library. A total of 66 publications were found, 57 of which were used representing 591 patients with BM from ovarian cancer. The median age of the patients was 54.3 years (range 20-81). A majority of patients (57.3 %) had multiple brain lesions. The location of the lesion was cerebellar (30 %), frontal (20 %), parietal (18 %) and occipital (11 %). Extracranial metastasis was present in 49.8 % of cases involving liver (20.7 %), lung (20.4 %), lymph nodes (12.6 %), bones (6.6 %) and pelvic organs (4.3 %). The most common symptoms were weakness (16 %), seizures (11 %), altered mentality (11 %) visual disturbances (9 %) and dizziness (8 %). The interval from diagnosis of breast cancer to BM ranged from 0 to 133 months (median 24 months) and median survival was 8.2 months. Local radiation, surgical resection, stereotactic radiosurgery and medical therapy were used. Factors that significantly increased the survival were younger age at the time of ovarian cancer diagnosis and brain metastasis diagnosis, lower grade of the primary tumor, higher KPS score and multimodality treatment for the brain metastases. Ovarian cancer is a rare cause of brain metastasis. Development of brain metastasis among older patients and lower KPS score correlate with less favorable prognosis. The more prolonged survival after using multimodality treatment for brain metastasis is important due to potential impact on management of brain metastasis in future.

TERT Promoter Mutation c.-124C>T Commonly Occurs in Low-Grade Fibromatosis-like Metaplastic Breast Carcinoma.

CONTEXT.­: Low-grade fibromatosis-like metaplastic carcinoma (FLMC) is a very rare subtype of triple-negative metaplastic (spindle cell) breast carcinoma. It is characterized by the proliferation of spindle cells closely resembling fibromatosis, which represents a benign fibroblastic/myofibroblastic breast proliferation. Unlike most triple-negative and basal-like breast cancers, FLMC has a very low potential for metastases, but demonstrates frequent local recurrences. OBJECTIVE.­: To genetically characterize FLMC. DESIGN.­: To this end, we analyzed 7 cases by targeted next-generation sequencing for 315 cancer-related genes and performed comparative microarray copy number analysis in 5 of these cases. RESULTS.­: All cases shared TERT alterations (6 patients with recurrent c.-124C>T TERT promoter mutation and 1 patient with copy number gain encompassing the TERT locus), had oncogenic PIK3CA/PIK3R1 mutations (activation of the PI3K/AKT/mTOR pathway), and lacked mutations in TP53. TERT was overexpressed in all FLMCs. CDKN2A/B loss or mutation was observed in 4 of 7 cases (57%). Furthermore, tumors displayed chromosomal stability, with only few copy number variations and a low tumor mutational burden. CONCLUSIONS­: We conclude that FLMCs typically show the recurrent TERT promoter mutation c.-124C>T, activation of the PI3K/AKT/mTOR pathway, low genomic instability, and wild-type TP53. In conjunction with previous data of metaplastic (spindle cell) carcinoma with and without fibromatosis-like morphology, FLMC is most likely distinguished by TERT promoter mutation. Thus, our data support the notion of a distinct subgroup within low-grade metaplastic breast cancer with spindle cell morphology and associated TERT mutations.

Validation of an immunohistochemical signature predictive of 8-year outcome for patients with breast carcinoma.

We recently reported that standardized quantitative immunohistochemical (IHC) assays allowed prediction of an adverse outcome among 572 node negative (N-) patients with breast carcinoma (BrCa). To further validate our prior findings, we repeated the IHC stains including a second series of BrCa diagnosed at Yale University. Tissue microarrays (TMAs) of two cohorts of patients with BrCa (418 Marseille University and 303 Yale University) were respectively investigated for IHC expression of 15 markers (HIF-1α, PI3K, pAKT, pmTOR, moesin, P21, 4(E) BP-1, P27, Ker5-6, pMAPKAPK-2, SHARP2, claudin-1, ALDH, AF6 and CD24). Quantitative measurements of immunoprecipitates densitometry assessed with an image analyzer were correlated with 8-year patients' outcome and compared in the two cohorts. The best predictive signature consisted of a combination of five markers that included HIF-1α, PI3K, claudin-1, AF6 and pAKT in N- BrCa. This combination permitted an accurate prediction of outcome in 92.34% (386/418) of N- patients in the first set (Marseille) and 89.8% (158/176) in the second set (Yale). The close results in both cohorts confirmed the validity of this original IHC signature predictive of prognosis in node negative BrCa. This validation suggests that in clinical practice, it would be possible with standardized kits (i) to identify patients with poor prognosis at diagnosis time, particularly in the N- BrCa subset, who would require more aggressive adjuvant therapy and (ii) to avoid useless expensive therapies and their side effects in N- patients with favorable prognosis.

Apoplectic leiomyomas: does ethnicity make a difference? a clinicopathologic study.

Apoplectic leiomyomas-benign uterine leiomyomas with morphologic changes including hemorrhage, hypercellularity, mitotic activity, nuclear atypia, and even necrosis-can be difficult to distinguish from uterine leiomyosarcomas. Apoplectic leiomyomas have been associated with hormonal therapy; however, the relationship between apoplectic leiomyomas, hormones, and ethnicity has not received much attention in the literature. We evaluated the relationship of hormonal therapy and ethnicity in 869 women with uterine leiomyomas, 136 of which qualified as apoplectic leiomyomas.Apoplectic leiomyomas were observed in 23.3% (49/210) of women exposed to hormonal therapy compared to 13.2% (87/659) of women not exposed to hormonal therapy (p < 0.0001). Women taking ethinyl estradiol/norethindrone (Lo-Estrin), leuprolide, and medroxyprogesterone were significantly more likely to have apoplectic leiomyomas compared to women taking other hormonal therapies. Apoplectic leiomyomas were observed in 28.9% (44/152) of African-American women compared to 12.4% (79/639) of Caucasian women (p < 0.0001), and this difference remained statistically significant regardless of hormone use. Apoplectic leiomyomas were observed in 22.1% (77/349) of women ≤ 45 years of age compared to 11.3% (59/520) of women > 45 years of age (p < 0.0001), and this difference remained statistically significant regardless of hormone use.This is the largest study to date examining apoplectic leiomyomas in women on known hormonal therapy compared to women with uterine leiomyomas, but not on hormonal therapy. Information about hormonal therapy, ethnicity, and age can be helpful in the diagnostic interpretation of apoplectic leiomyoma.

Myxoid leiomyosarcoma of the uterus.

AIMS: Recent guidelines have suggested the presence of tumour cell necrosis (TCN), atypia and mitotic index as major features in the distinction of myxoid leiomyosarcomas (MLMSs) from myxoid leiomyomas. The aim of this study was to focus on an invasive growth pattern as a significant feature in this distinction in the absence of TCN. METHODS AND RESULTS: Twelve uterine smooth muscle tumours with myxoid change in ≥60% of the lesion were interpreted as MLMS on the basis of the presence of focal mild atypia as well as one or more of the following features: (i) infiltrative growth pattern; (ii) vascular invasion; (iii) mitotic index of ≥5 mitotic figures (m.f.)/50 high-power fields (HPFs); and (iv) a combination of at least focal severe atypia and at least 2-4 m.f./50 HPFs. Unequivocal TCN was not evident in any of these tumours. The various morphological features were correlated with outcome. With follow-ups ranging from 19 to 113 months (mean 60 months), five of the 12 women developed recurrences, and two of them died. Nine of the 12 tumours had an infiltrative growth pattern, and all five recurrent tumours were from this group. CONCLUSION: In the absence of TCN, an infiltrative margin is a major factor related to the potential for aggressive behaviour of MLMS.

Chromosomal aberrations as detected by array comparative genomic hybridization in early low-grade intraepithelial neoplasias of the breast.

AIMS: Low-grade flat ductal intraepithelial neoplasia (DIN1a, flat epithelial atypia) is one of the earliest morphologically recognizable neoplastic lesions of the breast. Frequently, it occurs concomitantly with lobular intraepithelial neoplasia (LIN). We aimed to elucidate chromosomal aberrations in these early neoplastic breast lesions with the use of array comparative genomic hybridization analysis. METHODS AND RESULTS: Laser capture microdissection of 12 archival formalin-fixed, paraffin-embedded specimens harbouring foci of both DIN1a and LIN was performed. All analysed cases of DIN1a and LIN showed chromosomal gains and losses. The aberration encountered most often was loss of 16q, noted in seven DIN1a (70% of those successfully examined) and 10 LIN (91%) cases. The next most common alteration was a gain on 1q, noted in four DIN1a (40%) and seven LIN (64%) cases. CONCLUSIONS: The results show concurrent chromosomal aberrations of 1q gains and 16q losses in several cases with coexisting LIN and DIN1a. These aberrations are known to be common in low-grade invasive (ductal and lobular) carcinomas as well as in more advanced (conventional) types of low-grade ductal intraepithelial neoplasia (DIN) (low-grade ductal carcinoma in situ). Our results raise the possibility of similar molecular-genetic pathways in coexisting LIN and low-grade flat DIN.

Positioning of necrotic lobular intraepithelial neoplasias (LIN, grade 3) within the sequence of breast carcinoma progression.

Lobular intraepithelial neoplasia Grade 3 (LIN3) is a recently recognized variant of intraepithelial lobular neoplasia (LIN) of the breast composed of either uniform, generally small cells with massive lobular distension, pleomorphic cells, signet-ring cells, or any cell type with necrosis. In contrast to classic forms of LIN, there is no consensus on therapeutic strategies for LIN3. In part this is due to the paucity of molecular data that could assist in defining the relationship of LIN3 to classic LIN and carcinomas. In this study we have employed array comparative genomic hybridization to determine the patterns of chromosomal aberrations in nine LIN3 lesions. By comparison to array CGH data of 13 classic LIN lesions, we demonstrate that classic LIN and LIN3 share several recurrent changes, in particular gains of 1q and losses of 16q. Both aberrations are known to appear early in tumorigenesis and to be associated with good prognosis. However, apart from this overlap, there were a number of karyotypic features that were observed exclusively in LIN3. Clearly, this lesion was characterized by a significantly higher number of DNA copy number changes (9 vs. 31 on average), a considerable complexity of chromosomal rearrangements with more than 16 breakpoints in one chromosome and overlapping high copy amplifications encompassing a number of known oncogenes. Our data suggest that, at the genetic level, LIN3 represents a highly advanced lesion with considerable resemblance to carcinomas and, therefore, might represent the transition state from an intraepithelial neoplasm to breast carcinoma.

Preoperative chemotherapy decreases the need for re-excision of breast cancers between 2 and 4 cm diameter.

INTRODUCTION: It is accepted that preoperative chemotherapy can result in increased breast preservation for breast cancers greater than 4 cm. The benefits of preoperative chemotherapy are less clear, however, for patients who present with smaller tumors and are already candidates for breast-preserving surgery. The goal of this study is to assess the effect of preoperative chemotherapy on breast cancers between 2 and 4 cm diameter. METHODS: A retrospective chart review was conducted of patients diagnosed with new breast cancer at the Yale-New Haven Breast Center for the years 2002-2007. Patients were included in the study if their breast cancer was between 2 and 4 cm and their initial surgical treatment had been completed. Patients with distant metastases were excluded. RESULTS: There were 156 new cancers that met study requirements. Forty-seven patients underwent preoperative chemotherapy, and 109 patients had their surgery first, usually followed by chemotherapy. Initial surgery was lumpectomy for 31 out of 47 patients (66%) in the preoperative chemotherapy group compared with 62 out of 109 patients (57%) in the surgery group. For patients with lumpectomies, 2 out of 31 patients (6%) in the preoperative group had positive margins and required re-excision compared with 20 out of 62 patients (37%) in the surgery-first group (P<0.01). CONCLUSIONS: We conclude that, for tumors between 2 and 4 cm, preoperative chemotherapy is associated with a significantly decreased rate of re-excision following lumpectomy. This not only results in fewer mastectomies, but also avoids the morbidity and inferior cosmetic results associated with a re-excision lumpectomy.

Comparative analysis of P16 and P53 expression in uterine malignant mixed mullerian tumors.

Recent studies have shown that, in addition to cervical carcinomas, a substantial proportion of endometrial adenocarcinomas are also immunoreactive with p16. The expression of p16 in uterine malignant mixed mullerian tumors (MMMTs), in contrast, has not yet been analyzed in a large series. To our knowledge, we present the first study assessing p16 expression in both components of MMMTs. We performed p16 and p53 immunostains on 30 cases of uterine MMMTs. Both the epithelial and mesenchymal components were subclassified; p16 and p53 immunoreactions were assessed using a semiquantitative scoring system. p16 overexpression was noted in the carcinomatous component in 96.7% (29/30), and in the sarcomatous component in 86.7% (26/30) of cases. In comparison, p53 immunoreactivity was present in the carcinomatous component in 76.7% (23/30), and in the sarcomatous component in 83.3% (25/30) of cases. p16 immunoreactivity was more intense and diffuse than p53 in 40% of type I, 30% of type II carcinomas, and 27% of sarcomatous components. There was no significant difference in p16 or p53 immunoreactivity between the homologous and heterologous sarcomas. The concordance rates for p16 and p53 immunoreactivity between the 2 components were 83% and 90%, respectively. We conclude that p16 immunostain is positive in the vast majority of uterine MMMTs with no significant difference in staining between the 2 components. Compared with p53, p16 immunoreactivity is significantly more intense and diffuse in both components. Our findings indicate that alterations in the p16-Rb pathway play an important role in the pathogenesis of uterine MMMTs.

Predictors of recurrence of ovarian granulosa cell tumors.

OBJECTIVE: The prognosis of granulosa cell tumors (GCTs) is overall favorable, but a proportion of patients will experience recurrence. We report one of the largest series of patients with GCT for whom clinical, morphologic, and immunohistochemical markers have been assessed for their roles as predictors of recurrence. METHODS: Patients with the diagnosis of GCT were identified at 2 hospitals from 1974 to 2004; a detailed chart analysis was performed. Tissue blocks were analyzed immunohistochemically for mitotic index, luteinization, inhibin staining, epidermal growth factor receptor, and Ki67 expression. Univariate and multivariate analyses were performed. RESULTS: Sixty-seven patients were identified. Follow-up data up to 30 years were available. The mean age at diagnosis was 48.1 years. Twenty-five patients experienced recurrence. A statistically significant correlation (P < 0.05) was observed for age at diagnosis, with earlier age being an adverse factor (43.6 vs 50.9, P < 0.01), and use of adjuvant chemotherapy postoperatively (24% vs 40% in the nonrecurrence group). Luteinization and the immunohistochemical markers, such as inhibin, Ki67, and epidermal growth factor receptor, seemed to significantly increase the risk of recurrence if expressed. A multivariate analysis model confirmed that younger age at diagnosis and higher expression of inhibin and Ki67 are significant risk factors of GCT recurrence. CONCLUSIONS: Identification of patients who are at a high risk for recurrence of GCT is critical. Routine treatment for all patients with cytotoxic chemotherapy is not justified. We report a set of predictors of recurrence for GCT that identified subsets of patients who may benefit from prolonged surveillance and/or adjuvant systemic chemotherapy.

Complementary value of the Ki-67 proliferation index to the oncotype DX recurrence score.

Oncotype DX is a 21-gene assay that quantifies the recurrence risk in estrogen receptor-positive breast cancer, which is expressed as the recurrence score (RS). Studies have shown that patients with a high-risk RS will most likely benefit from adjuvant chemotherapy, but there is no proven advantage for patients with a low-risk RS who still face an average recurrence risk of 7%. In this study, the relationship between the RS and the cell cycle-related antigen Ki-67 was assessed in 32 breast carcinomas and evaluated for a potential association. Comparison of the RS with tumor type, grade, and the Ki-67 proliferation index (PI) revealed an overall concordance. However, some tumors with a low RS revealed a surprisingly high Ki-67 PI. These cases may correspond to the 7% of low-risk RS carcinomas that recur. Therefore, the authors propose a combined evaluation of the RS and Ki-67 PI to identify tumors with high recurrence potential from the low-risk and intermediate-risk RS groups.

Clinical and pathologic aspects of basal-like breast cancers.

Gene-expression profiling of breast cancers has shown that distinct molecular subclasses are present within tumors that are apparently morphologically similar. The molecular subclasses of cohorts classified by the 'intrinsic' gene set include the luminal A and B, erbB-2+, normal-breast-like, and basal-like tumors. Basal-like breast cancers have been reported to be associated with worse overall and disease-free survival compared with the luminal A subtype. In addition, there is an immunohistochemical surrogate for the basal-like profile, which has considerably facilitated their study in non-specialty laboratories. Basal-like breast carcinomas have markedly reduced expression of genes related to estrogen receptors and erbB-2, and express proteins that are characteristic of the normal myoepithelial cell. This Review appraises the current state of knowledge on the clinical and pathologic features of breast cancers classified as 'basal-like' by gene-expression profiling and/or immunohistochemical criteria. These tumors seem to be relatively heterogeneous according to a multitude of clinicopathologic parameters, which indicates that their most prognostically relevant subsets have yet to be defined. Similarly to tumors of luminal epithelial differentiation, carcinomas of the 'basal' type have a spectrum of morphologic and clinical characteristics.