Joseph T. Rabban

Pathologic Complete Response Predicts Recurrence-Free Survival More Effectively by Cancer Subset: Results From the I-SPY 1 TRIAL—CALGB 150007/150012, ACRIN 6657

PURPOSE Neoadjuvant chemotherapy for breast cancer provides critical information about tumor response; how best to leverage this for predicting recurrence-free survival (RFS) is not established. The I-SPY 1 TRIAL (Investigation of Serial Studies to Predict Your Therapeutic Response With Imaging and Molecular Analysis) was a multicenter breast cancer study integrating clinical, imaging, and genomic data to evaluate pathologic response, RFS, and their relationship and predictability based on tumor biomarkers. PATIENTS AND METHODS Eligible patients had tumors ≥ 3 cm and received neoadjuvant chemotherapy. We determined associations between pathologic complete response (pCR; defined as the absence of invasive cancer in breast and nodes) and RFS, overall and within receptor subsets. RESULTS In 221 evaluable patients (median tumor size, 6.0 cm; median age, 49 years; 91% classified as poor risk on the basis of the 70-gene prognosis profile), 41% were hormone receptor (HR) negative, and 31% were human epidermal growth factor receptor 2 (HER2) positive. For 190 patients treated without neoadjuvant trastuzumab, pCR was highest for HR-negative/HER2-positive patients (45%) and lowest for HR-positive/HER2-negative patients (9%). Achieving pCR predicted favorable RFS. For 172 patients treated without trastuzumab, the hazard ratio for RFS of pCR versus no pCR was 0.29 (95% CI, 0.07 to 0.82). pCR was more predictive of RFS by multivariate analysis when subtype was taken into account, and point estimates of hazard ratios within the HR-positive/HER2-negative (hazard ratio, 0.00; 95% CI, 0.00 to 0.93), HR-negative/HER2-negative (hazard ratio, 0.25; 95% CI, 0.04 to 0.97), and HER2-positive (hazard ratio, 0.14; 95% CI, 0.01 to 1.0) subtypes are lower. Ki67 further improved the prediction of pCR within subsets. CONCLUSION In this biologically high-risk group, pCR differs by receptor subset. pCR is more highly predictive of RFS within every established receptor subset than overall, demonstrating that the extent of outcome advantage conferred by pCR is specific to tumor biology.

Risk-reducing salpingo-oophorectomy (RRSO) in BRCA mutation carriers: experience with a consecutive series of 111 patients using a standardized surgical-pathological protocol.

Background: Women carriers of BRCA mutations often have occult malignancy found at the time of risk-reducing bilateral salpingo-oophorectomy (RRSO). We report outcomes in 111 consecutive BRCA-positive women who had RRSO using a rigorous surgical-pathological protocol from 1996 to 2008. Method: We identified risk factors associated with finding an occult malignancy at RRSO with outcomes followed for a median of 61 months. Results: A total of 111 BRCA carriers elected RRSO, 10 patients [9.1%] had 14 sites of occult neoplasia. Two patients had invasive serous fallopian tube carcinoma (TSC) only, 1 patient had invasive serous ovarian carcinoma (OSC) only, 5 patients had tubal intraepithelial carcinoma (TIC) only, and 2 patients had multifocal lesions of the ovary (OSC) and TIC. Occult ovarian carcinomas were only detected in BRCA1 patients, and all BRCA2 carcinomas involved only the fallopian tube. The odds of finding occult carcinoma is 4 times greater (odds ratio, 4.3; 95% confidence interval, 1.06-20.7) in women older than 50 than in younger ones (P = 0.023). A history of invasive breast cancer was associated with a reduced risk of occult carcinoma (odds ratio, 0.2; 95% confidence interval, 0.05-0.85). In median follow-up of 5 years, recurrence rate after detection of an occult carcinoma was 10% and the risk for primary peritoneal carcinoma was less than 1%. Conclusion: A rigorous surgical protocol with meticulous pathologic review at RRSO yielded an overall detection rate of 9.1% for occult gynecological carcinoma in BRCA mutation carriers followed by a multidisciplinary team at a single institution. Primary peritoneal carcinoma after RRSO is rare.

Inflammatory myofibroblastic tumor of the uterus: a clinicopathologic study of 6 cases emphasizing distinction from aggressive mesenchymal tumors.

Inflammatory myofibroblastic tumor (IMT) is an indolent spindle cell proliferation that can histologically resemble various malignant mesenchymal neoplasms; however, it generally behaves as a benign or locally recurrent tumor. Most IMTs involve the lung, mesentery, omentum, or retroperitoneum. We report the clinical and pathologic features of six IMTs of the uterus, one of which was included in a previous report, and emphasize the histologic and immunohistochemical features that distinguish IMTs from uterine spindle cell neoplasms that require aggressive treatment. Recently, translocations of the anaplastic lymphoma kinase (ALK) gene and immunohistochemical expression of ALK have been reported in IMTs of various anatomic sites. We compared ALK expression in uterine IMTs with that in uterine mesenchymal neoplasms with which it may be confused. Patients with IMT were between 6 and 46 years of age. None had a history of abdominal surgery; three were multiparous. The IMTs ranged from 1 to 12 cm in maximum dimension. Three grew as polypoid masses that arose in the lower uterine segment, and two of these prolapsed through the cervical os. The three other tumors grew as bulky myometrial masses with focally irregular borders and infiltrated the endometrium, parametrium, or cervical stroma. There were three main microscopic patterns: a hypocellular pattern, a fascicular pattern, and a hyalinized pattern. A lymphoplasmacytic infiltrate was present in all of the tumors, and most had a myxoid background. Mitotic activity ranged from 0 to 2 mitotic figures per 10 high power fields (HPF) except in one tumor that focally had up to 8 mitotic figures per 10 HPF. No nuclear atypia or necrosis was present. Immunohistochemical expression of ALK was present in a cytoplasmic pattern in all IMTs tested. No ALK expression was identified in uterine leiomyoma (n = 7), leiomyosarcoma (n = 6), carcinosarcoma (n = 4), endometrial stromal sarcoma (n = 4), or normal uterine tissues. Follow-up ranging from 1.5 years to 5 years in 4 patients with uterine IMTs revealed no recurrence or metastasis. IMTs should be differentiated from aggressive uterine mesenchymal tumors because they can be treated conservatively and have a more favorable prognosis. ALK expression appears to be of diagnostic value in conjunction with other immunohistochemical stains.

CD36 Repression Activates a Multicellular Stromal Program Shared by High Mammographic Density and Tumor Tissues

UNLABELLED Although high mammographic density is considered one of the strongest risk factors for invasive breast cancer, the genes involved in modulating this clinical feature are unknown. Tissues of high mammographic density share key histologic features with stromal components within malignant lesions of tumor tissues, specifically low adipocyte and high extracellular matrix (ECM) content. We show that CD36, a transmembrane receptor that coordinately modulates multiple protumorigenic phenotypes, including adipocyte differentiation, angiogenesis, cell-ECM interactions, and immune signaling, is greatly repressed in multiple cell types of disease-free stroma associated with high mammographic density and tumor stroma. Using both in vitro and in vivo assays, we show that CD36 repression is necessary and sufficient to recapitulate the above-mentioned phenotypes observed in high mammographic density and tumor tissues. Consistent with a functional role for this coordinated program in tumorigenesis, we observe that clinical outcomes are strongly associated with CD36 expression. SIGNIFICANCE CD36 simultaneously controls adipocyte content and matrix accumulation and is coordinately repressed in multiple cell types within tumor and high mammographic density stroma, suggesting that activation of this stromal program is an early event in tumorigenesis. Levels of CD36 and extent of mammographic density are both modifiable factors that provide potential for intervention.

Multistep Level Sections to Detect Occult Fallopian Tube Carcinoma in Risk-reducing Salpingo-oophorectomies From Women With BRCA Mutations: Implications for Defining an Optimal Specimen Dissection Protocol

Risk-reducing salpingo-oophorectomy (RRSO) significantly lowers the incidence of ovarian, tubal, peritoneal, and breast cancer in women who carry BRCA1 or BRCA2 germline mutations. A minority of RRSO specimens from these women will contain occult early-stage carcinoma. Most occult cancer is localized in the fallopian tube fimbriae and is as small as 1 mm in size. Pathologic detection is dependent on thoroughness of tissue examination. Recommended protocols to maximize tumor detection emphasize the role of thinly slicing the tubes and ovaries and embedding the entire specimen for microscopic examination. Additional multistep level sections of tubal fimbriae tissue blocks could theoretically increase detection of occult tubal carcinoma but the value of level sections has not been formally evaluated. This study tests the diagnostic utility of multistep level sections in RRSO specimens from 102 women with BRCA germline mutations. The original diagnoses were based on a single section from each block of thinly sliced (2 to 3 mm intervals) tissues of the entire RRSO specimen. Three multistep level sections were retrospectively obtained from each block containing tubal fimbriae. Clinically occult carcinoma ranging in size from 1 to 13 mm was initially detected in 11 of 102 women (5 in tubal fimbriae only, 1 in tubal isthmus only, 2 in fimbriae and ovary, and 3 in ovary only). Diagnoses in the original fimbrial slides and their level sections were concordant in all cases. All tubal cancers were detected in both the original sections and in the multistep level sections. None of the tubal carcinomas that were noninvasive on the original slides showed invasive growth on additional level sections. No tubal carcinoma was identified in the level sections of any case originally classified as benign. Clinical follow-up among women with benign RRSO findings revealed that 2 women subsequently developed peritoneal carcinomatosis at 22 and 62 months postoperatively. Retrospective exhaustive multistep level sectioning of all remaining tubal and ovarian blocks from both these women confirmed the original benign diagnosis in 1 woman but in the other woman, the deepest levels of 1 ovarian block revealed a single 1-mm nodule of cancer at the base of an ovarian surface epithelial invagination. This specimen was one of the first RRSO cases in our experience and on review of the original report, this ovary was not dissected into multiple slices along its short axis but was only bivalved along its long axis. We propose that there does not seem to be any diagnostic value in automatically performing multistep deeper level sections of RRSO specimens if the tissue is sectioned appropriately and if the specimen is sliced at intervals that are no more than 3 mm thick. Guidelines for evaluation of RRSO specimens should emphasize the use of an optimal dissection protocol and the importance of thin tissue slice intervals.

Dual loss of the SWI/SNF complex ATPases SMARCA4/BRG1 and SMARCA2/BRM is highly sensitive and specific for small cell carcinoma of the ovary, hypercalcaemic type.

Small cell carcinoma of the ovary, hypercalcaemic type (SCCOHT) is a lethal and sometimes familial ovarian tumour of young women and children. We and others recently discovered that over 90% of SCCOHTs harbour inactivating mutations in the chromatin remodelling gene SMARCA4 with concomitant loss of its encoded protein SMARCA4 (BRG1), one of two mutually exclusive ATPases of the SWI/SNF chromatin remodelling complex. To determine the specificity of SMARCA4 loss for SCCOHT, we examined the expression of SMARCA4 by immunohistochemistry in more than 3000 primary gynaecological tumours. Among ovarian tumours, it was only absent in clear cell carcinoma (15 of 360, 4%). In the uterus, it was absent in endometrial stromal sarcomas (4 of 52, 8%) and high‐grade endometrioid carcinomas (2 of 338, 1%). Recent studies have shown that SMARCA2 (BRM), the other mutually exclusive ATPase of the SWI/SNF complex, is necessary for survival of tumour cells lacking SMARCA4. Therefore, we examined SMARCA2 expression and discovered that all SMARCA4‐negative SCCOHTs also lacked SMARCA2 protein by IHC, including the SCCOHT cell lines BIN67 and SCCOHT1. Among ovarian tumours, the SMARCA4/SMARCA2 dual loss phenotype appears completely specific for SCCOHT. SMARCA2 loss was not due to mutation but rather from an absence of mRNA expression, which was restored by treatment with the histone deacetylase inhibitor trichostatin A. Re‐expression of SMARCA4 or SMARCA2 inhibited the growth of BIN67 and SCCOHT1 cell lines. Our results indicate that SMARCA4 loss, either alone or with SMARCA2, is highly sensitive and specific for SCCOHT and that restoration of either SWI/SNF ATPase can inhibit the growth of SCCOHT cell lines.

Early detection of high-grade tubal serous carcinoma in women at low risk for hereditary breast and ovarian cancer syndrome by systematic examination of fallopian tubes incidentally removed during benign surgery.

Early detection of sporadic pelvic serous carcinoma remains an elusive goal. In women at high risk for hereditary breast and ovarian cancer syndrome who undergo prophylactic salpingectomy, systematic pathologic examination of the fallopian tubes will detect occult tubal cancer, mostly in the fimbriae, of a minority of women. Such tubal cancers are the putative precursor to advanced-stage pelvic cancer. We hypothesized that early tubal cancer detection can also be accomplished in women at low risk using a similar approach. In this study, we performed complete and systematic examination of the fallopian tubes removed during surgery performed for benign indications. Among 522 women, 4 cases of serous tubal intraepithelial carcinoma (STIC) were identified. Three of these cases would have gone undetected using the current standard of care of sampling only a single random section of the tube. The fourth case was accompanied by occult ovarian carcinoma. The fimbriae contained STIC in 3 of the 4 cases and atypical mucosa in 1 case in which the STIC was in the nonfimbriated portion of the tube. The morphologic and immunohistochemical features (aberrant p53 and MIB-1) of these STICs were similar to those expected in high-risk women. All 4 patients with STIC underwent BRCA1 and BRCA2 gene testing; no germline mutations were identified in any patient. An additional 11 specimens contained atypical mucosal proliferations that fell short of morphologic and immunohistochemical criteria for STIC. Two of these 11 fulfilled criteria for a serous tubal intraepithelial lesion, and the remaining atypical proliferations exhibited normal p53 and MIB-1. For most specimens, the fimbriae could be completely submitted in 1 or 2 cassettes per tube. These results demonstrate that systematic examination of the tubal fimbriae can serve as a form of early detection of sporadic tubal cancer without incurring significant labor or cost. We propose that the tubal fimbriae should be completely examined in all patients undergoing benign surgery even if there are no clinical features to suggest risk for hereditary breast and ovarian cancer syndrome.

Molecular classification of endometriosis and disease stage using high-dimensional genomic data.

Endometriosis (E), an estrogen-dependent, progesterone-resistant, inflammatory disorder, affects 10% of reproductive-age women. It is diagnosed and staged at surgery, resulting in an 11-year latency from symptom onset to diagnosis, underscoring the need for less invasive, less expensive approaches. Because the uterine lining (endometrium) in women with E has altered molecular profiles, we tested whether molecular classification of this tissue can distinguish and stage disease. We developed classifiers using genomic data from n = 148 archived endometrial samples from women with E or without E (normal controls or with other common uterine/pelvic pathologies) across the menstrual cycle and evaluated their performance on independent sample sets. Classifiers were trained separately on samples in specific hormonal milieu, using margin tree classification, and accuracies were scored on independent validation samples. Classification of samples from women with E or no E involved 2 binary decisions, each based on expression of specific genes. These first distinguished presence or absence of uterine/pelvic pathology and then no E from E, with the latter further classified according to severity (minimal/mild or moderate/severe). Best performing classifiers identified E with 90%-100% accuracy, were cycle phase-specific or independent, and used relatively few genes to determine disease and severity. Differential gene expression and pathway analyses revealed immune activation, altered steroid and thyroid hormone signaling/metabolism, and growth factor signaling in endometrium of women with E. Similar findings were observed with other disorders vs controls. Thus, classifier analysis of genomic data from endometrium can detect and stage pelvic E with high accuracy, dependent or independent of hormonal milieu. We propose that limited classifier candidate genes are of high value in developing diagnostics and identifying therapeutic targets. Discovery of endometrial molecular differences in the presence of E and other uterine/pelvic pathologies raises the broader biological question of their impact on the steroid hormone response and normal functions of this tissue.

A practical approach to immunohistochemical diagnosis of ovarian germ cell tumours and sex cord–stromal tumours

Immunohistochemistry can be useful in the diagnosis of ovarian germ cell tumours and sex cord–stromal tumours. A wide variety of markers are available, including many that are novel. The aim of this review is to provide a practical approach to the selection and interpretation of these markers, emphasizing an understanding of their sensitivity and specificity in the particular differential diagnosis in question. The main markers discussed include those for malignant germ cell differentiation (SALL4 and placental alkaline phosphatase), dysgerminoma (OCT4, CD117, and D2‐40), yolk sac tumour (α‐fetoprotein and glypican‐3), embryonal carcinoma (OCT4, CD30, and SOX2), sex cord–stromal differentiation (calretinin, inhibin, SF‐1, FOXL2) and steroid cell tumours (melan‐A). In addition, the limited role of immunohistochemistry in determining the primary site of origin of an ovarian carcinoid tumour is discussed.

PAX2 distinguishes benign mesonephric and mullerian glandular lesions of the cervix from endocervical adenocarcinoma, including minimal deviation adenocarcinoma.

Mesonephric remnants of the cervix are vestiges of the embryonic mesonephric system which typically regresses during female development. Uncommonly, hyperplasia of the mesonephric remnants may occur. The differential diagnosis of exuberant mesonephric hyperplasia includes minimal deviation adenocarcinoma of the cervix, a tumor with deceptively bland morphology for which no reliable diagnostic biomarkers currently exist. PAX2 encodes a transcription factor necessary in the development of the Wolffian duct system, and the protein is expressed in several tumors of mesonephric origin, including renal cell carcinoma, Wilm tumor, and nephrogenic adenoma. We hypothesized that PAX2 may also be expressed in mesonephric lesions of the cervix and may distinguish mesonephric hyperplasia from minimal deviation adenocarcinoma of the cervix. We demonstrated that PAX2 was strongly and diffusely expressed in mesonephric remnants (6 of 6) and in mesonephric hyperplasia (18 of 18); however, no expression was noted in mesonephric adenocarcinoma (0 of 1). PAX2 was expressed in normal endocervical glands (including tunnel clusters and Nabothian cysts) (86 of 86), lobular endocervical glandular hyperplasia (5 of 5), tubal/tuboendometrioid metaplasia (8 of 8), and cervical endometriosis (13 of 14). In contrast, only 2 cases of endocervical adenocarcinoma were positive for PAX2 [invasive adenocarcinoma of the minimal deviation type (0 of 5), usual type (1 of 22), and endometrioid type (1 of 1)]. Adjacent adenocarcinoma in situ, as well as cases of pure adenocarcinoma in situ (0 of 6), were also PAX2 negative. PAX2 expression in the 2 positive endocervical adenocarcinomas was patchy and weak. Most (11 of 15) stage II endometrial endometrioid adenocarcinomas lacked PAX2 expression but 1 of 10 grade 1 tumors and 3 of 5 grade 2 tumors did express PAX2. These results suggest that PAX2 immunoreactivity may be useful to (1) distinguish mesonephric hyperplasia from minimal deviation adenocarcinoma, (2) to distinguish lobular endocervical glandular hyperplasia from minimal deviation adenocarcinoma, and (3) to distinguish endocervical tubal metaplasia or cervical endometriosis from endocervical adenocarcinoma in situ. Overall, a strong, diffuse nuclear PAX2 expression pattern in a cervical glandular proliferation predicts a benign diagnosis (positive predictive value 90%, negative predictive value 98%; P<0.001); however, PAX2 should not be interpreted in isolation from the architectural and cytologic features of the lesion as it may be expressed in some stage II endometrial adenocarcinomas involving the cervix.