Faculty Bibliography

As immune checkpoint inhibitors are rapidly developing into the standard of care for patients with advanced melanoma, the value of diagnostic metrics to predict response to immunotherapy is steadily increasing. Next-generation sequencing based parameters include tumor mutation burden (TMB) as well as genomic amplification of PD-L1/PD-L2/JAK2 at 9p24.1. At present, there are limited studies documenting response to checkpoint blockade in 9p24.1 amplified solid tumors. Herein, we have compared a cutaneous melanoma with a mucosal melanoma, both with 9p24.1 amplifications and durable response to immunotherapy. While the cutaneous melanoma had a high TMB, the mucosal melanoma had a lower TMB compared to the mean TMB for all melanomas within the institutional clinical sequencing cohort. In summary, PD-L1/PD-L2/JAK2 amplification was associated with durable response to therapy for both cases and this genomic signature is a potential valuable metric in predicting response to immunotherapy.

Gastric-type cervical adenocarcinoma (GCA) is a human papillomavirus-unassociated, aggressive, chemorefractory tumor. Well-differentiated examples may exhibit bland morphologic appearances, which could potentially lead to misdiagnosis, particularly in limited material. We sought to characterize the morphologic features of GCA in surgical biopsy and cytology specimens. We identified patients with histologic diagnoses of GCA or minimal-deviation adenocarcinoma between 2004 and 2017. Available slides from biopsy, curettage, and cytology specimens were reviewed. Fifty-nine specimens (37 histology, 22 cytology) were reviewed from 23 patients, including histology specimens alone from 6 patients, cytology specimens alone from 4 patients, and both types of specimen from 13 patients. The median patient age was 52 yr (range, 29-83 yr). Biopsies showed well-to-moderately differentiated adenocarcinomas composed of cells with pale or foamy cytoplasm and well-defined cytoplasmic borders. Nuclei exhibited mild-to-moderate pleomorphism with small nucleoli. The diagnosis was challenging in a minority of biopsies in which neoplastic glandular epithelium was scant, fragmented, and/or well differentiated. Cytology slides showed single and crowded clusters of tumor cells with pale, foamy, and/or vacuolated cytoplasm and well-defined cytoplasmic borders. Nuclei were moderately pleomorphic, round to oval with one or more nucleoli. Of 20 submitted biopsies, GCA was suspected by the submitting pathologist in only 5 (25%) cases. Awareness of the morphologic features and use of confirmatory ancillary studies (eg, immunohistochemistry for markers of gastric differentiation and human papillomavirus testing) will allow accurate diagnosis of these aggressive tumors in biopsy and cytology specimens.

PURPOSE/OBJECTIVE:Microsatellite instability (MSI) and/or mismatch repair deficiency (MMR-D) testing has traditionally been performed in patients with colorectal (CRC) and endometrial cancer (EC) to screen for Lynch syndrome (LS)-associated cancer predisposition. The recent success of immunotherapy in high-frequency MSI (MSI-H) and/or MMR-D tumors now supports testing for MSI in all advanced solid tumors. The extent to which LS accounts for MSI-H across heterogeneous tumor types is unknown. Here, we establish the prevalence of LS across solid tumors according to MSI status. METHODS:MSI status was determined using targeted next-generation sequencing, with tumors classified as MSI-H, MSI-indeterminate, or microsatellite-stable. Matched germline DNA was analyzed for mutations in LS-associated mismatch repair genes ( MLH1, MSH2, MSH6, PMS2, EPCAM). In patients with LS with MSI-H/I tumors, immunohistochemical staining for MMR-D was assessed. RESULTS:Among 15,045 unique patients (more than 50 cancer types), LS was identified in 16.3% (53 of 326), 1.9% (13 of 699), and 0.3% (37 of 14,020) of patients with MSI-H, MSI-indeterminate, and microsatellite-stable tumors, respectively ( P < .001). Among patients with LS with MSI-H/I tumors, 50% (33 of 66) had tumors other than CRC/EC, including urothelial, prostate, pancreas, adrenocortical, small bowel, sarcoma, mesothelioma, melanoma, gastric, and germ cell tumors. In these patients with non-CRC/EC tumors, 45% (15 of 33) did not meet LS genetic testing criteria on the basis of personal/family history. Immunohistochemical staining of LS-positive MSI-H/I tumors demonstrated MMR-D in 98.2% (56 of 57) of available cases. CONCLUSION/CONCLUSIONS:MSI-H/MMR-D is predictive of LS across a much broader tumor spectrum than currently appreciated. Given implications for cancer surveillance and prevention measures in affected families, these data support germline genetic assessment for LS for patients with an MSI-H/MMR-D tumor, regardless of cancer type or family cancer history.

PURPOSE/OBJECTIVE:The treatment paradigm for uterine clear cell carcinoma is often linked to serous carcinoma. This study compares oncologic outcomes between women with uterine clear cell and serous carcinoma. METHODS AND MATERIALS/METHODS:We reviewed 114 women with stage I-II uterine clear cell carcinoma (n = 17, 15%) or serous carcinoma (n = 97, 85%) who underwent hysterectomy and salpingo-oophorectomy at our institution from April 1992 to December 2011; 86 (76%) had stage IA, 14 (12%) had stage IB, and 14 (12%) had stage II disease. Median followup was 57 months. RESULTS:Patients with uterine clear cell and serous carcinoma did not differ significantly by age ≥60 years, stage, or rate of lymphovascular invasion. There was no difference in the number of patients with clear cell or serous histology who received adjuvant radiotherapy (71% vs. 84%, respectively; p = 0.31); however, significantly fewer patients with clear cell histology received adjuvant chemotherapy (35% vs. 67%, respectively; p = 0.02). At 5 years, there were no significant differences in disease-free survival (94% vs. 84%, respectively; p = 0.27), disease-specific survival (100% vs. 92%, respectively; p = 0.20), or overall survival (100% vs. 89%, respectively; p = 0.34). The differences in chemotherapy utilization did not impact pattern of relapse, specifically peritoneal spread (7% vs. 6%, respectively; p = 0.92) or other distant sites (0% vs. 9%, respectively; p = 0.17). CONCLUSIONS:Oncologic outcomes and recurrence patterns of women with stage I-II uterine clear cell carcinoma compared favorably with those of women with serous carcinoma, despite significantly less adjuvant chemotherapy use. Potential reduction in adjuvant therapy in women with clear cell carcinoma should be studied prospectively.

PURPOSE/OBJECTIVE:Advanced-stage endometrial cancers have limited treatment options and poor prognosis, highlighting the need to understand genetic drivers of therapeutic vulnerabilities and/or prognostic predictors. We examined whether prospective molecular characterization of recurrent and metastatic disease can reveal grade and histology-specific differences, facilitating enrollment onto clinical trials. EXPERIMENTAL DESIGN/METHODS:We integrated prospective clinical sequencing and IHC data with detailed clinical and treatment histories for 197 tumors, profiled by MSK-IMPACT from 189 patients treated at Memorial Sloan Kettering Cancer Center. RESULTS:= 0.006). Of the 68% of patients harboring potentially actionable mutations, 27% were enrolled to matched clinical trials, of which 47% of these achieved clinical benefit. CONCLUSIONS:Prospective clinical sequencing of advanced endometrial cancer can help refine prognosis and aid treatment decision making by simultaneously detecting microsatellite status, germline predisposition syndromes, and potentially actionable mutations. A small overall proportion of all patients tested received investigational, genomically matched therapy as part of clinical trials.

AIMS/OBJECTIVE:The most common BRAF mutation in ovarian low-grade serous neoplasms (LGSNs) involves substitution of valine by glutamic acid at position 600 (V600E). Small studies have demonstrated high specificity of immunohistochemistry with mutation-specific monoclonal antibody VE1. We sought to investigate the expression of VE1 protein in LGSNs and its correlation with BRAF mutation-associated histological features and BRAF mutation status. METHODS AND RESULTS/RESULTS:-mutated tumours and correlated with BRAF mutation-associated histological features (P < 0.0001). CONCLUSIONS:mutations.