Although the majority of low grade, early stage endometrial cancer patients will have good survival outcomes with surgery alone, those patients who do recur tend to do poorly. Optimal identification of the subset of patients who are at high risk of recurrence and would benefit from adjuvant treatment has been difficult. The purpose of this study was to evaluate the impact of somatic tumor mutation on survival outcomes in this patient population. For this study, low grade was defined as endometrioid FIGO grades 1 or 2, while early stage was defined as endometrioid stages I or II (disease confined to the uterus). Next-generation sequencing was performed using panels comprised of 46–200 genes. Recurrence-free and overall survival was compared across gene mutational status in both univariate and multivariate analyses. In all, 342 patients were identified, 245 of which had endometrioid histology. For grades 1–2, stages I–II endometrioid endometrial cancer patients, age (HR 1.07, 95% CI 1.03–1.10), CTNNB1 mutation (HR 5.97, 95% CI 2.69–13.21), and TP53 mutation (HR 4.07, 95% CI 1.57–10.54) were associated with worse recurrence-free survival on multivariate analysis. When considering endometrioid tumors of all grades and stages, CTNNB1 mutant tumors were associated with significantly higher rates of grades 1–2 disease, lower rates of deep myometrial invasion, and lower rates of lymphatic/vascular space invasion. When both TP53 and CTNNB1 mutations were considered, presence of either TP53 mutation or CTNNB1 mutation remained a statistically significant predictor of recurrence-free survival on multivariate analysis and was associated with a more precise confidence interval (HR 4.69, 95% CI 2.38–9.24). Thus, mutational analysis of a 2 gene panel of CTNNB1 and TP53 can help to identify a subset of low grade, early stage endometrial cancer patients who are at high risk of recurrence.
Although the majority of low-grade, early-stage endometrial cancer patients have good survival with surgery alone, patients who recur tend to do poorly. Identification of patients at high risk of recurrence who would benefit from adjuvant treatment or more extensive surgical staging would help optimize individualized care of endometrial cancer patients. CTNNB1 (encodes β-catenin) mutations identify a subset of low-grade, early-stage endometrial cancer patients at high risk of recurrence. Mutation of CTNNB1 exon 3 is classically associated with translocation of the β-catenin protein from the membrane to the nucleus and activation of Wnt/β-catenin signaling. Given the clinical utility of identifying endometrial carcinomas with CTNNB1 mutation, the purpose of this study was to determine if immunohistochemistry could act as a surrogate for CTNNB1 gene sequencing. Next-generation sequencing was performed on 345 endometrial carcinomas. Immunohistochemical localization of β-catenin was determined for 53/63 CTNNB1 exon 3 mutant tumors for which tissue was available and a subset of wild-type tumors. Nuclear localization of β-catenin had 100% specificity in distinguishing CTNNB1 mutant from wild type, but sensitivity was lower (84.9%). Nearly half of CTNNB1 mutant cases had only 5–10% of tumor cells with β-catenin nuclear localization. The concordance between pathologists blinded to mutation status in assessing nuclear localization was 100%. The extent of β-catenin nuclear localization was not associated with specific CTNNB1 gene mutation, tumor grade, presence of non-endometrioid component, or specific concurrent gene mutations in the tumor. For comparison, nuclear localization of β-catenin was more diffuse in desmoid fibromatosis, a tumor also associated with CTNNB1 mutation. Thus, nuclear localization of β-catenin assessed by immunohistochemistry does not detect all endometrial cancers with CTNNB1 gene mutation. The extent of nuclear localization may be tumor type dependent. For endometrial cancer, immunohistochemistry could be an initial screen, with CTNNB1 sequencing employed when nuclear localization of β-catenin is absent.
Primary mucinous ovarian cancer is a rare type of epithelial ovarian cancer. In this comprehensive review we discuss management recommendations for the treatment of mucinous ovarian cancer. Although most tumors are stage I at diagnosis, 15–20% are advanced stage at diagnosis. Traditionally, patients with primary mucinous ovarian cancer have been treated similarly to those with the more common serous ovarian cancer. However, recent studies have shown that mucinous ovarian cancer is very different from other types of epithelial ovarian cancer. Primary mucinous ovarian cancer is less likely to spread to lymph nodes or the upper abdomen and more likely to affect younger women, who may desire fertility-sparing therapies. Surgical management of mucinous ovarian cancer mirrors surgical management of other types of epithelial ovarian cancer and includes a bilateral salpingo-oophorectomy and total hysterectomy. When staging is indicated, it should include pelvic washing, omentectomy, and peritoneal biopsies; lymph node evaluation should be considered in patients with infiltrative tumors. The appendix should be routinely evaluated intra-operatively, but an appendectomy may be omitted if the appendix appears grossly normal. Fertility preservation can be considered in patients with gross disease confined to one ovary and a normal-appearing contralateral ovary. Patients with recurrent platinum-sensitive disease whose disease distribution suggests a high likelihood of complete gross resection may be candidates for secondary debulking. Primary mucinous ovarian cancer seems to be resistant to standard platinum-and-taxane regimens used frequently for other types of ovarian cancer. Gastrointestinal cancer regimens are another option; these include 5-fluorouracil and oxaliplatin, or capecitabine and oxaliplatin. Data on heated intra-peritoneal chemotherapy (HIPEC) for mucinous ovarian cancer are scarce, but HIPEC may be worth considering. For patients with recurrence or progression on first-line chemotherapy, we advocate enrollment in a clinical trial if one is available. For this reason, it may be beneficial to perform molecular testing in all patients with recurrent or progressive mucinous ovarian cancer.