The role of adjuvant treatment for early-stage uterine clear cell carcinomas.

BACKGROUND: Uterine clear cell carcinoma is a rare and aggressive subtype of endometrial carcinoma. Prospective clinical trials have not been feasible for this rare tumor, and data regarding the optimal adjuvant treatment regimen for early-stage uterine clear cell carcinomas is limited. Our study's objective was to determine if adjuvant chemotherapy or radiation therapy improves patients' outcomes in stage I and II uterine clear cell carcinoma. METHODS: Patients with stage I and II uterine clear cell carcinoma were identified at a single institution. All cases were reviewed by a gynecologic pathologist. Both pure and mixed non-serous uterine clear cell carcinomas were included. Primary outcomes were recurrence free survival and overall survival. RESULTS: A total of 71 patients were identified including 39 (55%) pure and 32 (45%) mixed clear cell carcinoma. Most patients were FIGO stage IA (77.5%). Most patients (n = 58, 82%) received adjuvant therapy, including 43 (61%) receiving chemotherapy, 50 (70%) receiving radiation therapy, and 35 (49%) receiving both. Recurrence free survival was not significantly different among patients receiving no or <6 cycles of chemotherapy versus patients receiving 6 cycles of chemotherapy (p = 0.39). However, median OS was significantly different among patients receiving no or <6 cycles of chemotherapy versus 6 cycles of chemotherapy (p = 0.004). On univariable analysis, 6 cycles of chemotherapy was significantly associated with improved OS (HR 0.1, 95% CI 0.01-0.07). Presence of LVSI, mutated p53, number of pelvic and para-aortic lymph nodes assessed, adjuvant chemotherapy (any number of cycles), and >2 medical co-morbidities were not significant predictors of OS on univariable analysis. On multivariable analysis, 6 cycles of adjuvant chemotherapy remained a significant predictor of improved OS (HR 0.1, 95% CI 0.01-0.8). CONCLUSIONS: In this study, administration of 6 cycles of chemotherapy appears to significantly improve OS. This finding suggests consideration of 6 cycles of adjuvant chemotherapy in patients with early-stage uterine clear cell carcinoma, however clinical trials are needed to confirm these findings.

Cost-effectiveness analysis of tumor molecular classification in high-risk early-stage endometrial cancer.

PURPOSE: Tumor molecular analyses in endometrial cancer (EC) includes 4 distinct subtypes: (1) POLE-mutated, (2) mismatch repair protein (MMR) deficient, (3) p53 mutant, and (4) no specific molecular profile. Recently, a sub-analysis of PORTEC-3 demonstrated notable differences in treatment response between molecular classification (MC) groups. Cost of testing is one barrier to widespread adoption of MC. Therefore, we sought to determine the cost-effectiveness of MC in patients with stage I and II high-risk EC. METHODS: A Markov decision model was developed to compare tumor molecular classification (TMC) vs. no testing (NT). A healthcare payor's perspective and 5-year time horizon were used. Base case data were abstracted from PORTEC-3 and the molecular sub-analysis. Cost and utility data were derived from public databases, peer-reviewed literature, and expert input. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with effectiveness in quality-adjusted life years (QALYs) and evaluated with a willingness-to-pay threshold of $100,000 per QALY gained. Sensitivity analyses were performed to test model robustness. RESULTS: When compared to NT, TMC was cost effective with an ICER of $25,578 per QALY gained; incremental cost was $1780 and incremental effectiveness was 0.070 QALYs. In one-way sensitivity analyses, results were most sensitive to the cost of POLE testing, but TMC remained cost-effective over all parameter ranges. CONCLUSIONS: TMC in early-stage high-risk EC is cost-effective, and the model results were robust over a range of parameters. Given that MC can be used to guide adjuvant treatment decisions, these findings support adoption of TMC into routine practice.