Epidemiology and outcomes of squamous ovarian carcinoma; A population-based study

OBJECTIVE: Squamous ovarian carcinoma (SOC) is a rare tumor. Scarcity of information about the epidemiology and prognosis of SOC hinders attempts at optimal patient management. This retrospective study of a large cohort details the clinicopathological and demographic characteristics and prognosis of women with SOC. METHODS: A cohort of patients drawn from the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database who were diagnosed with SOC between 1988 and 2012 were analyzed. Observed and disease-specific survival was estimated by Kaplan-Meier plots in women who underwent surgery as part of their cancer-related treatment. A Cox hazard regression analysis was performed to determine independent predictors of cancer-specific survival in patients with SOC. RESULTS: We identified 341 patients with SOC with a median age at diagnosis of 55 years. Stage I, II, III and IV tumors were noted in 34%, 15%, 20.5% and 24.9% of patients, respectively. Five-year cancer-specific survival was 86% for stage I, 54.3% for stage II, 36.3% for stage III and 2.8% for stage IV disease patients. Observed and cancer-specific survival was better for patients that underwent lymphadenectomy (p=0.031). Postoperative radiotherapy was not associated with improved survival. In a multivariate analysis, independent predictors of improved cancer-specific survival were younger age, lower disease stage and lymphadenectomy. CONCLUSIONS: SOC is typically a unilateral malignancy with a tendency toward loco-regional spread. Stage I patients have a relatively high survival rate; however, the prognosis is poor for women with abdominal or distant spread. Lymphadenectomy, but not postoperative radiotherapy, is associated with improved survival.