Clinicopathologic features, incidence, and survival trends of gynecologic neuroendocrine tumors: a SEER database analysis

BACKGROUND: Primary gynecologic neuroendocrine tumors are uncommon malignant neoplasms associated with poor prognosis. Clinically, these tumors present a significant challenge because of the lack of standardized management guidelines. OBJECTIVE: The objective of this study is to evaluate the clinicopathologic features, incidence, and survival trends in gynecologic neuroendocrine tumors. MATERIALS AND METHODS: The Surveillance, Epidemiology and End Results (SEER) cancer registry was queried for women diagnosed with primary gynecologic neuroendocrine tumors from 1987 to 2012. Data regarding stage, grade, presence of extrauterine disease, receipt of adjuvant radiation, surgical intervention, incidence, and overall survival were extracted. Patients were classified as having early-stage disease (International Federation of Gynecology and Obstetrics Stage I/II) or advanced-stage disease (Stage III/IV). Extrauterine disease was defined as either regional or distant metastasis. chi(2) Tests, Pearson correlation, and KaplaneMeier curves were used for statistical analysis. RESULTS: In all, 559 cases of gynecologic neuroendocrine tumors were identified during the study period: 242 cervical, 160 ovarian, 118 uterine, and 39 vulvar/vaginal. The majority of patients in all subsets of gynecologic neuroendocrine tumors presented with poorly differentiated tumors, extrauterine disease spread, and advanced-stage disease. Poorly differentiated tumors represented 65.0% of cervical tumors, 45.3% of ovarian tumors, and 57.4% of uterine tumors. Extrauterine disease at the time of diagnosis was present in the case of 66.9% of cervical tumors, 83.5% of ovarian tumors, and 83.6% of uterine tumors. The overall incidence of gynecologic neuroendocrine tumors increased 4-fold during the study period, from 0.3 in 1987 to 1.30 per million in 2012. The study period was divided into two 13-year periods (1987-1999 and 2000-2012) for time trend mean survival analysis. We observed no significant change in overall survival across all gynecologic neuroendocrine tumor subtypes. The mean survival time of cervical neuroendocrine tumors was 74.3 vs 45.4 months (P = .31), ovarian neuroendocrine tumors 47.8 vs 41.2 months (P = .56), and uterine neuroendocrine tumors 42.9 vs 47.7 months (P = .44) for each time period, respectively. CONCLUSION: Neuroendocrine tumors of the gynecologic tract are uncommon aggressive malignancies. These poorly differentiated tumors present at advanced stage, with a high incidence of extrauterine disease. Despite 25 years of advances in cancer therapy, we observed no improvement in overall survival.