The role of radiotherapy in neuroendocrine cervical cancer: SEER-based study.

Abstract

There are few randomised prospective data or guidelines for the treatment of neuroendocrine cervical cancer (NECC). In addition, the role of radiotherapy (RT) in NECC remains controversial. We used the Surveillance Epidemiology and End Results (SEER) database to investigate the role of RT for the treatment of NECC. Particular attention was paid to the different role of RT in patients with or without a metastasis (M1 or M0). The SEER database was queried for studies on NECC. We limited the year of diagnosis to the years 2000 to 2015. A Pearson's two-sided Chi-squared test, the Kaplan-Meier method and Cox regression analysis models were used for statistical analyses. The overall survival (OS) was studied for the overall group and between-subgroup groups. NECC was an aggressive disease with a mean OS of only 46.3 months (range of 0-196 months, median of 23 months). No significant differences were shown between the surgery (S) and S + RT groups (p = 0.146) in the M0 (without metastasis) arm. However, there was a statistically significant difference in OS between the S and S + RT groups in the M1 (with metastasis) arm (median of 44.6 months for the S group and 80.9 months for the S + RT group), p = 0.004. The mean survival was significantly longer for M0 patients than for M1 patients when treated with S only (S arm), that is, 82.1 months versus 44.6 months, respectively (log-rank p = 0.000). We also noted that when patients received adjuvant RT (S + RT arm), there were no significant differences between the M0 and M1 groups (median of 90.6 and 81.0 months, p = 0.704, respectively). Age at diagnosis, chemotherapy, T stage and N stage were significant factors for OS in the M0 arm. Interestingly, radiotherapy was the only significant factor for OS with a multivariate HR for death of 0.502 (95% CI 0.206-0.750, p = 0.006) in the M1 arm. RT may be carefully used in patients who are negative for metastases. Using SEER data, we identified a significant survival advantage with the combination of radiotherapy and surgery in NECC with metastases. This suggests that active local treatment should be conducted and has a significant impact on OS, even if a distant metastasis has occurred.