Adjuvant Chemoradiation Therapy for Cervical Cancer and Effect of Timing and Duration on Treatment Outcome

Abstract

Worse treatment outcomes can be expected with prolongation of the overall treatment time (OTT) during definitive chemoradiation therapy (CRT) for cervical cancer. In the adjuvant setting, data on the relative importance of the OTT and the importance of RT and chemotherapy synchronization are scarce. Using the National Cancer Database, we evaluated the effect of these treatment variables on overall survival in the adjuvant CRT setting. The present analysis included nonmetastatic cervical cancer patients undergoing hysterectomy followed by adjuvant CRT. The proportional hazard model was used to estimate the effect of prognostic factors (age, comorbidity, race, tumor size, tumor grade, tumor histologic type, number of high-risk pathologic factors) and time-related variables (surgery to RT start interval [SR], OTT [RT start to end dates], package time [from diagnosis date to CRT end date] and optimum CRT synchronization [whether chemotherapy and RT start dates coincided]) on survival. Of 3051 patients, 60% finished RT within 7weeks and 85% received optimum CRT. Among other factors, univariate analysis identified longer OTT (hazards ratio [HR] 1.33; P<.001), longer SR (HR 1.17; P=.05), and nonoptimum CRT timing (HR 1.21; P=.04) as poor prognosticators. Of these factors, SR (HR 1.20; P=.04) and OTT (HR 1.21; P=.002) retained significance on multivariate analysis. An OTT >7weeks remained a significant factor even after propensity score matching (P=.04). The results of our analysis suggest that prolongation of the adjuvant CRT duration >7weeks is associated with poor survival and SR of <8weeks should be attempted whenever clinically feasible.