Adjuvant Chemoradiotherapy in Cervical Cancer and the Impact of Timing and Duration on Treatment Outcome
Menée aux Etats-Unis à partir des données du registre national des cancers portant sur 3 051 patientes atteintes d'un cancer du col de l'utérus, cette étude évalue l'effet d'une chimioradiothérapie adjuvante sur la survie des patientes en fonction de la durée du traitement adjuvant et des délais entre l'intervention chirurgicale et la radiothérapie
Purpose : Worse Treatment outcomes are expected with prolongation of overall treatment time (OTT) during definitive chemoradiotherapy of cervical cancer. In the adjuvant setting, data on the relative importance of OTT and the importance of radiotherapy and chemotherapy synchronization are scarce. Using the National Cancer Data Base, we aimed to evaluate the impact of these treatment variables on overall survival in the adjuvant chemoradiotherapy setting. Methods : The analysis included non-metastatic cervical cancer patients undergoing hysterectomy followed by adjuvant chemoradiotherapy. The proportional hazard model estimated the effect of prognostic factors (age, comorbidity, race, tumor size, grade and histology, number of high risk pathologic factors) and time-related variables (surgery to radiotherapy start interval (SR), OTT (radiotherapy start to end dates), package time (from diagnosis date to CRT end date) and optimum chemoradiotherapy synchronization (if chemotherapy and radiation start date coincided) on survival. Results : Of the 3051 patients, 60% finished RT within 7 weeks and 85% had optimum chemoradiotherapy. Among other factors, univariate analysis identified longer OTT (hazards ratio (HR): 1.33; p<0.001), longer SR (HR: 1.17; p=0.05) and non-optimum CRT timing (HR: 1.21; p=0.04) as poor prognosticators. Of these factors, SR (HR: 1.20; p=0.04) and OTT (HR: 1.21; p=0.002) retained significance on multivariate analysis. OTT exceeding 7 weeks remained a significant factor even after propensity score matching (p=0.04). Conclusions : Our analysis suggests that prolongation of adjuvant chemoradiotherapy duration beyond 7 weeks is associated with poor survival, and surgery to radiotherapy interval less than 8 weeks should be attempted whenever clinically feasible.