The impact of the time factor on the outcome of a combined treatment of patients with laryngeal cancer

PurposeTo investigate the impact of the time factor on the locoregional control in combined treatment (surgery and postoperative radiotherapy) in patients with advanced laryngeal cancer.Materials and MethodsBetween January 1993 and December 1996, 254 patients with pT3 or pT4 and pN0-pN2 laryngeal cancer were treated by surgery and postoperative radiotherapy (RT). The median age of patients was 56.3 years (range: 30–70 years). The analyzed group consisted of 236 males (92%) and 18 females (8%). In all cases total laryngectomy was performed. 196 out of 254 patients underwent homolateral neck dissection and 58 out of 254 bilateral neck dissection. RT began 45 days postoperatively (range: 22 to 78 days) and continued for 47 days (range: 40–74 days). The primary tumour bed was irradiated to the median total dose of 61.2 Gy (range: 57 – 64 Gy) and all regional lymph nodes were treated in all patients to a dose of 50 Gy. Postoperative RT was indicated in case of close postoperative margins at the tumour site or pathological status of lymph nodes described as pN1 or pN2. Univariate and multivariate analyses were used to determine the predictors for locoregional failure. The following factors were studied for their prognostic importance of locoregional outcome: the overall treatment time (OTT), radiotherapy treatment time (RTT), the interval between surgery and the beginning of radiotherapy, age, sex, pT and pN categories.Results: The actuarial 5-year overall survival rate was 49%, the actuarial loco regional control rate was 70%. The univariate analysis, using a log-rank test indicated that prolongation of the overall treatment time (OTT), the time of radiotherapy (RTT), the interval time between surgery and radiotherapy, and the pN status were predicted for the loco regional control of postoperative radiotherapy. The multivariate analysis using Cox proportional hazard model indicated that only RTT, OTT, and the pathological status of lymph nodes were independent prognostic factors for the loco regional control.Conclusions: The analysis showed that the prolongation of the overall treatment time of the combined modality (OTT) and the time of radiotherapy course (RTT) were independent prognostic time factors correlated with lower loco regional control.