Gender-related significance of time interval between radiotherapy and surgery in hypofractionated preoperative radiotherapy for rectal cancer patients' survival.

AIM AND
BACKGROUND: An optimal break between radiotherapy (RT) and surgery in short-course of RT (SCRT) for locally advanced rectal cancer is not clearly established. The aim of the study was to investigate the influence of the break in the preoperative SCRT and overall treatment time (OTT) for locally advanced rectal cancer patients (whole group and male/female subgroups) on patients overall survival (OS), recurrence-free survival (RFS), metastasis-free survival (MFS).
MATERIALS AND METHODS: 131 patients were treated with SCRT (5 Gy/5 days), followed by surgery 3-53 days later. Break was calculated as the time interval between the end of irradiation to surgery and OTT as time interval from the beginning of RT to surgery.
RESULTS: Mean break was 21.5 (range 3-53.0) days and mean OTT was 26.5 (range 7-58.0) days. In univariate analysis, a break longer than 15 days and OTT >23 days were negative prognostic factors for OS for all patients, and particularly for the male patients' subgroup. RFS was non-significantly higher (P = 0.066) for patients treated with a break ≤15 days and OTT ≤23 days (P = 0.099), irrespectively of patients' sex. Patients treated with a break longer than 15 days and OTT >23 days had non-significantly lower level of MFS than those treated with a shorter break (P = 0.269) and OTT ≤23 days (P = 0.498).
CONCLUSION: In SCRT, a break in the treatment longer than 15 days, especially in the male patients subgroup, should be avoided, because it negatively affects patients' survival.