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


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).


CONCLUSIONS
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.
Department of Applied Radiobiology, Maria Sklodowska - Curie Memorial Cancer Centre and Institute of Oncology, Cracow Branch, Poland.
Anna
A
Gasinska
Department of Surgery, Maria Sklodowska - Curie Memorial Cancer Centre and Institute of Oncology, Cracow Branch, Poland.
Zbigniew
Z
Darasz
Department of Applied Radiobiology, Maria Sklodowska - Curie Memorial Cancer Centre and Institute of Oncology, Cracow Branch, Poland.
Agnieszka
A
Adamczyk
Department of Radiation Oncology, Maria Sklodowska - Curie Memorial Cancer Centre and Institute of Oncology, Cracow Branch, Poland.
Jan
J
Skolyszewski
Break in the treatment; Overall treatment time; Patients' survival; Preoperative radiotherapy; Rectal cancer