Gender-related prognostic significance of clinical and biological tumor features in rectal cancer patients receiving short-course preoperative radiotherapy

Abstract

Aim

To study the prognostic value of clinical and biological features of rectal cancer and potential gender differences in patients’ overall survival (OS), local recurrence-free survival (RFS) and metastasis-free survival (MFS) after short-course preoperative radiotherapy (SCRT) with short or long interval between RT and surgery (break).

Background

The length of the interval between RT and surgery in SCRT is debatable and gender-related differences in patients survival are not established yet.

Materials and methods

126 patients received SCRT with 5[[ce:hsp sp="0.25"/]]Gy dose per fraction during 5 days, followed by radical surgery after short break ≤17 days, and a long break >17 days. Pretreatment tumor proliferation (bromodeoxyuridine labeling index, BrdUrdLI and S-phase fraction) was evaluated by flow cytometry and proteins: CD34, Ki-67, GLUT-1, Ku70, BCL-2, P53 expression was studied immunohistochemically.

Results

The studied group included 84 men and 42 women. There were 33, 76, and 17 cTNM (AJCC) tumor stages I, II, III, respectively. The median follow-up time was 53.3 months (range 2–142 months). For the whole group Cox multivariate analysis revealed that tumor grade (G[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]1), interval between RT and surgery >17 days, pTNM stage >1 and P53 positivity[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]BrdUrdLI[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]7.9% were negative prognostic factors for OS. Tumor aneuploidy and MVD[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]140.8[[ce:hsp sp="0.25"/]]vessels/mm² were important for RFS. pTNM stage[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]1 and P53 positivity combined with BrdUrdLI[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]7.9% were risk predictors for MFS. Based on tumor biological features, gender-related difference in OS, RFS, and MFS were observed. In multivariate analysis, male patients age[[ce:hsp sp="0.25"/]]>[[ce:hsp sp="0.25"/]]62 years and break >17 days only appeared to be significant for OS.

Conclusions

In male rectal patients treated with SCRT, breaks between RT and surgery >17 days should be avoided because they negatively influence patients’ survival.