Gender differences in the treatment of rectal cancer: a population based study

Colorectal cancer is the second most common type of cancer in both women and men in Sweden. A National Quality Register for rectal adenocarcinoma in Sweden has included 97% of all rectal cancer patients since 1995. A previous study, based on data from the treatment program register in the Stockholm-Gotland region, found that women in Stockholm received preoperative radiotherapy (RT) less often than men [Martling A. Rectal cancer: staging, radiotherapy and surgery, ISBN: 91-7349-461-5. Stockholm: Karolinska Institute; 2003].(1) The aim of this study was to assess if women and men with rectal cancer receive equal treatment on a national level, and whether any potential dissimilarity causes measurable consequences in outcome, regarding postoperative morbidity and mortality, tumour recurrence and survival.

All patients with rectal cancer included in the National Quality Register between 1995 and 2002 (11,774 patients) were analysed. Gender was correlated to treatment, postoperative morbidity and mortality, local recurrence and death.

The proportion of women selected for preoperative RT was significantly lower than that of men (42.5% vs. 50.1%, p<0.001). After adjustment for other prognostic factors, the significant difference in the treatment strategy among women and men persisted. Postoperative mortality was significantly higher in men than in women and the gender difference was most pronounced in irradiated patients. RT improved local control significantly in both women and men but it had no effect on cancer specific survival.

For unknown reasons women less often received adjuvant RT than men. The opposite appeared to be a more adequate alternative. There is a need of improved selection criteria for RT in both men and women with rectal cancer.