A study of the effect of preoperative chemoradiotherapy on sexual dysfunction in men with locally advanced rectal cancer

Interventions: Observational Study of male sexual dysfunction. Duration of observation 18 months. Assessments will be made at baseline (before radiotherapy) and at 3, 6,9, 12 and 18 months following radiotherapy. Primary outcome(s): Rate of male sexual dysfunction at 6months post-treatment, as defined by an IIEF (International Index of Erectile Function[At 6 months following radiotherapy] Study Design: Purpose: Natural history;Duration: Longitudinal;Selection: Defined population;Timing: Prospective