11. Adjuvant Radiotherapy Is Associated With Increased Sexual Dysfunction In Male Patients Undergoing Resection For Rectal Cancer - A Predictive Model
Alexander G. Heriot, MD FRCS*, Paris P. Tekkis, MD FCRS*, Paul Neary, MD FRCSI*, Victor W. Fazio, MD MS, Ian C. Lavery, MB BS*
Department of Colorectal Surgery, Cleveland Clinic Foundation, Cleveland, OH
OBJECTIVE:To evaluate the effect of radiotherapy(RT) on sexual function in patients undergoing resection for rectal cancer. To develop a predictive model for quantifying the risk of sexual dysfunction for these patients.
METHODS:Data were prospectively collected on patients undergoing rectosigmoidectomy (Group-1: n=101) or adjuvant radiotherapy(45Gy) and resection (Group-2: n=100) for rectal cancer at a tertiary referral center between 1998-2004. Study endpoints were recorded at pre-operatively, 4-months, 8-months, 1,2,3 and 4-years post-operatively. These included: (1) ability to get an erection (2)maintain erection (3)attain orgasm (4)dry orgasm (5)being sexually active. Multilevel logistic regression for repeated measures was used. The predictive model developed was validated by comparing observed and model-predicted outcomes.
RESULTS:Radiotherapy significantly reduced the ability of patients to get an erection (68% vs. 75%;p<0.05), attain orgasm (71% vs. 81%;p<0.05), and be sexually active (59% vs. 77%;p<0.05) at 1-year following surgery in comparison with patients undergoing surgery alone. The effect of sexual dysfunction was age-dependent with marked deterioration at age >60 (OR for erectile function=0.77 per-year,p<0.001). A significant variability in sexual fuction was present between time points with maximal deterioration 8-months following surgery(p<0.001). The predictive model showed adequate discrimination at 1-year (area under ROC curve=77% group-1 and 73% for Group-2).
CONCLUSIONS:Radiotherapy has an adverse effect on sexual function, the effect being maximal at 8-months following surgery. The risk of sexual dysfunction can be quantified pre-operatively using the proposed index and can assist patients in making better informed choices on the type of treatment they receive.