Despite the decrease in overall cancer incidence and mortality rates in developed countries since the early 1990s, cancer remains a major public health problem. Sexual wellbeing may be altered by both the diagnosis and treatment of cancer. Sexual dysfunction is often unrecognized, underestimated and untreated. Biological factors such as anatomic alterations (rectum amputation, penile amputation), physiological changes (hormonal status) and secondary effect of medical intervention may preclude normal sexual functioning even when sex desire is intact. Side effects of the treatment such as nausea, vomiting, fatigue, hair loss can result in adverse effects on sexuality together with disfiguring surgery.

Radiotherapy and surgery are the most effective treatments for prostate cancer. Erectile dysfunction (ED) is reported in 6-80% after external-beam radiotherapy and 2- 61% after brachytherapy. ED after surgery is reported in 40- 100%. Testicular cancer affects mostly young men in their fertile and sexually active life. ED, loss of libido, decreased orgasm have been reported in about 20% of these patients. Surgery and radiation therapy for gynaecological cancer can alter vaginal sensation and may cause stenosis leading to painful penetration in 50% of the treated women. Cytotoxic and hormonal therapy in men can result in loss of libido and ED. In women these treatments lead to ovarian suppression, with vaginal discharge, dryness, dyspareunia and a loss of sexual interest.

Collecting data on an ongoing basis before and for as long as possible is mandatory.