Radiotherapy-induced vaginal fibrosis in cervical cancer survivors.

BACKGROUND: Cervical cancer survivors treated with radiotherapy report vaginal inelasticity and decreased lubrication that may affect their sexual health, but it is unknown which normal tissue reactions mediate these symptoms. The aim of this study was to investigate the morphology of the connective tissue of the vaginal wall in cervical cancer survivors treated with radiotherapy.

MATERIAL AND METHODS: We recruited 34 cervical cancer survivors treated with radiotherapy and 37 age-matched controls. Via clinical examination the degree of vaginal atrophy and pelvic fibrosis were estimated. We collected vaginal biopsies, which underwent morphometric analysis focused on elastin and collagen. Additionally, radiation dose at biopsy site were calculated and correlated to the clinical and morphological findings.

RESULTS: The survivors had marked morphological vaginal changes, most prominent in the survivors that had received the highest radiation dose at the biopsy site. Mucosal atrophy was observed in 91% and pelvic fibrosis in 97%. A shorter vagina was measured; 7.0 cm versus 10.3 cm in controls (p < 0.001). The area fraction of elastin was greater in survivors; 10.0% (range 5.8-12.9), compared with controls; 3.4% (range 1.8-5.8), p < 0.001. The survivors had signs of elastosis with thick aggregated elastin fibers irregularly scattered throughout the connective tissue, while the controls had elastin fibers in a thin sub-epithelial layer. The area fraction of high density collagen in the connective tissue was larger among the survivors (p < 0.001). The collagen with the highest density (fibrosis) was more common in the group of cancer survivors that had received external radiation.

CONCLUSIONS: We found drastic differences in the vaginal wall between the irradiated cervical cancer survivors and the controls, indicating that radiotherapy-induced vaginal symptoms are mediated by connective tissue fibrosis and elastosis. Our results also support that patients treated with external radiation have the highest risk of developing vaginal fibrosis with impairment of their sexual health.