Prevalence and Predictors of Sexual Dysfunction (SD) after Treatment of Localized Rectal and Anal Cancer (LRAC).

PURPOSE/OBJECTIVE(S): SD is possible after treatment of LRAC and is associated with distress and impaired quality of life. We report the prevalence of SD in our LRAC patients treated with curative intent. We also evaluate patient/treatment-related factors associated with SD.

MATERIALS/METHODS: LRAC patients from 2010-2022 were identified. Consented patients were surveyed and patient/treatment factors were collated from medical records. Sexual function (SF) was measured using the Female Sexual Function Index (FSFI) and the International Index of Erectile Function (IIEF). The impact of disease/treatment on SF since treatment was measured using the SF Questionnaire Medical Impact Scale (SFQ-MIS). FSFI ≤ 19.2 and IIEF ≤ 32.2 were considered SD based on the mean scores of SD patients in the primary literature. SFQ-MIS ≥ 15.5 was used to dichotomize responses into "at least some impact" versus "at least no impact." Spearman rank correlations examined correlations between FSFI/IIEF and factors. Comparisons involving componential domains and factors were based on a two-sided Mann-Whitney test. RT dose, surgery, the extent of lymphadenectomy, T stage, and time since treatment were factors assessed in all patients. In females, dilator use during RT, tumor distance (TD) from the anterior vaginal wall and whole vagina, and V25Gy, V45Gy, and mean dose to the anterior vaginal wall and whole vagina were other factors assessed. In males, TD from the neurovascular bundle (NVB), V25Gy, V45Gy, and mean dose to NVB was used.

RESULTS: Forty-five patients (13.5% response rate) completed study surveys (62% males; 80% white; 71% rectal cancer patients). The median age and time since treatment were 63 and 4 yrs. respectively. RT doses ranged from 25 - 54Gy. The overall prevalence of SD was 58% (71% in females; 50% in males). The proportion of patients who reported at least some SF impact was 56% (53% in females; 57% in males). There was a marginal association between higher total IIEF and receipt of surgery (p = 0.059). A correlation of 0.44 was seen between total IIEF and TD from upper NVB-the strongest among all comparisons. In the domains of IIEF, statistically significant associations were found between intercourse satisfaction (ISAT) and TD from upper NVB (p = 0.004), overall satisfaction (OSAT) and TD from lower NVB (p = 0.040), and ISAT and T stage (p = 0.047). There were marginal associations between TD from upper NVB and OSAT (p = 0.052), orgasm (p = 0.063), and erectile dysfunction (p = 0.097). There was a marginal association between V25Gy to the anterior vaginal wall and pain during penetrative sex (p = 0.095). No other association with FSFI or its domains was significant.

CONCLUSION: SD is prevalent in a large majority of patients studied (58%). In males, higher TD from NVB was associated with better overall SF, better intercourse, and overall satisfaction. While a higher proportion of females had SD, no significant associations were found in females likely due to their small sample size.