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.

The Effect of Stereotactic Body Radiotherapy (SBRT) Dose-Fraction (fx) Schema on Non-Small Cell Lung Cancer (NSCLC)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) dose-fraction (fx) schema for non-small cell lung cancer (NSCLC) varies at different centers and commonly involves 3 to 5 fx. Additionally, the frequency of treatment per week, or treatment schedules (TS), can also differ. We sought to evaluate and compare the effect of different dose-fx schemas on overall survival (OS).

MATERIALS/METHODS

We retrieved data from the National Cancer Database. Patient eligibility included early-stage NSCLC with cT1-2 N0M0 disease treated with SBRT using 3-5f x regimens. Demographics and clinical characteristics were identified. Biologically effective dose (BED) and total dose (TD) were calculated. TD included following: 45-60 Gy for 3 fx, 48-60 Gy for 4 fx, and 50-60 Gy for 5 fx. TS was classified as one of the following: daily, every other day, twice per week, or prolonged (less frequently than twice weekly). Non-prolonged TS was defined as daily, every other day, and twice per week. OS was calculated from the date of end of RT to the date of death and censored at the date of last contact. Kaplan Meier method was used to estimate OS and log-rank tests were used to compare the difference between groups. TS was compared pairwise within each individual fx-group. Univariable Cox proportional models with robust standard errors to account for within institution correlations were used to investigate the association between BED, TD, TS, fx-group and OS. Within each fx-group, BED was also assessed and compared.

RESULTS

A total of 3244 patients were identified, with median age 73. 48% were males and 52% females. 601 (19%) patients received 3 fx, 884 (27%) received 4 fx, and 1759 (54%) received 5 fx treatments. For the overall cohort, median and mean BEDs were 112 and 119, respectively. TS did not show a difference in OS among each individual fx group. Overall, prolonged vs non-prolonged schedules also did not show a difference in OS (p = 0.64). OS was superior in the 3 fx group compared to 4 and 5 fx groups, with median survival times of 61.5 vs 53.7 vs 52.6 months, respectively (p = 0.046). Overall, an increase in BED reduced risk of death (HR = 0.97 per 10-units, CI: 0.94-0.99, p = 0.04). When stratified by fx, each 10 unit rise in BED for those treated with 5 fx reduced the risk of death by 8% (HR = 0.92, CI: 0.87-0.97, p<0.01). However, increasing BED was not associated with change in OS for 3 fx (HR = 1.00, CI: 0.93-1.08, p = 0.93) and 4 fx (HR = 1.08, p = 0.08) regimens. Patients who received BED greater than the median (BED>112) had improved OS compared to those receiving BED£112 (HR = 0.86, p = 0.047). When evaluating the 5 fx-group individually, BED >100 (median of 5fx group) had superior OS compared to £100 (HR = 0.80, p = 0.02).

CONCLUSION

Three-fraction regimens have superior OS compared to 4 and 5 fx regimens. Higher BED improves OS in 5 fx regimens. Treatment schedule variations among individual fx-groups does not impact OS.

Liver Fat and Its Association with Time to Biochemical Failure (TTBCF) after Definitive Treatment to the Prostate

PURPOSE/OBJECTIVE(S)

Elevated body mass index (BMI) is associated with an increased risk of biochemical failure (BCF); however, BMI may not best capture underlying health. We examined a different metric, liver fat, which may better approximate the body's metabolic state, to see its association with time to biochemical failure (TTBCF) in patients treated definitively for prostate cancer.

MATERIALS/METHODS

Of 210 patients who received a PSMA PET/CT at our institution, we identified 60 men treated with either prostatectomy or definitive radiation without androgen deprivation therapy who developed BCF. BCF was defined as PSA ≥ 0.2 ng/mL if treated with prostatectomy or PSA nadir + 2 ng/mL for those treated with definitive radiation. All prostatectomy patients had a post-op PSA < 0.1. Liver fat was evaluated via the non-contrast portion of respective PSMA PET/CT scans. Average Hounsfield Units (HU) of the liver were used to split individuals into high (≤ 56.1) and low (> 56.1) liver fat. A threshold of 56.1 HU was chosen as it corresponds to 5.56% liver fat, or the 95th percentile of non-obese, non-diabetic controls. Liver fat was quantified by converting HU to proton density fat fraction (PDFF) using the formula: PDFF = -0.582*HU + 38.214. Median TTBCF was estimated using Kaplan Meier methods, and Cox Proportional Hazards Regression was used for covariate adjustment.

RESULTS

Forty-four patients were classified as having high liver fat (HLF) and 16 as having low liver fat (LLF). Patients with HLF were more likely to have a higher BMI, have high risk disease, undergo surgery, and have shorter TTBCF (Table). When adjusted for NCCN risk category and treatment type, HLF was associated with twice the risk of BCF per unit time (aHR = 2.02, 95% CI [1.09 - 3.73], p = 0.03). With additional adjustment for BMI (continuous), HLF was no longer an independent predictor of TTBCF (aHR = 1.75, 95% CI [0.94 - 3.25], p = 0.08).

CONCLUSION

In this small study of patients who had biochemical failure after completing definitive treatment to the prostate, those with liver fat ≥ 5.56% were more likely to fail sooner, adjusting for risk category and treatment type. This project suggests that a man with elevated liver fat, on average, experiences a shorter interval free from prostate cancer.