Background

The role of pelvic irradiation in men receiving external beam radiotherapy (EBRT) for prostate cancer is unclear, in part due to a lack of data on patient-reported outcomes. We sought to compare functional outcomes for men receiving prostate and pelvic versus prostate-only radiotherapy, longitudinally over 5 years.

Materials and methods

We performed a population-based, prospective cohort study of men with clinically-localized prostate cancer undergoing EBRT. We examined the effect of prostate and pelvic (n = 102) versus prostate-only (n = 485) radiotherapy on patient-reported disease-specific (using the Expanded Prostate Cancer Index Composite[EPIC]-26) and general health-related (using the SF-36) function, over 5 years. Regression models were adjusted for outcome-specific baseline function, clinicopathologic characteristics, and androgen deprivation therapy (ADT).

Results

587 men (median [quartiles] age 69 [64-73] years) met inclusion criteria and completed ≥1 post-treatment survey. More men treated with prostate and pelvic radiotherapy had high-risk disease (58% vs. 18%, P < 0.01) and received ADT (75% vs. 41%, P < 0.01). These men reported worse sexual (6 months-5 years), hormonal (at 6 months), and physical (6 months-5 years) function. Accounting for baseline function, patient and tumor characteristics, and use of ADT, pelvic irradiation was not associated with statistically or clinically significant differences in bowel function, urinary incontinence, irritative voiding symptoms or sexual function through 5-years (all P > 0.05). Marginally clinically important differences were noted in hormonal function at 3-years (adjusted mean difference 4.7, 95% confidence interval [1.2-8.3]; minimally clinically important difference (MCID) 4 to 6) and 5-years (4.2, [0.4-8.0]) following treatment. After adjustment, there was a transient statistically significant, but not clinically important, difference in emotional well-being at 6 months (3.0, [0.19-5.8]; MCID 6) that resolved by 1 year and no differences in physical functioning or energy and fatigue.

Conclusion

This prospective, population-based cohort study of men with localized prostate cancer treated with EBRT, showed no clinically important differences in disease-specific or general health-related quality of life with the addition of pelvic irradiation to prostate radiotherapy, supporting the use of pelvic radiotherapy when it may be of clinical benefit, such as men with increased risk of nodal involvement.

Purpose

The purpose of this work is to describe the association between body mass index (BMI) and (1) management option for localized prostate cancer (PCa) and (2) disease-specific quality of life (ds-QoL) after treatment or active surveillance.

Subjects/patients and methods

We analysed data from men with localized PCa managed with radical prostatectomy (RP), radiation therapy (RT), or active surveillance (AS) in a prospective, population-based cohort study. We evaluated the association between BMI and management option with multivariable multinomial logistic regression analysis. The association between BMI and ds-QoL was assessed using multivariable longitudinal linear regression. Regression models were adjusted for baseline domain scores, demographics, and clinicopathologic characteristics.

Results

A total of 2378 men were included (medians [quartiles]: age 64 [59-69] years; BMI 27 kg/m²; 77% were non-Hispanic white); 29% were obese (BMI ≥ 30). Accounting for demographic and clinicopathologic features, BMI ≥ 28 kg/m² was inversely associated with the likelihood of receiving RP (compared with RT) and became statistically significant at BMI ≥ 33 kg/m² (maximum adjusted relative risk ratio = 0.80, 95% CI 0.67 to 0.95, p = 0.013 for BMI ≥ 33 vs. 25). Conversely, BMI was not significantly associated with the likelihood of receiving AS compared with RT. After stratification by management option, obese men who underwent definitive treatment were not found to have clinically worse ds-QoL. Obese men initially on AS appeared to have worse urinary incontinence than nonobese men, but this was not significant on an as-treated sensitivity analysis.

Conclusions

Among men with localized PCa, those with BMI ≥ 33 kg/m² were less likely to receive surgery than radiation. Obesity was not associated with ds-QoL in men undergoing definitive treatment, nor in men who remained on AS.