Session Item

To prospectively assess the impact of patient-reported intestinal toxicity (IT) on 2-year health-related quality of life (HRQoL) in a large multi-institute cohort of patients (pts) who underwent radiotherapy (RT) including pelvic nodal irradiation (PNI) for prostate cancer (PCa) with different intent.

A prospective multi-Institute study aimed at evaluating IT after RT including PNI along with its detrimental impact on pts’ HRQoL recruited 886 between 2011 and 2021.

The Inflammatory Bowel Disease Questionnaire (IBDQ) was administered at baseline, at RT mid-point and end, at 3 and 6 months and thereafter every 6 months up to 5 years. IBDQ items analyze four Domains, that of Bowel symptoms (BOWEL) and their impact on Emotional (EMOT), Social (SOCIAL) and Systemic (SYST) aspects of HRQoL.

The 554 pts considered for the current analysis had complete baseline, 2-years and both RT mid-point and end RT (90%) questionnaires or at least one between RT mid-point and end (10%). The differences between baseline and 2-year single Bowel items (n=10) and Domain scores were investigated, accounting for the BOWEL baseline and Worst (defined as the largest BOWEL worsening between baseline and RT mid-point or end). Monotonic relationships between 2-year variations of single BOWEL items and EMOT, SOCIAL and SYST were also investigated to quantitatively assess the 2-year bowel symptoms mostly related to HRQoL worsening, through the Spearman’s rho coefficient.

The distributions of the differences between each IBDQ Domain score at baseline and at 2 years were tested via the Wilcoxon signed-rank test. Differences were found to be significant for three out of four Domains: EMOT completely recovered within 2 years from RT end (p=0.42), while the others did not (p<0.001). BOWEL baseline values did not impact the deterioration of BOWEL and SYST; on the contrary, baseline values below and above the first quartile (Q1) resulted in stable  impaired SOCIAL scores, respectively. Instead, patients with lower Worst values (Q1 did not show significant worsening: this result suggests that the intensity of acute bowel symptoms is associated to a degradation of the 2-year SOCIAL domain.

Spearman's rho coefficients suggest that the bowel symptoms related to “Urge to Go to Bathroom” (IBDQ24, ρ= 0.31-0.39), “Accidental Soiling” (IBDQ26, ρ= 0.28-0.37), “Gas Passage” (IBDQ17, ρ= 0.24-0.34) and “Abdominal Bloating” (IBDQ20, ρ= 0.26-0.34) were the ones more associated to individual deterioration of EMOT, SOCIAL and SYST.

Bowel symptoms and Bowel associated 2-year HRQoL were significantly worsened for SOCIAL and SYST domains while EMOT did not change. The severity of acute bowel symptoms were associated to the degradation of SOCIAL domain. Specific intestinal symptoms at 2 years were associated to 2-year EMOT, SOCIAL and SYST decline with respect to baseline.