Underascertainment of Clinically Meaningful Symptoms During Prostate Cancer Radiation Therapy—Does This Vary by Patient Characteristics?

Purpose: It is well known that physicians underascertain chemotherapy-related toxicity compared with patient self-report. However, symptom underascertainment in radiation therapy and characterization of patient groups at increased risk for underascertainment have not been examined. Methods and Materials: As part of routine clinical care, 7 urinary and gastrointestinal symptoms were prospectively collected with both patient-report outcomes (PROs) using the validated Prostate Cancer Symptom Indices and physician-graded symptoms using Common Terminology Criteria for Adverse Events (CTCAE) for 544 consecutive patients from 2010 to 2018 who received intensity modulated radiation therapy to the prostate or prostate bed. Data from weekly treatment visits and the first posttreatment follow-up were analyzed. Underascertainment was defined as an occurrence when a clinically meaningful symptom was indicated on PROs but not physician CTCAE assessment. Univariate and multivariable logistic regression examined characteristics associated with underascertainment. Results: Overall, 85.3% of patients had underascertainment of at least 1 symptom. Per PRO, 16.9% of assessments reported clinically meaningful symptoms, in contrast to only 3.4% per CTCAE, representing an approximate 5-fold difference. Multivariable analysis showed underascertainment was more common in patients who were unmarried (odds ratio [OR] 1.28; 95% confidence interval [CI], 1.18-1.38), lived in rural regions (OR 1.10; 95% CI, 1.01-1.21), incarcerated (OR 1.58; 95% CI, 1.36-1.84), retired/unemployed (OR 1.29; 95% CI, 1.18-1.40), received prostate gland (vs prostate bed) treatment (OR 1.43; 95% CI, 1.31-1.58), and received concurrent hormone therapy (OR 1.16; 95% CI, 1.04-1.29). Patients age >70 years were less likely to have underascertainment compared with those age <60 years (OR 0.82; 95% CI, 0.73-0.92). Conclusions: This is the first study to show underascertainment of clinically meaningful symptoms in radiation therapy patients in routine clinical care and further to demonstrate that certain patient groups are especially vulnerable to underascertainment. These results highlight the importance of incorporating PROs in the clinical care of radiation therapy patients. If PROs are not routinely used, vulnerable patient groups may need additional attention during cancer treatment to ensure accurate toxicity assessment and management.