Contribution of Patient-reported Symptoms Before Palliative Radiotherapy to Development of Multivariable Prognostic Models.

Background/aim: Typically, prognostic scores predicting survival in patients with metastatic cancer are based on disease- and patient-related factors, such as extent of metastases, age and performance status. Patient-reported symptoms have been included less often. Our group has assessed all patients with the Edmonton Symptom Assessment System (ESAS, a one-sheet questionnaire addressing 11 major symptoms and wellbeing on a numeric scale of 0-10) before palliative radiotherapy (PRT) since 2012. Therefore, we were able to analyze the prognostic impact of baseline ESAS symptom severity.

Patients And Methods: We performed a retrospective review of 102 patients treated with PRT between 2012 and 2015. All ESAS items were analyzed by two different methods, dichotomized by median score and by score <4 vs. ≥4. Uni- and multivariable analyses were performed to identify prognostic factors for survival, and from these a 4-tiered score was developed.

Results: The most common tumor types were prostate, breast and non-small cell lung cancer, predominantly with distant metastases. Despite differences between the two methods of ESAS data handling, the final multivariable models were strikingly similar. Therefore, the better reproducible cut-off was chosen, i.e. a score ≥4. Multivariable analyses resulted in 4 significant prognostic factors, which contributed equally to the 4-tiered survival score (performance status, more than one cancer diagnosis, progressive disease outside the PRT target volume(s), ESAS appetite). Estimated median survival for different point sums was 24.5 months (0), 8.4 months (1), 4.7 months (2) and 3.0 months (3), p=0.0001.

Conclusion: This score identified patients with different survival outcomes, including a good prognostic group with median survival of approximately 2 years. The results may be useful to inform PRT fractionation.