A Comparison of Patient-Reported Health-Related Quality of Life During Proton Versus Photon Chemoradiotherapy for Esophageal Cancer

Abstract

For the treatment of esophageal cancer, pencil beam scanning proton radiation therapy (PRT) produces a more favorable dose distribution compared to photon RT (XRT) with less integral dose delivered to the total body, heart, lungs, stomach, and bowel. However, the impact on clinical outcomes and quality of life (QOL) is unknown. The purpose of this study was to compare patient-reported outcomes (PRO) during PRT or XRT in patients with esophageal cancer. A retrospective review was performed of patients enrolled in a single institution prospective outcomes registry who received curative intent preoperative or definitive chemoradiation (CRT) for esophageal cancer between June 2015 and February 2018. Patients completed the Functional Assessment of Cancer Therapy – Esophagus (FACT-E) questionnaire at baseline prior to the start of CRT and during the last week of CRT. Analysis of variance testing was used to assess for association between patient/treatment characteristics and PRO score changes. A total of 189 patients had completed a baseline FACT-E and 125 patients completed an end of treatment FACT-E; the latter cohort forms the basis of the primary analysis. Among the 125 patients, 63 received XRT and received 62 PRT. The following characteristics were well balanced between PRT and XRT cohorts: 83.2% were male (81.0% XRT vs 85.5% PRT, p=0.63), 77.6% had adenocarcinoma (73% XRT vs 82.3% PRT, p=0.30), and 89.3% had stage II-III malignancy (91% XRT vs 88.7% PRT, p=0.66). The median age of the cohort was 66 years (range 32-89): this differed between RT modalities, as the PRT group was older (median XRT 64 years vs PRT 69.5 years, p=0.0014). The most common RT prescription dose was 50-50.4 Gy in 25-28 fractions. There was a significant difference in RT prescription dose between groups, as it was higher in the PRT group (≥ 50 Gy in 66.7% of XRT patients and 93.5% of PRT patients, p=0.0002). Concurrent chemotherapy was weekly carboplatin and paclitaxel in 96% of the cohort. In the 125 patients with both questionnaires available, the mean FACT-E score was 136.3 points (SD 21.0) at baseline and 119.6 points (SD 24.8) at the end of CRT, with mean change of -16.7 (SD 19.8). Baseline scores were comparable between XRT and PRT groups (135.9 points vs 136.7 points, p = 0.82). On univariate analysis, the only patient or treatment factor associated with post-CRT FACT-E change was RT modality: there was worse mean score decline in XRT patients compared to PRT patients (-20.6 vs -12.7, p=0.026). For patients receiving CRT for esophageal cancer, PRT was associated with significantly less decline in FACT-E scores during treatment, compared to XRT. Further work is needed to determine if changes in patient-reported outcomes during CRT are associated with long term toxicity and survival outcomes.