Effect Of Common Terminology Criteria For Adverse Events (Ctcae) On Quality-Of-Life (Qol) Linear Analogue Selfassessment (Lasa) In Breast Cancer (Bc) Patients Receiving Radiation Therapy (Rt): Single-Center Prospective Registry Experience

The relationship between clinical adverse events and overall QOL in breast cancer patients treated with curative intent radiotherapy is not clearly understood. We report the impact of CTCAE on overall LASA QOL in breast cancer patients undergoing RT in a single-institution prospective registry. From 2015-2019, all patients treated with RT for BC with curative intent at our institution were eligible. Breast-specific CTCAE and overall LASA QOL questionnaires were administered at baseline, end-of-treatment, 3, 6, 12 months, and then annually. Included patients must have had a baseline and one post-RT LASA QOL completed. LASA QOL scores were translated into a 100-point scale with higher scores representing better QOL. Provider recorded CTCAE was utilized using version 4 criteria and breast-specific CTCAE were identified as well as verified by two participating clinicians. Grade 2+ or 3+ CTCAEs were included and considered treatment related, if any scored AE was higher than the CTCAE recorded at baseline. Repeated measures mixed models were used to determine the effect any grade 2+ or 3+ CTCAE had on overall QOL based on LASA. There were 501 patients eligible for analysis with median follow-up of 2.3 years (range 0.4-3.9). Sixty-five percent (65%) of patients had an ECOG 0. Median body mass index (BMI) was 27.3 (range 16.4-53.8). Seventy-three percent (73%) of patients underwent lumpectomy and 42% received chemotherapy. Pathologic stage was primarily T1-2 (70%) and N0 (62%). Hormone receptor status was 81% ER+, 76% PR+, while 11% were Her2+. Median radiation dose was 40.05Gy (21.9-50.4Gy) with 42% of patients receiving a boost. Eighty-four percent (84%) were treated with photons while 16% were treated with protons. Mean overall LASA QOL did not significantly differ over time as scores were 78.5 at baseline, 79.8 at end of treatment, 79.8 at 3 months, 77.1 at 6 months, 79.4 at 12 months and 79.7 at 24 months. On univariate analysis, patients experiencing post-baseline grade 2+ CTCAE and grade 3+ CTCAE had a significant deterioration in LASA QOL score (both p<0.01). Standard fractionation (dose/fraction≤2) and increased BMI were also univariately significant predictors of worse LASA QOL score (both p<0.006). On MVA, adjusting for BMI and fractionation schedule, any grade 2+ CTCAE predicted for a 6.5 reduction in LASA QOL (p<0.01) while any grade 3+ CTCAE predicted for a 6.0 reduction in LASA QOL (p = 0.03). In patients undergoing RT for BC in the curative setting, grade 2+ and 3+ CTCAEs were statically significant predictors of worsening overall QOL employing LASA. Although overall QOL variations are multifactorial, in patients receiving radiation with a curative intent, grade 2+ toxicity affected negatively LASA QOL.