Patient(Pt)-reported toxicities by chemotherapy regimen for early breast cancer (BC) (LCCC1334/1440).

544Background: Pt-reported outcomes reflect toxicity of anticancer drugs, and can be measured using “moderate, severe or very severe” ratings (MSVS) that mirror physician-assessed CTCAE grades 2-4. Methods: We prospectively collected pt-reported MSVS in pts with stage I-III BC at each cycle of conventional (neo)adjuvant chemotherapy. Results: In 135 patients, mean age was 52, 26% non-white, 32% ≤high school education. Fatigue, arthralgia, constipation, diarrhea, nausea, myalgia, and peripheral neuropathy toxicities varied significantly by chemotherapy regimen (p < 0.05). Pts who received anthracycline-based chemotherapy reported significantly more MSVS toxicities compared those who did not (mean 5.3 vs 3.5, p < 0.001). Conclusions: Modern (neo)adjuvant chemotherapy has substantial toxicity that varies by regimen; anthracycline-based regimens appear particularly difficult. These findings support efforts to tailor therapy and minimize overtreatment. Clinical trial information: NCT02328313.Patient-reported M...