Background This study explores the incidence of patient‐reported major toxicity—symptoms rated “moderate,” “severe,” or “very severe”—for chemotherapy regimens commonly used in early breast cancer. Patients and Methods Female patients aged 21 years or older completed a validated Patient‐Reported Symptom Monitoring instrument and rated 17 symptoms throughout adjuvant or neoadjuvant chemotherapy. Fisher's exact tests compared differences in percentages in symptom ratings, and general linear regression was used to model the incidence of patient‐reported major toxicity. Results In 152 patients, the mean age was 54 years (range, 24–77), and 112 (74%) were white; 51% received an anthracycline‐based regimen. The proportion of patients rating fatigue, constipation, myalgia, diarrhea, nausea, peripheral neuropathy, and swelling of arms or legs as a major toxicity at any time during chemotherapy varied significantly among four chemotherapy regimens (p < .05). The mean (SD) number of symptoms rated major toxicities was 6.3 (3.6) for anthracycline‐based and 4.4 (3.5) for non‐anthracycline‐based regimens (p = .001; possible range, 0–17 symptoms). Baseline higher body mass index (p = .03), patient‐reported Karnofsky performance status ≤80 (p = .0003), and anthracycline‐based regimens (p = .0003) were associated with greater total number of symptoms rated major toxicities (alternative model: chemotherapy duration, p < .0001). Twenty‐six percent of dose reductions (26 of 40), 75% of hospitalizations (15 of 20), and 94% of treatment discontinuations (15 of 16) were in anthracycline‐based regimens. Conclusion Capturing multiple toxicity outcomes throughout chemotherapy enables oncologists and patients to understand the range of side effects as they discuss treatment efficacies. Continuous symptom monitoring may aid in the timely development of interventions that minimize toxicity and improve outcomes. Implications for Practice This study investigated patient‐reported toxicities for 17 symptoms recorded prospectively during adjuvant and neoadjuvant chemotherapy regimens for early breast cancer. An analysis of four commonly used chemotherapy regimens identified significant differences among regimens in both individual symptoms and total number of symptoms rated moderate, severe, or very severe. Longer chemotherapy regimens, such as anthracycline‐based regimens followed by paclitaxel, had higher proportions of symptoms rated major toxicities. The inclusion of patient perspectives on multiple toxicity outcomes at the same time at multiple time points during chemotherapy has the potential for improving patient‐provider communication regarding symptom management, patient satisfaction, and long‐term clinical outcomes. 摘要 背景。本研究探索了在常用于治疗早期乳腺癌的化疗方案中患者报告的主要毒性(即被评为“中度”、“重度”或“极重度”的症状)的发生率。 患者和方法。年满 21 岁或以上的女性患者填写一份经验证的患者报告的症状监测文件并对辅助或新辅助化疗期间的 17 个症状进行评级。Fisher's精确检验对症状评级百分比之间的差异进行比较，一般线性回归用于模拟患者报告的主要毒性的发生率。 结果。在 152 名患者中，平均年龄为 54 岁(范围介于 24–77 岁之间)，112 名患者 (74%) 为白种人；51% 的患者接受蒽环类方案治疗。在化疗期间的任何时间将疲劳、便秘、肌痛、腹泻、恶心、周围神经病变以及手臂或腿部肿胀评为主要毒性的患者的比例在 4 个化疗方案中显著不同 (p < 0.05)。在蒽环类方案和非蒽环类方案中，被评为主要毒性的症状的平均数 (SD) 分别为 6.3 (3.6) 和 4.4 (3.5)(p = 0.001；可能的范围，0–17 个症状)。基线较高的体质量指数 (p = 0.03)、患者报告的 Karnofsky 体力状态 ≤80 (p = 0.000 3) 以及蒽环类方案 (p = 0.000 3) 与被评为主要毒性的症状的总数较高相关(替代模式:化疗持续时间，p < 0.000 1)。在蒽环类方案中，剂量减少占 26%(40 名患者中的 26 名患者)，住院治疗占 75%(20 名患者中的 15 名患者)，治疗中断占 94%(16 名患者中的 15 名患者)。 结论。获取化疗过程中的多种毒性结果，可令肿瘤学家和患者在讨论治疗有效性时了解副作用的范围。持续的症状监测可能有助于及时地制定可以最大限度地减少毒性并改进预后的干预措施。 《肿瘤学家》 实践意义:本研究调查了患者报告的早期乳腺癌辅助和新辅助化疗方案中前瞻性记录的 17 个症状的毒性。针对 4 个常用化疗方案的分析在单项症状和被评为“中度”、“重度”或“极重度”的症状的总数方面确定了方案之间的显著差异。在较长的化疗方案中，如后续采用紫杉醇治疗的蒽环类方案，被评为主要毒性的症状占有较高的比例。同时，在化疗期间的多个时间点加入患者关于多种毒性结果的看法，这可能会改进患者和医疗服务提供者之间有关症状管理、患者满意度以及长期临床预后的沟通。 This article focuses on the incidence of patient‐reported major toxicity for chemotherapy regimens commonly used in breast cancer, especially considering the need for patient‐centered assessments of treatment tolerability as an important complement to the NCI's CTCAE.