A research study led by Dr. Masataka Sawaki at the Aichi Cancer Center Hospital in Nagoya, Aichi, Japan, supports trastuzumab monotherapy as a preferential treatment option for some senior women with early-stage HER2+ breast cancer.
The study, known as the RESPECT trial, was an open-label, randomized controlled trial studying early-stage HER2+ breast cancer in women ages 70 to 80 years old. It found trastuzumab monotherapy to be inferior to trastuzumab plus chemotherapy in three-year disease-free survival (Hazard ratio (HR): 1.36; 95% CI: 0.72 to 2.58; p = 0.51), restricted mean survival time (95% CI: -1.71 to 0.93; p = 0.56) and relapse-free survival (HR: 1.33; 95% CI: 0.63 to 2.79; p = 0.53). However, three-year observed loss of survival without chemotherapy was less than one month.
Moreover, trastuzumab monotherapy conferred improved health-related quality of life at two months (p = 0.016) and one year (p = 0.009), and less adverse events of anorexia (p < 0.0001), alopecia (p < 0.0001) and nonhematologic events (p = 0.0003). These results suggest that trastuzumab monotherapy can be considered as a preferential treatment option for some senior women.
A total of 275 female patients between the ages of 70 and 80 (mean age: 73.5) participated in the study. Over 85% of the patients had HER2+ breast cancer stages of I (43.6%) or IIA (41.7%). The participants were randomly assigned to either adjuvant chemotherapy plus trastuzumab or trastuzumab monotherapy for one year. They were followed for 0.3 to 8 years (mean follow-up: 4.1 years).1
The trial brings to light several health disparities experienced by geriatric patients with breast cancer, including a lack of organized geriatric oncology services, exclusion from clinical trials and a paucity of clinical trials with primary and secondary endpoints relevant to this underserved population. It concludes that geriatric individuals continue to experience breast cancer health inequities despite the International Society of Geriatric Oncology’s efforts to rectify these inequities.2
1. Sawaki, M., Taira, N., Uemura, Y., Saito, T., Baba, S., Kobayashi, K., Kawashima, H., Tsuneizumi, M., Sagawa, N., Bando, H., Takahashi, M., Yamaguchi, M., Takashima, T., Nakayama, T., Kashiwaba, M., Mizuno, T., Yamamoto, Y., Iwata, H., Kawahara, T., … Mukai, H. (2020). Randomized Controlled Trial of Trastuzumab With or Without Chemotherapy for HER2-Positive Early Breast Cancer in Older Patients. Journal of Clinical Oncology, 38(32), 3743–3752. https://doi.org/10.1200/jco.20.00184
2. de Azambuja, E. (2020, November 10). Are We RESPECTing Older Patients With Breast Cancer? [Comment on the article “Randomized Controlled Trial of Trastuzumab With or Without Chemotherapy for HER2-Positive Early Breast Cancer in Older Patients”]. Journal of Clinical Oncology. https://ascopubs.org/doi/10.1200/JCO.20.02329