Compared with tumors smaller than 8 mm among patients with hormone receptor (HR)-positive, ERBB2-positive (formerly HER2-positive) breast cancer, tumors between 8 and 10 mm benefited more from postoperative chemotherapy.
Compared with tumors smaller than 8 mm among patients with hormone receptor (HR)-positive, ERBB2-positive (formerly HER2-positive) breast cancer, tumors between 8 and 10 mm benefited more from postoperative chemotherapy, suggest study results recently published in JAMA Network Open.
Hormonal therapy also benefitted these patients, and together with chemotherapy, reduces their survival hazard by 47%.
Because the current National Comprehensive Cancer Network guideline does not provide concrete direction on treatments for smaller tumors (stage T1a and T1b), which have not been studied in depth in randomized trials, it recommends leaving “the consideration of chemotherapy for tumors 1 cm [10 mm] or smaller at the discretion of clinicians,” the authors wrote.
Women with these smaller tumors have a typical 5-year recurrence rate of 5% to 25%, with or without adjuvant therapy, they noted. Hoping to add to the guidance on optimal treatment options for smaller tumors in HR-positive, ERBB2-positive breast cancer, the team consulted the US National Cancer Database for cases diagnosed between 2010 and 2015. Treatment consisted of hormone therapy with or without chemotherapy.
They conducted an observational cohort study on the data they extracted, which they analyzed from November 2019 through January 2020. There were 10,065 patients in the overall population, of whom 5346 received chemotherapy and 4719 did not. Their median (interquartile range [IQR]) age was 59 (IQR, 51-67) years, and the median (IQR) follow-up was 41.8 (IQR, 24.3-62.6) months.
Overall, there was a 31% (hazard ratio [HR], 0.69; 95% CI, 0.52-0.90; P = .006) improvement in survival with chemotherapy. Broken down by tumor size, risk of death rose 7% (HR, 1.07; 95% CI, 1.03-1.12; P = .002) with each concordant 1-mm increase in tumor size.
Using Cox multivariable analysis on tumors between 2 and 9 mm, the authors determined that 8 mm was a statistically significant cutoff (P for interaction = .01). For tumors below that size, overall survival from chemotherapy did not improve (HR, 1.00; 95% CI, 0.70-1.43; P = .99); however, for tumors between 8 and 10 mm, it did (HR, 0.53; 95% CI, 0.36-0.78; P = .001).
The Kaplan-Meier method was also used for a matched-pair analysis between 1641 patients with tumors smaller than 8 mm and 648 patients with 8- to 10-mm tumors. The larger tumors were overwhelmingly shown to benefit from chemotherapy versus the smaller tumors:
“To our knowledge, this is the first report to suggest that there is an association between improved survival and adjuvant chemoendocrine therapy specifically for HR-positive, ERBB2-positive tumors 8 mm to 10 mm compared with those smaller than 8 mm,” they concluded. “It is evident that tumors 10 mm and smaller represent a heterogeneous group whose treatment should be tailored to improve the risk-to-benefit ratio of systemic therapy.”
Reference
Ma SJ, Oladeru OT, Singh AK. Association of survival With chemoendocrine therapy in women with small, hormone receptor—positive, ERBB2-positive, node-negative breast cancer. JAMA Netw Open. 2020;3(4):e202507. doi:10.1001/jamanetworkopen.2020.2507
Metabolic Syndrome, Obesity Contribute to Breast Cancer Mortality in Postmenopausal Women
May 13th 2024A large study finds that obesity and metabolic syndrome raise breast cancer mortality risk, but through different mechanisms. Metabolic syndrome is linked to a specific type of breast cancer, whereas obesity increases risk across all breast cancer subtypes.
Read More
Emily Goldberg Shares Insights as a Genetic Counselor for Breast Cancer Risk Screening
October 30th 2023On this episode of Managed Care Cast, Emily Goldberg, MS, CGC, a genetic counselor at JScreen, breaks down how genetic screening for breast cancer works and why it is so important to increase awareness and education around these screening tools available to patients who may be at risk for cancer.
Listen
Social Equity, Strong Health Care Systems Can Improve Advanced Breast Cancer Outcomes Globally
May 6th 2024Disparities in health care systems around the world limit access to effective treatments for advanced breast cancer, especially for people in low- and middle-income countries and marginalized communities. Stronger health systems and social education efforts are necessary to improve outcomes for all patients.
Read More
The Disproportionate Impact of the Pandemic on Health Care Disparities and Cancer
February 22nd 2022On this episode of Managed Care Cast, we discuss how already wide health care inequities in cancer are becoming much worse because of the COVID-19 pandemic, with guest Monica Soni, MD, associate chief medical officer at New Century Health.
Listen
USPSTF Lowers Age for Biennial Mammograms to 40, Citing Early Detection Benefit
April 30th 2024The USPSTF lowered the recommended starting age for mammograms from 50 to 40 years, citing moderate benefits for early detection in this age group. Disparities persist, especially for Black women, highlighting the need for improved access to health care and social support.
Read More