Erin Roesch, MD
The benefit of immunotherapy in combination with chemotherapy for programmed death–ligand 1–positive (PD-L1+) metastatic triple-negative breast cancer (mTNBC) has been shown in both the IMpassion130 and KEYNOTE-355 trials.[2,3] However, the IMpassion131 trial, which evaluated atezolizumab plus paclitaxel, did not show a progression-free survival (PFS) or overall survival (OS) benefit vs paclitaxel alone in PD-L1+ mTNBC.[4] Various explanations for these divergent results have been proposed, including the inherent properties of the chemotherapy backbone, patient populations, and the heterogenous nature of TNBC, which can affect response to immunotherapy. Of present, the various KEYNOTE-355 regimens (pembrolizumab plus investigator's choice chemotherapy [nab-paclitaxel, paclitaxel, or gemcitabine-carboplatin]) are US Food and Drug Administration approved for PD-L1+ mTNBC in the first-line setting. The phase 2 randomized TBCRC 043 trial investigated the effect of atezolizumab with carboplatin in patients with mTNBC and further looked at clinical and molecular correlates of response (Lehmann et al). A total of 106 patients were randomly assigned to carboplatin or carboplatin plus atezolizumab; the combination improved PFS (median PFS, 4.1 vs 2.2 mo; hazard ratio [HR] 0.66; P = .05) and OS (12.6 vs 8.6 mo; HR 0.60; P = .03). Grade 3/4 serious adverse events were more common with carboplatin-atezolizumab vs carboplatin alone (41% vs 8%). In addition, an association of better responses with PD-L1 immunotherapy was seen in patients with obesity, uncontrolled blood glucose levels, high tumor mutation burden, and increased tumor infiltrating lymphocytes. These data support the role of immunotherapy in mTNBC, highlight tumor heterogeneity within this subtype and encourage correlative studies to better define which patients benefit from immunotherapy.
Various studies have demonstrated the favorable impact of physical activity on breast cancer risk in postmenopausal women.[5] However, data in premenopausal women is less clear. Various mechanisms connecting physical activity to premenopausal breast cancer risk have been proposed including the effect of exercise on sex steroid hormones, fasting insulin levels, and inflammation.[6] A pooled analysis from 19 cohort studies including 547,601 premenopausal women, with 10,231 incident cases of breast cancer, aimed to examine the relationship between leisure-time physical activity (sports, exercise, recreational walking) and breast cancer risk in young women (Timmins et al). Higher (90th percentile) vs lower (10th percentile) levels of leisure-time physical activity were associated with a 10% reduction in breast cancer risk after adjustment for body mass index (BMI; adjusted HR 0.90; 95% CI 0.85-0.95; P < .001). They also found a significant reduction in risk: 32% (HR 0.68; P = .01) and 9% (HR 0.91; P = .005) for women with underweight (BMI < 18.5) and with average weight (BMI 18.5-24.9), respectively. Further, the effect of physical activity was most pronounced in the human epidermal growth factor receptor 2 (HER2)–enriched breast cancer subtype, wherein higher vs lower levels of activity were associated with an estimated 45% reduction in breast cancer risk (adjusted HR 0.55; 95% CI 0.37-0.82). These findings support the beneficial role of aerobic exercise and healthy body weight on breast cancer risk among premenopausal women and highlight the value of incorporating this information into counseling for our patients.
Additional References
- Figueroa JD, Gierach GL, Duggan MA, et al. Risk factors for breast cancer development by tumor characteristics among women with benign breast disease. Breast Cancer Res. 2021;23:34. doi: 10.1186/s13058-021-01410-1 Source
- Schmid P, Adams S, Rugo HS, et al, for the IMpassion130 Trial Investigators. Atezolizumab and nab-paclitaxel in advanced triple-negative breast cancer. N Engl J Med. 2018;379:2108-2121. doi: 10.1056/nejmoa1809615 Source
- Cortes J, Rugo HS, Cescon DW, et al, for the KEYNOTE-355 Investigators. Pembrolizumab plus chemotherapy in advanced triple-negative breast cancer. N Engl J Med. 2022;387:217-226. doi: 10.1056/NEJMoa2202809 Source
- Miles D, Gligorov J, André F, et al, on behalf of the IMpassion131 investigators. Primary results from IMpassion131, a double-blind, placebo-controlled, randomised phase III trial of first-line paclitaxel with or without atezolizumab for unresectable locally advanced/metastatic triple-negative breast cancer. Ann Oncol. 2021;32:994-1004. doi: 10.1016/j.annonc.2021.05.801 Source
- Eliassen AH, Hankinson SE, Rosner B, et al. Physical activity and risk of breast cancer among postmenopausal women. Arch Intern Med. 2010;170:1758-1764. doi: 10.1001/archinternmed.2010.363 Source
- Swain CTV, Drummond AE, Boing L, et al. Linking physical activity to breast cancer via sex hormones, part 1: The effect of physical activity on sex steroid hormones. Cancer Epidemiol Biomarkers Prev. 2022;31:16-27. doi: 10.1158/1055-9965.EPI-21-0437 Source