KEY TAKEAWAYS
- The study aimed to analyze longitudinal leukocyte changes in breast cancer development, comparing treated survivors and untreated women to discern treatment-related differences.
- Breast cancer survivors showed lasting leukocyte changes, possibly linked to chemotherapy or radiotherapy, impacting future disease risks.
Alterations in leukocyte composition frequently precede the onset of chronic diseases. Breast cancer survivors face elevated risks of subsequent chronic conditions. However, the enduring changes in peripheral leukocyte composition post-breast cancer diagnosis and treatment are yet to be elucidated.
Jacob K. Kresovich and his team conducted the study that aimed to analyze longitudinal peripheral leukocyte composition changes in women with and without breast cancer, investigating treatment-associated differences in breast cancer survivors.
The study obtained paired blood samples from 2315 women participating in The Sister Study, a nationwide cohort study comprising 50,884 women, during baseline (July 2003 to March 2009) and follow-up (October 2013 to March 2015) home visits, with an average (SD) follow-up duration of 7.6 (1.4) years. Approximately half of the women included had a history of breast cancer diagnosis and treatment between enrollment and the second blood draw. The study comprised a total of 410 women, with 185 being breast cancer survivors and 225 remaining breast cancer-free over a similar follow-up duration. Data analysis was conducted between April 21 and September 9, 2022.
The main outcomes and measures included breast cancer status and, among breast cancer survivors, the type of cancer treatment received (chemotherapy, radiotherapy, endocrine therapy, or surgery). Blood DNA methylation data, obtained in 2019 using a genome-wide methylation screening tool, were deconvoluted to estimate the percentages of 12 circulating leukocyte subsets.
Among the 410 women analyzed, the mean (SD) age at enrollment was 56 (9) years. Breast cancer survivors exhibited reduced percentages of circulating eosinophils (-0.45% [95% CI, -0.87% to -0.03%]; P = .03), total CD4+ helper T cells (-1.50% [95% CI, -2.56% to -0.44%]; P = .01), and memory B cells (-0.22% [95% CI, -0.34% to -0.09%]; P = .001) compared to breast cancer-free women. Conversely, breast cancer survivors displayed increased percentages of circulating naive B cells (0.46% [95% CI, 0.17%-0.75%]; P = .002). In breast cancer survivor-only analyses, radiotherapy correlated with decreased levels of total CD4+ T cells, while chemotherapy correlated with elevated levels of naive B cells. Conversely, surgery and endocrine therapy showed no significant associations with leukocyte changes.
The results demonstrated that the breast cancer survivors enduring alterations in peripheral leukocyte composition compared to those without breast cancer, potentially attributable to chemotherapy or radiotherapy treatment, which may impact subsequent chronic disease susceptibility. Research was funded by the Intramural Research Program of the National Institutes of Health.
Source: https://pubmed.ncbi.nlm.nih.gov/38358741/
Kresovich JK, O’Brien KM, Xu Z, Weinberg CR, Sandler DP, Taylor JA. Circulating Leukocyte Subsets Before and After a Breast Cancer Diagnosis and Therapy. JAMA Netw Open. 2024;7(2):e2356113. doi:10.1001/jamanetworkopen.2023.56113.
