SAN DIEGO – African-American women present with more aggressive breast tumors and at later stages than white women. Many factors have been proposed to explain these findings, including socioeconomic status, cultural beliefs and access to medical care.

A new military study, however, suggests that biology rather than socioeconomic factors may be the most important determinant in African-American women presenting with breast cancer at later stages and with more hormone-receptor negative tumors.

The study, published recently in the Annals of Surgical Oncology, sought to determine if stage at presentation would be equivalent in the Military Health System, which provides equal access to care and equivalent screening.1

To determine that, researchers from the Naval Medical Center San Diego (NMCSD) and the Uniformed Services University in Bethesda, MD, queried the NMCSD tumor registry from 2007 to 2012, considering eligible all those diagnosed and treated for breast cancer during the time period. Distribution of tumor stage — early vs. advanced — between racial groups was compared by age, treatment and receptor status.

Of the 624 participants, 88% had early-stage breast cancer (0–II), and 12 % presented with advanced stage (III or IV). Racial differences in distribution were significant among African-American and Hispanic women for early vs. advanced presentation, although no racial disparity was seen in screening patterns among women.

“In a military health system with equal access to care and standard screening recommendations, screening patterns did not vary with race but did vary with stage and active duty status,” according to the authors, who said that biology appeared to play the biggest role in the different breast cancer stages discovered during screening.

1 Oseni TO, Soballe PW. Breast cancer screening patterns among military beneficiaries: racial variations in screening eliminated in an equal-access model. Ann Surg Oncol. 2014 Oct;21(10):3336-41. doi: 10.1245/s10434-014-3961-6. Epub 2014 Aug 5. PubMed PMID: 25092162.

Breast Cancer Res Treat. 2015 Jan;149(1):191-8. doi: 10.1007/s10549-014-3213-2. Epub 2014 Nov 27.