Survival of women initially diagnosed with stage IV breast cancer has improved in the last 20 years, according to results of a retrospective cohort study.
Survival of women initially diagnosed with stage IV breast cancer has improved in the last 20 years, according to the results of a retrospective cohort study published in JAMA Surgery. The analysis of 21,372 women showed that survival improved particularly for women who underwent initial breast surgery.
Mary C. Schroeder, PhD, of the University of Iowa, and colleagues used data from the Surveillance, Epidemiology, and End Results (SEER) program to study the patterns of treatment and outcomes of women initially diagnosed with stage IV breast cancer. The analysis included patients diagnosed between 1988 and 2011 who did not receive radiotherapy as part of their initial treatment.
Median survival increased from 20 months between 1988–1991 to 26 months between 2007–2011. The rate of surgery declined between 1988 and 2011, yet those patients who had surgery on their primary tumor had improved survival (hazard ratio, 0.60 [95% confidence interval (CI), 0.57–0.63]).
Median age of the women in the full cohort was 63. Median age among patients who received surgery (8,330) was 62, and the median age among women who did not receive surgery (13,042) was 64. Larger tumor size of greater than 5 cm correlated with no surgery.
Among women diagnosed prior to 2002, 9.6% (353 of 7,504) of patients who had surgery survived for at least 10 years, while 2.9% (107 of 7,504) of patients who did not receive surgery survived 10 years (odds ratio, 3.61).
Clinical factors that were associated with prolonged survival included surgery, tumor size, hormone receptor status, marital status, and year of diagnosis.
Whether women who are initially diagnosed with stage IV breast cancer should have their primary breast tumor removed, as part of their treatment, remains a major clinical question. About 5% to 10% of women in the United States have a stage IV diagnosis at onset and have an intact primary breast tumor.
Prior retrospective studies suggested that women who had their primary tumor removed, despite disease spread to other organs, had better survival, but the results may have been biased as women who underwent surgery tended to be younger and healthier compared with patients who did not have surgery.
“Aggressive local therapy may benefit select women such as those with an already established potential for durable remission,” wrote Schroeder and coauthors. “Removal of the primary breast tumor in such cases could improve survival by providing local control, eradicating a potential seed source and possibly a stimulant of distant disease sites, and perhaps also by modulating immune response.”
In an accompanying editorial, Lisa A. Newman, MD, PHD, director of the University of Michigan Breast Care Center in Ann Arbor, Michigan, noted that the study found that a higher prevalence of African American women were among those diagnosed with late-stage disease, yet were 30% less likely to undergo surgery. “This treatment imbalance raises questions regarding selection of patients that are triaged toward more aggressive care,” Newman wrote.