Black Women Have More Aggressive Breast Cancers, Study Shows

Allison Gandey
November 13, 2007 (Los Angeles) — The largest cohort study to date suggests that black breast cancer patients have biologic differences that affect outcome. Researchers, presenting here at the American Society for Therapeutic Radiology and Oncology (ASTRO) 49th Annual Meeting , tracked women over a 27-year period and found significant differences between African American and white patients. They showed that despite similar access to care and treatment, black women present at a younger age, with a higher stage of disease at diagnosis and more aggressive markers.
Lead author and presenter Meena Moran, MD, from Yale University School of Medicine, in New Haven, Connecticut, also showed that black women have higher local-regional recurrence rates after breast-conservation therapy. Ten years after treatment, 17% of black women had local recurrence, whereas only 13% of white women did.
Despite this higher rate, Dr. Moran said that breast-conservation therapy remains a reasonable option for black women wanting to conserve their breast, provided the clinical scenario is appropriate. "Clinicians need to consider all factors that optimize local-regional control," she said.
Breast-Conservation Therapy Still an Option for Black Women
Dr. Moran said that it is not clear whether the choice of mastectomy over breast-conservation therapy for black women has been physician or patient driven, but that this is something that should be explored further, and the options for women should be expanded.
Dr. Moran suggested a number of possible biologic explanations for the differences observed in black breast cancer patients. Among these are a lower rate of estrogen and progesterone receptors, a higher rate of triple negative tumors, and the increased detection of p53 mutations.
Speaking during the question period following the presentation, Lori Pierce, MD, from the University of Michigan Medical School, in Ann Arbor, who has also conducted extensive research in this area, cautioned Dr. Moran and her team about making race-based assumptions.
She said that there could well be important biologic factors at play, but that they might not be based on race. Dr. Pierce suggested the researchers go back and take a closer look at the triple negative patients in their study. "If you separate out your triple negatives, I suspect that's where the money is," she said.
During an interview with Medscape Oncology, Shiv Khandelwal, MD, from the University of Virginia, in Charlottesville, said that he would not recommend any changes to practice on the basis of this study. "It is a fairly large-scale study, but it is still a retrospective study dating back many years — from 1975 to 2003 — and treatments have changed. We will need to confirm these findings in prospective trials with standardized therapies."
Some Surprised by the Findings
The study findings contradict many earlier studies. "A number of people I spoke with at the meeting were surprised by this," Dr. Khandelwal said. "But I don't consider it surprising." He complimented the study, which he said despite its limitations is "quite well done."
Session comoderator Lynn Wilson, MD, from the Yale University School of Medicine, told those attending the meeting that the clinical trial is very highly rated. This trial and others presented at the session were not eligible to be presented at plenary — in some cases because the work had been presented elsewhere — but Dr. Wilson said this study is important.
Speaking to reporters attending a news conference, Anthony Zietman, MD, from Harvard Medical School, in Boston, Massachusetts, and the education council chair for ASTRO, said he agrees: "We have long observed that black breast cancer patients tend to fair worse, and now we have evidence to support that observation."
The investigators looked at more than 2300 patients who had undergone breast-conservation therapy. Of these, 207 patients in the database were African American and 2164 were white. Patients underwent whole breast radiotherapy plus conedown. They received a median dose of 64 Gy. The median follow-up was 7 years.
The researchers reported that the percentage of patients who received chemotherapy and tamoxifen did not differ significantly by race. And the frequency of the various regimens used also did not differ between the 2 cohorts.
During the question period following the presentation, Felicia Snead, MD, from the University of Florida, in Jacksonville, asked to what extent compliance with treatment could factor into the differences in outcomes.
The debate over differences in patient compliance rates rather than any intrinsic biologic differences was also the topic of discussion at the news conference.
Dr. Moran and colleagues said they will address this question in detail in further research. "I look forward to it," Dr. Snead responded.
Dr. Moran concluded that her group's results underscore the need for research evaluating differences in breast cancers in black women and the importance of developing strategies to optimize treatment outcomes.
The researchers have disclosed no relevant financial relationships. The study was funded in part by the Susan G. Komen Foundation and the Yale Cancer Center Swebelius Fund.
American Society for Therapeutic Radiology and Oncology 49th Annual Meeting: Abstract 8. Presented October 29, 2007.