Study Finds No Relationship Between PCR Rate And Race In Women With Breast Cancer
October 24, 2011
Healthcare Prof:
Locally advanced breast cancer patients who received exactly the same class of neoadjuvant chemotherapy were found to have no evidence of disease in the time of their surgery, or achieved pathological complete response, in the exact same rate regardless of race, based on researchers at the University of Texas M. D. Anderson Cancer Center.
The study, presented in a poster discussion session at the 2009 Breast Cancer Symposium in San Francisco, may be the largest in a homogenous group of breast cancer patients evaluating pathological complete response (pCR) based on race. Only 1 other study, also conducted at M. D. Anderson but limited to triple negative breast cancer patients (estrogen and progesterone receptor negative, HER2 negative), has analyzed the relationship among the two.
“Our findings confirm pathological complete response can be a strong prognostic indicator as well as a surrogate for great survival, in spite of a patient’s race, and that it’s vital we continue to strive towards achieving this milestone for all women with breast cancer,” stated Mariana Chavez Mac Gregor, M.D., a medical oncology fellow at M. D. Anderson. “The study also mandates that we continue to study the differences across races in breast cancer.”
Racial disparities in breast cancer are known: the American Cancer Society (ACS) estimates that 19,540 blacks and 14,200 Hispanics will be diagnosed with the disease in 2009. While the overall incidence rate is 10 percent lower in blacks than whites, in 2001-2005, they had a 37 percent greater death rate. ACS also reports that overall breast cancer mortality rates are lower in Hispanic girls than white females.
Understanding the reasons for such disparities – be it access to care and screening, biological differences in tumors and/or breast cancer subtypes – will be the focus of ongoing investigation efforts across the cancer community, explained Chavez Mac Gregor, the study’s 1st author.
“While these disparities are known, we also comprehend that breast cancer patients who achieve pathological complete response have far better outcomes,” stated Chavez-Mac Gregor. “What we didn’t comprehend till now was if pathological complete response rates had any relationship with race. If a specific ethnic group had a greater or worse response rate, maybe we could then determine which groups might be in require of additional and /or improved therapies.”
Using the M. D. Anderson Breast Medical Oncology database, the retrospective study identified two,074 patients diagnosed with Stages II and III breast cancer and treated in the institution in between 1994 and 2008. Of the patients, 1,334 (64.three percent) had been white, 302 (14.6 percent) black, 316 (15.2 percent) Hispanic, and 122 (5.9 percent) had been classified as “other” race groups. The median age of the ladies was 50. All received neoadjuvant anthracycline- and taxane-based chemotherapy; receiving similar class of therapy was an critical component inside the design of the study, said Chavez Mac Gregor.
At the time of surgery, the researchers discovered no distinction of statistical significance in pCR rates amongst racial groups: 12.three percent in whites; 12.5 percent in blacks; 14.24 percent in Hispanics; 11.5 percent in other.
Among all patients, at a median follow-up of 30 months, there were 438 recurrences and 327 deaths. The 5 year unadjusted recurrence-free (RFS) and overall survival (OS) rates were: 71 percent and 79 percent in whites; 60 percent and 57 percent in blacks; 76 percent and 79 percent in Hispanics; and 75 percent and 84 percent in “other,” respectively. Lack of achieving pCR, HER2-positive and triple-negative subtypes, lymph node involvement had been all discovered to be independent predictors of worse RFS and OS.
In further analysis, the study reconfirmed what had been noted in literature – despite the fact that not statistically significant, blacks tended to have poorer outcomes, whilst Hispanics had improved outcomes compared to whites, said Chavez Mac Gregor.
The study is not without limitations, she noted: in design, it was each retrospective along with a single-institution study, and race was self-reported. Furthermore, the analysis focus was until the time of surgery, with less attention towards patients’ experience post-surgery, such as compliance to hormone therapies or other adjuvant remedies, other than RFS and OS.
In exactly the same cohort of patients, Chavez Mac Gregor plans further analysis of patients who did not achieve pCR to much better realize why they might not have reached this milestone.
The study was funded by grants from the National Cancer Institute and Susan G. Komen for the Remedy.
In addition to Chavez Mac Gregor, M. D. Anderson authors on the study contain: Gabriel N. Hortobagyi, M.D.; Ana Maria Gonzalez-Angulo, M.D., the study’s senior author; Jennifer Litton, M.D.; Vicente Valero, M.D.; and Huiqin Chen, all of the Department of Breast Medical Oncology; Funda Meric-Bernstam, M.D., Department of Surgery; and Melissa Bondy, Ph.D., Department of Epidemiology. Other authors consist of: Clifford A. Hudis, M.D., Memorial Sloan Kettering; and Antonio C. Wolff, M.D., The Sidney Kimmel Comprehensive Cancer Center.
About M. D. Anderson
The University of Texas M. D. Anderson Cancer Center in Houston ranks as 1 of the world’s most respected centers focused on cancer patient care, study, education and prevention. M. D. Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For six of the past eight years, such as 2009, M. D. Anderson has ranked No. 1 in cancer care in “America’s Best Hospitals,” a survey published annually in U.S. News & Globe Report.
Source: University of Texas M. D. Anderson Cancer Center
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