Several past studies have suggested that African Americans may have poorer survival rates from cancer than their peers partially due to less access to healthcare or other socioeconomic factors. However, a recent U.S. government-funded study suggests that the issues may be even more complex. Loyola University researchers recently found that African-Americans with breast, prostate, or ovarian cancers who received ideal treatment to other patients in the study were still more likely to die from cancer than their peers. The researchers say the study sheds light on important issues such as the interactions of tumor biology, treatment, sex, race, inherited genes, and survival.
Past research indicates that African-American women diagnosed with breast cancer may be up to twice as likely to die from the disease than white women. Some researchers have suggested that this may be due to poor access to mammography and less frequent breast cancer screenings among many African-American women. In fact, in the 1980s, deaths from breast cancer were nearly equal among white women and African-American women, but by 2000, African-Americans had a 32% higher rate of death from breast cancer. Researchers have attributed the disparity to reasons that include access to mammography and high-quality breast cancer treatments. For example, African-Americans are less likely than white women to receive radiation therapy after breast-conserving surgery (lumpectomy).
To further study the complexities of survival rates from cancer, researchers identified over 19,000 cancer patients enrolled in 35 different clinical trials and who were followed for at least 10 years after treatment. Twelve percent of the patients were African American. All patients, regardless of race, received the same treatments by the same healthcare providers.
During the course of the study, African Americans were 49 percent more likely than other races to die from early-stage, postmenopausal breast cancer; 41 percent more likely to die from early stage, premenopausal breast cancer; 61 percent more likely to die from advanced-stage ovarian cancer, and 21 percent more likely to die from advanced-stage prostate cancer.
"It was a level playing field for everyone, with the same quality care," said lead author Dr. Kathy Albain, a breast and lung cancer specialist at Loyola University Health System's Cardinal Bernardin Cancer Center, in a Loyola University news release. "So our findings cast doubt on a prevailing theory that African Americans have lower cancer survival rates because of poverty, poor access to quality care or other socioeconomic factors."
The findings surprised researchers since past research indicated that socioeconomic factors play a key role in the disparate survival rates among patients of differing races. However, the study, which was published in the Journal of the National Cancer Institute, found there was no statistically significant association between race and survival for lung and colon cancers, leukemia, lymphoma or myeloma.
"The good news for African Americans is that for most common cancers, they have the same survival rates as all other races," Albain said, in the news release. However, the study raises the question as to why African Americans fared poorer compared to their peers even though they received the same treatments.
The cancers that did show survival gaps among patients diagnosed with breast, prostate and ovarian may be gender-related. The findings therefore suggest that the survival gap is due to a complex interaction of biologic factors in the tumor and inherited variations in common genes that control metabolism of drugs and hormones, Albain said. People with different patterns of these genes metabolize cancer drugs and their own hormones differently, and experience different side effects.
"We are actively conducting new research based on these findings to explore interactions among tumor biology, treatment, sex, race, inherited genes and survival," Albain said.
Dr. Patrick Stiff, director of the Cardinal Bernardin Cancer Center: "This groundbreaking study will provide investigators with a road map for future research that will improve outcomes of patients of all races and socioeconomic status," stated Dr. Patrick Stiff, director of the Cardinal Bernardin Cancer Center, in the school's news release.
The study was funded by the National Cancer Institute.
Additional Resources and References
- The study, "Racial Disparities in Cancer Survival Among Randomized Clinical Trials Patients of the Southwest Oncology Group," was published on the Journal of the National Cancer Institute's web site on July 7, 2009, http://jnci.oxfordjournals.org/
- The July 7, 2009, news release, "Why Are African Americans Less Likely to Survive Certain Cancers?" was published on Loyola University's web site, (Loyola Medicine), http://www.loyolamedicine.org/
- To learn more about risk factors for breast cancer, please visit http://www.imaginis.com/breasthealth/bc_risks.asp
