Majority of women do not receive guideline-recommended breast cancer adjuvant therapy

A first-of-its kind study led by Xiao-Cheng Wu, MD, MPH, Associate Professor of Public Health at LSU Health Sciences Center New Orleans, reports that a significant number of women are not receiving guideline-recommended treatment for breast cancer and what factors contribute. The research is published online in the Journal of Clinical Oncology December 5, 2011 Early Release section.

The research team, which also included Vivien Chen, PhD, Professor and Director of the Louisiana Tumor Registry at LSU Health Sciences Center New Orleans School of Public Health, explored how race/ethnicity, insurance status, poverty, education, and hospital type were associated with the delivery of guideline-recommended adjuvant systemic therapy for breast cancers. Adjuvant systemic therapies like chemotherapy, a regimen of a group of specific chemotherapy drugs, and hormone therapy often follow an initial treatment like surgery to treat cells that may be too small to be seen and to reduce the chances of recurrence. Decisions about whether or not adjuvant systemic therapies are indicated, and which type, are determined by lymph node status, histology, tumor size, grade, and hormonal receptor status. The National Comprehensive Cancer Network (NCCN) guidelines were developed to improve cancer care and survival.

For this very large study of 6,734 women using Pattern of Care data from population-based cancer registries, the researchers grouped women by whether or not they received chemotherapy, chemotherapy regimen, or hormone therapy, according to the NCCN guidelines. The researchers found that 35% of the women studied received non-guideline chemotherapy (either no chemotherapy although recommended or use of chemotherapy when not recommended), 12% received non-guideline regimens (not treated with the chemotherapy drugs recommended), and 20% received non-guideline hormone therapy.

Significant predictors of non-guideline chemotherapy included Medicaid insurance, high poverty, and treatment at hospitals not accredited as Commission on Cancer (CoC) hospitals by the American College of Surgeons. Predictors of non-guideline regimens of specific chemotherapy drugs included lack of insurance and low education. Predictors of non-guideline hormone therapy included high poverty and treatment at non-CoC hospitals.

Previous studies focused primarily on racial differences and did not examine an association with poverty. This study found that women residing in high-poverty areas were less likely to receive guideline therapy. However, a number of other socioeconomic status factors may also contribute.

While women with Medicaid were less likely to receive guideline chemotherapy compared to women privately insured, uninsured women were not less likely to receive chemotherapy and hormone therapy according to the guidelines. They were, however, less likely to receive the recommended chemotherapy regimens than privately insured women. One of the reasons may be that uninsured women are often younger than privately insured women. Because younger women are more likely to receive chemotherapy than older women, the association may be diluted.

Not surprisingly, women were less likely to receive treatment according to the guidelines in hospitals not accredited by the American College of Surgeons. This is probably due to the multi-specialty approach, comprehensive care, and commitment to ongoing monitoring and improvement of cancer care by CoC hospitals. Women treated at CoC hospitals may also have greater access to oncology consultations.

"Guideline-recommended adjuvant systemic therapies for breast cancer are not disseminated proportionally in the community," notes Dr. Wu, who is also Assistant Director of the LSU Health Sciences Center New Orleans' Louisiana Tumor Registry. "Socioeconomically disadvantaged and medically under-served women are less likely to receive guideline therapies. Underlying causes for the disparities need to be identified so we can target interventions to help improve care and cancer prognosis for women across the board."

According to the American Cancer Society, breast cancer is the most frequently diagnosed cancer in women, excluding cancers of the skin. An estimated 232,620 new cases of breast cancer are expected to be diagnosed this year, with 39,970 deaths.

The study was funded by the Centers for Disease Control and Prevention's National Program of Cancer Registries. Besides LSU Health Sciences Center New Orleans School of Public Health, the team included researchers from Emory University, Duke University Medical Center, the Centers for Disease Control and Prevention, the University of Kentucky, the University of Wisconsin, and the California Cancer Registry.

"This is an example of how registry data, in conjunction with special studies, can help to ensure quality care for every cancer patient in Louisiana and beyond," concludes Dr. Vivien W. Chen, Professor of Public Health and Director of LSU Health Sciences Center New Orleans' Louisiana Tumor Registry.