Why are African-Americans more likely than Caucasians not only to be diagnosed with head and neck cancer, but also to die from the disease? While the answer isn't a simple one, differences in lifestyle, access to care, and tumor genetics may be partly to blame, according to a new study from Henry Ford Hospital.
The study, which was presented September 14 at the American Academy of Otolaryngology - Head and Neck Surgery Foundation's annual meeting in San Francisco, also found that African-Americans are more likely to be past or current smokers, one of the primary risk factors for head and neck cancer.
"We're really trying to understand why African-Americans with head and neck squamous cell carcinoma do so poorly," said lead author Maria Worsham, PhD, director of research in the department of Otolaryngology - Head and Neck Surgery at Henry Ford, in a news release. "Using a comprehensive set of risk factors that are known to have some bearing on the disease, we're able to gain a better understanding of what contributes to racial differences and work to help improve patient care."
This year alone, it's estimated that 52,140 new cases of head and neck cancer will be diagnosed, and roughly 11,460 will die in 2011 from oral cavity and pharyngeal and laryngeal cancers, she and her team members noted.
African-Americans are more likely to be diagnosed with late-stage head and neck squamous cell carcinoma (HNSCC) and have a worse five-year survival rate than Caucasians. It's unknown whether significant biological rather than socioeconomic differences account for some of the disparities in outcomes.
To get at the root of these differences, Worsham and her team used a large Detroit multiethnic group of 673 patients with HNSCC. Most notably, 42% of the study group was African-American.
The researchers took a broad approach to the study, examining many of the intertwined variables influencing health and disease to look for differences among African-Americans and Caucasians. In all, the study focused on 136 risk factors, including demographics (age, race, gender), smoking and alcohol use, access to care, and type of cancer treatment (radiation and/or surgery). Tumor characteristics, including stage, biology, and genetics, also were examined.
Among the study findings:
While 88% of African-Americans in the study had medical insurance, the majority had Medicare or Medicaid instead of private health insurance.
African-Americans also were more likely to be unmarried or living alone, both of which previous studies suggest have a negative impact on quality of life and survival.
In terms of cancer treatment, African-Americans in this study were more than two times more likely than Caucasians to receive radiation therapy. The study showed fewer African-Americans (43%) opted for surgery than Caucasians (49%).
African-American tumors were six to seven times more likely to present with lymphocytic response.
Compared to Caucasian tumors, African-American tumors were almost two times more likely to have loss of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene and gain of the small inducible cytokine A3 (SCYA3) gene. CDKN2A is important to cell cycle regulation, and the SCYA3 gene product has dual roles of tumor lymph node metastasis and local host defense against tumors in HNSCC.
