Racial disparities in head and neck squamous cell carcinoma

Squamous cell carcinoma of the head and neck refers to a variety of malignant tumors arising from the oral cavity and upper aerodigestive tract. The primary risk factors for head and neck cancer are tobacco and alcohol use, and more recently HPV has been defined as an independent risk factor for oropharyngeal tumors. Racial disparities among patients with head and neck squamous cell carcinoma (HNSCC) have remained unchanged for more than three decades. Persons of African ancestry have a higher incidence compared to persons of European ancestry. Notably, Black patients consistently have lower five-year survival rates as compared to White patients. Although studies of racial disparities in HNSCC have been conducted, many suggest that the observed differences may be related to barriers to care and screening; but we have shown that the differences may be independent of these factors. After matching on age and smoking-dose (pack-years) and adjusting for socioeconomic and insurance status, any tobacco and alcohol use, any family history of cancer, gender, and age, we observed that Black oral cavity cancer patients were more likely than Whites to be diagnosed with advanced-stage disease (AdjOR = 3.60, 0.97–13.41). Similarly, Black larynx cancer patients were more likely than Whites to be diagnosed with positive lymph nodes (AdjOR = 2.26, 0.92–5.61) and Black patients were more likely than White patients to develop second primaries, recurrences or metastasis (AdjHR = 1.47, 0.99-2.18). We believe that genetic and environmental risk factors and their interaction may contribute to the higher incidence of head and neck cancer in Black Americans. We are currently evaluating the interactions of tobacco/alcohol exposure and genetic variations in genes involved in these metabolic pathways in order to understand how these interactions contribute to the differences in cancer risk and outcome between Black and White populations.

Cancer Prevention Project of Philadelphia (CAP3 Study)

Through our community engagement efforts we have developed a successful model for population-based health disparities research studies. We provide the community not only with information about the importance of incorporating cancer prevention practice and screening into their lifestyle but we also provide community members with a better understanding of the importance of cancer disparities research and the value of participating in research studies. This approach over the years has led to an overwhelming acceptance, thus providing us with the ability to successfully recruit study participants of African Ancestry. This model involving community engagement and research recruitment has been successfully adapted in the Caribbean, the “Tobago Cervical and Oral Cancer Research Study”, as well as the US Philadelphia metropolitan area, the “Cancer Prevention Project of Philadelphia (CAP3)”. The CAP3 study is research registry of cancer-free participants and serves as a pipeline project for our population-based molecular epidemiology research studies. To date there are more than 750 participants of African Ancestry enrolled and recruitment is ongoing. To learn more please call Dr. Camille Ragin at 215-728-1148.

African Caribbean Cancer Consortium (AC3)

The AC3 is a multi-institutional collaborative network that focuses on studies of cancer risk and outcomes among populations of African ancestry (African-American, African and Caribbean). AC3 is a broad-based resource for education, training and research on etiology, screening, prevention, treatment and survivorship related to cancer in populations of African Descent. Our overarching goals are: a) To build knowledge, capacity and infrastructure b) To advance the science of cancer prevention and control in populations of African ancestry. Recognizing the public health significance of cancer in populations of African origin, and socio-cultural factors that influence disparities in health outcomes, we have provided a platform in the AC3 to report country-level findings and we have also fostered collaborative research to examine genetic and environmental contributions in carcinogenesis among populations of African origin. Our working groups focus on investigating gene x environment interactions. Since 2009, AC3 members have conducted studies of biomarkers of susceptibility to and outcomes from prostate cancer among men of African ancestry; cervical human papillomavirus (HPV) infections in Black women from the US, Jamaica, Tobago, Barbados, Guadeloupe and the Bahamas and assessments of knowledge, perception and attitudes of HPV and the HPV vaccine in the US, and Bahamas and many others. AC3 has conducted community education and research information sessions to the community since its conception in 2006. In addition, research skills training sessions during our AC3 meetings has contributed to developing and strengthening of population-based cancer research and cancer registration in the Caribbean to facilitate stronger collaborative research studies. We also provide research training opportunities in our CORE laboratory here at Fox Chase Cancer Center to undergraduate and graduate students where they learn molecular biology techniques, epidemiology study designs and applications. Additional information can be found at www.ac3online.org

Gene x environment interactions and prostate cancer risk in Black men

It is well documented that there is a disproportionate burden of prostate cancer among not only African-American men but also Black men from other parts of the world. Furthermore, the prostate cancer death rate among African-American males is higher than US males of European descent, and higher death rates have been reported in other populations of African descent in the Caribbean islands and Africa. Our recent study of GSTM1 polymorphisms and prostate cancer risk offers a classic example of gene x environment interactions. Studies in populations of European descent have demonstrated that a genetic variation in the GSTM1 gene resulting in a deletion is associated with an increased risk of prostate cancer among smokers and this risk increases with smoking dose. Therefore, we conducted a multi-national analysis of prostate cancer risk to evaluate the association of GSTM1 deletion among Black men and found that GSTM1 genotype modifies the effect of tobacco exposure on prostate cancer risk for African-American men but not for Black Caribbean men. Our findings suggest that other environmental factors unique to Caribbean men may contribute to prostate cancer risk. We are currently developing additional studies to further investigate gene-environment interactions and prostate cancer risk among Black men.igate gene-environment interactions and prostate cancer risk among Black men.