African American Men Have Lowest Survival Rates Among Patients With Anal Cancer
Over the past 30 years, squamous cell carcinoma of the anus has been one of the few cancers with a steadily rising incidence in the United States, with the most rapid increase seen in black men. To further investigate this trend, researchers at the University of Texas Southwestern Medical Center looked at more than 7,800 cases of anal cancer in the United States and found that the complex chemistry of social, economic, biologic, and cultural factors led not only to disparities in incidence, but also survival. Their findings were published by Arora et al in JNCCN – Journal of the National Comprehensive Cancer Network.
“[Squamous cell carcinoma of the anus] has a very high cure rate with standard, nonsurgical treatments. For a cancer that is so curable, even modest differences in the rate of treatment impact disease burden and overall survival. That is why we examined the differences in the rate of treatment for [squamous cell carcinoma of the anus],” explained Muhammad Shaalan Beg, MD, who led the team of researchers.
Using data from the Surveillance, Epidemiology, and End Results Program (SEER) from 2000 to 2012, Dr. Beg and his team studied a cohort of more than 7,800 patients, average age 58, and found that white women diagnosed with locoregional squamous cell carcinoma of the anus lived 80% longer than black men with the same disease. Overall survival for white women was 148 months, followed by black women at 146 months, white men at 111 months, and black men at 82 months.
Receiving Standard of Care
The standard of care for locoregional squamous cell carcinoma of the anus is a combination of chemotherapy and radiation therapy, with second- and third-line therapy reserved for those with residual or recurrent disease. However, after examining the SEER data, Dr. Beg and colleagues noted that black patients had a lower rate of radiation therapy. According to the researchers, there are several possible causes for this lack of receipt of standard therapy.
“Understanding health-care disparities in [squamous cell carcinoma of the anus] is crucial, as it largely affects at-risk and vulnerable populations, including ethnic minorities and those with human immunodeficiency virus (HIV). Indeed, through study of other cancer types, we have seen that nonwhite populations experience delays in diagnosis and treatment and are less likely to receive guidelines-adherent treatment,” said Dr. Beg.
The same socioeconomic and behavioral factors that inhibit access to standard therapy probably also negatively influence prevention of disease—as well as time of detection, diagnosis, treatment, and posttreatment quality of life—all factors that directly correlate with overall survivorship. Moreover, patients with a low socioeconomic status tend to have lower health literacy, lack of health insurance, and geographic barriers to high-quality care, the researchers noted.
Correlation Between HIV/HPV Status and Anal Cancer
Populations at risk for squamous cell carcinoma of the anus include ethnic minorities and those with HIV. HIV-positive individuals with anal cancer tend to be younger, male, and black. Moreover, previous studies show that HIV-positive men who have sex with men are at higher risk of harboring high-risk human papillomavirus (HPV) than HIV-negative men. High-risk HPV is known to be associated with anal dysplasia and squamous cell carcinoma of the anus.
Although women with HPV are at higher risk, the authors note that women are also more likely to receive radiotherapy and to adhere to treatment than men.
“This report from a large cohort provides critical observations that reinforce two important concerns. First, the incidence of anal cancer is increasing secondary to rising numbers of individuals with HPV infection and the association with HIV infection. Second, health-care disparities across diseases—including cancer—is a major problem in the United States, particularly for African American males. As tragically noted from this SEER database assessment, it is also resulting in unacceptable outcomes,” said Al B. Benson III, MD, of Robert H. Lurie Comprehensive Cancer Center of Northwestern University, and Chair of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Panels for Colon, Rectal, and Anal Cancers. “The authors provide insights as to the cause of disparities and methods to address the disparities, with the hope that communities across the country will intervene to assist this vulnerable population.”
Closing the Gap
According to the authors, primary care physicians should be encouraged to identify high-risk individuals to enable targeted screening efforts. Together with patient education on the importance of self-management of comorbid conditions, lifestyle modifications, and identification of and following up on existing nonmalignant anogenital warts, caretakers across the continuum of care can begin to put in place strategies for improving the outcome for all patients with squamous cell carcinoma of the anus.
According to Dr. Beg, “It is critical that patients and physicians are aware that anal cancer can be cured in most patients. Health systems should make every effort to increase health-care delivery to at-risk groups who are often also socioeconomically challenged. We do not see such a striking racial and gender difference in survival in most other cancers.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
