Survival with human papillomavirus (HPV)-associated cancers differs significantly between blacks and whites, men and women, and people in different age groups, according to findings from the Centers for Disease Control and Prevention (CDC) National Program of Cancer Registries (NPCR).
“We found racial and gender disparities,” Dr. Mona Saraiya from CDC, Atlanta, Georgia told Reuters Health by email. “A black person with an HPV-associated cancer was likely to die sooner than a white person with the same cancer. And we were surprised that men with an HPV-associated anal cancer were likely to die sooner than women with the same cancer.”
HPV DNA is present in an estimated 91% of cervical cancers, 75% of vaginal cancers, 69% of vulvar cancers, 91% of anal cancers, 63% of penile cancers, and 71% of oropharyngeal cancers. Little is known about survival with these HPV-associated cancers.
Dr. Saraiya and colleagues used NPCR data from 2001 through 2011 to study survival among patients diagnosed with HPV-associated cancers, as well as survival disparities by sex, race, and age.
The 5-year age-standardized relative survival was highest for vulvar (66%) and anal (65.9%) squamous cell carcinomas (SCCs) and lowest for penile (47.4%) and oropharyngeal (51.2%) SCCs, according to the November 6 Cancer online report.
Survival consistently declined with increasing age for cervical, penile, and oropharyngeal carcinomas, whereas survival increased slightly among patients diagnosed between age 40 and 49, compared with those diagnosed before age 40, for vaginal and vulvar SCCs.
Most HPV-associated cancers were diagnosed among whites, and 5-year age-standardized relative survival was consistently higher for whites compared with blacks for all HPV-associated cancers. The lowest survival and the greatest differences by race were for oropharyngeal carcinomas (32.4% for blacks vs. 53.5% for whites) and penile carcinomas (34.7% vs. 48.4%, respectively).
For cancers that occur among both men and women, more than half of the anal and rectal SCCs occurred among women, compared with only 20% of oropharyngeal SCCs. Five-year relative survival for anal carcinomas was higher among women (69.3%) than men (59.8%), as it was for rectal carcinomas (61.2% vs. 45.5%, respectively). But survival for oropharyngeal carcinomas was lower among women (49.8%) than men (51.7%).
Overall survival rates were higher for all HPV-associated cancers diagnosed at localized stage and lower for cancers diagnosed at regional and distant stages.
When population characteristics and disease stage at diagnosis were combined, the poorest 5-year relative survival was observed for men who had rectal SCCs (6.9%) and for patients age 60 or older who had rectal and vulvar SCCs (10.5% and 10.9%, respectively) diagnosed at distant stage.
“HPV vaccination and improved access to screening and treatment, especially among groups that experience higher incidence and lower survival, may reduce disparities in survival from HPV-associated cancers,” the researchers concludeFor many HPV-associated cancers (besides cervical cancer), there is no routine screening recommended,” Dr. Saraiya said, “so one major initiative to reduce disparities would be to focus on prevention - namely, HPV vaccination.”
“Cervical cancer screening is a proven strategy that works, but in order for it to be successful in improving outcomes, clinicians can work with their patients to ensure they get the correct follow-up after an abnormal screening result,” she said. “For other cancers, screening strategies are limited - but more research in good screening strategies and tests is needed for anal and oropharyngeal cancers. For example, there are trials underway to examine the role of anal cytology in screening for anal cancer in high-risk populations, and also research being done on the role of cytology or other strategies in screening for oropharyngeal cancers.”
“We were not able to examine in detail what disparities exist for treatment of these cancers; further investigation of those is needed,” Dr. Saraiya added.
Dr. Patti Gravitt from George Washington University's Milken Institute School of Public Health, Washington, DC, who has researched trends in HPV infection and cancer mortality rates, told Reuters Health by email, "The consistent trend for lower relative survival from HPV-associated cancers in black versus white men and women points to an important disparity that deserves more detailed understanding.”
“I think the research community needs to evaluate both behavioral and biological causes of the survival disadvantage in blacks,” she said. “While it is important to ensure that these don't reflect differential access to care (screening, diagnosis, and treatment), we should also consider other biological factors that may result in different responses to the HPV infection.”
“Oral and female genital microbiomes differ quite significantly by race and may modify the immune response to the virus or the effectiveness of treatment,” Dr. Gravitt said. “Research to understand the ecology of the oral and anogenital tracts on HPV infection and cancer risk and survival by gender, race, and age using systems approaches may be particularly informative.”
“Recent reports from the CDC show an increasing trend of non-viral sexually transmitted infections, such as chlamydia and gonorrhea, suggesting that the risk of sexually transmitted HPV continues to be high in the United States,” she added. “Unequivocally, the best strategy to reverse these trends is for providers to make strong recommendations for HPV vaccination in adolescence before the age of sexual debut.”
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