Cervical cancer incidence in the United States decreased by about 1% per year from 2001 to 2017, but at the same time there was an increase in the incidence of other human papillomavirus (HPV)-related cancers, a new study reveals.
Over the same period, there was an overall 1.3% annual increase in oropharyngeal, anal, rectal, and vulvar cancers in women, and a 2.3% annual increase in these cancers in men.
HPV is associated with more than 90% of cervical cancers and between 60% and 75% of oropharyngeal, vulvar, vaginal, and penile cancer in the US, the researchers note.
Oropharyngeal cancer incidence increased by 2.3% overall, with a 2.7% increase in men and a 0.77% increase in women. The incidence of this cancer was nearly fivefold greater in men at 8.89 per 100,000 population vs 1.68 per 100,000 population for women, the study found.
In addition, among women over age 50 years, anal and rectal cancer incidence increased by 3.5% per year; at the same time, cervical cancer incidence decreased 1.5% per year.
The increase in the incidence of oropharyngeal cancer and in anal and rectal cancers is expected to continue, the authors said.
The data showing these new trends come from an analysis of 657,317 individuals obtained from the US Cancer Statistics program, conducted by Cheng-I Liao, MD, of Kaohsiung Veterans Hospital, Taiwan, and colleagues.
The study was highlighted at a press briefing ahead of the annual meeting of the American Society of Clinical Oncology (ASCO), where the study will be presented June 6.
These incidence trends may reflect the availability of clear guidelines for screening and vaccination for the prevention of HPV-related cervical cancer — and the dearth of guidelines and standardized screening and vaccination for the other HPV-related cancers, the authors say.
The team also found cervical cancer accounted for 52% of all HPV-related cancers during the study period. The decrease in the incidence of cervical cancer over time was greater among women aged 20-24 (4.6% per year), compared with those aged 25-29 years (1.6%) and 30-34 years (1.1%),
Liao speculated that this age-based difference suggests a potential effect of HPV vaccination, greater vaccine acceptance among younger women, and clear guidelines for screening and vaccination.
However, an expert approached for comment was not so sure. It is likely too soon to give HPV vaccination too much credit for lower cervical cancer rates, said Jennifer Young Pierce, MD, MPH, a gynecologic oncologist at the Mitchell Cancer Institute, University of South Alabama, Mobile.
The continued rise in HPV-related cancers other than cervical cancers supports the point that screening — rather than vaccination — accounts for much of the decline observed in cervical cancer incidence, Pierce told Medscape Medical News.
Vaccination in men lags behind that of women, and there is a lack of good screening methods for head and neck cancers, she explained.
"When we have both vaccination and screening in these other cancers at high rates, we're going to see significant declines in those cancers also," she said.
"I'm very excited by the data but I do not believe it is related to vaccination as a method of prevention," said Pierce, a professor of interdisciplinary clinical oncology who has been involved in numerous HPV vaccine-related studies and initiatives to improve vaccine uptake since its approval in 2006.
The HPV vaccine was first approved for preventing HPV-related cervical cancer in 2006 with an indication for girls and women aged 9-26 years. The vaccine indication was expanded in 2011 to include boys aged 11-12 years and is now approved for those up to age 45 years.
However, neither standardized screening nor HPV vaccination is currently recommended for any HPV-related cancer other than cervical cancer, Liao said.
Vaccination during much of the current study timeframe (2001-2017) didn't apply to most of the people who got cancer, Pierce explained in an interview, noting that the vaccinated individuals "still aren't old enough to be part of the group we're talking about."
Rather, the increased use of HPV screening along with Pap testing for cervical cancer was becoming much more widespread at the time and was likely picking up more precancerous lesions — and thereby helping to decrease cervical cancer incidence in women in their 40s, 50s, 60s, and 70s, she said.
Pierce does, however, credit the vaccine movement for improving awareness of HPV risk.
"It has done a great job of educating the population about the dangers of these cancers …and that there's more we can do to prevent them," she said.
Like Liao, she stressed the need for research focused on finding more effective screening modalities and on vaccine efficacy.
Also commenting on the study, ASCO president Lori J. Pierce, MD, a radiation oncologist, professor, and vice provost for academic and faculty affairs at the University of Michigan, Ann Arbor, said the findings underscore the need for ongoing exploration of potential strategies such as HPV screening for high-risk populations.
"We can pick out higher risk populations so it would make sense to do a screen," she said.
"Clearly, this study shows that we still have a great deal of work to do in order to reverse the increasing incidence rates of other HPV-related cancers," she added in a press statement.
In an interview prior to the press conference, Pierce told Medscape Medical News that the findings are important because the outcome "opens all of our eyes into the trends of HPV-related cancers in the US.
"This is something that hasn't been studied well over time," she added, noting that where guidelines do exist for HPV-related cancers other than cervical cancer, they are inconsistent.
Further, it is possible that the vaccine will "cover a significant portion of the etiologic viruses that cause these cancers," thereby helping to prevent the other HPV-related cancers, she said.
For that reason, additional research and strategies for overcoming vaccine hesitancy, increasing overall vaccination rates, and for developing consistent guidelines are needed.
"I think there needs to be further resources and research to address the lack of screening for these other HPV-related cancers and we need to have consistent vaccination guidelines, because these cancers are preventable."
Liao and Pierce have disclosed no relevant financial relationships.
American Society of Clinical Oncology Annual Meeting: Abstract 107. To be presented June 6, 2021.
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Cite this: Cervical Cancer Rates Fall, but Other HPV Cancers Increase - Medscape - May 19, 2021.