Low HPV vaccine uptake among childhood cancer survivors
Uptake of the human papillomavirus (HPV) vaccine is low among child and adolescent cancer survivors, with a lack of recommendation by healthcare providers being a major contributor to the low uptake, a recent study found.
“We found that only a small proportion of young cancer survivors initiated HPV vaccination despite increased vulnerability to HPV-related morbidity in this population,” said the researchers. “[We also] found that most survivors had not received a recommendation from their provider prompting vaccine initiation,” they said.
Cancer survivors were more likely to be HPV-vaccine-naïve than their age-, sex-, and year-matched counterparts (odds ratio [OR], 1.72, 95 percent confidence interval [CI], 1.41–2.09; p<0.001). [J Clin Oncol 2017;doi:10.1200/JCO.2017.74.1843]
Survivors aged 13–26 years had lower HPV vaccine initiation rates compared with the general population (23.8 percent vs 40.5 percent; p<0.001). When stratified by age, vaccine initiation was significantly lower among survivors aged 13–17 years compared with their general population counterparts (22.0 percent vs 42.5 percent; p<0.001) but comparable between survivors and individuals aged 18–26 years in the general population (25.3 percent vs 24.2 percent; p=0.6).
Both female and male survivors aged 13–17 years had lower vaccination rates compared with the general population (32.6 percent vs 51.9 percent in females and 14.0 percent vs 33.8 percent in males; p<0.001 for both comparisons).
Conversely, female survivors aged 18–26 years had higher vaccination rates than the general population (45.7 percent vs 38.2 percent; p=0.04) while vaccine initiation rates in male survivors aged 18–26 years were similar to that of the general population (7.5 percent vs 8.3 percent; p=0.7).
The proportion of cancer survivors who received the complete HPV vaccine regimen was significantly lower than that of the general population (13.5 percent vs 20.8 percent; p<0.001).
The leading reason for noninitiation of HPV vaccine in cancer survivors was a lack of provider recommendation (OR, 10.8, 95 percent CI, 6.5–18.0; p<0.001), followed by a perceived lack of insurance coverage for the HPV vaccine among survivors (OR, 6.6, 95 percent CI, 3.9–11.0; p<0.001).
Other predictors of noninitiation were younger age (patients aged 9–12 years were less likely to have received the vaccine [OR, 3.7; p<0.001 compared with patients aged 13–17 years]) and male sex (OR, 2.9; p<0.001).
“The findings underscore the key role of healthcare providers to help increase HPV vaccination rates in this high-risk population,” said study author Dr James Klosky from the St Jude Children’s Research Hospital, Memphis, Tennessee, US.
“Without the recommendation of a healthcare provider, there was just a 1-in-20 chance that survivors in this study were vaccinated,” he said.
“We know that provider recommendation is a key predictor of HPV vaccination,” said study author Dr Wendy Landier from the University of Alabama at Birmingham, Alabama, US.
“Since cancer survivors often receive medical care from primary care providers as well as subspecialists, clear communication between healthcare providers is essential to ensure survivors receive the vaccine,” she said.
Researchers used the HPV Vaccination Survey to assess vaccine initiation among 982 child and adolescent cancer survivors from five cancer centres in the US who had completed therapy 1–5 years prior (mean age 16.3 years, mean age at cancer diagnosis 12.1 years, 54.6 percent male, mean time off therapy 2.7 years) and compared them with matched counterparts from the US population.
According to the researchers, adolescents and young adults make up a large proportion of childhood cancer survivors and are also at the highest risk for sexually transmitted infections. Furthermore, cancer survivors have an elevated risk for HPV-related cancers.
“These findings raise significant concerns, because they suggest that over 85 percent of young cancer survivors may lack protection against vaccine-preventable HPV, placing them at risk for infection and subsequent HPV-related morbidity, including malignancies,” they said.