Women with overweight and obesity had a higher risk for cervical cancer, but lower rates of cervical precancer, according to a retrospective analysis published in Journal of Clinical Oncology.
“The obesity epidemic is a significant, worldwide public health challenge, with important implications for global cancer rates,” Megan A. Clarke, PhD, MHS, postdoctoral fellow in the division of cancer epidemiology and genetics at the NCI, and colleagues wrote. “This problem is particularly acute in the United States, where obesity rates have tripled over the past 3 decades. Although some studies have reported an association of obesity with increased cervical cancer incidence and mortality, findings have been inconsistent, and the mechanism is unknown.”
Clarke and colleagues studied 944,227 women aged 30 to 64 years who underwent cytology and HPV DNA testing at Kaiser Permanente Northern California from 2003 to 2015 to evaluate associations between cervical precancer and cancer by BMI.
BMI was categorized as normal/underweight (< 25 kg/m2), overweight (25 kg/m2 to 30 kg/m2) or obese ( 30 kg/m2).
About 6.3% of women were HPV positive. Mean follow-up was 4.4 years.
Overall, 0.48% women developed cervical intraepithelial neoplasia grade 3 and adenocarcinoma in situ — precancer — of whom 44.4% had normal/underweight, 29.8% had overweight and 25.6% had obesity.
In total, 0.05% of women developed cancer, of whom 30.4% had normal/underweight, 31.4% had overweight and 38.2% had obesity.
Women with obesity had the lowest rate of 5-year precancer risk at 0.51% (95% CI, 0.48-0.54) compared with 0.73% (95% CI, 0.7-0.76) of women with normal/underweight. However, women with obesity had the highest rate of 5-year risk of cervical cancer at 0.08% (95% CI, 0.07-0.09) compared with 0.05% (95% CI, 0.04-0.06) of women with normal/underweight.
Results appeared consistent across age subgroups HPV status and histological subtype.
Study limitations included unknown timing of cancer development vs. detection, missing data on BMI for 13% of women and no information on comorbidities.
“Although HPV vaccination holds great promise, screening will remain the mainstay of cervical cancer prevention for decades to come,” the researchers wrote. “Considering this, along with the worldwide obesity epidemic, our findings have significant implications for the secondary prevention of cervical cancer and signify the need for greater awareness and possibly the development of specific clinical recommendations for screening overweight and obese women. Going forward, it will be important to validate which components of the cervical cancer screening process are failing.” – by Cassie Homer
Disclosures: Clarke reports no relevant financial disclosures. One researcher reports institutional consulting with Teva Pharmaceutical and institutional research funding from Bayer. Another researcher reports ties to Roche and Becton Dickinson.