In a study reported in the Journal of Clinical Oncology, Clarke et al found that increasing body mass index (BMI) was associated with lower rates of cervical precancer diagnosis and higher rates of cervical cancer diagnosis. The investigators had hypothesized that increased body mass could decrease the detection of cervical precancer, even with state-of-the-art screening methods.
The retrospective cohort study involved 944,227 women aged 30 to 64 years who underwent cytology and human papillomavirus (HPV) DNA testing at Kaiser Permanente Northern California between January 2003 and December 2015. BMI was categorized as normal/underweight (≤ 25 kg/m2), overweight (25 to < 30 kg/m2), or obese (≥ 30 kg/m2).
BMI and Risk
Overall, 4,489 cases of precancer and 490 cases of cancer were diagnosed. Increasing BMI was associated with a reduced risk of precancer diagnosis and increased risk of cancer diagnosis. The 5-year risks of precancer were 0.51% in obese women, 0.61% in overweight women, and 0.73% in normal/underweight women (P < .001 for trend). The 5-year risks for cancer were 0.083% in obese women, 0.071% in overweight women, and 0.056% in normal/underweight women (P < .001 for trend).
Results were consistent in subgroups defined by age, HPV status, and histologic subtype. Overall, it was estimated that approximately 20% of cervical cancers could be attributed to overweight or obesity in this population of women undergoing routine cervical screening.
The investigators concluded, “In this large, screened population, overweight and obese women had an increased risk of cervical cancer, likely because of underdiagnosis of cervical precancer. Improvements in equipment and/or technique to assure adequate sampling and visualization of women with elevated body mass might reduce cervical cancer incidence.”
The study was supported by the National Cancer Institute (NCI).
Megan Clarke, PhD, MHS, of the Division of Cancer Epidemiology & Genetics, NCI, is the corresponding author for the Journal of Clinical Oncology article.
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®.