Associations of A Body Shape Index (ABSI) with Cancer Incidence, All-Cause, and at 23 Sites-Findings from the UK Biobank Prospective Cohort Study.

Background: Few studies have explored the emerging adiposity marker A Body Shape Index (ABSI) with cancer risk. This study investigated the associations between ABSI and the incidence of cancer at 23 sites and all cancer combined.

Methods: Data from 442,610 participants from the UK Biobank prospective study were included in this study. ABSI was used as the exposure. Incidence of cancer at 23 sites was the outcome. Cox proportional hazard models were performed to explore the association of ABSI, and combined ABSI and body mass index (BMI) with cancer risk, after adjusting for multiple testing.

Results: 36,961 individuals developed cancer during the 8.8 years median follow-up. In multivariable analyses, participants in the highest tertile of ABSI had higher risk of lung [HR, 1.58; 95% confidence interval (CI), 1.44-1.74], liver (HR, 1.45; 95% CI, 1.18-1.77), esophagus (HR, 1.32; 95% CI, 1.12-1.57), colorectal (HR, 1.19; 95% CI, 1.10-1.28), and breast (HR, 1.05; 95% CI, 1.04-1.17) cancers, and all cancers combined (HR, 1.11; 95% CI, 1.08-1.14) compared with the lowest tertile. These associations remained significant after adjustment for BMI. When ABSI was combined with BMI, participants in the highest ABSI who also had a BMI ≥ 25 kg/m were at higher risk of uterus, esophagus, liver, stomach, colorectal, and breast cancers, as well as all cancers combined, compared with those in the lowest ABSI tertile with a normal BMI.

Conclusions: ABSI is associated with an increased risk of five cancers as well as all cancers combined, independently of BMI.

Impact: ABSI is a useful marker for adiposity. However, cancer risk prediction improves with the combination of BMI.