<b>OBJECTIVE</b>
<p>Obesity and type 2
diabetes are associated with serious, adverse health effects, including cancer.
Although bariatric surgery has been shown to reduce cancer risk in patients
with obesity, the effect of bariatric surgery on cancer risk in patients with obesity
and diabetes is less studied. We therefore examined the long-term incidence of
cancer after bariatric surgery and usual care in patients with obesity and
diabetes in the matched prospective Swedish Obese Subjects (SOS) study. </p>
<p><b>RESEARCH DESIGN AND
METHODS</b></p>
<p>The SOS study examines
long-term outcomes following bariatric surgery or usual care. The current analysis
includes 701 patients with obesity and type 2 diabetes at baseline, 393 of
which underwent bariatric surgery, and 308 who received conventional obesity
treatment. Information on cancer events was obtained from the Swedish National
Cancer Register. Median follow-up time was 21.3 years (interquartile range 17.6-24.8
years, maximum 30.7 years). </p>
<p><b>RESULTS</b></p>
<p>During follow-up, the
incidence rate for first-time cancer was 9.1 per 1000-person-years (95% CI,
7.2-11.5) in patients with obesity and diabetes treated with bariatric surgery and
14.1 per 1000-person-years (95% CI, 11.2-17.7) in patients treated with usual
obesity care (HRadj=0.63; 95% CI 0.44-0.89, p=0.008). Moreover, surgery was
associated with reduced cancer incidence in women (HRadj=0.58; 0.38-0.90, p=0.016),
although the sex-treatment interaction was non-significant (p=0.630). In
addition, diabetes remission at the 10-year follow-up was associated with
reduced cancer incidence (HRadj=0.40; 95% CI 0.22-0.74, p=0.003).</p>
<p><b>CONCLUSIONS</b></p>
<p>These results suggest
that bariatric surgery prevents cancer in patients with obesity and diabetes,
and that durable diabetes remission is associated with reduced cancer risk. </p>
Cancer incidence among First Nations adults in Canada: follow-up of the 1991 Census Mortality Cohort (1992–2009)