TOPLINE:
A diagnosis of type 2 diabetes (T2D) at a younger age is associated with an increased cancer risk, while the risk drops for T2D diagnosed at age 75 and older.
METHODOLOGY:
- A T2D diagnosis at a younger age is associated with a greater risk for complications and comorbidities, such as cardiovascular and kidney diseases, retinopathy, and dementia than that occurring at an older age.
- The study evaluated the association between the age at T2D diagnosis and subsequent risk for overall and 14 site-specific cancers in a Shanghai, China, cohort of 428,568 patients newly diagnosed with T2D (about half women) from 2011 to 2018.
- New cases of cancer from the T2D diagnosis to 2018 were identified through a tumor registry.
- Patients were categorized into six groups based on their age at T2D diagnosis: 20-54, 55-59, 60-64, 65-69, 70-74, and ≥ 75 years.
- The incidence rates of overall and 14 site-specific cancers were compared between patients with T2D and the general Shanghai population (older than 20 years).
TAKEAWAY:
- Compared to the general population, T2D increased the relative risk for all-cause cancer by 10% (standardized incidence ratios [SIRs], 1.10; 95% CI, 1.09-1.12).
- :
- 20-54 years: 1.48 (95% CI, 1.41-1.54)
- 55-59 years: 1.30 (95% CI, 1.25-1.35)
- 60-64 years: 1.19 (95% CI, 1.15-1.23)
- 65-69 years: 1.16 (95% CI, 1.12-1.20)
- 70-74 years: 1.06 (95% CI, 1.02-1.10)
- The overall cancer incidence risk in patients diagnosed with T2D at age ≥ 75 years was even lower than that in the general population (SIR, 0.86; 95% CI, 0.84-0.89).
- The risk (SIR) for most site-specific cancers (including respiratory, colorectal, stomach, liver, pancreatic, bladder, central nervous system, kidney, and gallbladder cancers and lymphoma) decreased with increasing age at T2D diagnosis.
IN PRACTICE:
“Our findings suggest that the carcinogenicity of T2D differs markedly by age at diagnosis and highlights the necessity of stratifying patients according to diagnosis age in management, screening, and preventative strategies,” wrote the authors.
SOURCE:
The study, led by Yanyun Li, Division of Chronic Non-Communicable Disease and Injury, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China, was published online in Diabetes Care.
LIMITATIONS:
Data on smoking history, alcohol consumption, and physical activity were available for nearly 60% of patients with T2D. The findings might only apply to patients with T2D who survive longer than the average and are therefore less applicable to the general population with diabetes. Patients with young-onset T2D had not reached the age where cancers are more prevalent despite as many as 8 years of follow-up.
DISCLOSURES:
This work was supported by the Foundation of National Facility for Translational Medicine, National Natural Science Foundation of China, Shanghai Municipal Health Commission, and Three-Year Action Plan of Shanghai Public Health. The authors declared no conflicts of interest.
A version of this article appeared on Medscape.com.