Author: Larry Hand
The risk for head and neck cancer (HNC) was almost 50% higher in patients with diabetes than in individuals without diabetes, according to an article published online July 24 in JAMA Otolaryngology. The estimated risk is higher for people 40 to 65 years old.
Kuo-Shu Tseng, PhD, from Tainan University of Technology in Taiwan, and colleagues conducted a retrospective cohort study comparing the records of 89,089 patients newly diagnosed with diabetes with those of control patients matched by age, sex, and comorbidities. They obtained the data from Taiwan’s Longitudinal Health Insurance Research Database, which has claims information on 23.3 million beneficiaries between 1996 and December 31, 2011.
The researchers compared differences in estimated risk for head and neck cancer between groups by sex, age, and number of follow-up years after the first diabetes diagnosis date (index year) for patients. The incidence of head and neck cancer was 1.47 times higher for the diabetes group compared with for controls (P < .001)
The mean age among the diabetes group for cancer diagnosis was 55.52 years, and the mean interval between the index date and cancer diagnosis was 4.48 years.
Individuals aged 40 to 65 years in the diabetes cohort had significantly higher risk of developing head and neck cancer (incident risk ratio, 1.57; P < .001), and men had higher risk than women (incident risk ratio, 1.48; P < .001 for men).
The researchers computed hazard ratios for head and neck cancer, using Cox proportional hazards regression analysis, adjusting for age, sex, comorbidities, geographic distribution, and monthly income. The comorbidities were obesity, hypertension, coronary artery disease, chronic kidney disease, and chronic obstructive pulmonary disease.
The diabetes group had almost a 50% higher risk (adjusted hazard ratio [AHR], 1.48; 95% confidence interval [CI], 1.31 – 1.67) than the control group.
The most prevalent site of head and neck cancer was the oral cavity (57.1%) in the diabetes group (AHR, 1.74; 95% CI, 1.47 – 2.06). The next most prevalent cancer site was the nasopharynx (15.3%; AHR, 1.40; 95% CI, 1.03 – 1.89).
Overall survival of patients without head and neck cancer was significantly higher among the control patients (P < .001). Although the researchers found no significant effect on overall survival for the people in the diabetes group who developed cancer, follow-up periods for all patients with head and neck cancer are limited.
The researchers write that possible mechanisms for the link between diabetes and head and neck cancer include:
- shared genetic risk factors;
- epigenetic modifications of inherited or acquired genetic mutations;
- long-term exposure to hyperinsulinemia, which leads to breast cancer;
- exposure to high levels of insulin and insulin-like growth factor, which can increase cellular proliferation; and
- metabolic dysfunctions parallel to diabetes.
A limitation of the study is that several suspected risk factors for head and neck cancer, such as patients’ histories of using alcohol, smoking tobacco, and physical activity, were not available in the database.
1. This research was supported by the Taipei Medical University and Chi Mei Medical Center Research Fund. The authors have disclosed no relevant financial relationships.
2. JAMA Otolaryngol. Published online July 24, 2014