Diabetes Increases Risk of Recurrence and Progression of Bladder Cancer

According to a study performed at the Chonnam National University Medical School in Gwangju, Korea, diabetes mellitus (DM) may be an independent predictor of disease recurrence and progression in patients who suffer from non-muscle invasive bladder cancer (NMIBC).

The retrospective study focused on 251 patients who underwent transurethral resection (TUR) for NMIBC; in comparison with non-DM patients, 92 patients with DM at the time of the surgery experienced a two-fold and nine-fold increased risk of disease recurrence and progression.

Overall, the researchers reported that the DM patients were older and suffered from a higher rate of hypertension in comparison to the non-diabetes patients. Further, they found that patients who had a hemoglobin A_1c level above 7% suffered from greater tumor multiplicity, a higher incidence of high-grade tumors, and were given considerably more intravesical therapy.

The investigators, led by Seung Il Jung, MD, and fellow colleagues at the university, concluded that “close follow-up and intravesical therapy may be beneficial in patients with DM, especially those with poor glycemic control.”

It is still uncertain as to how DM is a factor of bladder cancer. Previous studies have indicated that continual exposure to hyperinsulinemia or hyperglycemia can induce tumor cell proliferation and metastasis. Furthermore, other researchers have established a link between diabetes and an increased risk of urinary tract infection (UTI), which is a known to be related to bladder cancer risk; as such, the authors wrote, a UTI could influence the prevalence of recurrence or progression.

The authors concluded by stating that their study is limited by its retrospective design, relatively small sample size, and by the low frequency of tumor recurrence and progression. They also noted that they did not assess how long the DM lasted in each patient.

This study was published in the International Journal of Urology.