Diabetes, Higher BMI Identified as Risk Factors for RCC Upstaging

Diabetes and obesity increase the likelihood of upstaging in patients with clinical T1 renal cell carcinoma (RCC) undergoing partial or radical nephrectomy, a new study finds.

Emerging research indicates an association between metabolic syndrome and RCC outcomes. The current study extends the findings on prognosis.

Among 4092 patients undergoing partial nephrectomy (PN) and 2056 patients undergoing radical nephrectomy (RN) for clinical T1 tumors, pathologic upstaging to pT3a occurred in 4.9% of the PN and 23.3% of the RN group. Along with larger preoperative tumor size and older age, pre-existing diabetes increased the probability of upstaging in both the PN and RN groups, Deepak K. Pruthi, MD, of UT Health San Antonio in San Antonio, Texas, and colleagues reported in The Journal of Urology.

In the PN group, diabetes significantly increased the odds of upstaging to pT3a by 65%, whereas male sex increased the odds by 62%. Each 1 cm increase in preoperative tumor size increased the odds of upstaging by 26%. Each 1 kg/m² unit increase in body mass index (BMI) also was significantly associated with 3% increased odds of upstaging, as was every 1-year increase in age.

In the RN group, diabetes and male sex significantly increased the odds of upstaging to pT3a by 32% and 18%, respectively. Each 1 cm increase in preoperative tumor size increased the odds by 24%. Each 1-year increase in age was significantly associated with 2% increased odds of upstaging.

Diabetes was a risk factor for upstaging across PN and RN groups, sex, age, preoperative tumor size, and BMI, Dr Pruthi’s team reported.

According to the investigators, “diabetic patients represent a unique population for whom both nephron-sparing surgery is preferred if feasible [to delay chronic kidney disease], but these patients may harbor higher oncologic risk.”

Patients with hilar tumors undergoing PN and RN also had 1.9- and 2.2-fold increased odds of upstaging to pT3a, respectively, the investigators reported.

“With advancements in systemic therapies and as the utilization of [small renal mass] biopsy proliferates, identifying patients at risk for pathological upstaging will become increasingly important for patient counseling,” Dr Pruthi’s team wrote. “Hypothetically, patients who would be predicted to be upstaged may choose to undergo renal mass biopsy and, if found to have high-risk disease, they may undergo treatment pathways that, in the future, may include neoadjuvant immunotherapy.”

Patients received care at 11 centers in 7 countries across North America, South America, Europe, and Asia, so the study captures the diversity of the RCC population. The study was limited by a lack of information on patients’ smoking history.

“To date, none of the validated nomograms for renal cell carcinoma include obesity or other effects of metabolic syndrome for localized renal masses,” Simon P. Kim, MD, of the University of Colorado in Aurora noted in an accompanying editorial. Whether reducing obesity and controlling diabetes decreases the risk for aggressive RCC remains to be seen.

This article originally appeared on Renal and Urology News