Diabetes, obesity tied to upstaging in renal cell carcinoma

Diabetes and higher body mass index (BMI) contribute to pathological upstaging in renal cell carcinoma, according to a study. Preoperative tumour size, increased age, and male sex are also significantly associated with upstaging.

A retrospective international case-control study was conducted in consecutive patients treated surgically with radical or partial nephrectomy for nonmetastatic renal cell carcinoma (cT2 N0) between January 2010 and December 2018.

The authors used multivariable logistic regression models to explore the associations of preoperative risk factors with pT3a pathological upstaging in all patients, as well as subsets with those with preoperative tumours ≤4 cm, renal nephrometry scores, tumours ≤4 cm with nephrometry scores, and clear cell histology. Associations with pT3a subsets (renal vein, sinus fat, perinephric fat) were also assessed.

A total of 4,092 partial nephrectomy and 2,056 radical nephrectomy patients were included, among whom 4.9 percent and 23.3 percent experienced pathological upstaging, respectively.

Increasing preoperative tumour size, increasing age, and the presence of diabetes were independently associated with pT3a upstaging. Among partial nephrectomy patients, factors predictive of upstaging were diabetes (odds ratio [OR], 1.65, 95 percent confidence interval [CI], 1.17‒2.29), male sex (OR, 1.62, 95 percent CI, 1.14‒2.33), and increasing BMI (OR, 1.03, 95 percent CI, 1.00‒1.05 per 1-unit BMI).

In subset analyses, hilar tumours were frequently upstaged (partial nephrectomy: OR, 1.91, 95 percent CI, 1.12‒3.16; radical nephrectomy: OR, 2.16, 95 percent CI, 1.44‒3.25).