Impact of body mass index on the oncological outcomes of patients treated with radical nephroureterectomy for upper tract urothelial carcinoma.

PURPOSE: To evaluate the association between body mass index (BMI) and oncological outcomes in patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC).

METHODS

We retrospectively reviewed 237 consecutive patients treated with RNU for UTUC at our institution between 1990 and 2012. Univariable and multivariable cox regression models investigated the association of BMI with disease recurrence, cancer-specific mortality, and overall mortality.

RESULTS

From the 237 patients, 104 (44%) had a BMI < 25 kg/m2, 88 (37%) had a BMI between 25 and 29.9 kg/m2, and 45 (19%) had a BMI ≥ 30 kg/m2 at the time of surgery. Within a median follow-up of 44 months (IQR: 24-79), 53 patients (22.4%) experienced a disease recurrence, 85 patients (35.9%) had bladder recurrence, and 44 patients (18.6%) died from the disease. The 5 year recurrence-free and cancer-specific survival rates were, respectively, 32 and 56% for BMI ≥ 30 kg/m2, 45 and 74% for patients with BMI 25-29.9 kg/m2, and 69 and 81% for patients with BMI < 25 kg/m2. In multivariable analyses that adjusted for the effects of the standard clinico-pathological features, BMI ≥ 30 kg/m2 was associated with a higher risk of disease recurrence (HR 3.23; 95% CI 2.3-6.6, p < 0.001) and cancer-specific mortality (HR 3.84; 95% CI 2.8-6.5; p < 0.001).

CONCLUSIONS

Obesity was independently associated with higher risks of disease recurrence and cancer-specific mortality in patients treated with RNU for UTUC.