Weight loss after localized renal cell carcinoma (RCC) diagnosis may be a marker for disease progression and worse prognosis, according to results of a study presented at IKCS: North America 2025.
In RCC, previous studies have reported an obesity paradox, in which obesity increases risk for incident RCC, whereas patients with higher body mass index (BMI) are associated with better survival.
Investigators from Roswell Park Comprehensive Cancer Center in the United States examined the association between BMI trajectory and outcomes in RCC using data from the Oncology Research Information Exchange Network (ORIEN). Patients (N=1414) diagnosed with localized RCC between 2020 and 2022 were evaluated for overall survival (OS) and disease-free survival (DFS) on the basis of BMI at diagnosis and at 2- and 3-years post-diagnosis.
The patients were aged median 61.7 years, and they had a BMI of 29.8 kg/m2. At diagnosis, 13.7% of patients were classified as having normal BMI, 30.3% were overweight, 25.4% had obesity type I, and 30.6% had obesity types II or III.
OS was significantly related to BMI at diagnosis (hazard ratio [HR], 0.86; 95% CI, 0.75-0.98; P =.03),2 years post-diagnosis (HR, 0.75; 95% CI, 0.63-0.89; P =.0007), and 3 years post-diagnosis (HR, 0.74; 95% CI, 0.60-0.91; P =.004).
Better OS was associated with BMI of 35 kg/m2 or higher at diagnosis (HR, 0.56; P =.04), BMI of 30 kg/m2 or higher at 2 years post-diagnosis (HR range, 0.32-0.45; both P £.02), and BMI of 25 kg/m2 or higher at 3 years post-diagnosis (HR range, 0.16-0.27; all P £.0001) compared with BMI of less than 25 kg/m2.
Compared with individuals who maintained their weight from diagnosis, a 5% to 10% loss (HR, 3.58; 95% CI, 1.76-7.28; P =.0004) or greater than 10% weight loss (HR, 4.87; 95% CI, 2.48-9.57; P <.0001) at 2 years post-diagnosis was associated with worse OS. Similar trends were observed at 3 years post-diagnosis (HR range, 3.09-4.87; both P £.0004).
DFS was also related to BMI at diagnosis (HR, 0.86; 95% CI, 0.79-0.94; P =.001), 2 years post-diagnosis (HR, 0.85; 95% CI, 0.76-0.94; P =.001), and 3 years post-diagnosis (HR, 0.84; 95% CI, 0.75-0.95; P =.005).
As with OS, a prolonged DFS was associated with BMI of 35 kg/m2 or higher at diagnosis (HR, 0.63; P =.02), BMI of 30 kg/m2 or higher at 2 years post-diagnosis (HR range, 0.60-0.61; both P £.04), and BMI of 25 kg/m2 or higher at 3 years post-diagnosis (HR range, 0.39-0.52; all P £.006) compared with BMI of less than 25 kg/m2.
Weight loss of 5% or higher at 2 (HR range, 1.70-2.12; both P £.05) and 3 (HR range, 1.98-2.92; both P £.01) years post-diagnosis relative to baseline weight was associated with shorter DFS compared with maintaining a stable weight.
Weight gain after diagnosis did not significantly relate to OS or DFS.
The study authors concluded, “Post-diagnosis BMI change is an independent predictor of OS and DFS. Higher BMI after diagnosis is associated with better survival outcomes. […] Monitoring BMI changes during survivorship may help identify high-risk patients and guide supportive care strategies.”
Disclosures: The study authors reported having no conflicts of interest. Please see the original reference for complete disclosures.
This article originally appeared on Cancer Therapy Advisor
References:
Sarker M, Kauffman EC, Tang L, et al. Impact of post-diagnosis body mass index (BMI) change on survival in localized renal cell carcinoma. Presented at IKCS: North America 2025. November 13-15. Denver, Colorado.. Abstract J2.