Sarcopenia as a predictor of perioperative morbidity in metastatic renal cell carcinoma patients undergoing radical nephrectomy and IVC tumor thrombectomy.

Abstract

388 Background: Preoperative sarcopenia, as determined by the lumbar skeletal muscle index (SMI), has shown potential value for predicting adverse survival outcomes in metastatic renal cell carcinoma (mRCC) patients undergoing cytoreductive surgery. However, its utility for predicting perioperative morbidity in mRCC patients with IVC involvement is poorly elucidated. We hypothesize that preoperative sarcopenia, a severe deficiency in lean muscle mass, will be associated with major surgical complications and longer lengths of hospital stay in mRCC patients managed with radical nephrectomy and tumor thrombectomy. Methods: We retrospectively analyzed 99 mRCC patients who underwent radical nephrectomy and tumor thrombectomy from 2005 to 2020. Sarcopenia was diagnosed using optimally fit body mass index (BMI) and sex-stratified thresholds. For patients with a BMI < 30 kg/m², sarcopenia was defined as a SMI < 47 cm2/m2 for males and SMI < 38 cm2/m2 for females and for those with a BMI≥30 kg/m², as a SMI < 54 cm2/m2 for males and SMI < 47 cm2/m2 for females. Outcome measures were the presence of any major complications within 90 days after surgery, major complications within 1 year after surgery, and length of hospital stay post-nephrectomy ≥7 days. Major complications were defined as grade ≥3a on the Clavien-Dindo classification system. Associations between sarcopenia and major surgical complications and length of hospital stay were evaluated using multivariable analysis. Multivariable models were adjusted for age, race, gender, BMI, Charlson comorbidity index, T and N staging, Fuhrman grade, ECOG Score, and extent of IVC tumor thrombus. Results: Median time from preoperative imaging to surgery was 22 days (IQR 15-29). Of the 57 (58%) patients with preoperative sarcopenia in our cohort, 19 (33%) and 20 (35%) patients experienced a major surgical complication within 3 and 12 months after surgery, respectively, and 34 (60%) patients had a length of stay ≥7 days. Preoperative sarcopenia was significantly associated with the occurrence of a major complication within 90 days (OR = 4.84, 95%CI: 1.30-18.06, p = 0.019) and 1 year (OR = 6.43, 95%CI: 1.66-24.89, p = 0.007) after surgery. The presence of sarcopenia did not significantly change the odds of staying in the hospital for more than 7 days post-nephrectomy (OR = 1.41, 95%CI: 0.45-4.41, p = 0.551). Conclusions: Preoperative sarcopenia was associated with major surgical complications occurring within 3 and 12 months among mRCC patients after radical nephrectomy and tumor thrombectomy. Screening for sarcopenia preoperatively may assist in identifying patients at high-risk for increased perioperative morbidity, which ultimately may permit the implementation of preventive therapeutic strategies. Future validation is needed.