Body composition is associated with operative and oncologic outcomes in the management of retroperitoneal and trunk soft tissue sarcoma.

BACKGROUND: Sarcopenia, myosteatosis and obesity in cancer may confer negative clinical outcomes, but their prevalence and impact among patients with retroperitoneal and trunk soft tissue sarcoma have not been systematically studied. The aim of this study was to determine body composition among patients with retroperitoneal and trunk sarcoma, and assess impact on operative and oncologic outcomes. METHODS: Consecutive patients undergoing treatment with curative intent from 2009 to 2019 were studied. Subcutaneous fat area and visceral fat areas, intramuscular adipose, lean body mass and fat mass were determined at diagnosis by CT at L3. Univariable and multivariable linear, logistic and Cox proportional hazards regression were performed. RESULTS: 95 patients (43.2% retroperitoneal, 48.4% trunk, 46.3% multivisceral resection) were studied. Visceral obesity was evident in 47.4%. Postoperative morbidity occurred in 25.9%, with preoperative radiotherapy (OR10.53 [95% CI 1.08-102.39], P = 0.042) and fat mass (OR1.41 [1.12-1.79], P = 0.004) independently predictive on multivariable analysis, while intramuscular adipose independently predicted inpatient LOS (P < 0.001), wound infection (P = 0.024, OR1.20 [1.02-1.40]) and major postoperative morbidity (P = 0.027, OR1.15 [1.02-1.31]). Increasing fat mass, subcutaneous fat area and intramuscular adipose were associated with greater tumor size (all P < 0.01), while intramuscular adipose predicted disease progression during neoadjuvant therapy (P = 0.024), and independently predicted disease specific survival (DSS) (P = 0.005, HR1.11 [1.03-1.20]) and overall survival (OS) on multivariable analysis (P < 0.001, HR1.19 [1.08-1.31]). CONCLUSION: Visceral obesity is common in retroperitoneal and trunk sarcoma, and measures of adiposity are associated with adverse operative, but not oncologic outcomes. Myosteatosis is independently associated with postoperative morbidity and adverse oncologic outcomes. Body composition may represent a marker of risk among patients with retroperitoneal and trunk sarcoma.

Sarcopenia and obesity among patients with soft tissue sarcoma - Association with clinicopathologic characteristics, complications and oncologic outcome: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Sarcopenia and obesity may be associated with negative outcomes in many cancers, but their prevalence and impact in modern regimens for soft-tissue sarcoma (STS) have not been systematically studied. This study summarises and critically evaluates the current evidence-based literature on body mass index (BMI) and body composition among patients with STS, with respect to clinical and pathologic characteristics, treatment-associated morbidity and oncologic outcome. METHODS: A systematic literature search of the PubMed, Embase and Cochrane databases was performed. Meta-analysis of the relationship between BMI, body composition and pathologic characteristics, operative morbidity and oncologic outcome was undertaken using RevMan v.5.4 using fixed or random effects methods as appropriate. RESULTS: 14 studies including 3598 patients met inclusion criteria. Ten studies reported on BMI, two on CT and two on PET-CT assessment of body composition. BMI ranged from 14.6 to 63.7 kg/m2, with obesity in 18%-39% of patients. Although some studies demonstrated larger tumours among patients with obesity, this was not significant on meta-analysis (P = 0.31, I2 = 99%). There was no significant difference in tumour grade or histologic type according to BMI. Postoperatively, obesity was associated with increased risk of overall morbidity (odds ratio (OR) 2.03 [95% CI 1.41-2.92], P = 0.0001, I2 = 22%), and wound morbidity (OR 1.32 [95% CI 1.02-1.71], P = 0.03, I2 = 0%). Similar effects were observed in studies of visceral adiposity. No differences in functional outcomes were observed. There was a trend towards reduced local recurrence among patients with obesity (HR 0.64 [95% CI 0.38-1.08], P = 0.10, I2 = 0%), but no difference in distant metastasis (HR 1.00 [95% CI 0.76-1.30], P = 0.98, I2 = 0%) or overall survival (HR 0.98 [95% CI 0.43-2.22], P = 0.95, I2 = 64%). Various measures of sarcopenia were associated with poorer survival outcomes. CONCLUSION: While obesity is associated with increased postoperative morbidity, it had no significant association with long-term oncologic outcomes. Sarcopenia may be associated with a poorer long-term prognosis. A greater understanding of the impact of nutritional status on disease characteristics and treatment outcomes is essential to facilitate improvements in clinical care for patients with STS.