Low visceral fat area predicts poor survival in cancer patients

Visceral fat area (VFA) is a reliable prognostic indicator of muscle mass and is associated with nutritional, immune, and inflammatory status in patients with diverse types of cancer, such as gastric, colorectal, and nonsmall-cell lung cancers (NSCLC), claims a recent study.

“Furthermore, we identified a strong correlation between lower VFA and a poorer prognosis, regardless of muscle mass and subcutaneous fat content, particularly among Chinese patients with digestive cancer or malnutrition,” the researchers said.

This population-based multicentre prospective cohort study was conducted in patients with initial cancer between February 2012 and September 2020. The researchers obtained the patients’ clinical information, body composition indicators, haematologic test results, and follow-up data.

Principal component analysis was conducted to analyse the body composition indicators and identify the most representative indicators. The cutoff value was set according to the optimal stratification method. Finally, the researchers used Cox proportional hazards regression models to calculate the hazard ratio (HR) for mortality.

A total of 14,018 patients had complete body composition data. Analysis revealed that VFA was a better indicator for body fat content (principal component index, 0.961) than body mass index (principal component index, 0.850). The cutoff points for VFA were 66 cm² for mortality and 102 cm² for gastric/esophageal cancer and other cancers. [Am J Clin Nutr 2023;118:507-517]

Among 2,788 patients treated systematically, a lower VFA predicted a greater risk of death in patients with cancer of diverse types (HR, 1.08, 95 percent confidence interval [CI], 1.64; p=0.007), particularly gastric (HR, 2.13, 95 percent CI, 1.3‒3.49; p=0.003), colorectal (HR, 1.81, 95 percent CI, 1.06‒3.08; p=0.030), and NSCLC (HR, 1.2, 95 percent CI, 1.02‒1.59; p=0.040).

“Our findings revealed that VFA not only represents the body fat mass of the patients but also exhibits potential correlations with nutritional, immune, and inflammatory status,” the researchers said. “Poor nutritional status has been established as a negative predictor of cancer mortality.” [Eur Urol 2011;59:923-928; J Cachexia Sarcopenia Muscle 2021;12:393-402]

Predictor of poor survival

Compared with the heterogeneity of previous published data, the current findings evidently showed that lower VFA was predictive of a poorer survival among patients with cancer undergoing systemic therapy. Several reasons could have led to the discrepancies seen in earlier studies.

First, many studies concentrated the analysis on small samples of specific tumour types. This introduced selection bias due to the limited sample size and tumour histology, according to the researchers. [Oncologist 2011;16:1565-1571; Jpn J Clin Oncol 2015;45:210-216]

Second, there were differences observed in obesity levels between ethnic groups, which then contributed to conflicting findings. [Trends Cancer 2017;3:181-197; Adv Nutr 2015;6:803-819]

“Regarding fat distribution in Chinese populations, our study established the cutoff values for VFA based on the mortality risk in large-scale ‘real-world’ studies, suggesting that this cutoff value could serve as an ideal clinical prognostic marker,” the researchers said.