(HealthDay)—A grading system has been developed for clinically important weight loss (WL) in patients with cancer, which includes the independent prognostic significance of body mass index (BMI) and percent WL, according to research published online Nov. 24 in the Journal of Clinical Oncology.

Lisa Martin, R.D., from the University of Alberta in Edmonton, Canada, and colleagues used data from 8,160 Canadian and European patients with cancer to produce definitions of clinically important WL. A grading system was developed using the relationships between BMI and percent WL with overall survival.

The researchers found that both BMI and percent WL independently predicted survival (P < 0.01). Across five categories of BMI and five categories of percent WL there were differences in survival (both P < 0.001). The longest survival was seen for weight-stable patients with BMI ≥25.0 kg/m² (grade 0, 20.9 months); percent WL values associated with lowered categories of BMI correlated with shorter survival (grade 1, 14.6 months; grade 2, 10.8 months; grade 3, 7.6 months; and grade 4, 4.3 months; P < 0.001). There was survival discrimination by grade within specific cancers, stages, ages, and performance status, as well as in an independent validation sample of 2,963 patients.

"We systematically developed a cancer WL grading system that incorporates the two dimensions of percent WL and BMI and links them to survival," the authors write.

Two authors disclosed financial ties to the pharmaceutical industry.