High baseline BMI appeared to be independently associated with improved survival among patients with non-small cell lung cancer who received atezolizumab, according to results of a retrospective study published in JAMA Oncology.
Based on these findings, BMI should be considered as a stratification factor in immune checkpoint inhibitor trials, researchers concluded.
“This is an interesting outcome and it raises the potential to investigate further with other cancers and other anticancer drugs,” Ganessan Kichenadasse, MBBS, FRACP, medical oncologist at Flinders Centre for Innovation in Cancer in South Australia, said in a press release. “We need to do further studies into the possible link between BMI and related inflammation, which might help to understand the mechanisms behind paradoxical response to this form of cancer treatment.”
Kichenadasse and colleagues noted the complicated relationship between obesity and cancer prognosis. High BMI has been associated with increased incidence, rapid disease progression, recurrence and mortality in some cancers, but also protection from other cancers.
Previous studies have suggested an association between high BMI and lower lung cancer incidence and cancer-specific mortality. However, researchers had yet to determine whether high BMI influences outcomes of patients with NSCLC treated with immune checkpoint inhibitors.
Kichenadasse and colleagues analyzed 2,110 patients with advanced NSCLC who participated in one of four multicenter trials, including two single-arm phase 2 studies and two randomized, two-arm trials. All patients had been previously untreated or treated with one line of systemic therapy, and had measurable disease and good organ function with no contraindications for chemotherapy or checkpoint inhibitors.
Among these patients, 1,434 (median age, 64 years; range, 57-70; 62% men) received atezolizumab (Tecentriq, Genentech) and 676 (median age, 63 years; range, 57-69; 62% men) received docetaxel. Patients received the treatments once every 3 weeks until disease progression or unacceptable toxicity.
The association between BMI and OS, PFS and therapy-related adverse events served as the study’s primary objectives.
Results showed an association between obesity (BMI 30 kg/m²) and significantly improved OS (P < .001) among patients who received atezolizumab, but not among those who received docetaxel.
Researchers observed the strongest associations between BMI and OS and PFS among patients with high PD-L1 expression.
The investigators reported HRs among 436 patients with the highest category of PD-L1 expression ( 50% tumor cells or 10% tumor-infiltrating immune cells) of 0.36 (95% CI, 0.21-0.62) for those with obesity and 0.69 (95% CI, 0.48-0.98) for those with overweight (BMI = 25 kg/m²-29.9 kg/m²).
HRs for PFS for these patients were 0.68 (95% CI, 0.49-0.94) for those with obesity and 0.72 (95% CI, 0.56-0.92) for those with overweight.
Treatment-related adverse events did not appear to be associated with BMI.
“Our study provides new evidence to support the hypothesis that high BMI and obesity may be associated with response to immunotherapy,” Kichenadasse said. “[Although] our study only looked at baseline and during treatment, we believe it warrants more studies into the potentially protective role of high BMI in other cancer treatments.” – by John DeRosier
Disclosures: Kichenadasse reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.