Researchers at Osaka Metropolitan University have found that body mass index (BMI) significantly influences mortality risk in patients with advanced non-small cell lung cancer (NSCLC) undergoing immunotherapy versus conventional chemotherapy. The study, published in JAMA Network Open, analyzed data from over 500,000 lung cancer patients in Japan, revealing a complex relationship between BMI and treatment outcomes.
The research team, led by Yasutaka Ihara and Professor Ayumi Shintani, examined the association between BMI and mortality risk during immunotherapy and chemotherapy. Their analysis focused on patients with advanced NSCLC, a disease with a high mortality rate and significant treatment challenges.
BMI as a Factor in Treatment Selection
The study revealed that higher BMI was generally associated with lower mortality risk in both immunotherapy and chemotherapy, up to a BMI of 24. However, a critical threshold emerged around a BMI of 28. Patients with a BMI below 28 experienced lower mortality risk with immunotherapy compared to chemotherapy. Conversely, for those with a BMI of 28 or higher, immunotherapy's mortality risk increased, while chemotherapy continued to show a decrease in risk.
"Immunotherapy might not always be the optimal treatment method for obese patients with advanced non-small cell lung cancer, so the use of conventional chemotherapy should also be considered," stated Mr. Ihara. This suggests that treatment decisions should consider a patient's BMI to optimize outcomes.
Implications for Precision Medicine
The findings highlight the potential for personalized treatment strategies based on patient-specific factors. The researchers noted that factors beyond BMI, such as age, hormones, and gut microbiota, can also influence immunotherapy's effectiveness. Further research is needed to evaluate how these factors interact to improve survival rates.
"Evaluation of whether immunotherapy or conventional chemotherapy improves survival in the presence of these factors is expected to contribute to the development of precision medicine," Mr. Ihara added. This underscores the importance of a holistic approach to cancer treatment, considering various patient characteristics to tailor therapy.
Study Details and Limitations
The study utilized a Japanese administrative claims database, providing a large sample size for analysis. However, the observational nature of the study limits the ability to establish causality. Further prospective studies are needed to confirm these findings and elucidate the underlying mechanisms. The study adds to the growing body of evidence suggesting that the obesity paradox in cancer therapy may not apply uniformly across all treatments and patient populations.
