CN12 - Impact of diet on immune checkpoint blockade: Nurse-directed dietary intervention

Background

Gut microbiota modulates the response to immune checkpoint blockade (ICB) in various cancers, and diet represents the most natural and non-evasive method to shift its composition. A recent study suggests that a high dietary fiber intake may improve progression-free survival (PFS) of melanoma patients treated with ICB. However, the impact of diet on patients with advanced non-small cell lung cancer (NSCLC) has not been yet investigated. The objective of this study was to assess the effect of diet, including fiber intake, in patients with NSCLC amenable to ICB.

Methods

Our research nurse assessed the dietary habits of 102 patients with advanced NSCLC treated with ICB using a food frequency questionnaire (FFQ) on dietary habits and probiotics supplementation (approved by the ethics committee). Upon consent of each participant, answers to 47 questions included in the FFQ were recorded, analysed using a calculation tool to estimate 30 different nutrients and correlated with PFS.

Results

A total of 102 patients (49% men) completed the dietary survey with a median age of 67 years and a median follow-up of 18.6 months. In contrast to melanoma, a high fiber diet did not correlate with an improved PFS (median PFS: low fiber=16.0 months versus high fiber=9.8 months, p=0.42) in patients with NSCLC. Of note, the group median fiber intake was 11g/day compared to 20g/day in the melanoma study. Conversely, saturated fatty acids (SFA) dietary intake correlated with a favorable outcome in advanced NSCLC patients (median PFS: low SFA=9.1 months versus high SFA=17.4 months, p=0.03). The sources of SFA were mostly from dairy products.

Conclusions

In our study, NSCLC patients had a very low fiber diet that could explain the absence of survival benefit. However, SFA intake correlated with longer PFS. With the emergence of the gut microbiota in the immuno-oncology arena, providing evidence-based dietary recommendations and educational tools for nurses represents an important strategy to potentially increase ICB efficacy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.