Early Nutritional Intervention in Patients with Non-Small Cell Lung Cancer Receiving Concurrent Chemoradiotherapy: A Phase II Prospective Study

<b>Aims:</b> This phase II study aimed to evaluate the impact of early nutritional intervention on the nutritional status and survival of locally advanced non-small cell lung cancer (LANSCLC) patients undergoing concurrent chemoradiotherapy (CCRT). <b>Methods</b>: LANSCLC patients treated with CCRT were enrolled in the study group and received early nutritional intervention, including individualized nutrition counseling and oral nutritional supplements, from the initiation of CCRT to 2 weeks after its completion. The primary endpoint was the incidence of weight loss ≥5% during the CCRT. For comparison with the study group, a matched control group was retrieved from previous trials by the 1:1 propensity score matching method. <b>Results</b>: Sixty-seven patients were enrolled in the study group with a median follow-up of 52.4 months. Compared with the control group, the study group exhibited a lower incidence of weight loss ≥5% (<i>p</i> = 0.032), higher body mass index (<i>p</i> = 0.034) and prealbumin levels (<i>p</i> = 0.014) at the end of CCRT, as well as lower patient-generated subjective global assessments scores at the end of CCRT (<i>p</i> < 0.001) and 6 months after CCRT (<i>p</i> = 0.007). The study group also had a lower incidence of grade 2+ radiation pneumonitis (<i>p</i> = 0.023) and longer progression-free survival (13.5 vs. 11.3 months, <i>p</i> = 0.032). Patients who responded well to oral nutritional supplements had a higher Firmicutes/Bacteroidetes ratio at baseline (<i>p</i> = 0.036). <b>Conclusions</b>: Early nutritional intervention in LANSCLC patients undergoing CCRT improved nutritional status and reduced radiation pneumonitis. Gut microbiota was associated with the response to oral nutritional supplements.