Abstract 361P
Background
Treatment of advanced non-small cell lung cancer (NSCLC) with antiPD-1/PD-L1 immune checkpoint inhibitors (ICI) has improved patient survival. However, only 30–40% of subjects achieve long term benefit. The aim of this work is to analyze the prognostic and predictive value of microbial metagenomics in response and survival of advanced NSCLC treated with ICI.
Methods
A retrospective study was performed on tissues from biopsies of 36 advanced NSCLC patients (mean age: 69.2 years, 33.3% females, 72.2% adenocarcinomas) treated with ICI monotherapy or in combination with chemotherapy. Abundance of bacterial taxa was determined by 16S rDNA hypervariable regions sequencing with IonTM Torrent technology and correlated with efficacy outcomes.
Results
Long term survivors (≥ 2 years from the start of treatment) exhibited an increase in Proteobacteria and a decrease in Bacteroidota phyla. Regarding bacterial genera, Klebsiella, Brevundimonas, Undibacterium and Beijerinckiaceae (KBUBe consortium) were further selected by regression methods. Intratumor KBUBe showed significant prognostic value, while clinical parameters such as ECOG, PD-L1 level and neutrophil-to-lymphocyte ratio (NLR) did not. Furthermore, a high KBUBe score was associated with a significant benefit in overall response rate, progression-free survival and overall survival (Table).
Table 361PPerformance of prognostic markers in the evaluation of survival and response in ICI-treated NSCLC patients
| Cox and logistic regression for overall survival | ||||||
| Parameter | HR | HR P value* | Harrell's C | OR | OR P value‡ | AUC |
| PDL-1 | 0.99 | 0.123 | 0.63 | 1.02 | 0.081 | 0.67 |
| ECOG | 1.38 | 0.291 | 0.59 | 0.98 | 0.975 | 0.50 |
| NLR | 1.02 | 0.478 | 0.51 | 0.97 | 0.528 | 0.51 |
| KBUBe score | 0.46 | ConclusionsIn conclusion, tissue microbiota could be considered as a potential predictive biomarker to assess the benefit of immunotherapy in advanced NSCLC patients. Our group is testing these results in a prospective group of patients. Legal entity responsible for the studyThe authors FundingMutua Madrileña Foundation DisclosureAll authors have declared no conflicts of interest. This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used. For more detailed information on the cookies we use, please check our Privacy Policy.
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