2015P - Association between gene characteristics and mutation abundance with the prognosis of small cell lung cancer

Background

Genetic characteristics and mutation abundance need to be further explored in small-cell lung cancer (SCLC). This study aimed to analyze the correlation between genetic characteristics and mutation abundance and the prognosis of SCLC patients by next-generation sequencing (NGS).

Methods

Patients diagnosed with SCLC at Shanghai Chest Hospital from January 2017 to December 2020 were reviewed. All enrolled SCLC patients underwent NGS testing before initiating treatment.

Results

122 patients were enrolled in the final analysis, including 48 patients with limited-stage SCLC (LS-SCLC) and 74 patients with extensive-stage SCLC (ES-SCLC). The most common mutant genes were TP53, RB1, and SMAD4 in LS-SCLC and ES-SCLC. Furthermore, no significant difference in mutant genes and mutation frequencies was observed between LS-SCLC and ES-SCLC. Multivariate Cox regression analyses revealed that the presence of genetic abnormalities TP53 and BRCA2 was significantly related to overall survival (OS) in patients with LS-SCLC. In ES-SCLC patients, the genetic abnormalities TP53, NOTCH1, PTEN, and PIK3CA were significantly related to OS. TP53 mutation abundance was higher in ES-SCLC than in LS-SCLC (average 75.334% vs. 65.954%, median 82.395% vs. 76.820%, P = 0.046). In ES-SCLC patients, higher TP53 mutation abundance predicted poorer clinical outcomes, which is contrary to LS-SCLC patients.

Conclusions

This study reveals the relevance of genetic features of NGS and prognosis in SCLC patients. Contrary relationships were observed between TP53 mutation abundance and prognosis in patients with LS-SCLC and ES-SCLC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

This work was supported by the Beijing Xisike Clinical Oncology Research Foundation [Y-2019AZQN-1037] and the Science and Technology Innovation Program of Shanghai [20Y11913800].

Disclosure

All authors have declared no conflicts of interest.