2209P - Mutational status of non-small cell lung cancer in Portugal: A multicentric study

Background

Biomarker testing is key to identify subgroups of Non-Small Cell Lung Cancer (NSCLC) with targetable oncogenic driver alterations (alt). Most data are based on Asian patient (pts) cohorts which may not apply to other continents and might explain differences observed in clinical practice.

Methods

A multicentric, retrospective study was conducted in 5 Portuguese institutions. Pts with biopsy-proven NSCLC and a molecular biomarker study performed between Jan/2016-Dec/2021 were included. We aimed to determine the incidence of oncogenic alts in NSCLC in Portugal, compare overall survival (OS) between subgroups and identify risk and prognostic factors.

Results

Among 1652 NSCLC pts included, 529 (32%) had tumors with drugable oncogenic alts, median (MED) age 67yo (25-93), 320 (61%) male. Most pts had ECOG Performance Status (PS) ≤1 (397; 74%), smoking history (375; 75%) and adenocarcinoma histology (480; 90%). 393 (74%) pts were diagnosed in stage IV, MED 2 sites of metastases, mostly in lung (198; 37%), bone (182; 35%) and lymph nodes (140; 27%). Curative intent treatment was offered to 134 pts (25%), mainly in stages I-III (119, 89%). Most oncogenic alts were in KRAS (211; 13%), EGFR (171; 10%) and ALK (43; 3%) genes. Among tumors with gene alts, expression of PD-L1 was <1% in 200 pts (38%), higher in those harboring BRAF/ RET/MET/ROS alts. Detection of targetable alts determined 1st-line treatment in 133 (25%) pts and in 78 (15%) in later lines. With a MED follow-up of 44 months (mo) (CI95 39-49), 136 pts (26%) are alive at time of analysis. In metastatic setting, MED OS = 13 mo (CI95 11-15), numerically longer for pts with EGFR alts [17 vs 11 mo (CI95 8-14 vs 13-21); p=0,056]. Female gender, worse ECOG PS and number of sites of metastases were unfavorable prognostic factors for OS (p<0,05) in multivariate Cox-regression.

Conclusions

This is one of the largest real word dataset in Europe. The incidence of NSCLC gene alts is in line with published data, with oncogenic alts in in ∼30% NSCLC. KRAS (13%), EGFR (10%) and ALK genes (3%) were the most frequent alts found, but lower than previously reported. The retrospective nature of the study, small number of less common alts and inclusion of older pts, with poorer ECOG PS and bulky disease may explain lower than expected OS.

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.