Article Text

Download PDFPDF

529 Impact of histology and PD-L1 status on immune checkpoint inhibitors in the treatment of non-small cell lung cancer
  1. Khalil Choucair1,
  2. Hyejong Jang2,
  3. Shadia I Jalal3,
  4. Tarik Hadid4,
  5. Dipesh Uprety4,
  6. Seongho Kim2 and
  7. Hirva Mamdani4
  1. 1Wayne State University, Detroit, MI, USA
  2. 2Karmanos Cancer Institute/Wayne State University, Detroit, MI, USA
  3. 3Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, IN, USA
  4. 4Barbara Ann Karmanos Cancer Institute/Wayne State University, Detroit, MI, USA
  • Journal for ImmunoTherapy of Cancer (JITC) preprint. The copyright holder for this preprint are the authors/funders, who have granted JITC permission to display the preprint. All rights reserved. No reuse allowed without permission.


Background Immune checkpoint inhibitors (IO) have revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). In the pre-IO era, patients (pts) with squamous cell carcinoma (SCC) had worse survival outcomes than non-squamous (nSCC) pts.1 Landmark trials comparing IO to chemotherapy in SCC2 and nSCC3 suggest a numerical survival advantage for pts with nSCC irrespective of PD-L1 status. However, no head-to-head comparison of the effect of histology on response to IO, and with respect to PD-L1 status has been done.

Methods A systematic search of the PubMed and EMBASE databases (January 1, 2010- December 31, 2022) with additional search of ASCO and ESMO conferences, identified relevant randomized control trials (RCTs). Eligible studies included phase II/III RCTs in NSCLC pts (≥ 18 years; clearly defined subtype: SCC vs. nSCC) treated with IO (monotherapy/combination), irrespective of treatment lines. In a meta-analysis, hazard ratios (HR) and 95% confidence intervals (CI) were pooled to estimate overall survival (OS) and progression-free survival (PFS). Heterogeneity was tested and when substantial, a random-effect model was used.

Results In total, 23 studies were identified [N= 14,171 pts (SCC: 4,398; nSCC: 9,773); table 1]. Overall, as will be reported at the World Conference on Lung Cancer, there was no difference in these outcomes between nSCC and SCC [OS (HR 1.06; P=0.406); PFS (HR 1.09; P=0.506)], irrespective of the line of therapy (1st, P=0.341 vs. ≥ 2nd line, P=0.625) or IO regimen (monotherapy, P=0.268 vs. chemo-IO, P=0.864;table 2).

Here we report subset analysis based on PD-L1 expression. There was no difference in OS between SCC and nSCC based on PD-L1 status (PD-L1+ pts: HR 1.05; P=0.598; PD-L1- pts: HR 1.01; P=0.945). Similarly, both subgroups did not significantly differ in PFS (PD-L1+: HR 1.40; P=0.068; PD-L1-: HR 0.90; P=0.685). Within the same histology subgroup, no difference in OS was seen between PD-L1+ and PD-L1- (SCC: HR 0.995; P=0.965; nSCC: HR 1.04; P=0.749). PD-L1 status did not affect PFS across histologies (SCC: HR 0.68; P=0.096; nSCC: HR 1.06; P=0.841) (table 3).

Conclusions Despite distinct molecular landscapes and poorer survival for SCC pts in the pre-IO era, outcomes from IO-based therapy in NSCLC did not differ based on histology, and irrespective of PD-L1 status. While previous differences may be explained by higher prevalence of targeted mutations in nSCC, the introduction of IO to the landscape of NSCLC may have helped bridge the gap between both subtypes, by targeting a shared immune mechanism.


  1. Socinski MA, Obasaju C, Gandara D, Hirsch FR, Bonomi P, Bunn P, Kim ES, Langer CJ, Natale RB, Novello S, Paz-Ares L, Pérol M, Reck M, Ramalingam SS, Reynolds CH, Spigel DR, Stinchcombe TE, Wakelee H, Mayo C, Thatcher N. Clinicopathologic Features of Advanced Squamous NSCLC. Journal of Thoracic Oncology. 2016; 11 (9):1411–22.

  2. Novello S, Kowalski DM, Luft A, Gümüş M, Vicente D, Mazières J, Rodríguez-Cid J, Tafreshi A, Cheng Y, Lee KH, Golf A, Sugawara S, Robinson AG, Halmos B, Jensen E, Schwarzenberger P, Pietanza MC, Paz-Ares L. Pembrolizumab Plus Chemotherapy in Squamous Non-Small-Cell Lung Cancer: 5-Year Update of the Phase III KEYNOTE-407 Study. JCO .2023; 41 (11):1999–2006.

  3. Gadgeel S, Rodríguez-Abreu D, Speranza G, Esteban E, Felip E, Dómine M, Hui R, Hochmair MJ, Clingan P, Powell SF, Cheng SYS, Bischoff HG, Peled N, Grossi F, Jennens RR, Reck M, Garon EB, Novello S, Rubio-Viqueira B, Boyer M, Kurata T, Gray JE, Yang J, Bas T, Pietanza MC, Garassino MC. Updated Analysis From KEYNOTE-189: Pembrolizumab or Placebo Plus Pemetrexed and Platinum for Previously Untreated Metastatic Nonsquamous Non-Small-Cell Lung Cancer. J Clin Oncol. 2020; 38 (14):1505–17.

Abstract 529 Table 1

Totoal number of subjects by histology, PD-L1 status, and treatment received. IO: Immune checkpoint inhibitors; SCC: squamous cell carcinoma; nSCC: non-squamous cell carcinoma; OS: overall survival; PFS: progression-free survival.

Abstract 529 Table 2

Pooled hazard ratio of overall and progression-free survival and comparison between SCC and nSCC. OS: overall survival; PFS: progression-free survival; SCC: squamous cell carcinoma; nSCC: non-squamous cell carcinoma; HR: hazard ratio; 95% CI; 95% confidence interval; Ratio: ratio of HR between SCC and nSCC with SCC as a reference (Ref.); IO: immune checkpoint inhibitor; chemo-IO: chemotherapy/immune checkpoint inhibitor combination

Abstract 529 Table 3

Pooled hazard ratio of overall and progression-free survival and comparison between SCC and nSCC and PD-L1-positive (+) and negative (-). OS: overall survival; PFS: progression-free survival; SCC: squamous cell carcinoma; nSCC: non-squamous cell carcinoma; HR: hazard ratio; 95% CI; 95% confidence interval; Ratio: ratio of HR between SCC and nSCC (SCC as a reference-Ref.) and between PD-L1 + and negative (PD-L1 - as a Ref.)

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.