1221P - Surgically resected superior sulcus (SS) non-small cell lung cancer (NSCLC) after induction chemo (C)- and radiotherapy (R): A focus on the immune microenvironment (IM)

Background

The IM plays an important role in NSCLC development. C and R may modify the interplay between cancer and the immune system. Induction C-R is crucial in the management of SS-NSCLC. We investigated the effects of C-R on the IM.

Methods

We retrospectively analyzed consecutive paired samples, pre and post C-R, of SS-NSCLC cases from 2015 to 2019. We performed PD-L1-TPS determination and definition of the rate of residual viable tumor cells (RVTC). CD3, 4, 8 and 68 tumor-infiltrating immune cells (TIICs) were evaluated and categorized using a semiquantitative score. Radiological and metabolic responses were reviewed. We calculated neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) before surgery (S).

Results

Preliminary analysis included 8 patients, one female and seven males, all smokers. They received a carboplatin-based regimen of C, concomitant to R (median dosage: 50 Gray in 28 fractions). Radiological responses were 6 disease stabilities (SD) and 2 partial responses (PR). Metabolic responses were 4 SD and 4 PR.

A complete evaluation of IM in pre C-R tissue samples was not feasible because of insufficient tumor tissue.

On surgical samples, no oncogene addiction was detected, PD-L1 TPS was < 1% in all cases and median rate of RVTC was 10%. All TIICs had a score equal or higher than 2+, except for CD4+ that scored 1+ in 88% of cases. No TIIC was absent at immunohistochemistry evaluation. Median NLR and PLR were 3.5 (1.7-4.6) and 199 (132-264) respectively. No correlation was observed between CD3, 4 and 8 TIICs and radiological or metabolic response, RVTC and NLR or PLR values. CD68+ TIICs was correlated with metabolic response (p=0.020, Χ² test) and lower RVTC (Pearson’s correlation coefficient, PCC=-0.7, p=0.042). CD68+ TIICs presence was associated with higher pre-surgery PLR (PCC=0.8, p=0.020). Interestingly, higher pre-S PLR values seemed linked with lower RVTC (PCC=-0.2, p=0.047).

Conclusions

Pre-surgery PLR and CD68+ TIICs in surgical samples might be correlated to higher metabolic response to C-R and lower RVTC. These preliminary results could be useful for consolidation treatment selection and are going to be confirmed in a wider series of SS-NSCLC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Istituto Oncologico Veneto, IOV, Padua, Italy.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.