The prevalence of ALK rearrangement in pulmonary adenocarcinomas in an unselected Caucasian population from a defined catchment area: impact of smoking

Lung cancer patients with anaplastic lymphoma kinase rearrangement lose affiliation with labor market at diagnosis

Aim: The main purpose of the present study was to investigate the labor market affiliation of ALK+ NSCLC patients in long-term treatment as well as overall survival and incidence/prevalence. Materials & methods: Nationwide retrospective study of all patients with ALK+ NSCLC in Denmark diagnosed between 2012 and 2018. Results: During the study period ALK+ NSCLC patients had a median overall survival of 44.0 months and a 7.8-fold increase in disease prevalence. Six months prior to diagnosis, 81% of ALK+ NSCLC patients ≤60 years of age were employed. At the end of the 18-month follow-up period, 36% were employed. Conclusion: ALK+ NSCLC patients have prolonged survival following diagnosis, but a large fraction of patients lose affiliation with the labor market.

The prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung cancer in an unselected, consecutive population

Little is known about prevalence of PD-L1 expression in tumor cells of unselected patients with all stages of non-small cell lung cancer. The objective of this study is to assess the prevalence of PD-L1 positivity in patients with non-small cell lung cancer, to analyze the association between PD-L1 positivity and patients' clinicopathological characteristics, and to assess the use of immune-oncologic treatment in eligible patients. All non-small cell lung cancer patients diagnosed in a 10-month period in an unselected population of 1.7 million Caucasian inhabitants were evaluated with the PD-L1 IHC 22C3 pharmDx kit. A total of 819 patients were diagnosed with non-small cell lung cancer. Samples analyzable for PD-L1 expression were obtained from 97% of patients. In a multivariate analysis with cut-off at tumor proportion score ≥50%, lower stage was associated with lower prevalence of PD-L1 positivity with an odds ratio of 0.31 for stage I vs. stage IV. A significant difference in PD-L1 expression between squamous-cell carcinoma and adenocarcinoma was observed with odds ratio for adenocarcinoma 1.8. With cut-off tumor proportion score ≥1%, attenuated effects of the same direction were seen. For neither cut-off did type and location of material used for PD-L1 analysis, age, sex, smoking history, or performance status have statistically significant impact on the PD-L1 expression. Fifty four percent of the patients who were eligible for immune-oncologic treatment were actually treated in first-line with pembrolizumab monotherapy. In conclusion, 97% of the patients had material analyzable for PD-L1. If a patient in need of immuno-oncologic treatment has shifted stage, a negative or low positive PD-L1 test performed on a biopsy taken in a lower stage might not mirror the PD-L1 expression in the new metastatic lesion. Therefore, a re-biopsy should be considered.

ALK immunohistochemistry positive, FISH negative NSCLC is infrequent, but associated with impaired survival following treatment with crizotinib

OBJECTIVE

Metastasized non-small cell lung cancer (NSCLC) with an anaplastic lymphoma kinase (ALK) rearrangement is usually sensitive to a range of ALK-tyrosine kinase inhibitors. ALK-positive NSCLC have been identified in pivotal phase III trials with fluorescence in situ hybridization (ALK FISH+). These tumors are also expressing the fusion product (ALK immunohistochemistry (IHC)+). However, discrepant cases occur, including ALK IHC + FISH-. The aim of this study was to collect ALK IHC + cases and compare within this group response to crizotinib treatment of ALK FISH + cases with ALK FISH- cases.

MATERIALS AND METHODS

In this European prospective multicenter research study patients with Stage IV ALK IHC + NSCLC treated with crizotinib were enrolled. Tumor slides were validated centrally for ALK IHC and ALK FISH.

RESULTS

Registration of 3523 ALK IHC tests revealed a prevalence of 2.7% (n = 94) ALK IHC + cases. Local ALK FISH analysis resulted in 48 concordant (ALK IHC+/FISH+) and 16 discordant (ALK IHC+/FISH-) cases. Central validation revealed 37 concordant and 7 discordant cases, 5 of which had follow-up. Validation was hampered by limited amount of tissue in biopsy samples. The PFS at 1 year for ALK concordant and discordant was 58% and 20%, respectively (HR = 2.4; 95% CI: 0.78-7.3; p = 0.11). Overall survival was significantly better for concordant cases than discordant cases after central validation (HR=4.5; 95% CI= 1.2-15.9; p=0.010.

CONCLUSION

ALK IHC + FISH- NSCLC is infrequent and associated with a worse outcome on personalized treatment. A suitable predictive testing strategy may be to screen first with IHC and then confirm with FISH instead of considering ALK IHC equivalent to ALK FISH according to the current guidelines.