Is there a role for upfront next generation sequencing in extensive stage small cell lung carcinoma?  

The current standard of care is a combination of chemotherapy and immunotherapy (platinum-etoposide with atezolizumab; durvalumab may be an option as well based on the CASPIAN trial). There are no data for targeted therapy, nor is there any evidence to support using any biomarkers to guide immunothe...

Not yet. One potential reason to send is to search for MSI, but with incorporation of anti-PD-L1 therapy in the first line setting, that need is no longer justified. At this time, it is largely investigational. Subtyping and classification to guide therapy will come soon, but it is not here yet.