@merpreb I have not had this frank discussion with either yet as I've just noticed the problem after my regular 3 week bloodwork/Dr. Consult/Infusion yesterday. In typing up my notes afterwards I see a pattern wherein my 2nd-opinion-Dr suggests a course of treatment that my primary oncologist immediately overrides, then later arrives at the same conclusion and this has been very successful twice during my treatments which have included: simultaneous Cisplatin and radiation for 5 weeks one year ago. Followed with Imfinzi immunotherapy which allowed my cancer to spread in 2 months to lung 2 as well as into blood stream, lymph nodes. (I am of the 2% of Imfinzi patients that this happens to apparently. Lucky me.) Stage 3 is now at Stage 4 NSCLC. Another 2 months of Taxotere chemo followed that didn't arrest growth either. In addition to PET scans every 3 months, my CEA counts in my regular blood tests (every 3 weeks prior to infusions) have proven to be very accurate in tracking my successes and failures in treatment. Apparently this measurement isn't commonly used for lung cancer, but works precisely well for me. At this point I brought in my 2nd opinion oncologist who suggested I get Foundation One testing. Among other things this showed I had PDL of 70. He suggested I switch chemo to Alimta and my local onc agreed. This brought my CEA number way back down and PET scan showed great promise after 6 infusions. He also told me that "when Alimta stopped being effective" (as he knew it would apparently) we should ADD Keytruda simultaneously to Alimta. And that's where we are yesterday. CEA number has started slowly back up. My primary oncologist wants to get me into a clinical trial suggested by Foundation One and that is being more thoroughly investigated to see if I qualify and Keytruda will be ordered and processed through my insurance before I get it in 3 weeks. My primary is not sure about adding it to Alimta and is concerned about overwhelming side effects. In typing this to you just now I think I have answered my own question/concerns and should be glad that my primary is open to my secondary's suggestions and is thoughtfully concerned with side effects on me. So I guess I'll see how this all transpires in a few weeks with fingers crossed that Alimta can keep the wolves at bay in the meantime. Very grateful to have 2 good doctors who try to solve these mysteries and haven't given up on me.