TKI resistance and large cell endocrine caricinoma

Below is the other post kelybe wrote.  They are just enough different from one another that I wanted to copy it here.  But having 2 threads on the same subject gets confusing. 

"I was diagnosed with Stage 4 NSCLC adenocarcinoma with EGFR mutation 4 ½ years ago as a 42 year old non-smoker. I have been on Tagrisso for almost 3 years which has worked well, with a few spots of progression being treated with radiation the past couple of years. I have just started radiation for two fairly small tumors in my left lung (We are also watching a hot spot on my right side which looks like a lymph node). Due to the tumor size and the length of time I have been on Tagrisso, my doctor ordered a tissue biopsy on the largest tumor. It seems that there wasn’t evidence of the EGFR or T790m, and so the doctor will likely discontinue the Tagrisso. The biopsy also indicated evidence of large cell neuroendocrine carcinoma. I was told it could be another primary cancer or that my NSCLC transformed related to TKI resistance. After the radiation, we will take a “wait and see” approach to any future large cell growth.

I have a follow up appointment with my doctor in a few days, and am formulating my list of questions. I am wondering if there is risk to going off the Tagrisso completely. Is it possible that that is prevention T790m or EGFR-related progression elsewhere? I also understand that the treatment options for large cell is limited primarily to chemotherapy, which I haven’t had yet. It also appears that the prognosis for large cell neuroendocrine carcinoma of the lung is pretty poor. Am I to assume that the large cancer is also metastatic, or is there a chance that this primary tumor being treated may actually manage the disease? I know asking about prognosis is a dicey issue and difficult to predict. I have outlived my original prognosis, and understand it is just an estimated guess based on the information at the time.

While I have been fortunate to live so long with advanced NSCLC, the spread has been pretty slow and well managed up until now. I am very interested in how future treatments might affect my functioning and long term survival. I think I have a few months before we revisit, but I have a pretty intensive job and want to be thinking about what will actually be realistic for me in the next 6 months or so.

Any information you can provide would be very helpful.

Thanks so much!"

Hi kelybe,

I'm so sorry you're going through this.  You've got a lot of good questions and concerns.  My first thought if you stop tagrisso now and you're having the biopsied tumor with large cell radiated how will you know if that was the only large cell that would otherwise be tamped down?  This is a very individual situation and unfortunately, there are no hard and fast rules.  If there are one or 2 or even 3 places of progression it may be worth keeping tagrisso on board in case it's keeping other areas from progressing.  But there is a point at which it's obvious that tagrisso is no longer helpful. 

You'll never know for sure if the neuroendocrine nsclc is a new primary or not.  But we know that egfr tki can cause adeno to transform into neuroendocrine in a small but definite subset of people.  So it's probably transformed from nsclc to neuroendocrine. 

A good option is to get a second opinion from someone whose practice primarily deals with egfr mutated lung cancers in an academic research hospital.  Something I didn't realize until my husband was treated for nsclc was that you can get a 2nd opinion and continue with your home onc.  They often even collaborate.  (2 heads are better than one).  The aptly named article An Insider's Guide to the Second Opinion is an excellent explanation of why it's never a bad idea to get one and if there's ever a time to get one it would be before you decide on your next step (if you make an appointment let them know your situation to get in in a timely manner).

Prognosis is a good tool when looking at large numbers of people but it's not so useful when trying to determine for an individual.  As oncologists have often said on Grace, "oncologists are notoriously bad at guessing how long someone has to live".  My husband is an excellent example of that.  A hot spot showed up in his left lung (the other lung) a year after diagnosis it was 3cm and hot a biopsy was undiagnosable and caused a traumatic lung collapse so we decided to call it cancer (it quacked like a duck) and didn't/couldn't really try another biopsy.  It eventually went away without radiation (and chemo doesn't give complete responses) he's cancer free 7 years later.  It must not have been cancer even though everyone thought it was.  Point being, just because there's a 90% chance doesn't mean that you need to give up that 10% possibility when stakes are so high.

That being said many people take a combo of tagrisso and chemo if their health allows.  The thought being the tagrisso takes care of everything that hasn't acquired resistance, especially in the brain with the chemo taking care of the cancer with acquired resistance. 

There is a wide range of how chemo affects ones' daily life.  Some people have few to none and some have a hell of a time.  There are meds and actions that mitigate many of the side effects and usually go away when treatment is stopped.  Chemo side effects are usually cumulative growing with consecutive cycles.  Even if you breeze through fatigue usually catches up at some point.  Many if not most people continue with normal daily activities while on chemo.  My niece didn't miss a step while on chemo and didn't take anything other than the normal premeds during chemo infusions.  It's impossible to know where you'll stand in that spectrum until you're there. 

Please keep us posted.  I know I didn't cover everything so please let us know what else is on your mind.  We have a lot of informative video discussions on the subject of tki s and acquired resistance.  Here are a few links to get you started. 

Chemo and egfr inhibitors

Oligoprogression

egfr and high pdl1 role of immunotherapy in treatment

There are more videos in this playlist mostly towards the bottom that may pertain. 

All the best,

Janine

Kerry, no apologizes please.  We approve all the new threads to keep spam down.  It's confusing I know for the new user.  I even have to approve my threads. :)  That won't happen with posting on an existing thread, they should show up immediately.