Adenocarcinoma with Egfr+ mutation exon 18 & 20

Wed, 11/02/2022 - 20:24
sbunit
Posts:1

My 81 year old mother was recently diagnosed with stage 4 adenocarcinoma with metastasis to her spine along with a malignant pleural effusion (no other organ involvement and negative for brain meta sis). Prior to this she had been suffering from rheumatoid arthritis and was taking Embrel, a biologic, which her physicians suspect may have contributed to the cancer (she never smoked a day in her life). Her mutations on exon 18 and 20 are considered uncommon and between that and her rheumatoid arthritis, made treatment a little tricky as they did not want to try immunotherapy as an initial treatment (she tested 40% positive on PDL). Instead they decided to place her on Tagrisso which she has been taking for the past month with minimal side affects, just more frequent bowel movements and fatigue. We aren’t due for a follow up scan for about another month but I was wondering if anyone has any experience with these mutations and if feedback can be provided

For what it’s worth, I initially thought the exon 20 mutation was an insertion mutation based on Al my internet research and the limited information out there. Turns out that it is not an insertion mutation and instead it’s a substitution mutation on exon 20 which her oncologist seems to think will generate a favorable response from the Tagrisso. Again any insight and general prognosis would be greatly appreciated. My mom is symptom free for the time being aside from the frequent bowel movements and inconsistent fatigue.

JanineT Forum …
Posts: 459
Forum Moderator and former caregiver

Hi sbunit and welcome to Grace.  I'm sorry about your mom and you need to be here looking for answers.  Unfortunately there just aren't good answers to these questions.  But yes there seems to be better activity with EGFR TKIs with substitutions in exon 18 and 20 than in the insertions there.  While it is uncommon to see 2 driver mutations when it happens it's usually with these substitutions at 18 and 20. 

This is a link to a study on the subject.  As a layperson who had to read a bit of studies in school, I did a search/find of "substitution" as well as focused reading results and conclusions. 

 

Chemo usually has good efficacy in people with EGFR mutations.  There are excellent premeds that mitagate a lot or even most side effects, or smaller doses of chemo drugs can be used.  Sometimes radiation to bone mets are used to stablize the bone. 

 

I hope your mom does well on tagrisso for a long time.  Please let us know if you have further questions and keep us posted.

All the best,

Janine

I joined GRACE as a caregiver for my husband who had a Pancoast tumor, NSCLC stage III in 2009. He had curative chemo/rads then it was believed he had a recurrence in the spine/oligometastasis that was radiated. He's 10 years out from treatment.

sbunit
Posts: 1

As a follow up to my original question, the specific mutations my mom has are S768l and G719S. It’s very difficult finding concrete information regarding these mutations and treatment outcomes. Was wondering if anyone has any experience regarding these mutations and their general prognosis. Mom is currently on Tagrisso 80mg

JanineT Forum …
Posts: 459
Forum Moderator and former caregiver

Hi, I'm sorry that I missed your follow-up question. These subtypes are the ones discussed in the report I linked in my previous post. BTW, I don't think I was very clear when I tried to describe how I read professional study reports. So let me try again. When I was in school I had to read a lot of studies and I read a lot of them when learning about my husband's cancer. They are very difficult to impossible to understand. So what I do now is use my "find" key shortcut, in my browser "Ctrl F" to search for specific words or terms, and I usually skip to the "conclusions" and "results" of the study even if I go on the read other parts of the reports.

 

The reason for holding off of immunotherapy is that using TKIs after immunotherapy has caused a lot of pneumonitis so you want to use up TKI options before moving to immunotherapy.

 

I hope your mother is still doing well.

All the best,

Janine

I joined GRACE as a caregiver for my husband who had a Pancoast tumor, NSCLC stage III in 2009. He had curative chemo/rads then it was believed he had a recurrence in the spine/oligometastasis that was radiated. He's 10 years out from treatment.