Adenocarcinoma with Egfr+ mutation exon 18 & 20

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

Hi all

This is a follow up to my original post about 15 months ago when my mom was first diagnosed with stage 4 adenocarcinoma. She’s been on Tagrisso since and it has been working well, shrinking her primary tumor without any further evidence o progression. Unfortunately because she’s quite frail, she tends to experience a lot of stomach problems from the Tagrisso. This past September she was experiencing quite a bit of diarrhea, stool samples were negative and her oncologist was suspicious it was related to the Tagrisso so he halved her dose from 80 to 40 (I think these are the correct numbers but I am 100% sure the dosage was halved). She’s been on this half dosage since then, the diarrhea was resolved (her taste has also improved prior to this she was complaining everything she ate tasted bitter) but she still experiences GERD like symptoms and stomach pain (which were her initial symptoms prior to diagnosis!).

Finally to my question:
She just had blood work done and her CEA markers have been on the rise. She is due for her next set of CT scans. Her last scan in October showed everything to be stable with no appreciable changes. We are concerned with the rise in the CEA marker, does this indicate the cancer is growing again? I’ve read that CEA is not a good indicator for lung cancer but I also read other things that say it can be highly associated with egfr related lung tumors which mom has. If the tumor is growing again, can I assume the next step would be to raise the dosage of the Tagrisso again? Any insights are greatly appreciated

Janine thank you so much for the reply

Based on my mom’s recent symptoms (which after speaking to her today mimics all her symptoms prior to initial diagnosis last summer), and the fact her Tagrisso dose was halved about 4 months ago, I am highly suspicious and expecting to hear that her tumor has grown again once she gets her next scan (trying to get scheduled for this week). I was wondering,

1) is it common to see the tumor/disease progress after halving the dose of Tagrisso?
2) is the likelihood of the tumor/disease getting back under control high/good once you increase the dosage of Tagrisso again which is what I’m assuming will be suggested

Basically, is this a commonly seen scenario where the dose is lowered and the disease decides to progress but can be brought under control again later by increasing the dosage? Just worried about what the future may be holding and hoping there may be an easy fix to this. 15 months on Tagrisso (with the last 4 months only at half dosage) hopefully doesn’t mean it stopped working

As always, thank you so much Janine for your responses.

While we are awaiting her scan, the other question I have is regarding her chronic pleural effusion. At her initial diagnosis mom had malignant pleural effusion. As stated she was placed on Tagrisso (initially 80mg) since then with no other form of treatment and it seems to be working well (pending results of her upcoming scan of course). At her last Ct scan back in Sept 2023, The pleural effusion was still present with adjacent partial atelectasis (also present at initial diagnosis in August 2022) without significant interval change compared to prior scans. While I suppose the no change is great, I was wondering if it is common/typical for a chronic pleural effusion to still be present 15 months after initial diagnosis and treatment? The effusion did get smaller compared to the original size but it has never disappeared entirely. Mom has not had any symptoms until these past 4 weeks where she is suddenly experiencing primarily GI related symptoms (stomach pain, occasional vomiting of a yellow substance possibly bile) in addition to body chills at night and lower extremity pain. Hoping the cancer is not getting out of control and perhaps something else may be going on.

She is being scheduled for her CT scan and I will certainly be discussing matters further with her oncologist once we receive the scan results.

As an update to my previous post, we took mom today to her pulmonologist to see what we can do about her symptoms as we continue to wait for the insurance company to authorize her chest CT. Mom has been having worsening GI symptoms. An ultrasound was taken this morning and as suspected her pleural effusion has gotten bigger (She had the same symptoms prior to initial diagnosis of her cancer). She is scheduled to be drained in the next 48 hours which should alleviate her symptoms and discomfort. I didn't have a chance to discuss anything with her oncologist yet but of course I asked her Pulmonologist if this means her disease has progressed to which he responded yes likely.

As mentioned, her Tagrisso dosage was cut in half back in September (4 months ago) when she experienced 2 weeks of diarrhea without cessation. She's been on 40mg of Tagrisso since then. He told me the question now becomes, did the disease progress because of the lower dose or because the Tagrisso has stopped working entirely (I.e. resistance). He did not know the answer to this question but he will be reaching out to our Oncologist to inform her of today's findings. Do you know what happens next? If it stopped working, what options do we have? Mom has substitution mutations on exon 18 and exon 20. Is chemo going to be inevitable? Mom is very frail, only weighing 90lbs and i am very fearful she would not tolerate the Chemo. Again, thank you so much for your generosity with your time to answer my questions.