Hi, my husband was diagnosed with Stage IV nsclc lung cancer in March 2013, with mets to the liver, lungs and bone. He originally underwent radiation therapy, then 4 rounds of chemotherapy (gemcitabane & carbonplatin). During the treatment it was discovered that he had the ERGF mutation. The doctor decided to finish the chemotherapy, as it was thought it was working and then consider Tarceva. Scans at the end of the treatment showed progression of the cancer. At this stage it was decided he should be on Tarceva, at 150mg daily. He had an immediate skin reaction and as a result the doctor decided to reduce the dosage to 100mg. Scans at 3 months showed shrinkage and scans at 6 months showed almost no cancer, just one small spot on each of the liver and lymph node in the lung. Scans suggested metabolic remission.
The skin rash was still bad but under control. The doctor decided to reduce his dosage to 100gm every second day, this was in the first week of February 2014.
Since October 2014 his tumour markers have been less than 0.5, however blood tests in March showed his tumour marker had risen to 0.6. I realise this is low and a good sign.
My questions are - is it okay to take the Tarceva only every second day, and should we be concerned that the tumour marker has risen since he has been on Tarceva every second day.
We live in Perth, Western Australia.
Tonia
Reply # - March 16, 2014, 07:49 AM
Reply To: Tarceva Dosage
Hi Tonia,
Welcome to GRACE, and congratulations to you and your husband on his excellent response to Tarceva.
It is not at all unusual for patients who respond very well to an EGFR inhibitor to respond just as well to a lower dosage. Their cancer cells just seem to be extremely sensitive to the drug. And as long as he is being followed with scans, the dosage could be increased if necessary and perhaps ways could be found to try to better manage the skin issues. When a drug is approved, the standard dosage is set at the maximum which seems to be tolerated by most patients, not at the minimum which seems effective.
You can read a post from Dr. West on this subject here: http://cancergrace.org/lung/2010/05/24/dose-vs-efficacyof-egfr-tki/ He sums it up by saying:
"[This study] should allay anyone’s fears that the people who need to reduce dose of their EGFR inhibitor due to challenging side effects are compromising their treatment — at least for patients who have tumors with an EGFR mutation."
If you need suggestions on managing Tarceva skin issues, there is plenty of information in the archives here. You might want to start with Dr. Mario Lacouture's presentation here: http://cancergrace.org/cancer-treatments/files/2011/09/dr-lacouture-on-…
Tumor markers in lung cancer are not a reliable enough indication of response to treatment to warrant their use in making decisions regarding change of treatment or dosage. In addition, as you say, the level is very low and the change was insignificant. You can read Dr. West's post on that subject here: http://cancergrace.org/lung/2007/06/16/tumor-markers-in-lung-cancer/
Best wishes for continued response to Tarceva.
JimC
Forum moderator
Reply # - March 16, 2014, 07:52 PM
Reply To: Tarceva Dosage
I agree completely with Jim. The more common approach, and what I advocate for my own patients who have problems tolerating the current dose of an oral EGFR inhibitor like Tarceva (erlotinib), is to lower the once daily dose to whatever is the most that is tolerated well on a longitudinal basis. If 100 mg daily is too much, dropping down to 50-75 mg/day is very reasonable -- that's what they make the 25 mg tablets for. I suppose you could do 100 mg every other day, but that's not really a studied approach compared with just lowering the daily dose as needed.
As for the rise in his tumor markers, I completely agree with Jim that a rise from 0.5 to 0.6 is of no significance, and this situation provides a good illustration of how serum tumor markers can be misused. That anyone should be concerned about a rise from a low number to another very close low number, all within the normal range, highlights why many experts think they're a singularly bad idea to incorporate into clinical practice. There are too many real problems in the world to worry about to manufacture new ones that aren't even real. I don't mean to be harsh as much as to reassure you that a rise from 0.5 to 0.6 is about as worth worrying about as the world being destroyed by a giant meteor in the next 24 hrs.
Good luck.
-Dr. West