The Colon Club

Pyro wrote:Well I get my 8 week blood test results today,probably followed my a scan. Cross your fingers, I don’t know what to do if it hasn’t worked.

Pyro wrote:Well, it was 30. Didn’t expect that, went ahead with treatment. Thanks for thinking of me!

And high tumor mutation burden I think is a much better predictor at the end of the day of response versus MSI-high on its own. So I think MSI-high is just a surrogate

Jack&KatiesMommy wrote:i wanted to give you all an update on my off-label use of Keytruda (since I am MSS it is not approved for use by me....since it doesn’t generally work for colon cancer patients which microsatellite stable tumors.)

HOWEVER, it looks like it is working for me....and here is the reason why (according to my doctor and the Foundation One reps): it is not whether the tumor is MSS or MSI that is determinative as to whether the immunotherapy will work....it is the THE TUMOR’S MUTATION BURDEN THAT DETERMINES WHETHER KEYTRUDA WILL WORK.

Foundation One is seeing evidence that people whose tumors have a high (or moderately high) mutation burden tend to respond to the immunotherapy treatments. Generally MSI tumors have a high mutation burden and MSS tumors have just one or two mutations if any. In my case (probably dilute to the fact that I’ve had many different courses of treatments over the last 7 years) my MSS tumor has a moderate mutation burden (11 mutations.). So my local oncologist (who has been doing tons of work with immunotherapy over the last 6 years) got permission to treat me with Keytruda off-label.

My CEA (which is super sensitive and very accurate over the last 7 years) was 39.6 before my first Keytruda treatment. Three weeks later, before my second treatment, my CEA had risen to 66.4. Before my third treatment, my CEA was back down to 39.2, and three weeks later before my 4th treatment it was down to 13.0. On Friday, before my 5th treatment my CEA was down to 3.5 and my CT scan showed shrinkage of the only slightly enlarged lymph nodes in my hilar lung area to normal size.

This is an amazing breakthrough for MSS patients. If you are MSS, please get Foundation One Testing to see if you have a moderate or high mutation burden. If you do, immunotherapy couldvwork for you.

Please feel free to contact me if you have questions.
Cynthia

Jack&KatiesMommy wrote:Pyro:
It maybe on the downswing.....Mine did that a few times....it started to go up then stayed the same then went down. We thought that maybe it had continued to go up a bit then was coming down and we caught it on the downswing.

Next cycle will be telling. (Maybe you could ask your oncologist if you could get another CEA in say, 10 days....if you can't wait for 3 weeks. My oncologist did that for me at one point.)
Cynthia

behconsult wrote:
Cynthia, If I might add, I think it is amazing kindness and compassion that you reach out to members and educate them about this. Even I spoke with my onc about your posting. I am low mutation unfortunately, but many are not. Thank you

Jack&KatiesMommy wrote:

behconsult wrote:
Cynthia, If I might add, I think it is amazing kindness and compassion that you reach out to members and educate them about this. Even I spoke with my onc about your posting. I am low mutation unfortunately, but many are not. Thank you

BUT....my oncologist said that if they had tested my original tumor (or even after 1-2 years of treatment) I may have been identified as having a low mutation burden. My oncologist believes that my MSS high Mutation Burden may be due in fact to all of the years of many different treatments and changes that occurred in the colon cancer in response to those treatments. I don't know what tumor tissue they sampled when they measured your TMB...but if it wasn't from a recent sample....I would wonder if it accurately reflects the current TMB of your cancer now.

Cynthia

Pyro70 wrote:

Jack&KatiesMommy wrote:

behconsult wrote:
Cynthia, If I might add, I think it is amazing kindness and compassion that you reach out to members and educate them about this. Even I spoke with my onc about your posting. I am low mutation unfortunately, but many are not. Thank you

BUT....my oncologist said that if they had tested my original tumor (or even after 1-2 years of treatment) I may have been identified as having a low mutation burden. My oncologist believes that my MSS high Mutation Burden may be due in fact to all of the years of many different treatments and changes that occurred in the colon cancer in response to those treatments. I don't know what tumor tissue they sampled when they measured your TMB...but if it wasn't from a recent sample....I would wonder if it accurately reflects the current TMB of your cancer now.

Cynthia

That’s interesting. Pyro, how old was the tissue you had sequenced for TMB?

Thanks