Can excised tumors be tested for Keytruda effectiveness?

Posted By
lkb
8/8/2018 11:48pm
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lkb
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Replies: 4

Hi all,

My oncologist is on vacation for two weeks (short for her, long for me). My recent scan showed recurrence in lymph nodes. Considering another partial neck dissection. Does anyone know whether tumors, once excised, can be tested for probable response to Keytruda? Or must tumors remain in the body to test the response to Keytruda?

With thanks,

Lisa

October 2017 primary scalp WLE; SLNB removed and revealed two positive nodes in neck. July 2018 scan shows positive nodes same neck location. August 2018 partial neck dissection. Stage 3C. September 2018 started Nivo.

 

Hi Lisa, the only way to know if Keytruda worked for you is a biopsy of nodes that showed up on scans as possible melanoma. The pathologist needs to look at the sample under the microscope to be sure if melanoma is back. How long have you been on Keytruda for?

Thanks, Ed. I'm having a surgery next week for recurrence of melanoma in the lymph nodes of my neck. The plan is to start me on Keytruda soon after due to a likely microscopic presence. They will have live tumor with the excision and I'm hoping they can test it for Keytruda effectiveness.  I don't yet know what we will do if the test shows I'm not likely to respond to that drug--possibly a trial for a different drug? Do you--does anyone here-- have experience with testing tissue before starting the drug?

October 2017 primary scalp WLE; SLNB removed and revealed two positive nodes in neck. July 2018 scan shows positive nodes same neck location. August 2018 partial neck dissection. Stage 3C. September 2018 started Nivo.

 

So if I am following this correctly, you are not on Keytruda at present and based on the surgery your team is going to make a decision if it is actually melanoma, then if it is melanoma they are going to look at the Pd-L1+  status or % to decide if they should give you the Pd-1 drug!!! The problem with that approach is some patients that are low Pd-L1+ or negative actually respond to Keytruda or Opdivo, Pd-L1 status is not an accurate biomarker in melanoma. Clinical trials have shown that patients whose tumors were pd-L1+ With high % staining do better than those with lower levels but still some patient with negative staining responded to Pd-1 drugs.

First, good luck with the procedures, our thoughts will be with you.

second, my doctors at MSK expressed exactly what Ed has told you about success with anti pd-1. Her exact words to me were ‘ I have patients that expressed Pd-1 that didn’t respond and patients without pd-1 expression that have responded’. only Real way to find out is to try. Good luck.

Bill