Microsatellite instability fragment analysis...Insurance paid!!

lisa42 said:

so glad
Aren't insurance fights fun? Ha!
I know about that, for sure. My insurance is now balking at paying for the Gemzar I need. We'll see what happens.
Anyhow, wanted to comment on the MSI testing- I had it done (ins. did pay) & it came out that I do not have the marker (or mutation- whatever it's called w/ this one- I forgot).
Having this was a requirement for Dr. Lenz's PARP inhibitor trial. He said about 30% of the cancer population has it & for those who do, he believes the PARP inhibitor would work well. It won't for me, though, which is why I found out recently that I didn't qualify for that particular clinical trial. Just wanted to put that out there for anyone who tests positive in this particular genetic test- look into the PARP inhibitor trial (this is speaking to those of you who have already done 1st and 2nd line chemos and have had recurrences).

Best wishes to all-
Lisa

usakat said:

Microsatellite Instability
Hi Ladies,

MSI testing is often done on colon cancer tumors in young patients to determine if their cancer might be an inherited form of colon cancer. In a nutshell, MSI testing looks for errors/mistakes/mutations (instability) in DNA sequences, which affects cell repair mechanisms. People like me with HNPCC (Hereditary Non-Polyposis Colon Cancer) have mutated DNA - missing or mistakes in the DNA sequences related to cell repair function. How this manifests itself is that cells do not receive the communication/instruction from the cell nucleus to kill off mutated or damaged cells (cancer cells), so cancer cells then grow without the body's cell repair function - sort of like missing a quality control agent.

I've never heard that because a cancer is inherited or has high MSI that it is more or less responsive to chemo. My onc did say that HNPCC patients do have a higher risk of micro-mets so chemo is recommended for Stage II patients. In my humble opinion, everyone Stage II or greater should receive some kind of adjuvant therapy, be it chemo or alternatives - better safe than sorry.

Patients with high MSI usually get the suggestion for genetic counseling and/or testing, but that is another discussion. Those with high MSI or inherited cancers are at much higher risk for more colon cancer and cancer elsewhere in the body (for HNPCC the risk is higher for cancers of the endometrium, ovaries, kidney, urinary tract, small intestine, lung, gall bladder, skin, brain, and sometimes breast). People with high MSI and/or inherited cancers should receive regular screenings for all the cancers noted (I get colonoscopies and EGDs, mammograms, etc. every year).

For information on HNPCC screening guidelines see:
Journal of AMA - Recommendations for HNPCC Patients

Open link and under the heading "This Article" on the right of the window, select "PDF". I print this out and give it to my doctors to substantiate the need of various screenings.

I hope this helps!

BTW: Lisa, you are always in my daily thoughts and prayers. I'm pulling for you, sister!