Thursday, December 17, 2015

Cancer Genetics

Today was a day of appointments.  The first was a consult with a genetic counselor.  I learned about Lynch Syndrome, also known as Hereditary Non-Polyposis Colorectal Cancer (HNPCC), which is the most common hereditary form of colorectal cancer (and also uterine cancer).  Since I am a younger cancer patient, this is a possibility they consider - however in my case there really isn't anything in my family history to suggest it.  Here is some info from the Dana-Farber handout:

"Lynch syndrome is due to problems in the way that our cells repair themselves through alterations in genes... As the cells grow and divide, exact copies of these genes need to be made for the new cell that is formed.  When mistakes are made during this copying process, the wrong chemical letter may end up in the new gene that is created... One set of genes helps to find and correct a certain kind of typo, known as a DNA mismatch... five genes that are a part of or associated with the DNA mismatch repair process have been shown to cause Lynch syndrome.  They are called MLH1, MSH2, MSH6, PMS2, and EPCAM."

If those genes are not doing their job, these mismatches can add up and cells can lose their ability to regulate which may result in cancerous growth.  As it happens, a test was already done on my tumor (since it was removed) and they saw the presence of proteins that are the result of the above genes doing their job.  The counselor I spoke with today is therefore not expecting me to have Lynch syndrome.  Nonetheless, they offer genetic screening to check for it.  I was offered a panel screening of the above genes and about a dozen others that are linked to hereditary cancers.

All that said, only 5-10% of all cancers are hereditary.  That leaves a lot of room for all kinds of other causes including just plain bad luck.  I agreed to the full panel screening because I'm generally a data head and the results might help me with future treatments if the cancer recurs, or my kids if there is indeed a hereditary cause.  Between this screening and the clinical research trial I signed up for I'll probably have more data than I'll know what to do with.

I also saw my surgeon for a followup.  Everything looked good to her and I have no more restrictions on lifting anything or any kind of exercise.  Now I can lift Connor and rebuild my upper body strength!  That was positive.  She reminded me that one reason they didn't reconnect me during that long second surgery was so that if I was to have radiation therapy (which I will), there would be a "clear shot" to the affected area.  So I guess that's good too.  She also reminded me that if I wanted to go ahead and be reconnected and have the ostomy reversed, she would ideally want me to finish all therapies and then wait a little bit so that I was as healthy as possible, and so I could have a couple more scans to see if anything was regrowing anywhere.  She is thinking nine to twelve months from now (ugh).  Assuming scans were good then there would be TWO more surgeries - one to do the re-connection, which would involve giving me yet another ostomy in yet another place (and the current one reversed), and after everything had healed, one to reverse that final ostomy (ugh again). 

It was a little overwhelming to re-process that info.  My husband reminded me that she's said all that before, but I didn't really hear it before.  Waiting for my third and final appointment (CT scan) I was teary just thinking about two more surgeries, having to deal with the new normal for that long, the possibility of the cancer coming back... trying to put it all in the "to deal with later" bucket.  First finish chemo, then deal with radiation.  Then all the other stuff.. bah humbug.

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