Sunday, August 2, 2020

Lynch Syndrome



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Three years ago, my genetic code was studied to look for possible inherited mutations that could explain my family's cancer history: maternal grandmother-uterine cancer, mother-ovarian and colon, me-breast. New scientific information is constantly moving forward bringing to scientists, doctors, and the general public a better understanding of our genes. Two years ago I was informed I had no inherited genes. That has now changed. The variant with unspecified significance listed in my genetic test result from 2017 has become a trouble maker.

At the beginning of June, I received a call from a geneticist from UNC Hospitals. She let me know that she had been contacted about new information concerning my genetic testing. It is clear now that I in fact have a defective inherited gene which makes me more prone to a few different cancers compared to the general population. This defect is part of a group of genotypes classified as Lynch Syndrome.

I wrote about BRCA 1&2 PALB2 here and Lynch Syndrome here in 2017. 

The Lynch Syndrome genotype that I inherited is MSH6. The other genotypes involved in Lynch Syndrome are called MLH1, MSH2, PMS2. Depending on the genotype found depends on which cancers are more likely to occur. As is the case with BRCA 1 & 2, just because someone has inherited the defective gene does not mean the person will get breast cancer. Cancer will only occur if the other gene paired partner (one gene from the mother and one gene from the father)--mutates that cancer will develop.  Since my mutated gene, MSH6, can cause a few different cancers, cancer will only occur in the tissue where the partner gene mutates. Here is the breakdown and percentages of lifetime risk of particular cancers for all four genotypes:

The chance of getting any cancer in my life-time related to the genotype I carry varies greatly. In looking at the chart, you can see colorectal cancer has a 10-26% chance of occurring. Endometrial has a range of 16-71%. Those ranges are quite large. I have read that breast cancer may be a cancer related to Lynch Syndrome as well, but I am not familiar with which genotype. (I need to do more research.) 

With this new information concerning my inherited condition, I had appointments with a gastroenterologist and a gynecologist last week. For colorectal cancer, all that can be done to try and catch this cancer early is to do screenings. The doctor recommended colonoscopies every two years. As for gynecological cancers, that doctor believes a prophylactic approach is best. I am not opposed to this since my reproductive organs are doing nothing for me now. (If they are producing any hormones, it feels like the amount is minuscule. My thick, unruly hair of my youth is thin. My eyebrows and eyelashes are barely visible.) 

The doctor also said I am a good candidate for robotic surgery. (Seems strange to think of a robot cutting my organs out.)

The procedure could already be scheduled if not for my platelet problem. The doctor wants my count to be 100,000 platelets per microliter--normal is 150,000 to 400,000. Since platelets are what make our blood clot, they are important in surgery for obvious reasons. Unfortunately, because of my current treatment, mine swing from the 50,000's to the 80,000's which means for my platelet counts to recover enough for surgery, I have to stop treatment for several weeks. And, even then, there is no guarantee they will recover. I am not opposed to forgoing treatment for a few weeks, I have done it before for radiation and a few times to let my platelets recover, but not knowing how long it will take my platelets to get to the magical 100,000 is uncomfortable and perhaps not even possible.

Once surgery takes place it will be four weeks before I can lift anything heavier than a 1/2 gallon of milk. That complicates my working, but the risk of COVID19 infection currently has me not working in the classroom anyway so why not tack on another complication.

I must admit I am hesitant about surgery. Unplanned events can happen, including death. If I have a complete hysterectomy and then breast cancer decides it is time to do me in then I would have gone through an unnecessary procedure. If I were to live another seven years then it would be worth it. This is a good time to have a crystal ball telling me how long I will live with breast cancer except no such thing exists. 

Instead of the surgery, surveillance can happen with ultra-sounds of the uterus and ovaries. The blood test CA 125 can be performed to try to detect ovarian cancer. However, ovarian cancer is sneaky. It is often not detected until the late stages so probably not a good strategy. Tough decision for me to make. And to think, I was under the impression breast cancer would kill me before any other cancer could, but here I am, seven years later, now having to worry about other cancers, crazy.

Just another day in my not-so-normal life.