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Getting liquid biopsy for surveillance and treatment monitoring

Posted: Sat Mar 23, 2019 5:31 am
by mpbser
It has been an insanely busy week but I managed to get the following letter two of my husband's local doctors on Friday:

Dear Dr. *** and Dr. ***:

Please accept my apologies for this last minute request but, as explained below, exigent circumstances warrant the urgency. This letter is being sent to the two of you because Dr. *** is *****l’s oncologist and Dr. *** is his primary care physician with whom he has an appointment on March 28th (pre-treatment which commences April 1st at Memorial Sloan Kettering (“MSK”).

This week, we met with Dr. Kemeny, *****’s MSK oncologist, and requested that she order a FoundationOne “Liquid” test which is a ctDNA (circulating DNA) blood test aka “liquid biopsy.” We explained to her that we want to monitor his blood for genetic mutations of circulating tumor cells, specifically the mutant allele frequency percentage from liquid biopsy reports. Because Dr. Kemeny does not do this as part of her standard procedures, she declined and told us to “have someone else do it.”

The reason I am asking for a FoundationOne Liquid test in particular is that it includes the genetic mutations that were present in *****’s tissue specimen. Other companies, e.g. Guardant360, do not test for mTOR, tp53, or APC, *****’s three actionable variants. Plus, there is also the chance that other mutations will occur during treatment.

I have obtained a FoundationOne Liquid Specimen Collection and Shipping Kit for the blood draw once either of you have agreed to order the test. The Specimen Instructions, also enclosed, prefer that the specimen be shipped via Fedex Priority Overnight on the same day of collection.

The most efficient way to handle the paperwork with FoundationOne is to create an account at https://www.foundationmedicine.com/geno ... ting/order. FoundationOne requires the requisition of the test be from a medical provider by using the enclosed Test Requisition Form which can be uploaded to their site using the account you create. I have completed most of the form in an effort to make this process as easy as possible on you.

The company also requires copies of pathology reports and genetic testing with the Test Requisition Form. I emailed them in advance to FoundationOne to make this process easier for you.

I am also enclosing some literature on the topic of liquid biopsies as it is currently very “cutting edge.” In addition to monitoring treatment effects on ctDNA, reports help match cancer patients’ genomic profiles with targeted therapies, immunotherapies, and clinical trials to expand treatment options. The ctDNA findings will be especially important information in the event that the second-line treatment ***** will be receiving in the upcoming six months does not work.

I am also enclosing with this letter a template of an Excel spreadsheet that a fellow cancer patient provided with authorization to share with doctors to show the usefulness of liquid biopsy monitoring.

Because ****** starts chemotherapy on Monday April 1st, and a pre-chemo baseline is needed, time is of the essence to get a test kit and do the blood draw. He is in Boston Monday and Tuesday, leaving only Wednesday, Thursday, or Friday to do the labs.

If there is anything I can do to assist you with this process, please do not hesitate to ask.

We greatly appreciate your time and attention to this matter. Thank you so much for your assistance in advance. We look forward to hearing from one of your office’s soon to schedule the bloodwork and/or to pick up an order to bring to the **** lab for a walk-in visit.

Sincerely,

************

Encl. Technical Specifications, Test Requisition Form, Test Requisition Form Instructions, Specimen Instructions, Sample Excel Spreadsheet & Chart, Cure Today article


Fingers crossed one of them agrees to do this testing for us!

Re: Getting liquid biopsy for surveillance and treatment monitoring

Posted: Sat Mar 23, 2019 9:48 pm
by rp1954
Has there been any discussion about separation time required between 5FU / DFUR treatments, or 5FU residual in the blood, and the ctDNA draws while on treatment, to avoid interference?

Re: Getting liquid biopsy for surveillance and treatment monitoring

Posted: Sun Mar 24, 2019 6:08 am
by mpbser
No, not yet. I hadn't thought about that. Do you have any specific suggestions?

Re: Getting liquid biopsy for surveillance and treatment monitoring

Posted: Sun Mar 24, 2019 6:44 pm
by rp1954
Just get started on the ctDNA, a repeat sampling procedure while on chemo is another homework item over the next month or two.

I would suggest that you go ahead and do more of that extra initial bloodwork that I normally talk about e.g. AFP, LDH, cerruloplasin, ferritin, quantitative D-dimer etc. Minus the CA199, that is permanently absent.

Both for extra medical clues and backup longterm. Some generic panels might allow you to stretch out the ctDNA draws later.