Liquid biopsies and limitations

[mpbser]

My husband and I STILL have not read the report from his LB done at Weill-Cornell this fall. Unfortunately, my husband's Weill-Cornell doctor went MIA as has not followed up with us. We do have a downloaded copy of the report which neither of us have opened.

We have much trepidation about doing so because the research still is evolving on the subject. A doctor on one of the fb groups said that LBs are not appropriate when dealing with residual disease (something to that effect). I know that small, skewed studies show pretty strong evidence that LBs that yield negative (no cancer-mutated cfDNA) results can be false negative (simply missed the cfDNA) but that a positive result invariable means recurrence will occur.

Dr. Kemeny says that LB results would have absolutely no impact on her treatment decisions. She only goes by visible evidence of disease. So, we have been just doing the quarterly scans, hoping no visible recurrence happens. If something pops up on a scan that is suspected to be new cancer, we will then open the report.

Thoughts?

[Rock_Robster]

Hi mbpser,

This is obviously just one datapoint, but here’s my experience. My oncologist is an active researcher into LBs and ctDNA testing (Lab Head with current trials, 3 days per week), and he is actively against me having it done. His arguments are (I can’t verify these, merely relaying here):

- there are no commercially available test methods with sufficiency accuracy currently available to the public outside of trials
- We have no context for what a result means in the context of residual cancer or prognoses
- There is no translation between a result and treatment - he would not change my treatment or surveillance protocol on the basis of a ctDNA test
- The result is therefore useless. If I get a ‘negative’ test (very unlikely) any hope I get from this would be false hope due to inaccuracies. If I get a positive (or high) result this will only cause me more anxiety and reduce my quality of life (true), whilst having no bearing on my treatment plans.

I think it’s a bit of a different argument if you’re using LBs to do things like mutation or biomarker testing; or even perhaps to track treatment response, mutation burden or even recurrence over longer periods of time. There’s also some promising data in stage II and III to identify higher recurrence risk and thus justify adjuvant chemo. But none of these cases apply to me now.

I also asked my surgical oncologist about this, his answer was that “one day in the future they will be standard of care, but currently outside of a trial context they are not helpful”.

Anyone, just one person’s experience.

Good luck,
Rob

[mpbser]

Thanks, Rob!

Those are all the reasons why we haven't opened and read the report only articulated better than I could.

I think we are making the "right" decision" not to read it, for now. Should a recurrence happen (god forbid!), then it may come in handy. We had it done to get a "baseline", in any case.

[Rock_Robster]

Thanks, Rob!

Those are all the reasons why we haven't opened and read the report only articulated than I could.

I think we are making the "right" decision" not to read it, for now. Should a recurrence happen (god forbid!), then it may come in handy. We had it done to get a "baseline", in any case.

No worries at all, hope it’s of some use.

I also asked my onc about the “test but leave it sealed in the drawer” option. He refused this on the basis of test accuracy (ie even as a baseline the result isn’t necessarily meaningful), and also a belief that I wouldn’t be able to leave it unread (100% true).

Personally I’m actually more positive/hopeful about ctDNA than he is, but it’s hard to effectively argue with an active researcher with a PhD in the topic!

Thanks
Rob

[mpbser]

If he's an expert as it gets in the area of LB's, then I will definitely value his opinion on this.

I don't know what happened to my husband's Weill-Cornell doctor. We got the the test done with the intention of having a consultation with her to go over the results. I called twice to set up that appointment but have not heard back. It's the strangest thing.

My husband does not want to read the results without her input, so we are in a holding pattern. I raised the question with him about whether we should try again to make an appointment. The conversation was left open-ended. Since my husband has been really in a "I'M NED AND PLAN TO FOREVER BE" state-of-mind lately, I have let it go. Given the enormous amount of stress we were under this fall (scanxiety included but mostly not medical stress), he could use the rest.