Pancreatic Tumor Genome/Mutation testing

Posted by yellie @yellie, Feb 18 8:38pm

Hello. Does anyone know what is criteria for further genomic/mutation testing of Pancreatic tumor post Whipple? My husband had PDAC. Completed 9 rounds of Neoadjuvant Flofirinox. Successful Whipple with T1NOMO. Genetic testing was negative despite his mother and biological Aunt both having had Pancreatic cancer. We had thought that beyond the surgical pathology there would be tumor markers or mutation testing, oncology said only if metastatic or reoccurrence or that the surgeon can request. Has anyone had further tumor testing? What was cause for that? It seems mostly all studies want that information. Can you just request it? Thanks for sharing.

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bzabeli | @bzabeli | Feb 19 10:10am

Great question:
Here's some information from Grok that might partially answer your question.
https://x.com/i/grok/share/31150ba5ea25433f8518eb6d5542cb7f

yellie | @yellie | Feb 19 4:04pm

Thank you! Helpful. So from what I can interpret is his germcell/genetic blood tests were negative. Somatic or tumor testing/NGS same as tumor Biomarker testing is recommended but doesn’t clearly specify if that is or was done with the pathology report from his Whipple, which possibly has to be requested or completed. Will ask his surgeon more specifically at his visit next month. 🙏

gamaryanne | @gamaryanne | Feb 20 9:36pm

As an aside, mutations can continue to occur. Just as the tests continue to be able to identify more and more genes.
My somatic testing was done in 2022. Last year we decided to do another biopsy to determine whether additional actionable mutations were present.
Disappointingly, they did not take a large enough sample to be useful.

stageivsurvivor | @stageivsurvivor | Feb 21 5:57am

In the National Cancer Institute (NCI) Centers of Excellence and National Pancreas Foundation (NPF) recommend Ed Comprehensive Cancer Centers, Tumor genomic testing using Next Generation Sequencing (NGS) has essentially become a standard of care test procedure following a Whipple or Distal Pancreatectomy. At centers that are not high volume NCI or NPF centers, they are less familiar in doing this as standard proactive and may need to request it. The surgical pathology report performed on tissue blocks is unrelated to NGS. It focuses on cellular dysplasia, surgical margins and related parameters.

NGS looks at somatic mutations, gene fusions and actionable biomarkers. Each is a distinct entity and knowing this information is importantly so the treating oncologist can customize a treatment plan to exploit the respective findings or help in searching for a targeted clinical trial. There are several NGS reference laboratories and medical centers will have one of preference. Examples are Foundation One which routinely tests for a gene defect in DYPD. This is critical to know if a patient will go on (m)Folfirinox chemo regimen. Receiving (m)FFX when there is a defect in the DYPD gene responsible for metabolizing a component in this chemo regimen (5-Fluorouricil) can result in severe morbidity and lead to mortality. Other NGS labs are Tempus, Invitae and Guardant360.

yellie | @yellie | Feb 21 8:10am

Thank you so much for this explanation it’s very helpful. I remember when he underwent Neoadjuvant chemo in June they discussed the risk of the reaction to the Flofirinox, I believe it was presented to him as low and he decided to just got forward with the chemo and take the risk. The hospital who diagnosed him was smaller with a lower volume his oncologist felt that unless he had metastatic or reoccurrence it wasn’t needed. Maybe a second opinion would be helpful. He sees the surgeon who was from a larger, higher volume medical center in March with another repeat CT. Will ask specifically for the NGS. Thank you for your explanation.