TiredandTroubled wrote:...Question: At what point would genetic testing happen? Can they use the biopsy for that or do they need a blood sample? Do you need that information before getting a treatment plan? Do I need to ask them to do genetic testing or do they do that automatically?
First of all there is a difference between
genetic testing and
genomic testing.
Genetic testing tests the DNA of your whole body (based on a blood sample) to see if you have any relevant inherited mutations present since birth, such as an elevated risk for Lynch Syndrome, FAP, endometrial cancer, etc..
Genomic testing, on the other hand, tests for mutations in the tumor tissue only (based on a tissue sample from the original primary tumor), for purposes of finding out what kinds of chemo the tumor and its metastases might be most susceptible to.
You don't need
genetic testing right now if you have no family history of colorectal cancer or colorectal polyps.
You don't need
genomic testing right now, either, because you are Stage III-B and don't have any confirmed remote metastases. As a Stage III-B patient without a family history of CRC, all of the 1st-line treatments approved for you right now (e.g., FOLFOX, XELOX(CAPOX), etc.), are without restriction. (The exception on genomic testing is
MSI testing. All CRC patients need to have MSI testing done, regardless of stage.)
However, if you ever have a recurrence you will definitely need to have genomic testing done because some of the treatment regimens used to treat mCRC come with restrictions. The restrictions for you are indicated in
red in the list below.**
Since you are at risk of possibly having a recurrence in the future, you might want to have the relevant testing done right now so that you know what your tumor's genomic profile is. However, for a Stage III-B patient your insurance may not cover this type of testing since it is useful only for confirmed Stage IV / mCRC patients. So you might need to pay for these tests yourself unless your oncologist has made strong arguments to the insurance company that you really need these tests.
O Stoma Mia wrote:For reference, here are the main chemo drugs and chemo drug-combinations in use right now, along with their dates of original FDA approval :
Drugs used in colorectal cancer
1962 5-FU (Fluorouracil Injection) - no restrictions
1998 Xeloda (Capecitabine) - no restrictions
2000 Camptosar (Irinotecan Hydrochloride) - no restrictions
2004 Avastin (Bevacizumab) - mCRC 1st line+
2004 Eloxatin (Oxaliplatin) - no restrictions
2004 Erbitux (Cetuximab) - mCRC 1st line+, KRAS wild type only
2006 Vectibix (Panitumumab) - mCRC 1st line+, KRAS wild type only
2012 Keytruda (Pembrolizumab) - mCRC 1st line, MSI-H only
2012 Zaltrap (Ziv-Aflibercept) - mCRC 2nd line
2012 Stivarga (Regorafenib) - no restrictions
2014 Cyramza (Ramucirumab) - mCRC 2nd line
2015 Lonsurf (Trifluridine and Tipiracil Hydrochloride) - no restrictions
2017 Opdivo (Nivolumab) - mCRC 1st line+, MSI-H only
2018 Yervoy (Ipilimumab) - mCRC 1st line+, MSI-H only
2019 Zirabev (Bevacizumab.alt) - mCRC 1st line+
2020 Braftovi (Encorafenib) - mCRC, BRAF V600E only
Drug Combinations Used in Colorectal Cancer
FOLFOX - no restrictions
XELOX (CAPOX) - no restrictions
5FU+LV -no restrictions
FOLFIRI - no restrictions
FOLFIRINOX - no restrictions
XELIRI (CAPIRI) - no restrictions
FOLFIRI+AVASTIN(BEVACIZUMAB) - mCRC 1st-line+
FOLFIRI+ERBITUX(CETUXIMAB) - mCRC 1st-line+
** Please note that the annotated table above is intended only for the case of Stage III patients without family history of CRC . A different annotated table would be needed for other cases, such as Stage I, Stage II-A, Lynch Syndrome patients, FAP patients, etc., etc.