Does genetic testing help in treating colon cancer?

Question

Hello doctor,

My dad was recently diagnosed with late-stage colon cancer, and the oncologist mentioned something about genetic or genomic testing to guide treatment. I am confused about the difference between testing for inherited genes and testing the tumor itself.

What exactly does this kind of testing show, and can it help pick a better treatment?
Is this the same as personalized medicine?
We are also worried about time. Does it delay treatment by waiting for these results?

We just want to give him the best possible shot, and if there is something that can help target his specific cancer, we are all for it.

Please help.

Thank you.

Answer 1

Hi,

Welcome to icliniq.com.

I have gone through your query and understand your concern.

Your questions are incredibly important, especially during such a difficult time. Genetic and genomic testing are tools that can help personalize your father’s treatment. Genetic testing usually refers to inherited genes. These tests can show whether your father (and possibly family members) has mutations like BRCA (breast cancer) or Lynch syndrome, which increase cancer risk.

Genomic testing, on the other hand, looks at the tumor’s DNA (deoxyribonucleic acid) to identify specific mutations or markers that drive its growth. These tumor-specific changes can sometimes be matched with targeted therapies or immunotherapy that would not otherwise be considered. This is the essence of “personalized medicine”, choosing the most effective treatment based on the unique biology of the cancer. While these tests can take a bit of time (usually a couple of weeks), they often run in parallel with other planning steps and do not necessarily delay the start of treatment.

In many cases, the information gained is worth the wait, as it can lead to more precise and effective options. It is encouraging that your father’s oncologist is exploring this. Keep asking questions, and do not hesitate to request a genetic counselor or precision oncology specialist if one is available.

I hope I have answered your question.

Let me know if I can assist you further.

Thank you.