No mutations or copy number alterations was detected in stage I of cancer

Question

[nazaninhoseinkhan]

Dear all,

I found no mutations or copy number alterations in about %30 of my tumor samples (stage one of tumor).

Would you please tell me if it is strange?

have anybody faced with the same issue?

Regards

Nazanin

Answer 1

[German.M.Demidov]

No mutations is indeed strange. Do you use panel sequencing?

1) tumor may be driven by epigenetic changes 2) mutations may be located outside of targeted regions 3) purity of the biopsy may be too low 4) other structural variants such as fusions may drive cancer

[nazaninhoseinkhan]

Thank you so much for the explanation

[German.M.Demidov]

Check out this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720395/ - it is not about alternative mechanisms, but more about how many important mutations you may find for Different tumor types

[nazaninhoseinkhan]

Sure, thank u German

[Ram]

If an answer was helpful, you should upvote it; if the answer resolved your question, you should mark it as accepted. You can accept more than one answer if they all work.

[German.M.Demidov]

being honest I don't like my answer - it does not go into details and is partially contradictive with well-accepted theories such as "epigenetic changes are a consequence of genomic changes" - so it is usually considered as non-driving event, that's why I wrote it as a comment in the beginning. I also feel the list is not full. I'd wish more people contribute to this question - I'd also like to read the full and well-motivated list.

E.g. here is the mutational burden per cancer type - https://genomemedicine.biomedcentral.com/articles/10.1186/s13073-017-0424-2/figures/2 - but this is only a part of the answer