Hello Josemarii & welcome to 3FC!
We're mostly a weightloss support & advice board, but you're within General Chatter where many issues non-weight related are discussed. And perhaps if you start a thread in this section you will find some other 3FC members who have had to deal with cancer wish to contribute.
However, since 3FC is not a cancer forum, you may not find what you're looking for here. If you're looking for a board that is more cancer-specific, and where you may find more information & support I suggest you may want to Google "cancer forum" or "cancer support" where many, many links are given.
All the best to you