In a rush here, so replying your PM in the open forum, in case it helps others
--My mum's genetic test shows KRAS mutation. Practically speaking, I know there are certain kinds of targeted drugs are not useful on her right now.
With a KRAS mutation, Erbitux and Vectibix can't be used. There are certain data that certain submutation of KRAS, G13D, might respond to them, anyway, but you need further testing. Having or not having the mutation adds one more line of therapy, that might last months, but doesn't affect the curable/non curable status.
--Does it mean that my mum cant be cured unless the mutation being cured? (Even Avastin is not curing the disease but just pushing the deadline? And I am wondering even though we remove tumors in her body through surgery, is it very likely to develop again as the mutation is still in place...Am I right?)
You are right on every point. Even if the chemo or the monoclonal antibody, Avastin, make her NED --not evidence of disease--, that lasts during a while. It might be months or one year, but the cancer reappears. The KRAS mutation is not important, regarding that --it is what happens with all the unresectable metastatic CRC. Those who are metastatic and had one/two spots in the liver, or one/two on the lungs and had a resection, have durable responses; they are ''cured'', some people say. Still, we see recurrences.
KRAS mutation is not relevant, at the present, for immunotherapy. What it is important is knowing if a patient is MSS --like 85 per cent of CRC-- or MSI-high --the rest. For those MSI-high, immunotherapy *monotherapy* (that is, on its own, like Keytruda, Opdivo, etc.) might mean ''durable'' response --as cautiously veckon said. For the rest, the MSS, being unresectable, the treatment that offers some chance of durable response is a *combination* immunotherapy trial (many times, an anti PD-1) PLUS ''something else''. That would be also the path for the MSI-high who doesn't respond to immunotherapy on its own, or progress on it.
In my signature, there is a link to a trial finder for MSS --most trials are for MSI-high, too-- that our fellow Tom Marsilje (DK37, in this forum) curates.
I already mentioned one trial that you have available in HK.
On the other hand, the best clinical data that we have of immunotherapy working for MSS is for a cohort where most were KRAS mutant. See literature in the thread from your HK colleague: viewtopic.php?f=1&t=58371
I hope I didn't make many mistakes... Hang in there!