Obviously advice received from strangers through the internet should always be checked out.
in general assume you can treat. It’s a common sense thing. The idea that massage can spread cancer around the body is misguided nonsense. If massage spread cancer then people would be told not to run, to avoid saunas and certain types of foods - and sometimes people are told to avoid these things so you shouldn’t massage them unless you have oncology training. The do not treat rule is aimed at students with no knowledge - and it’s sensible. Once you’re qualified, more knowledgeable etc then you can treat with discretion - you should stay within your training.
You can massage at every stage of a person’s cancer journey, you just need to adapt your treatment and you need to know a few moves. It may be that you don’t know the moves that are appropriate for someone in unrelenting pain, who is very fragile, but that doesn’t mean that they can’t have a treatment, just that they can’t have a treatment from you.
For people that are basically healthy, you can treat. Just have a detailed consultation etc. If they have substantial post surgery scarring and your gut says to avoid this area, refer them to someone who can take care of their whole body, scar tissue and all. In general, gliding effleurage will be fine (it just might not achieve much improvement). If they feel fine and they are comfortable to have a “normal” massage with no “no go” areas, then just do what you normally would, working mindfully and adjusting your pressure as you would for any client. Heat, aromatherapy, etc, are all fine, deep tissue might feel uncomfortable so adapt as required.
Oncology massage is really about touch treatments for people who feel very unwell, who are frightened and in pain and who might want to chat about their treatment and recovery journey. It covers practical issues like the types of pain medication you might find attached to their body and ways to bolster to support drips etc. Very much about hospice work. It provides reassurance for your insurers that you aren’t going to do something dumb like book someone in for a 90 minute hot stone massage when they’re receiving cancer treatments such as radiology or chemo.
hope that helps