My friend has advanced stage 4 breast cancer, which is metastasized in her spine. I have been in a natural way massaging her feet when I go to visit her.
I was specifically wondering where I would best massage on her feet, but as you say, all over is probably best.
Yes, you might be trying to comfort the cancer patient and make her more comfortable, rather than curing the cancer.
There are so many interactions
with glands organs, etc., that a full session is better than guessing,
especially when it's not a simple acute ailment.
If you can tell where she feels the reflex pressure more and emphasize those reflexes more, then it will be of benefit and who knows, could end up being a tremendous help. But be gentle enough not to cause more stress. The general reflexology should be combined with soothing, relaxing motions on the hands and feet. It is usually nice to do the hands also, often first.
And yes, simple natural massage can be beneficial in itself.