Which is better for cancer patients? royal jelly or manuka umf 30 honey

Either: Which ever tastes better!

Neither, but...: There are a variety of false claims on the internet about how they can help cancer patients. In fact, the only good scientific evidence on these suggests that royal jelly can actually harm a patient with estrogen-receptor positive breast cancer, because royal jelly can stimulate these cancer cells to grow. Thus manuka is probably safer, but it does not help treat cancer.

Both worthless: I'm sorry that you have cancer. I'm also sorry that the world is full of people who are out to deceive you. Ignore the glitzy promotions. These people are trying to make money off your desperation. Don't reward them for doing this, even if you suppose "It doesn't cost much and can't hurt."