Is it legal for cancer patients to travel in sick?

Legal. It is legal for cancer patients to travel on sick leave, because they can arrange their own sick leave, spend it in the hospital or travel to see a better world, so as not to delay treatment or leave regrets for their future. The employer has no right to interfere with the choice and freedom of the parties, so it is legal. During the sick leave, cancer patients can choose to go to some tourist attractions with few scenic spots and certain cultural connotations to make themselves more open-minded and actively fight cancer.