I got a new perscription yesterday. It came with an info leaflet from the pharmacy and I figured, hey, they're all the same, right? "Use as directed. Severe side-effects, while rare, should be reported immediately. Blah blah blah." So, in the notes for this particular substance I was surprised to find:
WARNING: This medication may increase your risk of certain types of cancer (e.g., skin cancers, lymphoma) by weakening your immune system, which protects against cancer.
SIDE EFFECTS: Remember that your doctor has perscribed this medication because the benefit to you is greater than the risk of side effects.