cure-2
Explanation
The Joke
A scientist complains that "this thing where every chemical ever tested has anti-cancer properties" needs to stop. A colleague explains why this happens: if you pour enough of any substance onto cancer cells in a petri dish, it is bound to kill some of them, which technically means it has "anti-cancer properties." The key point is that killing cancer cells in a dish is not the same as curing cancer in a patient. But then another character asks, "Don't you dare stop them" -- implying they enjoy the misleading headlines. The final panel shows a newspaper with the headline: "CANCER FOUND TO POSSESS ANTICANCER PROPERTIES."
The absurd logical endpoint of this trend is that cancer itself, applied to cancer cells, would also kill them -- making cancer technically an anti-cancer agent.
The Humor
The humor satirizes the way scientific studies get reported in the media. It is a well-known issue in science communication that in vitro studies (experiments on cells in dishes) get breathlessly reported as potential "cures" when in reality, as the joke goes, you can kill cancer cells in a dish with a handgun too -- that does not make it a cure. The comic takes this to its logical extreme: if anything that kills cancer cells counts as having "anti-cancer properties," then cancer itself qualifies, because adding more cancer cells to existing cancer cells in a dish would disrupt and kill some of them. The newspaper headline "CANCER FOUND TO POSSESS ANTICANCER PROPERTIES" is the perfect reductio ad absurdum of clickbait science journalism.
References
The comic references a genuine problem in science journalism where in vitro (lab dish) studies are reported as if they represent viable medical treatments. The gap between killing cells in a petri dish and curing disease in a living patient is enormous, involving issues of bioavailability, toxicity, dosage, and many other factors that in vitro studies do not address.