As a cancer survivor, just wanted to let you know that the poor taste exhibited here is pretty sad. When you want to make your point next time, use a title that doesn't include something that kills people. Thank you.
I am sure cancer sucks more than anything I had to experience but the world is not going to change its figures of speach for you and it is not directly derogatory at all it just reminds you of your misfortune.
Btw I am not criticizing you for asking the OP to change his headline I just think it is an impossible crusade.
To be clear, the title is intended to point out how absurd the original title was (node.js is a cancer). I strongly suspect the author agrees with you on using this kind of language when describing a language/framework, which is exactly why he did include it in the title.