The unassailable excuse of cancer patients and their immediate family that gets them out of events and responsibilities as needed.
John didn't want to go to his cousin's wedding. So at the last minute, he played the cancer card and told his aunt he didn't feel well enough to make it. While his aunt fretted about what his absence meant for John's health, John watched college football all afternoon in his underwear.
What "certain folks" with cancer like to cry to make other people feel bad.
"i tried calling in sick today, but my boss who has a breast disease pulled the cancer card on me, so i came in anyway."