writersoul, what differentiates cancer is one its pervasive nature (which is cheating because cancer is more of a group of diseases than a disease, it is more comparable to kidney disease than to ESRD.) Cancer is among the leading causes of death in ALL age groups. ESRD isnt nor are ALS depression and other diseases mentioned thus far.
PErhaps what causes cancer to stand out even more than the above is how it often will presnt with vague or even no symptoms. Nobody wakes up one day and has ESRD it is a long process of kidney faiure (generally). Some cancers such as pancreatic cancer present as vague abdominal pain perhaps some weight loss, and next thing an otherwise healthy 50 year old is told he has(on average) less than a year to live. I dont think it is ahrd to understand why this helps make the thought of cancer terrifying to the point that it has this stigma associated with it.
Im not saying it is good that it has this stigma, but that it is understandable and even deserved