Breast cancer is not contagious and has no chance of becoming a pandemic. The issue with a pandemic is every person infected is several more infectees in the future; geometric death effects instead of linear.
At the risk of starting a flamewar... wasn't the difference actually just the pure volume of severe sickness and death? The clinical trials didn't even attempt to test viral spread, they tested prevention of symptoms.
If suddenly 50% of the world population got breast cancer at once, I'm willing to bet we'd be fine rolling out new technologies faster than the typical standard, despite it being non-contagious.
A major difference is that no two breast cancers are the same. You're probably correct in your second point due to the sheer demand, but developing a treatment for any cancer is not the same as developing a treatment for an infectious disease because there is no one-size-fits-all strategy. A situation like the one you describe with simultaneous onset of breast cancer in a large population would definitely facilitate research and help lead to a better standard of care, though.
Breast cancer is not contagious and has no chance of becoming a pandemic. The issue with a pandemic is every person infected is several more infectees in the future; geometric death effects instead of linear.