supportive strapless bra?

[trix-are4-kids.livejournal.com]

My mom's, best friend's mom has some sort of cancer and therefore has a tube coming out of her chest on her left side, where her bra strap would go.

Shes a fairly big woman (which includes the chest area) so she needs some sort of support system. Strapless bra's aren't enough support for her- so my moms friend is looking to me to make something...

I figured you ladies are problem solvers, and I am totally stumped, so please help!