What about
:
BreastCancerTeenSupport or TeenSupportBreastCancer
BreastCancerTeenHotline or TeenHotlineBreastCancer
BreastCancerHotline4Teens
BreastCancerTeenLine
BreastCancerTeenGuide or TeenGuideBreastCancer
Unfortunately, any domain that contains "breast cancer" will be a long domain. However, I personally do not think the ones mentioned thus far are tooooo long.
On a different note, I have done breast cancer research for 2.5 years, so if you're looking for a science consultant or writer, let me know
Sherif