Cancer is cancer - cures for breast cancer or basic research will translate into basic understanding and/or cures for other cancers.

As for all the funding that goes into breast cancer research, funding for basic research is really tough right now - so any money that's being raised towards a cure is great. And it means that if you're working on some aspect of prostate cancer or lung cancer, you'll make sure to do your results in parallel on a breast cancer line so that you can apply for that funding... Something that you would have made sure to do anyways just to make sure and validate that what you're seeing is not specific for prostate cancer only...