Your post is an example of a phenomenon known as what-about-the-men-ism. It is nearly inevitable that any article, tweet, etc that discusses women's issues will get one or more replies essentially asking "... but what about the men?"
Honest question: If this were an article about leukemia death rates would you have posted about prostate cancer? Most people wouldn't because it wouldn't be relevant to the article. The only way I can see this topic being relevant is if you believe in "battle of the sexes" theories or think men are systematically victimized by society (we aren't) and want to point out this as an example. I don't know if you believe in either of those things or if you have a different explanation? Linking to DC implies an agenda but based on the principle of charity I will assume you just weren't thinking about the implications when you posted this.
There are several reasons prostate cancer doesn't get the same attention as breast cancer.
1. Fewer high-profile people organizing around it and starting foundations to study it. You may wish the world worked on a slightly more utilitarian scale where we distributed medical research resources fairly according to need and impact. The reality is the squeaky wheel gets the grease.
2. Prostate cancer isn't nearly as squeaky of a wheel:
a) men who get it usually get it later in life compared to women who get breast cancer. Dying at 45 of cancer is a tragedy. Dying at 75 of cancer is a day that ends in Y.
b) most forms of prostate cancer are slower-growing and less metastatic; as a result even men who get it often choose not to get treatment and end up dying of heart failure or other ailments before the prostate cancer has any negative effects. In the US, the 5-year survival rate for prostate cancer diagnosis is 99%.
I'm glad research is being done on prostate cancer and breast cancer at the same time; I don't see any need for an "equal" funding principle. If such rules did exist it would have to be based on # of affected people and life-expectancy. Under such a system prostate cancer would probably rank as over-funded right now.