Cancer and heart dis. For women 40-44, the leading causes of death are cancer, unintentional injuries, heart disease, suicide, and stroke. For women 45-49, they are: cancer, heart disease, unintentional injuries, and stroke. It's interesting to think of how many of these premature deaths could be prevented - about half. A good resource on how to prevent disease by age is an iphone app called my health checklist 2012.