[mikenuman]

In the case of ovarian cancer, as described in the article, it's likely that "early" ovarian cancer is a separate disease from disseminated ovarian cancer.

Assuming that one leads to the other has lead to a large research effort that has failed to help. Screening is ineffective at best, and probably harmful as it:

picks up the earlies that would have been detected and cured in an ad hoc fashion; picks up a host of benign pathology, removal of which leads to iatrogenic harm; fails to pick up aggressive cancer which spreads almost immediately and may even arise in multiple locations at the same time.

The current best methods for prevention are using the contraceptive pill, removing the Fallopian tubes (50% of "ovarian cancers" are probably tubal), and removing the tubes and ovaries of people in high-risk families after childbearing.

Screening does not work.

[elemeno]

Sources to back up the idea that early stage ovarian cancer is separate from late state ovarian cancer?

[bryanlarsen]

The article mentions the hypothesis that the particularly malignant ovarian cancers are actually fallopian cancers that have spread.

[mikenuman]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2928939/