A counterpoint to these stories of early diagnosis is that not all cancers are equal, and there are some cancers which may not ever have affected the patient had they not been treated (or detected). Examples include some prostate and breast cancers. Autopsy studies have shown occult prostate cancer in about half of men > 70 years old who were asymptomatic and died of other causes.

Of course it is often impossible to know which cancer will or won't kill you, but it should be recognized that there is a risk to scanning oneself without a proper indication, for example, getting a prostatectomy for indolent prostate cancer and risking impotence.