Very much a chicken&#x2F;egg problem.<p>&gt;The effectiveness of screening for a given disease before signs and symptoms appear depends on a host of conditions... including whether there’s an effective treatment for whatever is found...<p>There are so very few ways to even think about, treat, or even test for the earliest stages of a disease precisely because we don&#x27;t have data about the early stages.  Getting that data would certainly provide for data upon which to design better early-stage therapies.  The use of measuring PSA (as mentioned) works great in more advanced stages of prostate cancer, and probably doesn&#x27;t work well for early stages - but if we had good and regular testing we could find an indicator for those early stages.<p>So which comes first, the readout, or the therapy?  Of course, it&#x27;s the readout.  Just because we don&#x27;t have those new early-stage-targeting therapies yet doesn&#x27;t mean a new array of (<i>accurate</i> and <i>reliable</i>) testing wouldn&#x27;t be extraordinarily helpful.