Scientific method (basically me just paraphrasing Imre Lakatos):
1) Explore and describe aspects of the world in detail, figure out what situations naturally arise or that can be devised that produce consistent, stable phenomenon.
2) Abduce (guess) an explanation for these consistent, stable phenomenon.
3) Explore the logical consequences of assuming your guess is correct. Figure out a few otherwise surprising (ie, inconsistent with other explanations people may have) predictions that can be deduced from it.
4) Collect data and compare it to the predictions generated in #3
5) Discard the guess or modify it to make it more consistent with the data produced in #4
6a) If the guess is modified, Go to 3.
6b) If the guess is discarded, Go to 2.
A lot of cancer research seems to be failing at step 1, ie they can't even get into the "testing otherwise surprising predictions" loop since there is no consistent, stable phenomenon to trust.