a study that is funded by NCI, focused on cancer, long term, a prospective cohort, and ongoingYou can say:
a long-term, ongoing, NCI-funded, cancer-focused prospective cohort study
(And we could keep going all day with the stacking -- if we wanted too, although as your editor, I would advise against it!)
Typically, as part of this process, you lose the final "-s" on plural nouns. For example, if you were discussing the "quality controls" implemented in your lab:
*quality controls proceduresCorrect:
quality control procedures
Where this process gets sticky is when you have a collective noun that looks like a plural (and ends in "-s") but that is grammatically singular. Especially sticky, in my experience, are such nouns created from adjectives. Recent examples of these that have made their way across my editing desk include "bioinformatics", "proteomics", and -- more recently -- "metabolomics".
These are nifty, exciting-sounding nouns. I like them! However, they make for rather awkward noun stacking:
I never quite know. It's awkward and weird-sounding to my ear, because as an adjective-derived noun, "metabolomics" and its cousins retain their adjectivalness just enough that I want to change the example above to "metabolomic assay". But that doesn't have quite the same meaning, so I end up leaving it alone. And wincing ever so slightly every time I re-read it.
Ah, the life of an editor! Forever twitching over minutiae...