I don't think it is appropriate, timely or necessary to immediately ask a new member if they are/were a tobacco user.
Instead, if they have a DX of Oropharynx OC, then it would be much more appropriate to ask if they were tested for
HPV and briefly explain that
HPV and Tobacco use are the two known major causes of Oropharynx OC.
Regardless, anyone with Oropharynx OC should really have their biopsy or tumor tested for
HPV and eventually this should become a standard practice.