I have posted the information below on the General Board and I believe it will apply to you.
Your problem with white patches and lichen planus may be somewhat rare so getting an expert second opinion can be very important (and I know personally that Dana Farber has specific expertise in that area)..
Leading cancer hospitals often offer the ability to get a second opinion by submitting your information electronically.
If you have any question about how your cancer is being treated, get a second opinion from a leading cancer center. You may want to link to a center close to you in the event you decide to go to that facility. Search that center name and "electronic second opinion".
Here's information from Dana Farber Cancer Institute.
https://www.dana-farber.org/appointments-and-second-opinions/online-second-opinion-program/