Have had reflux for 3-4 years, and have controlled diet and lifestyle for past year. had laryngoscopy about 7 months ago (which was negative). is scope accurate? and how likely is it that i have developed cancerous lesions in the throat since then?

Must go deeper.: The area of the esophagus that would potentially house precancerous areas would not be visualized via laryngoscopy. You need to have an EGD with a GI doctor every two to three years to search for this "Barrett's esophagus".

Throat cancer: You're pretty young to be developing throat cancer. The scope is pretty accurate because of direct visualization of a lesion and allowance for biopsy. The surgeon doing your scope is very knowledgeable regarding how a cancerous lesion in your throat. Feel free to talk to him about it and your concerns.