1. Your Leukoplakia
(white patches on tongue) are most probably related to smokeless tobacco
use over the last two decades.
2. Leukoplakia is considered benign but a potential precancerous lesion
with a risk of turning cancerous in 5 to 15% persons.
3. Stopping the irritative factor, such as smokeless tobacco in your case, lowers the risk. Usually, the Leukoplakia stabilizes or reduces after the original irritation that caused it has been stopped.There are some other causes besides tobacco which can lead to other types of Leukoplakia.
4. There is no substitute for direct examination and biopsy.
5. There is no harm in waiting for three months with true Leukoplakia, however if the lesion turns cancerous, it will spread fast as the tongue is a very vascular organ
rich in lymphatics which drain to both sides of the body.
6. One option for you is a brush biopsy with Oral CDX which you can easily arrange for.