Can they do to stop it from spreading to give mets from oral cancer in smokers?

Early treatment. Early treatment of any cancer may prevent metastases.
Treat it. The best way to prevent a cancer from spreading is to treat it. In the case of oral cancer that would be a combination of chemotherapy, surgery and radiation.
Surgery, radiation. In localized disease, surgery and radiation are done for cure. Locally advanced disease is the most common presentation. Surgery and radiation are also done with this but radiation and chemotherapy with Cisplatin and 5-fluorouracil is equally effective.