A 52-year-old woman with a 20-year history of reverse smoking (smoking from the burning end inside the mouth) presents with a 4-month history of a painless, white patch on the hard palate. On examination, there is a 1.5 cm × 1 cm white, slightly raised lesion with a central red area (erythroplakia within leukoplakia) on the hard palate. The lesion is non-tender. Oral hygiene is poor. She denies any systemic symptoms. Biopsy shows dysplasia with foci of invasive squamous cell carcinoma. What is the most appropriate next step in management?