Case : A 50 -year -old female patient, heavy smokers came for treatment at an oral dental hospital with complaints that there was a wound that did not heal on the right edge of the tongue since 6 months ago

Case : A 50 -year -old female patient, heavy smokers came for treatment at an oral dental hospital with complaints that there was a wound that did not heal on the right edge of the tongue since 6 months ago. From the results of the history stating the wound has been treated with antiseptic mouthwash 2x a day, but there is no change. Then the patient also uses herbal mouthwash since 10 days ago but it does not heal. Patients smoke 1 pack of cigarettes per day since 10 years ago. The results of intra-oral examination showed a 3×2 cm diameter ulcer, red, rising edge, and hard on the right edge of the tongue. The ulcer does not hurt unless it is bitten. Teeth 46 caries with sharp and rough teeth surface. Teeth 36, 37 Edentulous. Dirty mouth hygiene accompanied by gingivitis in the upper jaw and lower jaw teeth. On extra oral examination, showing swelling of the lymph nodes of the submandibular area of ​​the right 3 cm in diameter, can be moved, and not sick. Furthermore, the patient is referred to the medical anatomy pathology section for scrapping on the tongue ulcer and fine needle aspiration in the right submandibular lymph nodes. Histopathological diagnosis in the form of squamous cell carcinoma on the tongue and local metastases in the lymph nodes.

Question : Why is the wound on the tongue still does not heal even though a mouthwash has been used ?