Treatment Outcomes and Patterns of Disease Recurrence of Patients with Carcinoma of the Buccal Mucosa.

Locally advanced buccal mucosa cancer is typically treated with surgery and adjuvant postoperative radiation therapy, which includes concurrent Cisplatin 100 mg/m2 on Day 1, plus 5-Fluorouracil 1000 mg/m2 from Day 1 to 4 every three weeks. Ipsilateral face radiotherapy is a de-escalated treatment that spares the opposite side of the face, enhancing post-treatment chewing function. The availability of electron beam radiotherapy for treating recurrences on the opposite side has increased the use of ipsilateral face radiotherapy. This retrospective study aimed to assess treatment outcomes and patterns of disease recurrence in patients with carcinoma of the buccal mucosa treated with different schedules. We retrospectively reviewed records of 54 patients with a pathological diagnosis of buccal mucosa cancers treated between 2018 and 2023. We extracted patients' demographic, disease, and treatment criteria. Indications for postoperative radiotherapy included a close margin of less than 3 mm and lymph node positivity. The primary tumor (face) and neck were considered separately for radiotherapy treatment. One patient who refused surgery, radiotherapy, and chemotherapy but regularly came for follow-up after receiving Ayurvedic treatment died of the disease after 2 years and 1 month. Fifty-three patients received concurrent chemoradiotherapy with Cisplatin 100 mg/m2 on Day 1, plus 5-Fluorouracil 1000 mg/m2 from Day 1 to 4 every three weeks for three cycles. Postoperative patients were treated with radiotherapy fields covering the face (bilateral or ipsilateral wedged fields) and the whole neck field with central shielding for the initial 44 Gy in 22 fractions over 4.5 weeks followed by a boost dose of 16 Gy to the primary tumor and involved neck. For radical radiotherapy, patients received a similar radiation field but the boost dose delivered was 26 Gy in 13 fractions over 2.5 weeks. For ipsilateral radiotherapy fields, the average face anterior field size was 6 W x 8 cm; the thick edge of the wedge laterally; depth 4 cm and lateral 8 W x 8 cm radiation field with a thick edge of the wedge anteriorly; depth 3 cm. The median dose to high-risk clinical target volume was 60 Gy/30 fractions in postoperative cases. Forty-eight patients received radical radiotherapy with a higher dose (66 Gy/33 fractions to 70 Gy/35 fractions); twenty-eight patients received radiotherapy fields of bilateral face and neck with a central spinal shield of 2 cm. Statistical analysis was conducted at the Community Medicine Department using SPSS software version 21.0. The Chi-square test and Fisher Exact test were applied to compare various groups. Fifty-four patients were analyzed. The median follow-up was 9 months. Surgery consisted of Composite Resection (Commando operation) plus Radical Neck dissection in three (5.5%) patients and non-composite resection surgeries (Wide excision of the lesion plus supra-omohyoid dissection) in nine (16.6%) cases, of which six (50%) cases had lymph node involvement but no patient with positive dissection had extracapsular extension. Tumor thickness by histopathology was found to be between 5 and 15 mm. Sixteen (28.1%) patients failed locally and 11 (20.3%) had lymph node recurrences. One patient (1.8%) with mucoepidermoid cancer had bony metastases at D9, L1, and the pelvis after 4 months of treatment. Death occurred in 12 (20.3%; one due to a non-oncologic cause) out of 54 patients during our study. The majority (88%) of patients in our study are male, aged less than 50 (55%). A KPS of 70/>70 was present in 83.3% of patients. The majority of patients in this study are T3 (37%) and T4a (29.6%). Nodal status of patients included 29.6% N0; 27.7% N1, and 35.1% N2. The majority of patients (57.4%) have well-differentiated carcinoma followed by moderately differentiated carcinoma in 38.8% of patients. The difference in death is non-significant when ipsilateral face + neck radiotherapy is compared to bilateral face + neck radiotherapy by Fisher Exact test (statistical value = 0.1246;  > 0.05, statistically not significant), and in other groups, it could not be compared due to the small number of patients. Our results show the non-inferiority of non-composite resection surgery + bilateral face + neck radiotherapy to non-operative radical radiotherapy (bilateral or ipsilateral face wedged radiotherapy + neck radiotherapy), so the majority of patients can be treated by these modalities of treatment. De-escalation of radiotherapy by the use of ipsilateral face wedged + neck radiotherapy is possible as there is no statistically significant difference in local and nodal relapse when compared to bilateral face + neck radiotherapy, and it results in sparing of the opposite side of the face. Buccal mucosa carcinoma in eastern Uttar Pradesh is a very aggressive disease, with 12 (20.3%; one due to a non-oncologic cause) out of 54 patients dying. Our results are different compared to historical data, possibly due to the use of concurrent Cisplatin + 5-Fluorouracil chemotherapy and the lower number of patients in the composite resection group as the majority of patients were frail and did not consent to composite resection.