Multiple tumour recurrence in oral, head and neck cancer: Characterising the patient journey.

Background: Oral squamous cell carcinoma (OSCC) is the 15th most common cause of cancer-related mortality worldwide and approximately one oral cancer-related death occurs for every two new diagnoses. Death-due-to-disease is usually ascribed to inoperable primary tumours, treatment complications, second primary tumours arising due to field cancerization, or locoregional recurrence and distant metastases.

Methods: A retrospective review of OSCC patients treated over a 19-year period, betweenOctober 1 , 2000 and October 1 , 2019. Patient demographic records were collected from consecutively treated adult patients with clinical subtypes corresponding to ICD-10 C00-C06, C09 and C10 were retrieved from the database. Patients who had suffered three or more recurrences after diagnosis of the primary tumour are defined as multiple-recurrent patients.

Results: A total of 467 OSCC patients were treated during the study period. One hundred and fifty-five patients developed recurrent OSCC, amongst which 22 were designated as multiple cases. The time between initial OSCC diagnosis and first tumour recurrence varied from 3 to 276 months. Nine of the 22 multiple patients (41%) were diagnosed with buccal mucosal SCC as the primary tumour, which is significantly higher than the average prevalence (or 4.4, 95% CI (1.8, 10.8), p < 0.001) for buccal tumours within the cohort. All patients were treated initially by surgical tumour excision. There were no demonstrable differences in adjuvant chemo-radiotherapy regimes in any of the study groups.

Conclusion: Multiple OSCC development may occur either synchronously or metachronously during the course of oral cancer disease and poses an important management problem in contemporary oncology practice.