What is the Incidence of Oral Cancer Recurrence in Patients Reconstructed With a Microvascular Free Flap, Endosseous Implants, and an Oral Prosthesis and How Does the Timing of Implant Placement Influence Recurrence?

PURPOSE: In patients with malignant oral disease, there is concern that immediate implant placement at the time of ablative and microvascular free flap surgery can contribute to tumor recurrence or delay the diagnosis of recurrence. The purpose of this study is to 1) estimate the incidence of recurrence in patients with malignant disease treated with immediate microvascular free flap reconstruction, endosseous implants, and an oral prosthesis, 2) measure and compare the timing of implant placement, immediate versus delayed, and the time to complete oral rehabilitation, and 3) measure the association between the timing of implant placement and tumor recurrence. MATERIALS AND METHODS: This is a retrospective cohort study utilizing medical record analysis involving patients with malignant oral cancer undergoing tumor resection and immediate microvascular reconstruction from 1996 to 2019 at the Mayo Clinic, Rochester, MN by the Division of Oral and Maxillofacial Surgery. Additional inclusion criteria comprised of immediate or delayed endosseous implant placement, the fabrication of an oral prosthesis, and a minimum of 2-year follow-up. Data on patient demographics, tumor characteristics, timing of implant placement and prosthesis loading, type of prosthesis, tumor recurrence, or second primary tumor events were analyzed. RESULTS: Thirty-three patients with a mean follow-up of 6.4 years were included. Twenty-four patients (72.7%) were diagnosed with squamous cell carcinoma with 3 patients experiencing tumor recurrence. Fifteen patients had immediate implant placement while 18 patients had delayed implant placement. The mean number of days to prosthetic loading of the implants was 680.4 days and 330.1 days for the delayed implant group and immediate implant group, respectively, which was statistically significant (P = .004). The timing of implant placement and the event of a recurrence were not statistically significant (P = .075). CONCLUSION: The incidence of recurrence in patients with malignant oral cancer treated with microvascular reconstruction, endosseous implants, and an oral prosthesis was 12.5% with one recurrence occurring beneath the oral prosthesis. Delayed implant placement resulted in a statistically significant delay in the completion of oral rehabilitation compared to immediate implant placement. There was no difference in the incidence of recurrence in the immediate implant group compared to the delayed implant group.