PP142: Recurrent oral squamous cell carcinoma after resection and mandibular implant rehabilitation: A preliminary report of eight patients

Abstract

Introduction Restoration of function by dental implants following complete tumor removal has high priority in tumor surgery. Recurrent squamous cell carcinoma (SCC) after this procedure led us to search for possible causes. Method 16 patients with primary oral SCC had undergone resection, postop. radiotherapy, various reconstructive procedures and functional rehabilitation by endosseous mandibular implants. In eight patients a recurrence was observed. The charts of these patients were examined for possible causal factors. Results The primary SCC had always been located in the floor of the mouth and/or the mandibular alveolar process, and had been removed with sound margins. The time interval between primary resection and the placement of implants was 18–118 months (mean 43 mos). The recurrent SCC occurred in a similar area 1–69 months (mean 34 mos) after implantation. This area was again resected in seven patients 23–95 months after the first resection (mean 65 mos). Three patients died within 2–17 months (mean 7 mos) due to tumor progression. One patient died after 4 months because of pulmonary embolism. The follow-up period of the other four patients (three tumor-free, one alive with disease) was 6–38 months (mean 26 mos). Conclusion In our opinion the following factors may play a role: Close resection margins with remaining epithelial dysplasia, field cancerization, chronic inflammation due to poor oral hygiene, passive smoking, loss of sensitivity in the mandible after continuity resection, clinical misinterpretation of SCC as “granulation tissue”, HPV infection etc. The low number of patients does not allow unequivocal conclusions. We recommend a small mucosal biopsy at the time of implant placement. Symptoms of periimplantitis in former tumor patients should be considered as a serious sign. Short-term controls are mandatory as patients may not suffer from discomfort due to the loss of sensitivity.