Metastasis to a percutaneous gastrostomy site from head and neck cancer: Radiobiologic considerations

Background. The use of percutaneously placed feeding tubes has increased in recent years in an effort to maintain adequate caloric balance in patients receiving combined therapy for head and neck cancers, particularly concurr ent radiotherapy and chemotherapy. Methods. We report a case of a metastasis to a percutaneous endoscopic gast rostomy site occurring in a patient with an advanced tonsillar squamous cel l carcinoma and review the published literature regarding this subject. Rad iobiologic principles were examined to explain the most likely cause of suc h metastases. Results. Six cases of percutaneous endoscopic site metastases occurring in patients with head and neck primary tumors have been reported in the litera ture. The interval from performance of the procedure to development of the metastases ranged from 3 to 16 months. Tumor kinetics suggest that a signif icant tumor burden (10(5)-10(6) cells) would need to be present at the site to manifest a metastatic lesion in such a short time interval. Conclusions. The development of metastases at percutaneous endoscopic gastr ostomy sites is a relatively uncommon occurrence. Direct tumor implantation by means of instrumentation at the time of the procedure is most likely ex planation for such metastases, although hematogenous seeding cannot be comp letely discounted. Techniques should be used so as not to disrupt the tumor bed. particularly when gross residual disease is present. (C) 2000 John Wi ley & Sons, Inc.