No Relationship Between Head And Neck Cancer Tumor Site And Location Of Swallowing Dysfunction

Posted on September 25th, 2006 by chriscolhoun.

Over the past twenty years there has been a significant shift from surgery towards chemoradiation therapy as primary treatment for certain head and neck cancers. While primary chemoradiation allows many patients to avoid surgery and its concurring postoperative complications, it may be associated with significant post-treatment dysphagia, or difficulty in swallowing,  which can be debilitating and potentially lethal. During treatment, radiation is typically given over a wide field which encompasses both the primary tumor and its associated lymphatic drainage. As a consequence, structures vital to swallowing are subjected to high doses of radiation which may result in complications such as silent aspiration and feeding tube dependence. The addition of chemotherapy to radiation provides a synergistic effect which has been shown to further improve locoregional control. While chemotherapeutic agents act as radiosensitizers and thereby increasing tumor control rates, they also result in increased acute toxicity as well as late complications secondary to collateral injury to surrounding healthy tissue. A team of scientists from Philadelphia, PA have conducted a study to identify which stages of swallow function are differentially affected by chemoradiation treatment for head and neck cancer, to describe the incidence of long term complications including clinical pneumonia and prolonged feeding tube dependence, and to correlate the clinical variables to the modified barium swallow findings. The authors of the study, “Post Chemoradiation Dysphagia” are Benjamin S. Bleier MD, Marc S. Levine MD, Rosemarie Mick PhD, Stephen E. Rubesin MD, Stephen Z. Sack MD, PhD, Kibwei McKinney BA, and Natasha Mirza, MD. They are presenting their findings at the 110th Annual Meeting & OTO EXPO of the American Academy of Otolaryngology-Head and Neck Surgery Foundation, being held September 17-20, 2006, at the Metro Toronto Convention Centre, Toronto, Canada.

Methodology:

A retrospective review of 30 patients treated at an academic, tertiary care referral medical center between 1996 and 2005 was conducted. All patients completed a modified barium swallow study after presenting with dysphagia following primary radiation therapy with or without concomitant chemotherapy for Stage I-IV squamous cell carcinoma of the oral cavity, oropharynx, nasopharynx, and larynx. Patients were excluded from the study if they had any prior history of radiotherapy, primary tumor resection except neck dissection, or any other head and neck lesions. None of the patients had documented dysphagia prior to radiotherapy.

Results:

Pharyngoesophagrams were analyzed for 21 separate criteria by one of three attending gastrointestinal radiologists and experienced speech-language pathologists. The most common abnormalities included laryngeal penetration, impaired epiglottic tilt, and abnormal pharyngeal contraction. The least common abnormalities included impaired cricopharyngeal opening, and soft palatal atrophy. A Fisher’s exact test was used to correlate several clinical variables to modified barium swallow findings. No significant relationship was found between pharyngoesophagram abnormalities and a history of neck dissection, tumor stage, or patient age. Duration from radiotherapy to modified barium swallow also had no significant impact on swallow findings.

Conclusions:

The research team found no significant relationship between primary tumor site and location of swallow dysfunction. The researchers did note that while patients with oral and oropharyngeal lesions demonstrated abnormalities throughout the swallowing cascade, all patients with laryngeal lesions had normal function in the oral phase of swallow. The study also demonstrated abnormal epiglottic inversion and laryngeal penetration to be the most common problems in post radiation patients who had treatment for oropharyngeal and pharyngeal malignancies. The next most frequent problem identified in the study was abnormal pharyngeal contraction. Functional disturbances in this area manifest as abnormalities in clearance of swallowed boluses from the pharynx. Weakness or incoordination in this pharyngeal contraction sequence results in portions of the bolus remaining in the pharynx at the end of the swallow. Both the oropharyngeal and laryngeal group suffered from this pharyngeal muscle hypomobility. While the relatively normal oral swallowing apparatus in patients with laryngeal lesions may relate to the use of parotid and oral cavity sparing radiotherapy techniques, further studies with larger patient populations are needed to truly understand the significance of these findings. The study also suggests that close follow up of these patients with a modified barium swallow early in the post treatment period may help identify sites of swallowing impairment. This may in turn help reduce subsequent morbidity form pneumonias and long term feeding tube dependence. American Academy of Otolaryngology Head and Neck Surgery (AAOHNS) One Prince St. Alexandria, VA 22314 United States American Academy of Otolaryngology Head and Neck Surgery