Treatment of a young, nonsmoking female patient with oral tongue cancer represents a well-recognized clinical challenge.
In this case, the patient presented clinically as T1N0M0. However, after partial glossectomy and elective neck dissection, pathology revealed a pT2N1 lesion that was upstaged based on a depth of invasion of 7 mm .
There is a temptation to consider treatment complete and spare this young patient the long-term morbidity of adjuvant radiation. However, the presence of occult nodal metastasis in T1-2 oral cavity cancer increases the risk of dying of disease. Moreover, for T1-2N0 oral tongue cancer in patients deemed low risk after partial glossectomy and negative neck dissection who were observed, the presence of a depth of invasion of 4 mm or greater predicted a >20% risk of regional failure.
Importantly, approximately 40% of the failures occurred in the contralateral neck. Of the patients who experienced failure, only approximately 1 in 3 could be salvaged. Given this significant rate of contralateral lymphatic drainage of even lateralized tongue cancer, we often recommend sentinel node mapping and excision at the time of surgery.
For this case, we would recommend adjuvant radiation to the bilateral neck and the primary site to include in-transit lymphatics. Treatment of the ipsilateral neck would encompass levels I-IV, prescribed to a dose of 60 Gy to levels I-III, 57 Gy to level IV, and 54 Gy to the retrostyloid nodes. Contralateral neck treatment would include elective treatment to levels IB-III to a dose of 54 Gy with sparing of the retrostyloid area.
With regard to brachytherapy for the treatment of early-stage tongue cancer, our group and others have shown excellent outcomes incorporating adjuvant brachytherapy as a boost or standalone treatment in patients with close/positive margins and/or focal perineural invasion at the primary site.
For this patient, the main risk of failure is regional; therefore, she would not benefit from brachytherapy.
Enrollment in a clinical trial would be ideal. However, this patient would have not been eligible for Radiation Therapy Oncology Group (RTOG) 0920, which required 1 “intermediate” risk factor (perineural invasion, lymphovascular invasion, a single lymph node greater than 3 cm or 2 lymph nodes involved, and/or close margins), nor would she have been eligible for the current neoadjuvant immunotherapy trial enrolling clinically node-positive patients. Future trials are needed to address this unique cohort of patients.
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