Relationship between lymph nodal status and primary tumor control probability in tumors of the supraglottic larynx.

A retrospective review of 248 patients with squamous cell carcinoma of the supraglottic larynx was undertaken to determine the relationship between the probability of control of the primary lesion, the extent of neck nodal disease at initial presentation, and its ultimate control. All patients were treated at the U.T. M. D. Anderson Hospital between 1960 and 1980, and had a minimum of 3 years follow-up. The primary lesion was staged T1 in 38 patients, T2 in 132, T3 in 50 and T4 in 28. The initial volume of neck nodal disease was scored on a scale of 0 (no palpable nodes) to 9 (bilateral neck nodes greater than 6 cm in diameter). All primary lesions were treated definitively with megavoltage radiation therapy. Treatment to the neck varied according to the extent of lymph node involvement. There was no significant difference in the range of total radiation doses delivered to the primary lesion, stage for stage, in patients who presented with clinically negative or positive nodes, or in those with controlled versus uncontrolled neck disease. Analysis of the probability of primary tumor control was made by life table methods because of the poorer survival expectation in node positive patients. For T1 and T2 primary lesions, any positive node decreased the probability of primary tumor control (p = 0.06). For T3 and T4 lesions, a single node less than 3 cm in diameter did not worsen the chance of primary tumor control, but any greater degree of lymph node involvement did (p = 0.03). For both T stage groupings, the probability of primary tumor control at 5 years decreased progressively with increasing neck nodal disease. Primary tumor control probability was also significantly associated with control of the neck disease, independent of the modality of neck treatment. No correlation could be demonstrated between the histological grade of the primary tumor and initial lymph node status or tumor control probability. Possible interpretations of this manifestation of biological heterogeneity are discussed.