Pathogenesis of Metastatic Recurrences on the Operative Field after Radical Neck Dissection for Oropharyngeal Cancer

Abstract

In 1080 patients operated on at the National Cancer Institute of Milan from 1937 to 1964, 84 recurrences appeared on the operative field after radical neck dissection for oropharyngeal cancer. There was no evidence of the primary tumor almost 2 years after treatment. 78 recurrences concerned 930 determined cases (8.9%): 7 appeared among 407 dissections in which no microscopic involvement of lymph nodes was demonstrated (1.72%); 77 among 673 operations for histologically positive nodes. Most recurrences (75/84) were localized in the upper regions of the operative field (upper carotid, retromandibular, submastoid area). In all but 3 cases they occurred in the region nearest to the primary. Clinically, recurrences appeared as isolated or multiple tumor nodes adherent to the skin or to deep structures or both; only in 7 cases they were movable, and among these 5 were external to the operative field. Histological examination of the node was performed in 35 cases; residual lymph node tissue was found only in the movable ones. In nearly all cases isolated « foci» were found, and these findings suggest a sowing of cancer cells. Pathogenesis of recurrences is discussed, and the conclusions are that: — In 50% of cases cancer cells spread out actively from the walls of the lymph node by an invasive mechanism; — In 40% of cases sowing was due to the surgical section of lymph vessels or, rarely, of the lymph node capsule; — In 2.7% of cases the recurrence was localized in lymph nodes not removed at surgery; — In 4.7% of cases the typical dissection was not sufficiently extensive, and recurrences can appear outside the operative field, often in the parotid gland, very seldom in the spinal chain. Since the therapy of cervical recurrences is very deceptive prognosis can be improved only by preventing them, and this can be attained by earlier operations (prophylactic dissections) and surgical refinements in technique and tactics.