[Treatment of bilateral neck metastases in laryngeal cancer]

Laryngeal cancer is one of the most curable malignancies. One of the reasons is that most of them are in the early stage. However, the prognosis of advanced bilateral neck metastases is still poor. Based on loco-regional failure and cause of death, the effective procedure of neck dissection and the efficacy of postoperative irradiation were investigated retrospectively. A total of 1022 patients with laryngeal squamous cell carcinoma were registered in our hospital between 1979 and 1991, 58 of them (5.7%) had bilateral neck metastases. Clinical N2c cases accounted for 52% (32/58). In the other patients, the metastatic nodes were revealed by elective neck dissection for a clinically negative neck. The T stages of the 58 cases were as follows; T2 in 14 cases, T3 in 22 and T4 in 22. Forty-nine of the patients treated curatively by bilateral neck dissection were analyzed, 48 with total laryngectomy and 1 with partial laryngectomy. The remaining 9 patients were excluded because of radical irradiation in 3, distant metastases found the diagnosis in 3, unresectable recurrent neck metastases treated in other hospitals in 2 and no treatment because of severe myocardial infarction in 1. Cumulative crude and cause-specific 5-year survival rates for the 49 patients were 32.2% and 52.2%, respectively. Nineteen patients died of their disease; 10 of them of an uncontrolled neck lesion. From a comparison of the surgery alone group (28 cases) with a surgery plus irradiation group (21 cases) which consisted of preoperative irradiation in 2 and postoperative in 19, addition of irradiation may be effective for loco-regional control. Eight patients died of an uncontrolled neck lesion in the surgery alone group, while there were only 2 deaths in the postoperative irradiation group. Nevertheless there were no significant differences in survival: the cumulative crude and cause-specific 5-year survival rates in the surgery alone group were 34.4% and 56.2%, respectively, while those in the surgery plus irradiation group were 28.6% and 46.3%, respectively. It is obvious that the procedure of neck dissection influenced the loco-regional control. Excluding the recurrence-free patients who died of intercurrent diseases within 2 years, recurrence in the ipsilateral neck was found in 1 of 12 patients with radical neck dissection (RND), in 1 of 3 with modified radical neck dissection (MRND), in 2 of 15 with lateral neck dissection (lateral ND) and in 9 of 11 with regional neck dissection (regional ND). Recurrence is the contralateral neck were found in none of 2 with RND, of 3 with MRND and of 20 with lateral ND, but in 6 of 16 with regional ND. These results suggest that regional ND was insufficient to accomplish loco-regional control in those patients and that lateral ND or MRND or RND may be required bilaterally. Since 1986, all patients except 1 were treated by more extensive maneuvers than lateral ND bilaterally, so that loco-regional recurrence was found in only 1 case, in spite of the fact that the surgery alone group accounted for 73% (19/26). Cumulative crude and cause-specific 5-year survival rates for the patients prior to 1985 (23 cases) were 26.1% and 32.6%, respectively, while those for the patients since 1986 (26 cases) were 38.5% and 76.9%, respectively. There was no significant difference (p = 0.73) in cumulative crude 5-year survival rates between the 2 groups, but the difference in their cause-specific 5-year survival rates was statistically highly significant (p = 0.0032). It was concluded that lateral ND, MRND or RND should be required bilaterally for the patients with bilateral neck metastases and that addition of irradiation is not always indispensable for patients treated by curative neck dissection, such as lateral ND, MRND or RND.