Prognostic value of size of lymph node metastases in patients with cutaneous melanoma

To determine the prognostic significance of the size of the lymph node mass as measured by physical examination (PE) and of the size of the largest node measured by pathologic analysis (path) in patients with cutaneous melanoma and nodal metastases.

The medical records of all patients with nodal metastases seen at The University of Texas M.D. Anderson Cancer Center from January 1, 1973 to December 31, 1989 were reviewed. Patient eligibility criteria included the following: (1) availability of data describing the nodal size either by PE or by path and the number of positive nodes; (2) no history of preoperative chemotherapy or radiotherapy; and (3) no history or presence of in-transit, satellite, local, or distant metastases. Eleven variables, including largest diameter of the nodal mass by PE and diameter of the largest node by path, were examined as potential prognostic factors for disease-free survival (DFS) and overall survival (OS).

Of 800 patients evaluated, 442 met the eligibility criteria and are the subjects of this study. In the univariate analysis, size of the nodal mass by PE was marginally significant for survival as a continuous variable (P = .045), but not as a categorical variable using a cutoff size of < or = 3 or more than 3 cm as indicated by the American Joint Committee on Cancer (AJCC) staging system (P = .61). Size of the largest node by path was not significant for survival. In the multivariate analysis, only the number of positive nodes (P < .001), age (P < .001), and tumor thickness (P < .001) were significant for survival.

Size of the nodal mass by PE and size of the largest node by path are not useful prognostic factors for survival and should be eliminated from the current staging system. More powerful and well-established prognostic factors, such as the number of positive nodes, should be considered for inclusion in staging.