Clinicopathological Analysis of Systemic Anaplastic Large Cell Lymphoma

ABSTRACT

BACKGROUND: Several studies from western countries have reported variable prognoses for patients with systemic anaplastic large cell lymphoma (ALCL) depending strongly on the expression of anaplastic lymphoma kinase (ALK). However, no prognostic significance of ALK expression in Koreans was reported in a single report regarding these patients, although the number of cases was limited in that study. METHODS: We analyzed the clinicopathological features of ALK+ ALCL and ALK- ALCL in 30 Korean patients diagnosed with primary systemic ALCL. RESULTS: ALK expression was detected in 60% of all ALCL patients (18/30), and there was no statistical significance to ALK expression in overall survival. Patients with ALK+ ALCL were younger in age and had negative bcl-2 expression; these differences were statistically significant. Tumors positive for ALK protein and granzyme B expression, and negative for bcl-2 expression with a null-cell phenotype tended to have better survival outcomes, althought this trend failed to reach statistical significance (p<0.2), probably due to the limited number of cases in this study. CONCLUSION: ALK protein expression and the absence of bcl-2 in tumor cells tend to result in better survival despite the failure of this trend to achieve statistical significance. Further studies that examine potential pathologic prognostic factors combined with the expression of ALK and apoptotic factors such as bcl-2 are needed. Additional larger-scale studies are also needed to conclude that ALK expression has no prognostic significance among Koreans.