Improved prognosis for localized malignant lymphomas of the head and neck.

CONCLUSION: In this study we found localized malignant lymphomas of the head and neck to be highly treatable and to have a significantly improved prognosis with recent treatment methods. The head and neck surgeon should keep in mind that the prognosis, especially for diffuse large B-cell lymphoma, has improved if the patient receives the optimal treatment. OBJECTIVES: The purpose of this study was to ascertain the current prognosis of localized malignant lymphoma of the head and neck given recent advancements in treatment and diagnostic features, as well as adding histological subtypes to the literature according to the 2001 classification. METHODS: We present a retrospective study including a cohort of 100 consecutive patients who had localized malignant lymphoma within the head and neck region diagnosed at a single centre from 2000 to 2007. RESULTS: The histology was revised according to the WHO classification and showed 58% with diffuse large B-cell lymphoma. The estimated 5-year overall survival rate was 83%, which should be seen in contrast to survival rates of 40-70% 25 years ago.

Frequent hypermethylation of DBC1 in malignant lymphoproliferative neoplasms.

Allelic loss at chromosome 9q31-34 is a frequent event in many lymphoproliferative malignancies. Here, we examined DBC1 at 9q33.1 as a potential target in lymphomagenesis. DBC1 is a putative tumor suppressor that has been shown to be involved in the regulation of cell growth and programmed cell death. The methylation status of the DBC1 promoter CpG island was examined by methylation-specific PCR, bisulfite sequencing, and methylation-specific melting curve analysis. DBC1 was hypermethylated in 5 of 5 B-cell-derived lymphoma cell lines, 41 of 42 diffuse large B-cell lymphomas, 24 of 24 follicular lymphomas, 5 of 5 mantle cell lymphomas, 4 of 4 small lymphocytic lymphomas, 1 of 2 lymphoplasmacytoid lymphomas, and in 12 of 12 acute lymphoblastic leukemias, but was unmethylated in 1 case of splenic marginal zone lymphoma, in 12 of 12 multiple myelomas, in 24 of 24 reactive lymph nodes, and in 12 of 12 samples of blood lymphocytes from random donors. DBC1 hypermethylation was associated with transcriptional silencing in lymphoma cell lines, and reexpression of this gene could be induced by treatment with the demethylating agent, 5-aza-2'-deoxycytidine. Our data suggest that hypermethylation of the DBC1 promoter region is a frequent event during the development of lymphoproliferative malignancies, and that DBC1 hypermethylation may serve as a marker for these cancers.