P53, N- and K-Ras, and beta-catenin gene mutations and prognostic factors in nasal NK/T-cell lymphoma from Hokkaido, Japan

Comparative genomic hybridization analysis of cutaneous large B-cell lymphomas

The aim of the present study was to identify genetic aberrations in a series of patients with cutaneous large B-cell lymphoma (LBCL) using comparative genomic hybridization (CGH). Eighteen consecutive patients with primary (13 patients) (PCLBCL) and secondary (five patients) (SCLBCL) cutaneous large B-cell lymphoma were included in the study. Nine cases corresponded to PCLBCL leg type and four cases primary cutaneous follicle centre-cell lymphoma (PCFCL). Chromosomal imbalances (CIs) were detected in 14 of 18 samples (77.8%). All of nine cases with PCLBCL leg type and two of four cases with PCFCL showed CIs (100% and 50%, respectively). Regarding SCLBCL, in three of five cases (60%), CIs were detected. The most frequently detected gains involved 2q, 5q, 3 and 7q and amplifications affected 18, 12 and 13. Frequent losses were found in 17p. In PCLBCL leg type, the most frequent gains involved 2q and 7q, amplifications were localized in chromosomes 12, 13 and 18 and losses affected chromosomes 17p and 19. In PCFCL, gains located in 3q, 4 and 7q were found. Our study seems to confirm clear-cut differences between primary cutaneous LBCL and nodal diffuse LBCL, and it suggests the presence of genotypic differences between cases of PCLBCL leg type and cases of PCFCL.

TP53 gene mutation, an unfavorable prognostic factor for malignant lymphomas in autoimmune diseases

OBJECTIVES

To investigate whether mutations of the TP53 tumor suppressor gene are associated with a poor prognosis in lymphoproliferative disorders (LPD) developing in patients with a history of autoimmune disease (AID).

METHODS

Fifty patients, 15 males and 35 females ranging in age from 23 to 83 (median, 61) years, were examined. Rheumatoid arthritis (21 cases) is the commonest type of AID followed by systemic lupus erythematosus (10), dermatomyositis (9), progressive systemic sclerosis (4), and autoimmune hemolytic anemia (6). The interval between the diagnosis of AID and LPD ranged from 1 to 660 months (mean 42 months). Histological, immunohistological, and in situ hybridization studies revealed that 37 tumors were B cell lymphomas and 13 were T cell lymphomas with the Epstein-Barr virus genome present in the tumor cells in 24% of cases. Stage of disease was I in 15 cases, II in 5, III in 9, and IV in 21.

RESULTS

Polymerase chain reaction-single strand conformation polymorphism followed by direct sequencing revealed TP53 mutations in 45.9% of B cell and 53.8% of T cell lymphomas. The follow-up study revealed an unfavorable prognosis in cases with mutations compared with those without: the 1-year survival rate was 43.5 and 73.0% in B cell and 16.7 and 50% in T cell lymphoma, respectively.

CONCLUSIONS

The occurrence of a TP53 mutation is an unfavorable prognostic factor not only in B cell but also in T cell LPD in AID.