CYTOGENETICS ADDS INDEPENDENT PROGNOSTIC INFORMATION IN ADULTS WITH ACUTE LYMPHOBLASTIC-LEUKEMIA ON MRC TRIAL UKALL XA

Cytogenetic classification of 350 adults with acute lymphoblastic leuk aemia on MRC UKALL XA trial showed the following statistically signifi cant associations: t(9;22) (11%) increased with increasing age and leu cocyte counts (WBC) and most had a C/pre-B immunophenotype. t(4;11) (3 %) was associated with higher WBCs, increasing age and null immunophen otype. Other abnormalities of 11q (abn11q) (4%) were associated with m ale sex and T-cell ALL. High hyperdiploidy (7%) and abn9p (5%) decreas ed with increasing WBC. High hyperdiploid patients were younger and te nded to have C/pre-B ALL. Triploidy/tetraploidy (3%) decreased and pse udodiploidy (11%) increased with increasing WBC. Cytogenetic classific ation was prognostically important (chi-square for heterogeneity of cl assification = 53 . 56: P < 0 . 0001) and added significance to age, s ex and WBC. A poor prognosis for patients classed as t(9;22) (13% dise ase-free survival at 3 years), as t(4;11) 24% at 3 years) and hypodipl oid (11% at 3 years), and good prognosis for abn12p (4% of subjects) a nd high hyperdiploidy (74% and 59% at 3 years respectively) were stati stically significant, but the 54% 3-year disease-free survival for pat ients with t(1;19) was not, The prognosis of patients classed as t(9;2 2) was independent of other single variables. Abn12p, abnormalities of 11q (including t(4;11) cases) and hypodiploidy added prognostic signi ficance to all other variables combined.