Outcomes in older adults with acute lymphoblastic leukaemia (ALL): results from the international MRC UKALL XII/ECOG2993 trial

Abstract

Although the incidence rate of acute lymphoblastic leukaemia (ALL) is slightly higher in older than in younger adults, response rates to induction chemotherapy and survival rates are poorer. The contribution of disease-related versus treatment-related factors remains unclear. We analysed 100 older patients (aged 55-65 years) treated on the UKALLXII/ECOG2993 trial compared with 1814 younger patients (aged 14-54 years). Baseline characteristics, induction chemotherapy course, infections, drug reductions and survival outcomes were compared. There were more Philadelphia-positive (Ph+) patients in the older group (28% vs. 17%, P = 0·02), and a trend towards higher combined cytogenetic risk score (46% vs. 35%, P = 0·07). The complete remission rate in older patients was worse (73% vs. 93%, P < 0·0001) as was 5-year overall survival (21% vs. 41%, P < 0·0001) and event-free survival (EFS) (19% vs. 37%, P < 0·0001). Older patients had more infections during induction (81% vs. 70%, P = 0·05), and drug reductions (46% vs. 28%, P = 0·0009). Among older patients, Ph+ and cytogenetic risk category as well as infection during induction predicted for worse EFS. Poorer outcomes in these patients are partly due to cytogenetic risk, but there is significant morbidity and mortality during induction chemotherapy with frequent delays and drug reductions. New approaches, including better risk stratification and use of targeted therapies, could improve treatment for these patients.

Conflict of interest statement

Disclosure of Conflicts of Interest

The authors declare no competing financial interests.

© 2012 Blackwell Publishing Ltd.

Figures

Figure 1

Survival of patients by age at entry to study showing (A) overall survival and (B) event free survival in all patients and (C) overall survival in just those who received chemotherapy.

Figure 2

Patient flow diagram showing outcomes following induction in all patients aged 55 years and over. aIncludes 3 without CR status recorded – presumed to be CR. bIncludes 1 alive 4 years post-autograft, then lost to follow-up cIncludes 2 patients lost to follow-up at 2.4 and 8.2 years