[Absolute lymphocyte count as a prognostic factor in children with acute lymphoblastic leukemia]

Recent studies have suggested that the absolute lymphocyte count (ALC) may be a prognostic indicator in malignant diseases, in that those patients who have higher ALC at certain times during treatment may have a better chance of survival. The influence of T cells and natural killer cells in the immune system of the patient with cancer as a response to cancer cells is particularly noted.

We prospectively assessed the prognostic value of absolute lymphocytic count (ALC) in 105 pediatric patients with acute lymphoblastic leukemia (ALL), treated in the Cuban Immunology and Hematology Institute from 1995 to 2008. ALC was studied at days 15 (ALC-15) and 28 (ALC-28) of treatment.

In our patients, 1000 cells/uL was the median ALC value for patients who relapsed or died. Using 1000/uL we found that ALL patients with an ALC-15 <1000 cells/μl had a 5-year relapse free survival (RFS) of 51%. In contrast, an ALC-15 >1000 cells/uL showed an excellent prognosis, with a 5-year RFS of 83% (p=0.02). Similarly in our study, an ALC-28 <1000 cells/μl predicted a 5-year overall survival (OS) of 66%, whereas an ALC-28 >1000 cells/μl predicted excellent outcome, with a 5-year OS of 86% (p=0.01). Importantly, ALC is also a strong predictor in multivariate analysis with known prognostic factors. ALC is a simple, statistically powerful measurement for patients with de novo ALL.

The results, when combined with previous studies, demonstrate that ALC is a powerful new prognostic factor for a range of malignancies.