Early Lymphocyte Recovery and Outcome in Osteosarcoma
Early lymphocyte recovery following chemotherapy has been associated with improved outcome in many cancers, including in one small study of osteosarcoma patients.Materials and Methods:
To confirm this finding, we retrospectively reviewed data from 53 patients with newly diagnosed osteosarcoma who had blood counts on day 14 (±1 d) following the first cycle of cisplatin and doxorubicin.Results:
The median absolute lymphocyte count (ALC) 14 days after starting the first cycle of chemotherapy (ALC-14) was 1990 cells/μL (range: 600 to 6470). For 32 patients with an ALC-14≥1800 cells/μL, the 5-year progression-free survival (PFS) was 69%, compared with 33% for patients with an ALC-14 of <1800 cell/μL (P=0.036). In multivariable analysis of factors including age, sex, metastatic disease, and favorable histologic response to induction chemotherapy, ALC-14 was significantly associated with PFS (P=0.0081) and overall survival (P=0.0131). The use of ALC-14 appears to further stratify PFS and overall survival among patients when grouped by histologic response.Conclusions:
We confirmed that early lymphocyte recovery was associated with outcome in pediatric osteosarcoma. Although presumably reflecting immune-mediated tumor control, the precise mechanism for this is unclear. Further study of peripheral blood lymphocyte subpopulations in prospectively treated patients is underway.