Significant predictors of treatment outcome are poorly defined for patients with T-lineage acute lymphoblastic leukemia (T-ALL). A high WBC at diagnosis, which has traditionally been a predictor of poor response in T-ALL, has considerably weakened prognostic significance in the face of modern, more intensive chemotherapy. To test the hypothesis that bone marrow stroma-supported leukemic cell recovery might identify children at high risk for relapse, we measured the ex vivo recovery of T-ALL lymphoblasts from 29 newly diagnosed patients using a stromal cell co-culture assay. In all cases the T-ALL lymphoblasts showed an increase in recovery of T-ALL cells (RTC), ranging from 4 to 343%, in comparison to samples maintained without stroma. Since we were blinded to patient outcome in this case-control study, we then correlated patient outcome with RTC. The RTC for 18 patients in complete continuous remission (CCR) for greater than 4 years was stochastically larger than for the 11 patients who eventually relapsed (P = 0.011, by the two-sided Wilcoxon test). Furthermore, 100% of patients with an RTC of more than 26% had a CCR greater than 4 years while 78% of the patients with an RTC of less than 25% relapsed within 4 years. This is the first report to show that higher lymphoblast recovery may predict a more favorable outcome for children with T-ALL. A prospective study is needed to test whether stroma-supported leukemic cell recovery might serve as a basis for assigning risk-adjusted therapy.
What is the meaning of recovery here? It puzzles me as a non-native speaker of English. Do the authors simply mean "the number of cells that survive"? Or is there some "recovery process" - if yes, what is the nature of this process?
P.S. The question arose from a question asked by a fellow translator. She translates a text in which T cells transduced with gene for a receptor against leukemic cells are co-cultured with such cells, after which
"T cells transduced with the receptor markedly reduced leukemic cell recovery".
The translator has trouble understanding how to put it in Russian, because translating "recovery" verbatim would imply some process in which a cell recovers, say, from injury.
Is "recovery" just "the percentage of cells that survived, relative to the overall number of cells"?