This randomized phase III trial is studying low-dose vincristine to see how well it works compared with high-dose vincristine when given together with different combination chemotherapy regimens in treating young patients with intermediate-risk relapsed B-cell acute lymphoblastic leukemia. Drugs used in chemotherapy work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) and giving the drugs in different ways and different doses may kill more cancer cells..