This randomized phase III trial is studying different combination chemotherapy regimens and their side effects and comparing how well they work in treating young patients with newly diagnosed T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma. 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) may kill more cancer cells. It is not yet known which combination chemotherapy regimen is more effective in treating T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma.