Sentence: Trials have demonstrated decreased relapse with perioperative methotrexate , vinblastine , doxorubicin and cisplatin ( M-VAC ) chemotherapy in patients with muscle invasive bladder cancer .
Drug combination annotation:
[{'class': 'POS', 'spans': ['methotrexate', 'vinblastine', 'doxorubicin', 'cisplatin'], 'is_context_needed': False}]