(S (S (BASENP (NNP Herceptin)) (VP (VBZ has) (VP (VBN shown) (S (VP (TO to) (VP (VP (VB prevent) (NP (BASENP (DT the) (NN recurrence)) (PP (IN of) (BASENP (NN cancer))))) (PP (IN in) (NP (BASENP (NN 30) (NN %)) (PP (IN of) (BASENP (DT these) (NNS patients))))))))))) (PERIOD .))