Fascinating! Here is the study you might be referring to?
http://clincancerres.aacrjournals.or...ent/6/1/1.full
Most interesting.
If I had to guess, I would say there are several factors in play here.
edit: This phase two study wasn't quite a positive, but still statistically relevant
http://clincancerres.aacrjournals.or.../9/5/1666.full