Although this next comment is highly speculative, it is certainly ironic to see the modified form of poliovirus destroying brain cancers when the polio vaccines around 1960 we’re contaminated with SV 40 virus, which is suspected to have a causal role in the formation of brain cancers in rare instances in those people who’ve received it.
A wild speculation might include the possibility that some genetic combined information from the original polio and SB 40 combination gave rise to some of the tumors being treated, and that the new modified poliovirus is cross reactive to some aspect of the brain tumor, and thus sets off a cross reactive immune attack against it.
I hope to have the opportunity someday to tie together some of these various treatments, based on insights from our past studies at the NCI.