Geen tea can induce apoptosis of human myeloma cells in multiple myeloma which is a plasma cell malignancy. A study done by Tomonori N et al from Japan has shown these effects of green tea. Can drinking green tea lead to abort pre-cancerous cells before they start differentiating into myeloma?

supposedly, yes.

from this abstract (for example): http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15781612&query_hl=1
i understand that the effect is also in vivo, and that the in vitro concentrations of the active ingredient(s) are based on in vivo findings in blood of green tea drinker.

just one more thing:
the green tea may affect the cells only after they become cancerous, but not neccessarily at pre-stages of cancer.
you'll have to read some research about it to be sure.