A chemical extract in green tea can treat two types of skin cancer without producing side effects associated with chemotherapy, scientists have discovered.

The epigallocatechin gallate (ECGg) compound is too weak to work when consumed in tea, but researchers were able to kill or shrink two-thirds of cancer cells within a month when they applied the extract to tumours in a lab.

Researchers from the universities of Strathclyde and Glasgow say this is the first study to show this type of treatment made from green tea extract can shrink or destroy cancerous cells.

Results, published in the journal, Nanomedicine, found 40 per cent of tumours vanished in both carcenoma and melonoma after treatment. Meanwhile 30 per cent of carcinoma cancers and 20 per cent of melonoma cases shrank.


The extract also stabilised a further 10 per cent of melonoma so they didn't change, Medical Daily reported.

"These are very encouraging results which we hope could pave the way for new and effective cancer treatments," lead researcher Dr Christine Dufes said in a statement.

"This research could open doors to new treatments for what is still one of the biggest killer diseases in many countries."

Skin cancer is the most common cancer affecting New Zealanders - with some of the highest rates in the world. The most recent figures, from 2009, reveal melanoma was the fourth most common cancer, with just over 2,200 registered cases.