SAN FRANCISCO -

Each year, more than 76,000 Americans are diagnosed with melanoma, and 9,000 die. Once it's spread, this type of cancer is extremely difficult to treat.

Now, researchers say a new therapy is helping them shock away some of the most stubborn tumors.

With 20 acres of grapes to grow, animals to feed, and grass to cut, Martin Bajuk is a busy man.

"There are always things to do," Bajuk said.

A recent diagnosis of melanoma, however, threatened to slow down the active 77-year-old. 

"I noticed sort of like a wart," Bajuk explained.

He had three surgeries, but the cancer spread and Martin was running out of options.

"It’s a frustrating cancer to treat, and it's also very resistant," said Dr. Adil Daud, medical oncologist, University of California San Francisco Medical Center.

Daud is studying electroporation for advanced melanoma. He injects a gene, called IL12 into the tumor and uses the device to deliver electricity. The charge opens pores in the tumor so it can absorb the IL12. Then, the body's immune system sends special cells to destroy the cancer.

"Then, once the immune system has done that, there's what's known as memory cells, and so those memory cells circulate around and if they see other melanoma, they will get rid of that too," Daud explained.

In a trial, eight of nine patients saw all or most of their tumors shrink. None reported side effects. One downside is that the treatment is painful. Just ask Bajuk.

"It's over 1,200 volts of electricity. That is just unbearable," Bajuk said.

The pain, however, lasts for just a second, and with his cancer in check, Bajuk can focus on what he loves most, working in the outdoors.

The procedure is given three times over eight days. Each shock lasts only a few milliseconds. Researchers said the therapy would likely be combined with others to see maximum benefits. Five other centers across the country are involved in the electroporation study.

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