A new treatment for skin cancer made from the sap of a common garden weed has proven effective on 71 percent of basal cell carcinomas (BCCs). In phase II test results released this week in Australia, the PEP005 Topical gel cleared up the most common type of skin cancer in just two applications on two consecutive days.

Petty spurge (Euphorbia peplus) has been used for years in Australia to treat cancerous spots on the skin. A toxic, milky sap within the plant normally causes blisters and rash, but when applied directly to a cancerous growth causes swelling and an enlarged sore which eventually develops a scab that dries and falls off. . .

The Brisbane-based company called Peplin (named for the plant?) claims to have identified the molecule responsible for that activity and formulated a gel and developed a manufacturing technology. Peplin believes the molecule penetrates the skin and destroys the malignant tissue.

The company's managing director and chief executive, Michael Aldridge said, "This is the first time two days of therapy have shown to be effective in clearing skin cancers." Peplin hopes to start phase III trials later this year.

BCC's develop typically on older caucasians with a history of sun exposure. The trials involved 60 people throughout Australia, a country where a quarter million people were treated for such skin cancers in 2002.

Petty spurge is an erect garden weed, a prolific seeder originally native to Europe. It is also naturalized throughout North America.