After 30-years of false starts, doctors have found another way apart from surgery, chemotherapy and radiation to fight cancer, by using the immune system, the body's natural defender.

The new approach called a cancer vaccine, treats the disease rather than prevents it.

According to researchers, one such vaccine kept a common form of lymphoma from getting worse for over a year, a huge success in a field where the success of a new treatment is often measured in weeks or even days.

After struggling for decades in the lab, in recent weeks experimental vaccines against three other cancers i. e. prostate, melanoma and neuroblastoma, an often fatal childhood tumour, also yielded positive results in late-stage testing.

Too soon to declare victory in the fight with cancer, one still has to determine how long the benefits will last, whether boosters will be need to keep the disease in check, or whether vaccines will be the cure for cancer, whether they have to be custom-made for each patient, including how practical they will be, and what they will cost?

There are many cancers about the vaccine, but no answers yet, with the biggest problem being to get the immune system to see cancer as a threat. While, flu and polio viruses are easily spotted by the immune system, because they look different from human cells, cancer comes from our own cells, and the immune system has trouble distinguishing the normal cells from the cancer cells.

In order to do that, cancer vaccines take a substance from a cancer cell's surface and attach it to something the immune system already recognizes as foreign i. e. a shellfish protein in the lymphoma vaccine's case.

With no serious side effects, the vaccine therapy holds allure, unlike the toxic effects of chemotherapy and radiation, therapeutic vaccines are designed to destroy only malignant cells.

The vaccine is given six months after chemotherapy, which by itself typically treats the cancer initially.

Biovest International, which plans to market the vaccine under the name BiovaxID, has already begun talks with the FDA to seek conditional approval.