Researches say, cancer could become a “controllable chronic disease”. The breakthrough described by medical experts as startling may lead to a range of new treatment that would allow patients to live with the disease, instead of trying to destroy it.

Using mice engineered to develop cancer with injections of a tar component found in cigarette smoke, researchers in United states found out that the animals' immune system could keep the spread of tumours in check over an extended period. Researchers in the United States found out that the animals' immune system could keep the spread of tumours in check over an extended period. The study states that immune system can no longer contain the cancer cells and they begin to grow.

The new discovery could also explain the presence of hidden tumor cells in the prostate, for example in individual with no symptoms of the disease. The research suggest ramification for therapy and irradiation. A downside could be the escape of dormant tumor cells from immune control. Dormant cells themselves are likely to be less susceptible to these treatments, which primarily target rapidly dividing cells. This findings could save thousands,existing treatment work for 50 percent in cancer patient, according to the Association for International Cancer Research.

The main treatments are drugs(chemotherapy),radiation(radiotherapy) and surgery. Immune systems can recognize and destroy molecules foreign to the body, such as toxins,bacteria and viruses. However, discovering why the immune system cannot attack the new molecules created when cells become cancerous remain a puzzle.