Traditionally, blood cancers like leukemia have been difficult to treat, especially in patients over 50. A host of complications make the chances of a successful marrow or stem-cell transplant unlikely, and the prognosis is typically gloomy. But doctors appear to have found a new way to introduce healthy cells into patients suffering from blood cancers.

There are three major forms of blood cancer -- lymphoma, leukemia and multiple myeloma. Lymphomas account for over half of all new cases, while leukemia accounts for a further 28 per cent. The cancers occur when there is abnormal cell growth in either the bone marrow or the lymphatic tissues. Blood cancers alter the way the body manufactures blood, and affects our overall immunity from other diseases.

Thirty years ago, patients were 50 per cent less likely to survive from these cancers. Recent advances in chemotherapy and radiation treatments have increased survival rates. But no modern advance can match the potential impact of the recent breakthrough announced by doctors at Stanford University.

There are two key requirements when it comes to bone marrow or stem cell transplants. The first is effectively killing as many cancerous cells in the blood cell manufacturing part of the body -- the bone marrow -- as possible. The second is training the recipient's body to accept new cells from their donors. Often, a recipient's body will battle the new cells, killing them off before they can successfully assimilate -- a condition called graft-versus-host disease. A donor and a host's cells living harmoniously, or as clinicians put it, a 'blended' life, is the field's ultimate aim. Usually, this requires strong anti-rejection drugs.

The Stanford trials used some newly identified techniques, and achieved significant positive results. 37 test patients (with an average age of 52) were treated with a combination of two weeks of low-dose chemotherapy and immune suppressing drugs after receiving their transplants. Only two patients developed graft-versus-host disease when, under normal circumstances, nearly half would have. One year later, almost 70 per cent of the patients were alive and cancer was in complete remission in 24 patients.

Although this is a small-scale study, the results appear very encouraging. Additionally, these techniques have proved highly successful in laboratory studies on mice. In all, it appears that there are some hopeful treatments for older blood cancer patients in the offering.

While there is no known cause for leukemia and blood cancers, certain high risk factors have been identified. Exposure to high levels of radiation and hazardous chemicals can play a role, especially the chemicals asbestos and benzene (found in unleaded gasoline). Some pesticides are known carcinogens, and should be avoided. If you must come into contact with these substances, use the appropriate protection -- and always be aware of their potential effects.

Oncologists are aggressively targeting the diseases, and making leaps and bounds in how they are treated. At the current rate of innovation, mortality rates should decline even further in the coming years.