The war on cancer is still in progress
Since the “War on Cancer” was declared with the inception of the National Cancer Act of 1971 significant progress in the treatment of cancer has occurred. In the United States, the National Institute of Health (NIH) reports that approximately 461 new cases of cancer occur per 100,000 people yearly, while the mortality rate is 178 per 100,000 – down from 199 per 100,000 in 1975. Furthermore, the 5-year relative survival rate for all cancers has increased from 50% in 1975 to 68% by 2007. Despite this progress, many cancers still remain incurable – pancreatic cancer for example.
Undoubtedly, early detection of cancer is correlated with better survival rates as is oft expressed in the repeated mantra “early detection of cancer saves lives”. Survival rates for the eight most common cancers, bladder, bowel, breast, cervical, womb, malignant melanoma, ovarian and testicular cancers, are three times higher when diagnosed early. For instance, just over 80% of cancer patients survive over ten years when the disease is diagnosed at stage one or two, but this reduces to 25% when first diagnosis occurs at stage three or four. Ten-year survival rates balloon to 90% when cancer is diagnosed at stage one compared to just 5% when first diagnosed at stage four. Cancer stages are based on the size of the tumor and how far they have spread through the body. Consequently, early detection catches tumors before they have grown large and/or metastasized throughout the body to other organs, which makes treatment more difficult and ineffectual. Thus, early detection of cancer can be seen as one of the most important aspects of cancer treatment.
No smoke without a fire
Researchers at Swansea University Medical School in Wales have recently announced the development of a new blood test that can detect cancer much earlier than has previously been possible. The research team, led by Professor Gareth Jenkins, produced a simple test that can distinguish mutations in red blood cell surface proteins. Normally, red blood cell surface proteins act to stick other proteins to the cells’ outer surface; however, mutated blood cells lack this stickiness and cannot accumulate other proteins on their outer surface. When fluorescently labeled antibodies are added to red blood cells they attach to the surface of the non-mutated cells but not the mutated ones. The fluorescence signal of attached antibodies can then be detected and measured allowing the frequency of mutant cells per sample to be calculated. The researchers found that in healthy people the frequency of mutant red blood cells was approximately five mutations per million cells, whereas this increased 10-fold to 50-100 mutants per million in cancer patients.
Importantly, the mutation to the red blood cells does not play a direct role in the development or progress of the cancer itself, rather it appears to be produced as a form of by-product of a developing cancer. Furthermore, it appears that changes to red blood cell mutation frequency can be detected before any overt cancer symptoms are noticeable, leading the research team to liken the mutation to “smoke” in so far as there cannot be “smoke without fire”, in this case cancer. According to the researchers, this could potentially be up to ten years before a patient shows any symptoms of the disease. It is this fact that lends itself to the huge potential that this test represents. By taking a simple, non-invasive method, cancer screening can be conducted relatively quickly and cheaply allowing extremely early detection of cancer. Early detection would lead to early treatment, and this may well lead to significant increases in long-term cancer survival rates.