A New Perspective on Cancer

cancer cellsNew research is showing that cancer doesn’t mean a death sentence.Many cancers grow so slowly they never spread to other parts of the body, some even regress naturally. As a result many current cancer screening tests are being looked at with a dubious eye. For example the U.S. Preventative Services Task Force doesn’t recommend men taking the prostate PSA test saying,  

Prostate cancer is a serious health problem that affects thousands of men and their  families. But before getting a PSA test, all men deserve to know what the science tells us about PSA screening: there is a very small potential benefit and significant potential harms. We encourage clinicians to consider this evidence and not screen their patients with a PSA test unless the individual being screened understands what is known about PSA screening and  makes the personal decision that even a small possibility of benefit outweighs the known risk of harms.

And,

A better test and better treatment options are needed. Until these are available, the USPSTF has recommended against screening for prostate cancer.

Studies suggest that too many cancers don’t require action—22 to 54 percent of breast cancers discovered via mammograms, and 22 to 42 percent of prostate cancers determined through the PSA test did not threaten life. Cancer researcher H. Gilbert Welch at the Geisel School of Medicine at Dartmouth says,

The glands of the breast, the prostate, and the thyroid can all harbor a lot of small cancers that are detectable at autopsy but were not the cause of death.

The problem is it’s very difficult to distinguish between dormant or aggressive cancers in their early stages, and as a result, many more treatments of radiation, chemotherapy or surgery are performed unnecessarily—an extremely serious matter, where men can lose sexual function and women their breasts, along with the psychological suffering attendant with it. What is needed are tests that can identify aggressive cancers, and research is going on in that regard. Welch says that the aggressive cancers usually manifest with symptoms rather than tests. And that,

We’ve overstated the need to act quickly and underplayed the diagnostic
value of time.

Doctors at the University of Pennsylvania have discovered the presence of a protein called Vav2 in breast tissue that may predict a cancerous condition called ductal carcinoma (DCIS) that can develop into aggressive breast cancer. Right now, two-thirds of DCIS conditions never progress into invasive cancer. Dr. Clifford Hudis, president of the American Society of Clinical Oncology said, 

which means when we treat DCIS, we are treating many people who would never have developed invasive cancer.


improved future testing
Dr. Ronald DePinho at the Dana-Farber Cancer Institute in Massachusetts, is a researcher working with a new test that may determine aggressive prostate cancer better than any other testing available today. Funded by the Prostate Cancer Foundation, he and his team examined 405 tumor specimens from prostate patients, and looked for a four-gene signature. It seems these four genes excite cancer cells’ ability to grow and invade other tissues. This test combined with other current tests, improved the accuracy to determine aggressive cancers to 91 percent from 84 percent.
WWWresearcherAnother promising indicator is the discovery that dormant or aggressive breast and prostate cancers can potentially be determined with biomarkers that are found in the blood or tissues of people with these cancers. The potential of these biomarkers is promising, but Dr. Hudis said it’s not useful yet because it hasn’t been clinically validated.
WWWResearchers at John Hopkins are working with chromosomes. Particularly the genetic sequences at the end of chromosomes called telomeres. Telomeres protect chromosomes, and function in a way that’s similar to the plastic binders at the end of shoelaces, which keeps them from unraveling. They’ve found that those men with short telomeres in their immune cell chromosomes are at twice the risk to develop aggressive prostate cancer. Elizabeth Platz, researcher in the department of epidemiology at John Hopkins Bloomberg School of Public Health expressed,

We don’t yet know why having short telomeres in blood leukocytes [white blood cells] seems to be associated with risk of aggressive prostate cancer. It may tell us about a person’s exposure to factors that increase their risk of prostate cancer, or it may be an indication of an inherent inability to maintain telomere length, which could put them at increased risk for this disease. If so, it might be that measuring telomere length in blood leukocytes could even predict risk of many different forms of cancer.

Although these are promising protocols, at this point they are just that…promising. But given the accelerated growth of medical technology, and all technology for that matter, they’re most likely closer than the horizon.

1 http://www.reuters.com/article/2010/06/18/us-prostate-cancer-idUSTRE65H5MP20100618

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