Prostate cancer lives from birth: slow and benign growth or rapid and dangerous growth

This year, more than 238,000 American men are diagnosed with prostate cancer. In most cases, the cancer is small knots of abnormal cells grow slowly in the size of the prostate gland of a walnut. For many men, the cancer cells grow so slowly that they never break free of the gland, spread to distant sites, and represent a serious risk to health and longevity.

There is growing evidence that early treatment with surgery or radiation ultimately prevents relatively few men die of prostate cancer while leaving many with urinary or erection problems and other side effects. As a result, more men may be willing to consider a strategy called active surveillance, in which doctors monitor low risk closely and consider treating cancer when the disease appears to make threatening gestures towards the growth and spread.

This week, a study by Harvard researchers found that the aggressiveness of prostate cancer at diagnosis appears to remain stable over time for most men. If this is true, then the appropriate treatment can be reserved for the most likely to be a threat cancers, while men may reasonably choose to watch and wait for other purposes.

"If you chose active surveillance, then it might make you feel more confident in your decision," said Kathryn L. Penney, Sc.D., professor of medicine at Harvard Medical School and lead author of a report published today in the journal Cancer Research.

Early lethality established cancer 

The study analyzed changes in the aggressiveness of cancer in men diagnosed with prostate cancer between 1982 and 2004. All the men had their prostates removed after diagnosis, and biopsies were taken from the glands. The Harvard team revisited the samples and classified using a tool called the Gleason score, which assigns a number 2-10 based on how abnormal the cells look under a microscope. A high score or "high-grade cancers," tend to be the most deadly.

During the study period, fewer men were diagnosed with prostate cancer, the latter advanced that had spread beyond the prostate gland. This reflects the increasing use of the antigen (PSA) for prostate-specific prostate cancer diagnosis earlier and earlier. In contrast, the proportion of high-grade cancer, as measured by the Gleason score, was relatively stable rather than becoming progressively more aggressive. Previous studies have seen a similar trend.

"This is a very interesting study that confirms what previous studies have found," says Dr. Marc B. Garnick, prostate cancer specialist at Harvard-affiliated Beth Israel Deaconess Medical Center, who was not involved in the study. "There may be rare exceptions, but in most cancers born with a Gleason score in particular."

This means that most prostate cancers that seem to be increasingly at diagnosis might as well stay long enough that the man is likely to die of other causes before the cancer spreads beyond the slow prostate. "Those who are poor and lazy is likely to cause problems in the life of a man," says Dr. Garnick, editor of the Annual Report on Prostate Disease, Harvard Medical School. In addition, it adds, most prostate cancers are also born this way and behave aggressively.

Gleason is one of the best predictors of death from prostate cancer. "Men with low-grade disease are much less likely to die from prostate cancer than men with high-grade cancer," says Penney. He cautioned, however, that the study focused on men as a group, and in this population Gleason seemed quite stable. "You can see the progression of an individual, but we believe it is not common," she said. "We can not rule out this possibility in our study."

How to enable monitoring jobs 

The Gleason score is only one way that doctors monitor prostate cancer during active surveillance. They also monitor the periodic biopsies and measured PSA levels, which may increase if the cancer begins to spread in the prostate. 

Doctors may recommend treatment earlier if PSA begins to rise rapidly or if a follow-up biopsy revealed more widespread than or score in prostate cancer Gleason. This is an inexact science that depends on the skill and experience of the physician and the will of a man waiting for signs that cancer is a clear threat before opting for the treatment and its potential side effects.

Penney said she and her colleagues at Harvard are among the many scientists are now looking for better ways to predict prostate is likely to be the deadly cancer that can be monitored and untreated. The answer can be found in the genetic changes in the cancer cells of the prostate indicating greater threat. But a better way to predict who tend to use lethal prostate cancer is far from guaranteed.

"Some [researchers] believe that it is not possible," said Penney. "After the cancer is diagnosed, so many things can change in unknown ways." Diet, exercise and other lifestyle factors, for example, could affect whether the cancer at low risk prostate to become more aggressive or threatening weather.