For early, localized prostate cancer, doctors and patients sometimes decide that the best option might be to keep a close watch on the cancer and wait to see if it develops further. Previous studies have shown that this method works well; a group of Swedish researchers found that survival rates in men with mild cancer who weren't treated right away are comparable to those who immediately go into treatment for as long as 10 or 15 years. But then the team followed the same patients past that point and came up with surprising results.

What the researchers wanted to know: What is the survival rate of patients who initially do not seek treatment for localized, mild prostate tumors over the long term?

What they did: The researchers tracked more than 220 patients in Sweden with prostate cancer for 21 years, the longest of any prostate cancer study. The patients were, on average, 72 years old when first diagnosed, and initially received no treatment for their cancer, though they were examined regularly and some received treatment when their cancer progressed. The doctors kept track of how many of the patients progressed to a more advanced stage of prostate cancer and how many died due to prostate cancer.

What they found: The researchers published a paper several years ago using these same patients, at which time they found that 10 to 15 years after the initial diagnosis, only a few had died or had progressed to more advanced cancer. But, the number whose cancer progressed or who died from prostate cancer during the next stage of the follow-up, 15 to 21 years after the initial diagnosis, jumped sharply upwards; the mortality rate increased threefold compared with the previous 15 years. Overall, of the men they studied, 91 percent died during the follow-up period (most were older than 70 at the beginning of the study), 17 percent of those from prostate cancer.

What it means to you: Because of the jump in recurrence rate 15 years after initial diagnosis, the authors recommend more aggressive therapies for the treatment of prostate cancer, especially for younger men, or those who are initially diagnosed with high-grade prostate cancer. For some older men, the watch and wait method may still work because there is a long period of time in which the cancer progresses slowly, and other health complications may take precedence over cancer treatment.

Caveats: In the later years of this study, more-sensitive tests were developed to test for the progression of prostate cancer, including the prostate-specific antigen (PSA) test. These tests have only recently come into widespread use, and the increase in cancer progression may have been because it became easier to detect cancer progression and not because the actual rate increased.

On the other hand, the authors' recommendation of aggressive treatment for cancers detected early may not apply in the era of PSA tests, because the men in this study had their cancer diagnosed by older, less sensitive methods. PSA tests can detect cancer that may not progress for an even longer time than those in the study, meaning that less aggressive treatment might be the best option.

Find out more: The National Cancer Institute has a wealth of information on prostate cancer. For men with prostate cancer and their families, the Prostate Cancer Research Institute has information, ways to get support, and information about events and conferences dealing with prostate cancer.

Read the article: Johansson, J. et al. "Natural History of Early, Localized Prostate Cancer." Journal of the American Medical Association. June 9, 2004, Vol. 291, No. 22, pp. 2713.