Low-Risk Prostate Cancers Less Likely to Cause Death

Study finds patients with low-risk prostate cancers be monitored in an active surveillance program.

According to a recent study, men with lower-risk prostate cancers have less of a chance of succumbing to the disease. The findings come as a result of a 20-year study performed by the Brady Urological Institute at Johns Hopkins.

The study found that just 2 of the 1298 men enrolled over the 20-year period died of prostate cancer, and 3 patients developed metastatic disease.

“Our study should reassure men that carefully selected patients enrolled in active surveillance programs for their low-risk prostate cancers are not likely to be harmed by their disease,” said H. Ballentine Carter, MD, the Bernard L. Schwartz Distinguished Professor of Urologic Oncology and director of adult urology.

Carter acknowledges that the favorable results of the study may in part be due to the fact that doctors carefully selected patients for active surveillance.

“With longer follow-up, the data may change, but they’re unlikely to change dramatically, because men in this age group tend to die of other causes,” he said.

The results of the study may also be skewed due to the fact that many of the participants were of Caucasian descent and results may be different for the African American population, who tend to have more aggressive cancers.

For the study, men with prostate tumors classified as low or very low risk for aggressiveness opted to enroll in an active surveillance program at The Johns Hopkins Hospital. Risk levels were determined in part by Gleason scores, which measure the aggressiveness of the cancer from prostate biopsy tissue.

The study began in 1995 and urologists performed biopsies annually on the enrolled individuals until they reached age 75. Doctors no longer require annual biopsy for low risk patients; however, when they do perform a biopsy, they use MRI-guided technology and will often ask pathologists to check biopsy tissue levels of proteins made by the PTEN gene, a biomarker for prostate cancer aggressiveness.

During the study, 47 men died of non-prostate cancer causes, most of which were attributed to cardiovascular disease. Nine of the 47 men received treatment for their prostate cancer.

The results of the study revealed that overall, patients were 24 times more likely to die from a cause other than prostate cancer over a 15-year period.

After 10 and 15 years of follow-up, survival free prostate cancer death was 99.9%, and survival without metastasis was 99.4% in the group.

Approximately 36% of the study participants had their prostate cancers reassessed to a higher level of risk within 2 years of enrollment in the active surveillance program. The risk of grade reclassification in very low-risk patients to a level that would have precluded involvement in the study over a period of 5, 10 and 15 years was 13%, 21% and 22%, respectively.

For low-risk patients, the risk increased to 19%, 28% and 31%, respectively. Over the same time frames, the cumulative risk of a grade reclassification to a level that would be considered potentially lethal in most cases but still curable was no more than 5.9% for both very low and low-risk prostate cancers, Carter noted.

Of those involved in the study, 109 men opted for surgical or radiation treatment, despite the fact that the status of their low-risk cancer was unchanged. In those whose cancers were reclassified, 361 opted for treatment.

“The natural progression of prostate cancer occurs over a long period of time, some 20 years, and most men with low-risk prostate cancer will die of another cause,” said Carter, a member of the Johns Hopkins Kimmel Cancer Center. “There is a careful balance, which is sometimes difficult to find, between doing no harm without treatment and overtreating men, but our data should help.”

Only 30 to 40% of US men with eligible prostate cancers go ahead with active surveillance. In Scandinavian countries, the percentage increases to 80%. The reasons for less use in the US could stem from fear of losing the opportunity for a cure.

But active surveillance has some great benefits of which patients may not be aware of. There is clear reduction in the rates of complications and costs of prostate cancer treatments in active surveillance.

Additionally, a recent report revealed that 20 percent of men undergoing prostate cancer treatment were readmitted to the hospital within 5 years of treatment for a complication relating to the original treatment.

“Our goal is to avoid treating men who don’t need surgery or radiation. The ability to identify men with the most indolent cancers for whom surveillance is safe is likely to improve with better imaging techniques and biomarkers,” said Carter.

With the results of this study in mind, Carter suggests that all patients with low-risk prostate cancers see urology specialists to be monitored in an active surveillance program.