Age is not a predictor of prostatectomy outcomes

August 15, 2005

San Antonio--Youth, usually seen as an asset in clinical situations, confers no advantage in clinical outcomes following radical prostatectomy. In fact, a study from the Mayo Clinic, Rochester, MN, found that high-risk patients younger than age 55 years were more likely to suffer systemic disease progression than older, high-risk patients and that age at treatment offers little to no prognostic value when all other clinical factors are being considered.

San Antonio-Youth, usually seen as an asset in clinical situations, confers no advantage in clinical outcomes following radical prostatectomy. In fact, a study from the Mayo Clinic, Rochester, MN, found that high-risk patients younger than age 55 years were more likely to suffer systemic disease progression than older, high-risk patients and that age at treatment offers little to no prognostic value when all other clinical factors are being considered.

This is not to say that youth is a disadvantage.

"I don't think that is a reflection of the character of the cancer," Dr. Siddiqui said. "Patients younger than 55 with high-risk features have a reduced progression-free survival when compared to a similar cohort of older patients. We think we are seeing this because they are more likely to be alive 15 to 20 years after their diagnosis. They are going to be in their 70s and they are going to progress. We need to be able to inform younger patients of this and suggest that they need aggressive treatment for localized cancer."

Study size significant

The size and duration of the study give Dr. Siddiqui's observations and other findings weight and significance. He and his colleagues identified 5,509 patients who had been treated for prostate cancer at the Mayo Clinic between 1987 and 1995, the era in which the PSA assay came to the fore as a screening test for prostate cancer. They stratified these patients into five age groups (<55 years, 55 to 59 years, 60 to 64 years, 65 to 69 years, and >70 years) and then analyzed cancer-specific survival and progression-free survival.

As Dr. Siddiqui noted, younger patients had better preoperative PSA levels, better biopsy specimen Gleason scores, and were diagnosed at better pathologic stages than older patients. Cancer-specific survival and progression-free survival were similar across all age categories, but older patients (>70 years) had a lower risk of prostate cancer-specific death, and all older age groups had a lower risk of clinical progression than patients younger than 55 years.

Subset analysis showed no difference for cancer-specific survival when the age groups were stratified by risk, as defined by stage, grade, or ploidy. The progression-free survival rate among patients younger than 55 years was 70.6% (±5.4)% compared with 81.9% to 86.6% in the other age ranges. The relative risk of clinical progression in all age groups was lower (RR=0.57 to 0.62) than that seen in the younger patients.

Dr. Siddiqui said that the study was initiated when it became apparent that age and PSA levels were declining in the general population of prostate cancer patients being treated at the clinic.

"We are seeing a much wider range of ages than before. We are seeing age migration, with the average age of the prostatectomy patient only 61, as well as a downward PSA migration. Despite the shift, the proportion of patients with Gleason pattern 4 disease remains constant around 35%. Even though patients are younger with lower PSAs, our rate of detection of clinically significant cancers has not changed in the last 15 years," he said.