In the SPCG-4 trial, the mean age was 65, the mean PSA level was 13 ng/mL, and 12% of patients had T1c tumors at enrollment. In the PIVOT trial, the mean age was 67, mean PSA was 7.8 ng/mL, and 50% of patients had T1c tumors at enrollment.
In the SPCG-4 trial, there was a 43% increased risk of distant metastasis over 18 years of follow-up, and in PIVOT, the risk of bone metastasis was increased by 60% with surveillance compared with radical prostatectomy after 8 years.
This begs the question of whether the upfront potential adverse effects, albeit treatable, of surgery or radiation, are worse than the risk of metastasis with the long term and generally not reversible adverse effects of lifelong androgen deprivation.
“What does metastatic disease mean? It means life-long medical castration or hormonal therapy, the side effects of which many would consider much worse than the side effects of surgery or radiation, because the side effects of surgery and radiation can be treated and reversed,” said Dr D’Amico. The prevalence of adverse events is also much lower for surgery or radiation compared with life-long androgen deprivation.
It is important, however, to consider that the surveillance protocols of today are more involved than what was possible with the ProtecT study. In the study, the diagnosis was made with a 10-core biopsy rather than 12 cores, and repeat annual biopsies were not mandated. “We have multiparametric MRI now; we can do guided biopsies with MRI and ultrasound fusion, which was not possible, given that the technology did not exist, during the ProtecT trial,” said Dr D’Amico.
Whether the added measures to surveillance translates into a lower risk of metastasis compared with the ProtecT trial is yet to be shown, according to Dr D’Amico. “We don’t know how much value is added with MRI, repeat biopsies, and more cores.
“Healthy men—that is those with more than a 10 year life expectancy, which was the median follow up of men in ProtecT—should be made aware that despite the fact that cancer death rates are very low at 10 years (around 1%), they can expect at least a doubling of the metastatic risk at 10 years, and prostate cancer-related death to follow about 6 years after metastatic disease presents, if they are monitored with PSA. They should at least have that discussion with the person who is following them.”
Men with other serious health complications, however, can be monitored, because they are unlikely to die from prostate cancer.
Disclosures: The author has no relevant relationships to report.
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