Men with early-stage prostate cancer who opt for an active surveillance program rather than treatment for the malignancy are greatly disinclined to follow the recommended monitoring guidelines.

That is the main finding from an observational study conducted at the University of North Carolina Lineberger Comprehensive Cancer Center and presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago last week.

Prostate cancer often grows slowly,and only a small proportion of men who develop this malignancy will die of it. Many experts advise that men with a low or intermediate risk for cancer progression can safely defer immediate treatment—and avoid its potential complications—and instead undergo regular monitoring to promptly detect progression if it occurs.

The researchers in the new study followed 346 men newly diagnosed with low- or intermediate-risk (82% and 18% of the cohort, respectively) prostate cancer between 2011 and 2013. The men, who all opted for active surveillance rather than immediate treatment, had a median age of 67 years old; 75% were white. Nearly half were covered by Medicare, and 31% had private insurance.

The investigators wanted to know whether the study participants would adhere to the National Comprehensive Cancer Network (NCCN) guidelines for active surveillance of prostate cancer, which recommend men receive prostate-specific antigen (PSA) tests at least every six months, annual digital rectal exams and a repeat biopsy within 18 months of their cancer diagnosis.

Men with prostate cancer “need regular PSA tests, they need prostate exams, they need prostate biopsies so you can watch the cancer very closely and you don’t lose the opportunity to treat the cancer when it starts to grow,” Ronald C. Chen, MD, MPH, an associate professor in the UNC School of Medicine Department of Radiation Oncology, said in a university press release.

After six months of follow-up, 67% of the men in the study had received a PSA test; by 12 months, 70% had undergone a digital rectal exam. Additionally, 37% of the participants had received a repeat biopsy 18 months following their diagnosis. But at the 24-month mark, only 13% had consistently adhered to all the NCCN guidelines.

Having parsed the adherence rates according to the men’s income, race and age, the study authors’ analysis could not identify any factors that predicted whether participants would adhere to the monitoring guidelines.

“This raises the question of whether we need to investigate whether active surveillance is a safe option when patients do not receive routine monitoring,” said Chen, who called for more research into factors that may predict adherence to the NCCN guidelines. “Our goal is not to reduce the number of patients choosing active surveillance; rather, the results of this study should increase awareness and efforts to ensure that active surveillance patients are monitored rigorously.”

Within the first two years of follow-up, 19% of the participants ended active surveillance and switched to treatment for their prostate cancer. The investigators found that disease progression was associated with a 6.2-fold greater likelihood of switching to treatment while having anxiety about prostate cancer was associated with a 2.2-fold increase. Two years into the study, 94% of participants said they had no regret about their decision.

To read the conference abstract, click here.

To learn more about prostate cancer, click here.