ORLANDO, Florida — In "real world" practice, men with prostate cancer are walking away from active surveillance at much higher rates compared with what is seen in prospective trials at academic centers, according to a new study that offers a rare look into the "lost to follow-up" phenomenon in everyday practice.
"At 2 years, about 50% of men on active surveillance at a Los Angeles public hospital were lost to follow-up, and about 20% at a nearby private hospital," lead study author, Ryan Kraus, a medical student at the Keck School of Medicine, University of Southern California in Los Angeles, told Medscape Medical News.
Socioeconomic status appears to play a large role in the rate, as the men from the public hospital were of low income and those from the private hospital had insurance and were considered more affluent.
Lost to follow-up was defined as missing two consecutive visits and then never returning to see the treating physician.
Kraus presented the study as a poster here at the Genitourinary Cancers Symposium (GUCS) 2017.
However, both the affluent and low-income men had notably higher rates of dropping out of active surveillance compared with what has been reported in the prospective study literature.
"In prospective studies, 2% to 10% of patients are lost to follow-up, which is significantly different from what we see in the real world," he said.
For example, Lawrence Klotz, MD, and colleagues reported a 2.5% drop-out rate among their large prospective active surveillance cohort with a median follow-up of 10 years at Sunnybrook Health Sciences Centre in Toronto, Ontario, Canada.
Kraus and coauthors state that there have been no real-world data — until their new study.
"For patients not in a prospective study, there are no data illustrating if they follow through with their active surveillance protocol," they write.
There was an active surveillance study in men at a community hospital in Switzerland that indicated drop-out rates, which was presented at the American Urological Association (AUA) 2014 Annual Scientific Meeting and reported by Medscape Medical News. However, the study was prospectively done.
Elisabeth Heath, MD, chair of genitourinary oncology at the Karmanos Cancer Institute at Wayne State University in Detroit, Michigan, said the new study "is indeed what occurs out in the real world," when asked for comment.
She noted a related problem is that many prostate cancer patients have more than one health concern and are often "side tracked" by going to other doctors.
"The patient needs to distinguish prostate cancer active surveillance as a different medical visit than the primary care visit to address hypertension. For the 'professional patient,' going to the doctor is easy, but for others, not so much," she told Medscape Medical News.
Should Some Patients Not Be Offered Active Surveillance?
For the study, the University of Southern California team, which included senior author Leslie Ballas, MD, performed a chart review of patients diagnosed with nonmetastatic prostate cancer between 2008 to 2014 at Los Angeles County Hospital, a public '"safety net" institution, and the private Norris Cancer Center, also in Los Angeles. The two share roughly the same physicians, said Kraus.
Investigators categorized patients' surveillance status as far out as June 2015. They found 116 men at the public hospital and 98 men at the private hospital who were managed with active surveillance.
Among the 116 men at the public hospital on active surveillance, 53 were lost to follow-up, with the probability of being lost increasing for each of 5 consecutive years. For example, at 2 years the probability was 45% ± 5%, and at 5 years was 57% ± 7%.
Among the 98 men at the private hospital on active surveillance, 23 patients (23.5%) were lost to follow-up. Again, with each passing year, the likelihood of being lost increased. For example, the probability of being lost to follow-up at 2 years was 15% ± 4%, and at 5 years was 32% ± 6%.
Kraus said that the "disparity between real-world and prospective studies" might be explained by physician motivation in the different settings. In short, study authors have "higher incentives" to make sure their patients are following up. "In the real world, physicians don't have those incentives," he said.
Furthermore, the fact that the poor men had such high drop-out rates concerns the investigators.
"Further study is warranted to look at this population of patients and determine whether active surveillance should remain a recommended course of treatment for this population," they write.
Dr Heath suggested that commonsense should guide physicians in these decisions.
She offered a different set of cancer patients to illustrate the problem of losing patients to follow-up and possible solutions.
"This is a problem we encounter when treating young men with testicular cancer," she explained. In early stage testicular cancer, chemotherapy, radiation therapy, or active surveillance are equally acceptable treatment options.
"One of the issues we often consider prior to committing to a treatment option is the patient's circumstance regarding reliability, insight into his disease, social support infrastructure, and willingness to return monthly," she said.
Dr Heath also said that a "key to a successful active surveillance program" is patient education, awareness, and insight. In addition, the healthcare team has to be engaged with and committed to the patient, she emphasized.
Kraus and Dr Heath have disclosed no relevant financial relationships.
Genitourinary Cancers Symposium (GUCS) 2017. Abstract 197. Presented February 16, 2017.
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Cite this: In Sunny LA, Prostate Cancer Patients Just Walk Away - Medscape - Feb 20, 2017.