Delaying primary treatment of prostate cancer (PCa) up to 6 months does not appear to adversely affect outcomes, but longer delays can increase the likelihood of biochemical recurrence of disease, according to a new study.
“Time to receive treatment or treatment delays is an important quality metric in patient-centered care that has been shown to impact outcome among various cancers,” said study investigator Kosj Yamoah, MD, PhD, an oncologist and an Assistant Professor in the Department of Radiation Oncology and Cancer Epidemiology at H. Lee Moffitt Cancer Center in Tampa, Florida. “However, the clinical implications of delays in prostate cancer treatment remain unclear, with some studies suggesting no association between treatment delays and prostate cancer outcomes.”
Dr Yamoah and colleagues conducted a retrospective study with 1,807 patients who underwent radical prostatectomy (RP) as primary treatment for clinically localized PCa at 2 large tertiary referral centers from 1987 to 2015. The median follow-up time was 46 months (range 18–86 months). Initial delay up to 6 months did not adversely affect outcomes, but a delay in treatment beyond 6 months was associated with a nearly 2-fold increased risk of biochemical recurrence, the investigators reported in Cancer Epidemiology, Biomarkers & Prevention.
Most patients (61.5%) underwent RP at 3 months or less after diagnosis, whereas 31.1% underwent RP more than 3 months and up to 6 months after diagnosis, and 7.4% underwent RP more than 6 months after diagnosis.
The overall 5-year rates of freedom from biochemical failure were 78% and 82% for time to treatment of 0–3 month and greater than 3 but not more than 6 months after diagnosis, respectively, compared with 69% for time to treatment greater than 6 months.
The investigators defined biochemical recurrence as a clinician documented single PSA value of 0.2 ng/mL or higher or 2 consecutive PSA values of 0.2 ng/mL after RP.
“As a clinician, it was surprising that treatment delays were significantly associated with short-term outcomes like biochemical recurrence or early treatment failure, contrary to some reports in contemporary literature,” Dr Yamoah told Renal & Urology News. “In addition, we also observed that African-American men, who are at higher risk of poor PCa outcomes, were more likely to experience treatment delays.”
These findings suggest that treatment delays should be categorized as potential risk factors when working with ethnic minorities, he said.
Although the cohort in the current analysis consisted of patients not on active surveillance (AS), the results may still have implications on existing practices related to repeat biopsy in men on AS, especially among those who are likely to experience treatment delays, according to the authors.
“There is significant discordance between studies on association of treatment delays and PCa prognosis,” Dr Yamoah said. “In addition, studies have even recommended treatment delays as long as several years without emphasizing short-term clinical implications, such as biochemical recurrence, as a result of unwanted delays.”
In the era of shared decision-making, patients often rely on clinical literature in addition to physician consultation once they are diagnosed, he said. The existing ambiguity around treatment delays may mislead patients about their risk of disease progression, possibly resulting in some men missing a window for curative treatment.
Mark Garzotto, MD, Professor of Urology and Radiation Medicine at the Oregon Health & Science University and Director of Urologic Oncology at Portland VA Medical Center in Portland, said there are definitely cases where a delay in treatment leads to an increase in cancer recurrence. “However, since this is a retrospective cohort of referred patients, I would be very cautious in the interpretation of these results. In this study, we do not have any data on why patients chose to wait 6 months or longer,” Dr Garzotto said. Patients whose treatment was delayed beyond 6 months made up only 7% of the cohort, so they appear to be a highly selected group, Dr Garzotto pointed out.
“The delayed group may have initially chosen active surveillance but had a change of heart due to the development of some high-risk feature such as a PSA rise, genomic testing results, or MRI finding. We just don’t have enough information from this study to answer the question about the impact of treatment delay.”
Awasthi S, Gerke T, Park JY, et al. Optimizing time-to-treatment to achieve durable biochemical disease control after surgery in prostate cancer – A multi-institutional cohort study. Cancer Epidemiol Biomarkers Prev. 2018; published online ahead of print.