A recent study from a team of investigators from the Czech Republic suggests prompt monitoring of prostate specific antigen levels (PSA) in patients after a radical prostatectomy (RP) may be a reliable measure to determine the necessity of post-surgical radiotherapy to prevent disease recurrence. Lead investigator Dr. Stepan Vesely from the Charles University 2nd Faculty of Medicine University Hospital in Prague, and his colleagues published a report of their findings in the journal BMC Urology.
The study involved the participation of 116 patients known to have positive surgical margins (PSMs) after undergoing RP for localized prostate cancer, and had not received any form of radio- or hormonal therapy. At 14 days post-operation, the participants’ PSA levels were evaluated using an ultrasensitive assay, which was repeated on day 30, 60, 90, and 180, followed by more distanced monitoring every 3 months.
According to their findings, 47 percent of patients were noted to have biochemical failure (BCR), which is defined as having a PSA level of at least 0.2 ng/mL during a follow-up after an average 31.4 months. The group pointed out that the risk for BCR increases significantly by 4.3-fold and 9.6-fold with PSA levels higher than 0.073 and 0.41 ng/mL on days 30 and 60 respectively.
“Applying the PSA cut-off at day 30 as the indicator for adjuvant radiotherapy would result in the decrease of overtreatment from 61 patients to 8 patients”, the researchers wrote in their study titled “The use of early postoperative prostate-specific antigen to stratify risk in patients with positive surgical margins after radical prostatectomy“.
While a number of previously published studies suggest adjuvant radiotherapy to be essential in patients with PSM to prevent disease recurrence, Dr. Vesely’s team believes PSMs do not definitively cause it and that adjuvant post-surgical radiotherapy may be unnecessary in some patients who are not at immediate risk. The researchers attribute these observations to the known kinetics of post-op PSA level decline.
Some of the rationales the authors point out to justify why PSMs does not necessarily relate to disease recurrence, include the effect of post-surgery ischemia and fibrosis, which can eradicate areas with residual cancer, along with potential tissue disruption during specimen handling, which may lead to unintentional damage, thus falsely appearing as a PSM.
The researchers believe further research is necessary to establish the reliability of post-op PSA level monitoring as an indicator for adjuvant radiotherapy, as their time frame for follow-up was not considered long-term. These findings further emphasize the need to view each cancer patient as a totally unique case, with potentially significantly different outcomes.