For the majority of patients, PSA levels become undetectable after prostatectomy indicating cancer remission, which is good news. However, in some cases, PSA levels may be detectable or rise, indicating a potential recurrence of cancer cells. Here’s what you need to know:

Defining Biochemical Recurrence

A PSA level of 0.2 ng/mL or higher is defined as a biochemical recurrence [1], although most clinicians recommend further investigation or treatment if the PSA level rises to 0.1 or above. This level of PSA suggests the presence of remaining cancer cells after surgery but this is not always the case.

Possible Causes of Detectable PSA

1. Cancer recurrence: A steadily increasing PSA level may indicate the presence of growing prostate cancer cells.  This is due to a few cancer cells being left behind after surgery either due to incomplete removal of the tumour or due to microscopic cells that had spread beyond the gland before surgery but were not detectable on scans. 
2. Benign prostate tissue: Sometimes, detectable PSA can be due to benign prostate cells left behind after surgery. In this case, PSA levels may be detectable but stable or fluctuating without a sustained rise[1].