How to diagnose prostate cancer recurrence

Currently, radical prostatectomy is one of the main methods for treating localized prostate cancer. However, many patients face the problem that after prostate cancer treatment, the chance of recurrence is very high, and patients have to undergo repeated treatments. Moreover, many people only discover the recurrence when the condition is very serious. So, how should we diagnose the recurrence of prostate cancer?

The purpose of comprehensive evaluation of patients with biochemical recurrence is to determine whether the patient has clinical recurrence of the tumor. If clinical recurrence has occurred, it should be determined whether it is local recurrence confined to the prostate fossa or whether regional lymph node metastasis or distant metastasis has occurred. The appropriate treatment plan should be selected based on the results of the comprehensive evaluation.

1. Rectal examination

For patients with biochemical recurrence after radical prostatectomy, rectal examination is of little significance when the PSA level is low. Obek et al. reported that only 5.5% (4/72) of patients with biochemical recurrence after radical prostatectomy could be found abnormal by rectal examination[13]. If an abnormal nodule is found during rectal examination, further rectal ultrasound examination and guided puncture biopsy should be performed.

2. Transrectal Ultrasound and Biopsy

Rectal ultrasound examination and puncture biopsy under its guidance are commonly used clinical methods to determine whether there is local recurrence in the prostate fossa after radical surgery. After biopsy, the exact location of local recurrence is determined, which helps to formulate a more appropriate radiation therapy irradiation field. When a prostate fossa mass is found by rectal examination or a low-echo nodule is found by rectal ultrasound, puncture biopsy can achieve an 80% diagnosis rate [14-15]. Connolly et al. reported that 2/3 of the patients had tumor recurrence at the anastomosis, and the remaining recurrence foci were found in the bladder neck and the retrospermatic space. Ninety percent of the recurrence foci showed low-echo areas under ultrasound. The PSA value at the time of biopsy is related to the results of the biopsy. The positive rate of biopsy in patients with PSA < 0.5 ng/ml is 28%, while the positive rate in patients with PSA > 2.0 ng/ml is 70% [16]. A negative biopsy does not mean that local recurrence can be ruled out. It should also be considered comprehensively. Sometimes multiple biopsies are required to confirm the diagnosis. Connolly et al. [16] reported that 1/3 of the patients were diagnosed after more than two biopsies.

3. Bone scan and CT

If the patient's serum PSA level is <20 ng/ml or the PSA rise rate is <20 ng/ml/year, the sensitivity and specificity of bone scans, pelvic and abdominal CT scans for tumor lesions are very low[17-18]. Cher et al[17] reported that for patients who underwent radical surgery but did not receive postoperative adjuvant endocrine therapy, a positive bone scan would only be detected if the PSA level was at least greater than 46 ng/ml.

The above are a series of evaluation methods for the recurrence of prostate cancer after radical prostatectomy. In clinical practice, these methods are widely used and are the main evaluation methods. We must carefully observe the symptoms that we usually don’t pay attention to and evaluate them in time, otherwise it is easy to cause the recurrence and spread of prostate cancer.