Preoperative and postoperative evaluation of prostate-specific antigen in localized prostatic cancer treated by radical prostatectomy

Prognostic significance of a novel indicator (PSApostd3/PSApre) for PSA recurrence in patients after radical prostatectomy

Purpose

Radical prostatectomy (RP) is a common treatment for prostate cancer, but a fraction of patients may experience PSA recurrence after surgery, manifesting as an elevation in prostate specific antigen (PSA). Vast literature has reported different prognostic factors for PSA recurrence without reaching a consensus. This retrospective study investigated the efficacy of a new indicator in predicting PSA recurrence in patients after RP.

Patients and methods

From October 2000 to December 2015, 102 PCa patients who underwent laparoscopic prostatectomy in the Urology Department of Peking Union Medical College Hospital were analyzed. We calculated PSA_postd3/PSA_pre, defined as the ratio of the PSA on day 3 postop as the numerator and the pre-operative PSA as the denominator, in these patients to represent PSA decrement after surgery, and investigated its relationship with PSA recurrence during follow-up.

Results

The receiver operating characteristic (ROC) curve of PSA_postd3/PSA_pre derived a cut-off at 0.453 (sensitivity=0.704, specificity=0.853, P<0.0001), suggesting an increased risk of PSA recurrence in patients whose PSA on day 3 postop did not decrease to approximately half of their preoperative levels. Among several factors, PSA_postd3/PSA_pre (P<0.0001), pathological T stage (P=0.042) and Gleason Grade (P=0.021) were determined to be significantly associated with PSA recurrence by Fisher’s exact test, while only PSA_postd3/PSA_pre (P<0.001) was significantly related to PSA recurrence-free survival (PRFS) by multivariate logistic regression analysis.

Conclusion

These results imply that PSA_postd3/PSA_pre could provide substantial information for PSA recurrence prediction in patients after RP.

Combined orchiectomy and external radiotherapy versus radiotherapy alone for nonmetastatic prostate cancer with or without pelvic lymph node involvement: a prospective randomized study

PURPOSE

We compare the combination of orchiectomy and radiotherapy to radiotherapy alone as treatment for pelvic confined prostate cancer, that is T1-4, pN0-3, M0 (TNM classification).

MATERIALS AND METHODS

In this prospective study 91 patients with clinically localized prostate cancer were, after surgical lymph node staging, randomized to receive definitive external beam radiotherapy (46) or combined orchiectomy and radiotherapy (45). Patients treated with radiotherapy alone had androgen ablation at clinical disease progression. The effects on progression-free, disease specific and overall survival rates were calculated.

RESULTS

After a median followup of 9.3 years (range 6.0 to 11.4) clinical progression was seen in 61% of the radiotherapy only patients (group 1) and in 31% of the combined treatment patients (group 2) (p = 0.005). The mortality was 61 and 38% (p = 0.02), and cause specific mortality was 44 and 27%, respectively (p = 0.06), in groups 1 and 2. The differences in favor of combined treatment were mainly caused by lymph node positive tumors. For node negative tumors there was no significant difference in survival rates.

CONCLUSIONS

The progression-free, disease specific and overall survival rates for patients with prostate cancer and pelvic lymph node involvement are significantly better after combined androgen ablation and radiotherapy than after radiotherapy alone. These results strongly suggest that early androgen deprivation is better than deferred endocrine treatment for these patients.

Prostatic specific antigen

PSA is a 34-kDa 240-amino-acid glycoprotein produced exclusively by prostatic epithelial cells. PSA is a serine protease, is a member of the kallikrein gene family, and has a high sequence homology with human glandular kallikrein. It has chymotrypsin-, trypsin-, and esterase-like activities. In the serum it is present mainly in a complex form with alpha 1-antichymotrypsin. It is secreted in the seminal plasma and is responsible for liquefaction of the seminal coagulum. The production of PSA proteins appears to be under the control of circulating androgens acting through the androgen receptors. The PSA gene is up-regulated predominantly by androgens at both the protein and mRNA levels. DRE causes minimal changes in the PSA level, while prostate massage, ultrasonography, systoscopic examination, and prostate biopsy can all cause clinically significant elevations. Other conditions, such as prostatitis, prostate intraepithelial neoplasia, acute urinary retention, and renal failure can also elevate the PSA level. The value of PSA as a screening tool is questionable because of the great deal of overlap in PSA levels between BPH and prostate cancer. However, if used in men over 50, in conjunction with DRE and/or ultrasonography, it may become a vital part of the early detection program. PSA's role in determining the clinical and pathological stage is also limited, in spite of the direct correlation between the pathological stage and the PSA level, because of great overlap in the PSA levels in various stages. The most important clinical utility of PSA is in monitoring patients after definitive therapy. PSA is most sensitive and reliable in the detection of a residual tumor, possibly recurrence, or disease progression following treatment, irrespective of the treatment modality. PSA can accurately predict the tumor status and can detect recurrence several months before its detection by any other method. PSA is also a very sensitive and specific immunohistochemical marker for tumors of prostatic origin. Compared to PAP, PSA is a more precise and meaningful marker in all clinical situations. With the development of ultrasensitive assays and the adoption of an international standard PSA calibrator, so that results from multicenter studies can be compared, PSA could become one of the most useful tumor marker in cancer biology.