Significance of androgen deprivation prior to radical prostatectomy, with special reference to prostate-specific antigen

Is androgen deprivation therapy for prostate cancer associated with cardiovascular disease? A meta-analysis and systematic review

BACKGROUND

Androgen deprivation therapy (ADT) is widely being applied in men who suffered from prostate cancer. Whether androgen deprivation therapy (ADT) is associated with an increased risk of developing cardiovascular-related disease is poorly defined.

OBJECTIVES

The aim of the present meta-analysis is to explore the relationship between ADT and the risk of cardiac events. MATERIALS AND METHODS: For this systematic review and meta-analysis, we searched databases from inception to April 2019 for randomized controlled trials (RCT) or observational studies that reported data on ADT administration and cardiac event incidence. The connection was evaluated through estimating relative risk ratio (RR) and 95% confidence intervals (CIs).

RESULTS

A significantly increased acute myocardial infarction (AMI) was detected in the ADT group compared with the control group (RR = 1.19, 95% confidence interval (CI), 1.02-1.39, P < .05). A significant difference between cardiovascular disease (CVD) and ADT was also observed, with summary RR = 1.25, 95% CI, 1.11-1.40, P < .05. Furthermore, our study also suggested ADT was not related to increased incidence of sudden cardiac death (SCD) (RR = 1.13, 95% CI, 0.92-1.38, P = .24); AMI and CVD were not connected with the duration of ADT (AMI: RR = 1.31; 95% CI, 0.66-2.63, P = .44, for > 5 year group; CVD: RR = 1.12, 95% CI, 0.97-1.30, P = .12, for > 5 year group). In addition, the RR for risk of CVD was 1.28 (95% CI, 1.01-1.62, P < .05) for men with PCa on new hormonal agents.

DISCUSSION

Various ADT modalities have different impact on cardiovascular disease risk in different level. Long-term application of ADT is not associated with increased risk of AMI and CVD. Both abiraterone and enzalutamide could significantly increase the incidence of cardiac events in patients who suffered from prostate cancer. Cautions and periodic cardiovascular elevation are necessary for patients before the ADT starting.

CONCLUSIONS

Androgen deprivation therapy is associated with increased risk of AMI, CHD, in contrast, this association is not detected in SCD.

[Hormono-radiotherapy of non-metastatic prostate cancers]

Patients presenting with non-metastatic cancer of prostate have a high probability of relapse if they are treated by either surgery alone or irradiation alone, when poor prognosis factors are present. Clinical stage (> or = T3a), Gleason score, and PSA level (> 20 ng/mL) are the more significant factors. It is likely that many patients can draw benefit of combined androgenic suppression and radiotherapy. However, despite results of European and American trials published the last decade, a number of questions remain without a clear response, especially on the modalities of treatment according to the characteristics of the disease.

Neoadjuvant hormonal therapy in carcinoma of the prostate

The rising incidence of and mortality from prostate cancer has generated great interest in improving the results of current methods of treatment. It is well-established that large tumour volumes and positive surgical margins are correlated with higher rates of local failure and distant metastasis. Significant decreases in both tumour volume and the rates of positive surgical margins are seen with NHT. Follow-up data from one randomized trial of hormonal therapy before RT have shown significantly improved disease-free survival, but so far there has been no benefit in overall survival. However, the addition of adjuvant hormonal therapy has been reported to improve survival. The results suggest that neoadjuvant and adjuvant hormonal therapy may be a viable option in men with locally advanced prostate cancer in whom cure is probably impossible, but disease progression can potentially be slowed. What remains to be determined is whether hormonal therapy alone can produce the same results. For younger men with clinically localized prostate cancer, radical prostatectomy is increasingly the treatment of choice. Prospective randomized trials of NHT have produced impressive statistics for decreasing the incidence of positive surgical margins, but the potential to down-stage tumours remains controversial. Follow-up serum PSA measurements have thus far shown no benefit from neoadjuvant therapy. The possibility that patients who fail biochemically, whether they are from the pretreated or control group, may simply represent a subgroup with aggressive tumours that may not respond to androgen withdrawal, has yet to be proved. As more follow-up data are analysed within the next several years, there must be a clear survival advantage if NHT is to be offered as a treatment option. Despite the potential of neoadjuvant therapy, the use of androgen withdrawal before definitive surgical treatment should be limited to clinical trials until a clearer picture emerges. Some may argue that although there is no evidence of a true advantage for NHT, neither is there evidence of harm. However, it must be recognized that androgen withdrawal therapy has side-effects and adds significantly to the overall cost of treatment. Furthermore, NHT delays definitive treatment; clearly, this can be a source of anxiety for the patient and the impact on survival is unknown. Currently, the rates of pathologically organ-confined disease are high in some subsets of patients (e.g. low-stage, low-grade and low PSA) so that NHT is unlikely to have great additional benefit. Although the influence of hormones on prostate growth has been known for many decades, we are only now elucidating the biological mechanisms of hormonal therapy. Although androgen ablation therapy has been used in men with metastatic prostate cancer for more than 50 years, further research at the cellular and molecular level is essential if we are to refine treatment modalities for both localized and advanced disease. Furthermore, until we have more follow-up data from randomized clinical trials of NHT, it cannot be considered part of the standard treatment for carcinoma of the prostate. There are still too many unknown factors; only time will tell if the initial promise of NHT will be fulfilled.

Why neoadjuvant androgen deprivation prior to radical prostatectomy is unnecessary

Neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy has been advocated for downstaging of tumors and reducing the rates of positive surgical margins with the expectation that disease-free survival will be improved. Despite the apparent favorable impact on pathologic findings, randomized trials to date show no benefit of NHT in prostate-specific antigen progression rates. Consequently, there is serious concern about the validity and biologic significance of the apparent downstaging and decreased rate of positive margins, and no evidence exists that there is improved time to progression and survival; therefore, the authors do not recommend NHT outside of a clinical trial.

Is there a role for induction androgen deprivation prior to radical prostatectomy?

The potential advantages of neoadjuvant androgen deprivation include decreased prostatic size, reduced vasculature, and reduced incidence of positive margins. The potential disadvantages are the side effects of hormonal medication, cost, tissue reaction, treatment "delay," and progression of androgen-independent clones. Many theories have been postulated to explain the observed reduction in the incidence of positive margins with neoadjuvant hormonal treatment. It is possible that the reduced prostate size and the frequently found periprostatic tissue reaction facilitate dissection, allowing better cancer clearance. It is possible, however, that the fibrosis may also increase the surgical difficulty, which critics argue may increase the risk of a positive margin. It is difficult to conceive of a research methodology that could resolve this issue. The occurrence of tumor cell death is likely a more significant explanation for the improved results. Whether tumor cells beyond the prostatic capsule are consistently affected to pathologically downstage the disease is unknown. The careful pathologic assessment in the randomized trials discussed previously suggests that pathologic downstaging is not as common as earlier reports have suggested. Difficulty in interpreting pathologic specimens after neoadjuvant treatment must be considered. At this point, neoadjuvant hormonal treatment prior to surgery would appear appropriate for those patients at high risk of having a positive surgical margin. Specifically, this includes clinical stage T2b, PSA elevation greater than 10 to 20 ng/mL, and a high Gleason score on the prostatic biopsy. Research to date suggests that neoadjuvant hormonal therapy prior to radical prostatectomy has a significant effect in reducing the incidence of positive surgical margins. The treatment is well tolerated with minimal side effects. Whether this will translate into improved disease-free survival remains to be determined. Fortunately, the randomized trials have been completed and follow-up data will be forthcoming.

Pathology of androgen deprivation therapy in prostate carcinoma. A comparative study of 173 patients

BACKGROUND

Leuprolide, an agonist of luteinizing hormone-releasing hormone (LH-RH), and flutamide, an antiandrogen, increasingly are being used in the treatment of clinically localized prostate cancer. Only two small series (of 23 and 12 patients) have been published on the distinctive pathologic changes induced in the prostate by androgen deprivation therapy with discrepancies on the presence of squamous metaplasia, necrosis, and possible tumor destruction by combined androgen deprivation therapy.

METHODS

One hundred and thirteen radical prostatectomy specimens obtained after at least 3 months of leuprolide-flutamide androgen inhibition therapy and 60 nonhormonally treated prostates in randomly selected clinical Stage T2 prostate adenocarcinoma patients were entirely sectioned. Distinctive histologic findings were tabulated and their statistical value determined.

RESULTS

Resection margins of excision were involved by tumor in 43% of untreated and in 19% of androgen-deprived patients. Characteristic changes in androgen-inhibited nontumor glands included atrophy, basal cell prominence, vacuolated luminal cell layer, and squamous and transitional cell metaplasia. Prostatic intraepithelial neoplasia (PIN) was observed in 35% of treated patients. The presence of small tumor glands separated by stroma was the most frequently noted effect of androgen deprivation on prostate adenocarcinoma; pyknosis and branching empty spaces were less frequent. Large clear tumor cells within an inflammatory response was a third histologic pattern. Apparently unaltered tumor areas were observed in 43% of prostates exposed to androgen deprivation therapy.

CONCLUSIONS

Androgen deprivation therapy results in histologically distinctive changes that can be recognized in both nonneoplastic and neoplastic prostate tissue. Residual tumor was present in all 113 treated radical prostatectomy specimens. In addition to glandular shrinkage, therapy was associated with statistically significant reductions in the frequency of high grade PIN and extension of cancer to prostate specimen margins of excisions.