Expectant management of localized prostate cancer

Radical prostatectomy versus deferred treatment for localised prostate cancer

BACKGROUND

Prostate cancer is a common cancer but is oftentimes slow growing. When confined to the prostate, radical prostatectomy (RP), which involves removal of the prostate, offers potential cure that may come at the price of adverse events. Deferred treatment, involving observation and palliative treatment only (watchful waiting (WW)) or close monitoring and delayed local treatment with curative intent as needed in the setting of disease progression (active monitoring (AM)/surveillance (AS)) might be an alternative. This is an update of a Cochrane Review previously published in 2010.

OBJECTIVES

To assess effects of RP compared with deferred treatment for clinically localised prostate cancer.

SEARCH METHODS

We searched the Cochrane Library (including CDSR, CENTRAL, DARE, and HTA), MEDLINE, Embase, AMED, Web of Science, LILACS, Scopus, and OpenGrey. Additionally, we searched two trial registries and conference abstracts of three conferences (EAU, AUA, and ASCO) until 3 March 2020.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared RP versus deferred treatment in patients with localised prostate cancer, defined as T1-2, N0, M0 prostate cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of references and extracted data from included studies. The primary outcome was time to death from any cause; secondary outcomes were: time to death from prostate cancer; time to disease progression; time to metastatic disease; quality of life, including urinary and sexual function; and adverse events. We assessed the certainty of evidence per outcome using the GRADE approach.  MAIN RESULTS: We included four studies with 2635 participants (average age between 60 to 70 years). Three multicentre RCTs, from Europe and USA, compared RP with WW (n = 1537), and one compared RP with AM (n = 1098). Radical prostatectomy versus watchful waiting RP probably reduces the risk of death from any cause (hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.70-0.90; 3 studies with 1537 participants; moderate-certainty evidence). Based on overall mortality at 29 years, this corresponds to 764 deaths per 1000 men in the RP group compared to 839 deaths per 1000 men in the WW group. RP probably also lowers the risk of death from prostate cancer (HR 0.57, 95% CI 0.44-0.73; 2 studies with 1426 participants; moderate-certainty evidence). Based on prostate cancer-specific mortality at 29 years, this corresponds to 195 deaths from prostate cancer per 1000 men in the RP group compared with 316 deaths from prostate cancer per 1000 men in the WW group. RP may reduce the risk of progression (HR 0.43, 95% CI 0.35-0.54; 2 studies with 1426 participants; I² = 54%; low-certainty evidence); at 19.5 years, this corresponds to 391 progressions per 1000 men for the RP group compared with 684 progressions per 1000 men for the WW group) and probably reduces the risk of developing metastatic disease (HR 0.56, 95% CI 0.46-0.70; 2 studies with 1426 participants; I² = 0%; moderate-certainty evidence); at 29 years, this corresponds to 271 metastatic diseases per 1000 men for RP compared with 431 metastatic diseases per 1000 men for WW. General quality of life at 12 years' follow-up is probably similar for both groups (risk ratio (RR) 1.0, 95% CI 0.85-1.16; low-certainty evidence), corresponding to 344  patients with high quality of life per 1000 men for the RP group compared with 344 patients with high quality of life per 1000 men for the WW group. Rates of urinary incontinence may be considerably higher (RR 3.97, 95% CI 2.34-6.74; low-certainty evidence), corresponding to 173 incontinent men per 1000 in the RP group compared with 44 incontinent men per 1000 in the WW group, as are rates of erectile dysfunction (RR 2.67, 95% CI 1.63-4.38; low-certainty evidence), corresponding to 389 erectile dysfunction events per 1000 for the RP group compared with 146 erectile dysfunction events per 1000 for the WW group, both at 10 years' follow-up. Radical prostatectomy versus active monitoring Based on one study including 1098 participants with 10 years' follow-up, there are probably no differences between RP and AM in time to death from any cause (HR 0.93, 95% CI 0.65-1.33; moderate-certainty evidence). Based on overall mortality at 10 years, this corresponds to 101 deaths per 1000 men in the RP group compared with 108 deaths per 1000 men in the AM group. Similarly, risk of death from prostate cancer probably is not different between the two groups (HR 0.63, 95% CI 0.21-1.89; moderate-certainty evidence). Based on prostate cancer-specific mortality at 10 years, this corresponds to nine prostate cancer deaths per 1000 men in the RP group compared with 15 prostate cancer deaths per 1000 men in the AM group. RP probably reduces the risk of progression (HR 0.39, 95% CI 0.27-0.56; moderate-certainty evidence; at 10 years, this corresponds to 86 progressions per 1000 men for RP compared with 206 progressions per 1000 men for AM) and the risk of developing metastatic disease (RR 0.39, 95% CI 0.21-0.73; moderate-certainty evidence; at 10 years, this corresponds to 24 metastatic diseases per 1000 men for the RP group compared with 61 metastatic diseases per 1000 men for the AM group).The general quality of life during follow-up was not different between the treatment groups. However, urinary function (mean difference (MD) 8.60 points lower, 95% CI 11.2-6.0 lower) and sexual function (MD 14.9 points lower, 95% CI 18.5-11.3 lower) on the Expanded Prostate Cancer Index Composite-26 (EPIC-26) instrument, were worse in the RP group.

AUTHORS' CONCLUSIONS

Based on long-term follow-up, RP compared with WW probably results in substantially improved oncological outcomes in men with localised prostate cancer but also markedly increases rates of urinary incontinence and erectile dysfunction. These findings are largely based on men diagnosed before widespread PSA screening, thereby limiting generalisability. Compared to AM, based on follow-up to 10 years, RP probably has similar outcomes with regard to overall and disease-specific survival yet probably reduces the risks of disease progression and metastatic disease. Urinary function and sexual function are probably decreased for the patients treated with RP.

[Active surveillance for prostate cancer]

Active surveillance is a valuable treatment option in patients with newly diagnosed low-risk prostate cancer. Studies considering a watchful waiting approach showed favourable cancer-specific survival rates in such patients and it is assumed that patients benefit from a definitive therapy if life expectancy exceeds 10-15 years. Therefore active surveillance is especially valuable in older men and in patients with an elevated comorbidity profile. Precise identification of histologically and clinically insignificant prostate cancers is still not possible today. Active surveillance includes regular PSA measurements combined with follow-up biopsies; however, no standardized protocol exists so far. Histological progression in the follow-up biopsy and PSA elevation are the most important criteria for initiating definitive therapy. Today only a minority of low-risk patients join an active surveillance protocol and a substantial proportion of these men leave such a protocol early without evidence of progression. The psychological burden of living with an untreated cancer seems to be responsible for this. Active surveillance has the potential to lead to undertreatment as there is some evidence that prolonged treatment delay might adversely affect outcome of definitive therapy.

Active surveillance for favorable-risk prostate cancer: who, how and why?

Active surveillance for favorable-risk prostate cancer has become increasingly common in populations in which screening for prostate cancer is widespread, owing to evidence that in many patients screening results in the detection of disease that is not clinically significant (i.e. untreated, it would not pose a threat to health). The approach is supported by data demonstrating that patients who have clinically insignificant disease can be identified with reasonable accuracy, and that patients who are initially classified as low risk but reclassified over time as higher risk and are treated radically are still cured in most cases. It is important to identify patients who have a low probability of disease progression during their lifetime according to clinical and pathologic features of the disease, patient age and comorbidity. Close monitoring of patients over time and availability of reasonable criteria for intervention, which will both identify more-aggressive disease in a timely fashion and not result in excessive treatment, are crucial. It is also important to communicate appropriately with the patient, to reduce the psychological burden of living with untreated cancer. The results of active surveillance, the criteria for patient selection and the appropriate thresholds for intervention are reviewed in this article.

High Concordance of Gene Methylation in Post-Digital Rectal Examination and Post-Biopsy Urine Samples for Prostate Cancer Detection

PURPOSE

We evaluated the concordance between post-digital rectal examination and post-prostate biopsy urine samples using conventional methylation specific polymerase chain reaction analysis of 3 gene promoters in patients with suspected or confirmed prostate cancer.

MATERIALS AND METHODS

Voided urine specimens were collected from 17 men after 15-second digital rectal examination and again after transrectal ultrasound guided biopsy of the prostate for suspected malignancy or for followup biopsy as part of an expectant management protocol. Urine sediment DNA was isolated and subjected to bisulfite modification. Methylation of GSTP1, EDNRB and APC promoters was determined by conventional methylation specific polymerase chain reaction analysis in post-digital rectal examination and post-biopsy samples, and correlated with clinical information.

RESULTS

Prostate cancer was detected on prostate biopsy in 12 of 17 patients (71%). Promoter methylation was detected in post-digital rectal examination urine specimens for GSTP1 (24%), APC (12%) and EDNRB (66%). Promoter methylation was detected in post-biopsy urine specimens for GSTP1 (18%), APC (18%) and EDNRB (77%). The concordance between post-digital rectal examination and post-biopsy urine samples was 94% for GSTP1 and APC, and 82% for EDNRB. Overall 100% of patients with biopsy proven prostate cancer had at least 1 gene methylated in urine vs 60% of those without evidence of prostate cancer on biopsy.

CONCLUSIONS

Gene analysis using conventional methylation specific polymerase chain reaction is a reliable method for detecting abnormal DNA methylation in voided urine samples obtained following digital rectal examination or prostate needle biopsy. The concordance between post-digital rectal examination and post-biopsy urinary samples for promoter methylation is high (82% to 94%), suggesting that urine collected after digital rectal examination may be used for genetic analysis with results similar to those in post-biopsy urine samples.

Prostate saturation biopsy in the reevaluation of microfocal prostate cancer

PURPOSE

We evaluated the ability of an extended, 32-core repeat transrectal ultrasound prostate biopsy protocol to improve the characterization of low volume, well differentiated disease in men with a diagnosis of potentially insignificant microfocal prostate cancer, as defined by 1 single focus positive core of 10 with less than 5 mm of Gleason score 6 or less tumor on primary biopsy.

MATERIALS AND METHODS

A total of 35 consecutive patients, who were 62 to 75 years old, had a median serum prostate specific antigen of 8 ng/ml (range 0.5 to 14) and a diagnosis of minimal prostate cancer, and were willing to consider observation with delayed treatment at progression, were offered repeat saturation prostate biopsy with a median of 32 cores (range 18 to 36) under local anesthesia. This biopsy was to determine whether more extensive prostate sampling would confirm or disprove the initial diagnosis of microfocal, well differentiated prostate cancer.

RESULTS

The procedure was aborted in 1 patient because of massive rectal hemorrhage. Another patient had acute prostatitis with gram-negative sepsis. Of 34 evaluable biopsy sets 11 (32%) were negative for cancer, suggesting that tumor detected at the primary biopsy was probably of low volume and amenable to observation with delayed treatment. Of the biopsies 23 (68%) were positive, 17 were at multiple sites and 7 were upgraded to Gleason score 7 or greater. These patients were then considered to have significant tumors and were offered active treatment.

CONCLUSIONS

This study is to our knowledge the first to describe the clinical use of prostate saturation biopsies for re-evaluating potentially insignificant prostate cancer. Of patients with minimal disease on standard 10-core biopsy, results show that this technique may be helpful for distinguishing the 30% who probably have minimal disease based on negative repeat saturation biopsy from the 70% who almost certainly have a significant tumor, as characterized by multiple positive cores, with or without an increased Gleason score. The latter patients should be offered active therapy.

Comorbidity is poor predictor of survival in patients undergoing radical prostatectomy after 70 years of age

OBJECTIVES

To investigate several comorbidity classifications as possible predictors of mortality, because the value of comorbidity as a prognostic factor is uncertain in patients older than 70 years of age and radical prostatectomy in patients older than 70 years is controversial.

METHODS

A total of 214 consecutive patients aged 70 years or older who underwent radical prostatectomy from December 1992 to December 2002 were stratified according to the Charlson score, American Society of Anesthesiologists physical status classification, New York Heart Association classification of cardiac insufficiency, classification of angina pectoris from the Canadian Cardiovascular Society, and age (70 to 72 versus 73 to 74 versus 75 years or older). The mean follow-up in the surviving patients was 5.1 years (range 1.3 to 12.5). A sample of 240 consecutive patients aged 67.0 to 69.9 years treated during the same period was used for comparison. The overall and comorbid mortality were the study endpoints. Mantel-Haenszel hazard ratios were calculated. Comparisons were made using the log-rank test.

RESULTS

Unlike for patients aged 67.0 to 69.9 years, for those 70 years old or older, only one of the investigated stratifications reached significance as a predictor of mortality. A New York Heart Association classification of 2+ versus 0 was significant for overall mortality (hazard ratio 5.8, P = 0.021) and comorbid mortality (hazard ratio 15.9, P = 0.046).

CONCLUSIONS

Comorbidity is of limited prognostic value in patients selected for radical prostatectomy and 70 years old or older.

Micro-Focal Prostate Cancer: A Comparison of Biopsy and Radical Prostatectomy Specimen Features

OBJECTIVES

To study the pathologic features of radical prostatectomy (RP) specimens of patients operated on the basis of a potentially "Insignificant" prostate cancer (Ca P) characterized by one single focus (less than 3mm) of moderately differentiated adenocarcinoma - Gleason score < or =6, out of 6-10 biopsies and to determine which characteristics, if any, are predictive of the presence of a "non significant" prostate cancer in the specimen characterized by a low volume (<0.5 ml) moderately differentiated organ confined, cancer (Gleason score less than 6).

PATIENTS AND METHODS

PSA, biopsy features, and surgical specimens of a series of 56 patients submitted to RP for "insignificant Ca P" on TRUS prostate biopsies between 1988 and 2004 were compared regarding the number of tumor foci, Gleason grade and score, tumor volume determined by the cylinder method, as well as extraprostatic extension (EPE) and positive surgical margins (P.SM.).

RESULTS

70% of the patients had multifocal microfocal cancer apart from the index tumor. The presence of grade 4 was ignored by the biopsy in 50% of the cases, however the primary grade was correctly evaluated in more than 70% of the biopsy sets. 42% of the patients had a cancer volume less than 0.5 ml and 29% met the definition of insignificant/unimportant cancer characterized by a moderately differentiated (Gleason score < or =6) of low volume (less than 0.5 ml) however no feature accurately predictive of insignificant cancer could be individualized. In this whole series, only 8% of the patients had EPE. When the pre-operative PSA was <10 ng/ml, 98% of the patients had an organ confined tumor.

CONCLUSION

Patients diagnosed with prostate cancer on the basis of one single focus less than 3 mm of moderately differentiated (Gleason < or =6) prostate cancer have 30% of chances of harboring an insignificant tumor in their prostate and are therefore, at risk of being overtreated, however there is at this time no specific feature able to identify these patients pre operatively.

Evidence-based medicine, medical decision analysis, and pathology

Recent advances in molecular pathology and other technologies such as proteomics present pathologists with the challenge of integrating the new information generated with high-throughput methods with current diagnostic models based mostly on histopathology and clinicopathologic correlations. Parallel developments in the field of medical informatics and bioinformatics provide the technical and mathematical methods to approach these problems in a rational manner. However, it remains unclear whether pathologists or other medical specialists will become primarily responsible for the development and maintenance of these multivariate and multidisciplinary diagnostic and prognostic models that are hoped to provide more accurate, individualized patient-based information. Evidence-based medicine (EBM) and medical decision analysis (MDA) are relatively new disciplines that use quantitative methods to assess the value of information, differentiate fact from myth, and integrate so-called best evidence into multivariate models for the assessment of prognosis, response to therapy, selection of laboratory tests, and other complex problems that influence individual patient care. We review from an epistemological viewpoint the current approach to information in pathology and describe some of the concepts developed by the practitioners of EBM and MDA.