Predicting prostate cancer many years before diagnosis: how and why?

Prostate Cancer: Biology, Incidence, Detection Methods, Treatment Methods, and Vaccines

Cancer of the prostate are cancers in which most incidences are slow-growing, and in the U.S., a record of 1.2 million new cases of prostate cancer occurred in 2018. The rates of this type of cancer have been increasing in developing nations. The risk factors for prostate cancer include age, family history, and obesity. It is believed that the rate of prostate cancer is correlated with the Western diet. Various advances in methods of radiotherapy have contributed to lowering morbidity. Therapy for hormone- refractory prostate cancer is making progress, for almost all men with metastases will proceed to hormone-refractory prostate cancer. Smoking cigarettes along with the presence of prostate cancer has been shown to cause a higher risk of mortality in prostate cancer. The serious outcome of incontinence and erectile dysfunction result from the cancer treatment of surgery and radiation, particularly for prostate- specific antigen detected cancers that will not cause morbidity or mortality. Families of patients, as well as patients, are profoundly affected following the diagnosis of prostate cancer. Poor communication between spouses during prostate cancer increases the risk for poor adjustment to prostate cancer. The use of serum prostate-specific antigen to screen for prostate cancer has led to a greater detection, in its early stage, of this cancer. Prostate cancer is the most common malignancy in American men, accounting for more than 29% of all diagnosed cancers and about 13% of all cancer deaths. A shortened course of hormonal therapy with docetaxel following radical prostatectomy (or radiation therapy) for high-risk prostate cancer has been shown to be both safe and feasible. Patients treated with docetaxel-estramustine had a prostate-specific antigen response decline of at least 50%. Cancer vaccines are an immune-based cancer treatment that may provide the promise of a non-toxic but efficacious therapeutic alternative for cancer patients. Further studies will elucidate improved methods of detection and treatment.

Primary care perspective and implementation of a multidisciplinary, institutional prostate cancer screening algorithm embedded in the electronic health record

PURPOSE

In response to controversy regarding prostate cancer (CaP) screening recommendations, a consolidated Duke Cancer Institute (DCI) multidisciplinary algorithm for CaP screening was developed and implemented. We conducted an online survey within the year following its implementation to assess primary care provider (PCP) attitudes and adoption as well as to evaluate how this program affects screening rates.

METHODS

A web-based 18-item survey was programmed and was electronically mailed to practicing PCPs at clinics affiliated with the Duke Primary Care system. The survey assessed provider practices and attitudes regarding CaP screening, factors that influenced their general screening recommendations and the confidence related to communicating with patients about screening. The rate of PSA screening before and after implementation of the algorithm was reported across age and race categories.

RESULTS

In sum, 94 of 106 respondents (88.6%) reported discussing the benefits and harms of screening and let their patients decide (52.8%) or recommended for (31.1%) or against (4.7%) screening. Three-fourths of respondents followed a specific panel recommendation such as the United States Preventative Services Task Force (USPSTF) (48.1%), DCI (20%), or the American Urological Association (AUA) (7.4%) guidelines. After integrating this algorithm into the electronic health record, the rate of prostate screening increased between 11% and 20.4% and 15.6% and 16.4% among different age and race categories, respectively. Overall, 79.2% of PCPs felt very confident regarding their ability to communicate the topic of CaP screening with patients.

CONCLUSION

The DCI multidisciplinary CaP screening algorithm was well adopted among PCPs shortly after its implementation. The rate of screening increased among all age and race categories thereafter. The majority of PCPs involved in this survey felt confident regarding their CaP screening knowledge and most discuss this topic with patients in a shared decision-making model.

Multigene panels in prostate cancer risk assessment: a systematic review

PURPOSE

Single-nucleotide polymorphism (SNP) panel tests have been proposed for use in the detection of, and prediction of risk for, prostate cancer and as prognostic indicator in affected men. A systematic review was undertaken to address three research questions to evaluate the analytic validity, clinical validity, clinical utility, and prognostic validity of SNP-based panels.

METHODS

Data sources comprised MEDLINE, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, and EMBASE; these were searched from inception to April 2013. The gray-literature searches included contact with manufacturers. Eligible studies included English-language studies evaluating commercially available SNP panels. Study selection and risk of bias assessment were undertaken by two independent reviewers.

RESULTS

Twenty-one studies met eligibility criteria. All focused on clinical validity and evaluated 18 individual panels with 2 to 35 SNPs. All had poor discriminative ability (overall area under receiver-operator characteristic curves, 58-74%; incremental gain resulting from inclusion of SNP data, 2.5-11%) for predicting risk of prostate cancer and/or distinguishing between aggressive and asymptomatic/latent disease. The risk of bias of the studies, as assessed by the Newcastle Ottawa Scale (NOS) and Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tools, was moderate.

CONCLUSION

The evidence on currently available SNP panels is insufficient to assess analytic validity, and at best the panels assessed would add a small and clinically unimportant improvement to factors such as age and family history in risk stratification (clinical validity). No evidence on the clinical utility of current panels is available.Genet Med 18 6, 535-544.

Screening for prostate cancer in the US? Reduce the harms and keep the benefit

While the benefit of prostate-specific antigen (PSA) based screening is uncertain, a significant proportion of screen-detected cases is overdiagnosed. In order to make screening worthwhile, it is necessary to find policies that minimize overdiagnosis, without significantly increasing prostate cancer mortality (PCM). Using a microsimulation model (MISCAN) we project the outcomes of 83 screening policies in the US population, with different start and stop ages, screening frequencies, strategies where the PSA value changes the screening frequency, and strategies in which the PSA threshold (PSAt) increases with age. In the basecase strategy, yearly screening 50-74 with a PSAt of 3, the lifetime risk of PCM and overdiagnosis equals, respectively, 2.4 and 3.8%. The policies that reduce overdiagnosis the most (for maximum PCM increases relative to basecase of 1%, 3%, and 5%, respectively) are with a PSAt of 3, (1) yearly screening 50-74 where, if PSA <1 at age 65 or older, frequency becomes 4 years, with 3.6% (5.9% reduction), (2) 2-year screening 50-72, with 2.9% (24.3% reduction), and (3) yearly screening 50-70 (PSAt of 4 after age 66), with 2.2% (43.4% reduction). Stopping screening at age 70 is a reasonable way to reduce the harms and keep the benefit. Decreasing the stopping age has a larger effect on overdiagnosis reduction than reducing the screen frequency. Screening policies where the frequency of screening depends on PSA result or in which the PSAt changes with age did not substantially improve the balance of harms and benefits relative to simple yearly screening.

Efficacy of Repeated Transrectal Prostate Biopsy in Men Younger Than 50 Years With an Elevated Prostate-Specific Antigen Concentration (>3.0 ng/mL): Risks and Benefits Based on Biopsy Results and Follow-up Status

PURPOSE

Prostate cancer is rare in men younger than 50 years. Digital rectal examination (DRE) and measurement of prostate-specific antigen (PSA) concentrations are standard screening methods for detecting prostate cancer. We retrospectively investigated the risks and benefits of repeated transrectal ultrasonography-guided prostate needle biopsies in relation to the follow-up status of men younger than 50 years with a consistently high PSA concentration (>3.0 ng/mL).

MATERIALS AND METHODS

During the period from January 2000 through February 2013, we reviewed patient's ages, dates of procedures, DRE results, frequencies of biopsies, results of the biopsies, periods of follow-up, PSA concentrations, and prostate volumes in Chonbuk National University Hospital records. We conducted telephone interviews in patients who did not undergo regular follow-up.

RESULTS

The mean age of the patients was 44.7 years, and the mean PSA concentration was 8.59 ng/mL (range, 3.04-131 ng/mL) before biopsy. The PSA concentration was significantly different (p<0.001) between the patients with prostate cancer and those with benign prostatic hyperplasia (BPH). Nineteen patients underwent repeated prostate biopsy; however, in only one patient did the pathologic findings indicate a change from BPH to prostate cancer. We identified several complications after transrectal biopsy through an evaluation of follow-up data.

CONCLUSIONS

All patients with benign prostatic disease based on their first biopsy were shown to have benign disease based on all repeated biopsies (15.83%), except for one patient; however, several complications were noted after biopsy. Therefore, the risks and benefits of repeated biopsy in young patients should be considered because of the low rate of change from benign to malignant disease despite continuously high PSA concentrations (>3.0 ng/mL).

Emerging PSA-based tests to improve screening

This article updates advances in prostate cancer screening based on prostate-specific antigen, its derivatives, and human kallikrein markers. Many men are diagnosed with indolent disease not requiring treatment. Although there is evidence of a survival benefit from screening, the numbers needed to screen and treat remain high. There is risk of exposing men to the side effects of treatment for nonthreatening disease. A screening test is needed with sufficiently good performance characteristics to detect disease at an early stage so treatment may be offered with curative intent, while reducing the number of negative or unnecessary biopsies.

Men (aged 40-49 years) with a single baseline prostate-specific antigen below 1.0 ng/mL have a very low long-term risk of prostate cancer: results from a prospectively screened population cohort

OBJECTIVE

To study the use of a baseline prostate-specific antigen (PSA) and digital rectal examination in men (aged 40-49 years) in predicting long-term prostate cancer risk in a prospectively followed, representative population cohort.

PATIENTS AND METHODS

Since 1990, a random sample of men in Olmsted County (aged 40-49 years) has been followed up prospectively (n = 268), with biennial visits, including a urologic questionnaire, PSA screening, and physical examination. The ensuing risk of prostate cancer (CaP) was compared using survival analyses.

RESULTS

Median follow-up was 16.3 years (interquartile range 14.0-17.3, max 19.1). For men with a baseline PSA <1.0 ng/mL (n = 195), the risk of subsequent Gleason 6 CaP diagnosis by 55 years was 0.6% (95% confidence interval [CI] 0%-1.7%) and 15.7% (95% CI 6.5%-24.9%) for men with a baseline PSA ≥ 1.0 ng/mL. No man with a low baseline PSA developed an intermediate or high risk CaP, whereas 2.6% of men with a higher baseline PSA did (95% CI 0.58%-4.6%).

CONCLUSION

Men (aged 40-49 years) can be stratified with a baseline PSA. If it is below 1.0 ng/mL, there is very little risk for developing a lethal CaP, and as many as 75% of men might be able to avoid additional PSA screening until 55 years. Conversely, men aged 40-49 years with a baseline PSA level >1.0 ng/mL had a significant risk of CaP diagnosis and should be monitored more closely.

The prostate-specific antigen test

Before the 1980s, prostate cancer (PC) was considered a deadly disease. The mortality-incidence ratio showed that 1 out of each 2 - 3 PC patients died of this disease. On the other hand, autopsy studies have shown that latent PC is common in middle-aged men. The prostate-specific antigen (PSA), a glycoprotein produced by the epithelial cells of the prostate gland, received FDA's approval in 1986 for monitoring treatment response, and in 1994 as a screening aid for the diagnosis of PC. After the publication of two randomized trials on PC screening using the PSA test, it is generally accepted that systematic PSA-based screening, as compared to a clinical situation with virtually no screening, can reduce suffering from metastatic disease and PC mortality. However, what is also shown is that PSA-based screening coincides with a considerable amount of unnecessary testing and overdiagnosis. Should we abandon the use of the PSA test for the diagnosis of PC, or should we encourage PSA testing and make it freely available for all men at any time? Both the answers should be "No." What we must do is use the test as wisely as is currently possible and inform men, who want to be tested, in a balanced way about harms and potential benefits.

Comparison of oncologic outcomes after radical prostatectomy in men diagnosed with prostate cancer with PSA levels below and above 4 ng/mL

PURPOSE

To assess whether the PSA level (threshold 4 ng/mL) is a prognostic factor in biochemical recurrence-free survival in men with prostate cancer (PCa) with an initial PSA level <10 ng/mL who underwent robotic-assisted laparoscopic radical prostatectomy (RARLP).

METHODS

We prospectively recruited data for consecutive patients treated by RARLP for PCa with an initial PSA level below 10 ng/mL between 2003 and 2011 at our institution. We divided the population into two groups: patients with a PSA level below 4 ng/mL (G1; n = 53) and patients with a PSA level between 4 and 10 ng/mL (G2; n = 371). Biochemical recurrence was defined as a single increase in PSA greater than 0.2 ng/mL after surgery. Multivariate analysis was used to assess prognostic factors of recurrence-free survival.

RESULTS

Overall, 424 patients were included, and the median age was 62 (58-67) years. The median PSA was 5.8 ng/mL (4.8-7.7 ng/mL). Overall, 6 patients from G1 and 34 patients from G2 experienced a biochemical recurrence. Overall, the 5-year recurrence-free survival rate was 86.6 %. The PSA level at diagnosis (under or over 4 ng/mL) was not significantly linked to recurrence-free survival (HR = 0.59, p = 0.25). However, positive margins and a Gleason score >7 on the specimen were significantly linked to recurrence-free survival with respective hazard ratios of 4.30 (p < 0.0001) and 6.18 (p < 0.0001), respectively.

CONCLUSION

A PSA level <4 ng/mL alone appears to be obsolete as a cut-off to define a population of men likely to have indolent disease.