Screening for prostate cancer---the controversy continues, but can it be resolved?

Serum Autoantibodies in Chronic Prostate Inflammation in Prostate Cancer Patients

BACKGROUND

Chronic inflammation is frequently observed on histological analysis of malignant and non-malignant prostate specimens. It is a suspected supporting factor for prostate diseases and their progression and a main cause of false positive PSA tests in cancer screening. We hypothesized that inflammation induces autoantibodies, which may be useful biomarkers. We aimed to identify and validate prostate inflammation associated serum autoantibodies in prostate cancer patients and evaluate the expression of corresponding autoantigens.

METHODS

Radical prostatectomy specimens of prostate cancer patients (N = 70) were classified into high and low inflammation groups according to the amount of tissue infiltrating lymphocytes. The corresponding pre-surgery blood serum samples were scrutinized for autoantibodies using a low-density protein array. Selected autoantigens were identified in prostate tissue and their expression pattern analyzed by immunohistochemistry and qPCR. The identified autoantibody profile was cross-checked in an independent sample set (N = 63) using the Luminex-bead protein array technology.

RESULTS

Protein array screening identified 165 autoantibodies differentially abundant in the serum of high compared to low inflammation patients. The expression pattern of three corresponding antigens were established in benign and cancer tissue by immunohistochemistry and qPCR: SPAST (Spastin), STX18 (Syntaxin 18) and SPOP (speckle-type POZ protein). Of these, SPAST was significantly increased in prostate tissue with high inflammation. All three autoantigens were differentially expressed in primary and/or castration resistant prostate tumors when analyzed in an inflammation-independent tissue microarray. Cross-validation of the inflammation autoantibody profile on an independent sample set using a Luminex-bead protein array, retrieved 51 of the significantly discriminating autoantibodies. Three autoantibodies were significantly upregulated in both screens, MUT, RAB11B and CSRP2 (p>0.05), two, SPOP and ZNF671, close to statistical significance (p = 0.051 and 0.076).

CONCLUSIONS

We provide evidence of an inflammation-specific autoantibody profile and confirm the expression of corresponding autoantigens in prostate tissue. This supports evaluation of autoantibodies as non-invasive markers for prostate inflammation.

Effects of prostate cancer screening on health-related quality of life: results of the Finnish arm of the European randomized screening trial (ERSPC)

BACKGROUND

As prostate cancer (PC) mortality reduction results are not unequivocal, a special emphasis has to be put on other aspects of the prostate-specific antigen (PSA) screening, including effects on quality of life. In the present study we describe the short-term effects of various phases of PC screening on health-related quality of life (HRQL).

MATERIAL AND METHODS

The study participants were randomized into the screening arm within the Finnish component of the European Randomized Study on Screening for Prostate Cancer (ERSPC). The RAND 36-Item Health Survey on HRQL and questionnaires on sociodemographic and behavioral factors were delivered to participants at various phases of the first screening round: 1) 500 participants at invitation; 2) 500 after screening; 3) 500 after obtaining the PSA result; 4) to 300 participants after undergoing digital rectal examination (DRE) (but prior to being informed of its result); and 5) approximately 300 after prostate biopsy. At each stage, a new sample of participants was recruited.

RESULTS

Response rates were 59% at invitation, 77% after PSA blood test, 54% after PSA result and 69% after DRE. The men recruited at each stage were comparable in respect to socioeconomic variables. The HRQL scores in RAND-36 subscales showed little variation in the different phases of the screening process. Compared with the previous phase, the social function score was slightly lower after obtaining the PSA result than after blood test, the emotional role score lower after DRE than after PSA result and the pain-related score lower after DRE than after TRUS and biopsy. The screening participants were comparable to the general population as their HRQL scores were similar to an age-stratified general Finnish male population.

CONCLUSION

Short-term HRQL effects of prostate cancer screening appear minor and transient.

Estimates of cancer burden in Liguria

Aims and background

The regional health care system of Liguria caters for a resident population which is among the oldest in Europe. One population-based cancer registry is present in the region, providing incidence and survival data for the Genoa province (covering 55% of the regional population). This paper will estimate the incidence, prevalence and mortality in the Liguria region for cancers of the lung, breast, prostate, colon-rectum, stomach and uterine cervix and melanoma of the skin in 1970—2015.

Methods

The estimated figures were obtained by applying the MIAMOD method. Starting from mortality and survival data, incidence and prevalence were derived using a statistical back-calculation approach. Survival was modeled on the basis of published data from the Italian cancer registries. The MIAMOD method was applied also to estimate the colorectal cancer incidence, mortality and prevalence rates in the Ligurian provinces in the period 1988—2015.

Results

In 2012 about 1,500 new cases of breast cancer were expected in Ligurian women. The estimates for the other cancer sites were considerably lower, ranging from 839 (colon-rectum) to 54 (cervix). In men about 1,400 new cases were estimated for prostate cancer, while the incidence for the other sites ranged from 1,118 (colon-rectum) to 208 (skin melanoma). The breast cancer prevalence rate was more than 10 times the incidence rate in women, and the lung cancer prevalence rate was more than double the incidence rate in both sexes. Mortality rates were highest for lung cancer in men and breast cancer in women; the lowest rates were estimated for melanoma and cancer of the uterine cervix.

Conclusion

In Liguria a large portion of the health expenditure has been devoted to diagnostic and therapeutic resources. This may have contributed to the reduction of mortality rates and to the improvement of cancer survival. This phenomenon, added to population aging, will inflate the cancer prevalence. One of the major challenges for the Liguria region is to face the increasing demand for oncology services.

Rastreamento do câncer de mama: as três luzes do semáforo

A interpretação do rastreamento do câncer de mama como um semáforo com três luzes convida a uma revisão rápida da evidência científica e à retenção dos principais pontos que esse procedimento revela. As recomendações a favor do rastreamento são produzidas por autores que conferem a ele uma luz verde, de avanço, porque acreditam que o saldo risco/benefício é favorável a sua aplicação em mulheres em idades-alvo e com risco médio. Mas, tal como a própria expressão risco/benefício sugere, existe um risco que deverá ser levado em conta no início do rastreamento, um alerta que assume a luz vermelha. É notório, pela evidência avaliada por autores independentes, que existe uma relação entre prós e contras (luz amarela). O papel de salvaguardar o equilíbrio dessa balança pertencerá, talvez, ao médico de família, cabendo, então, em última instância, à mulher em idade-alvo colocar o último peso sobre um dos dois pratos.

Risk stratification in prostate cancer screening

Screening for prostate cancer is a controversial topic within the field of urology. The US Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial did not demonstrate any difference in prostate-cancer-related mortality rates between men screened annually rather than on an 'opportunistic' basis. However, in the world's largest trial to date--the European Randomised Study of Screening for Prostate Cancer--screening every 2-4 years was associated with a 21% reduction in prostate-cancer-related mortality rate after 11 years. Citing the uncertain ratio between potential harm and potential benefit, the US Preventive Services Task Force recently recommended against serum PSA screening. Although this ratio has yet to be elucidated, PSA testing--and early tumour detection--is undoubtedly beneficial for some individuals. Instead of adopting a 'one size fits all' approach, physicians are likely to perform personalized risk assessment to minimize the risk of negative consequences, such as anxiety, unnecessary testing and biopsies, overdiagnosis, and overtreatment. The PSA test needs to be combined with other predictive factors or be used in a more thoughtful way to identify men at risk of symptomatic or life-threatening cancer, without overdiagnosing indolent disease. A risk-adapted approach is needed, whereby PSA testing is tailored to individual risk.

Hiperplasia Prostática Benigna e PSA: o efeito dominó

Após a publicação de uma recomendação contra o rastreio câncer prostático pela U.S. Preventive Services Task Force, a comunidade médica não poderá desvincular-se das particularidades relacionadas com o antígeno prostático específico (PSA). O enfoque dado às guidelines da Hiperplasia Prostática surge pela possível partilha, a determinado ponto da sua abordagem, de um trilho que cursa também com a solicitação do PSA. Os resultados de dois grandes ensaios clínicos constituem o maior corpo da evidência actual e deles sobressai que o número de homens que evitaram a morte por câncer prostático após submetidos ao rastreio foi reduzido. Há evidência de que 100-200 em 1000 homens rastreados terão um falso-positivo, a maioria dos quais será biopsada, com possíveis danos psicológicos e orgânicos. O Médico de Família deverá relembrar que não é recomendado que se ofereça esta análise, sem que primeiro discuta, juntamente com o paciente, as questões inerentes ao PSA.

Expression changes in the stroma of prostate cancer predict subsequent relapse

Biomarkers are needed to address overtreatment that occurs for the majority of prostate cancer patients that would not die of the disease but receive radical treatment. A possible barrier to biomarker discovery may be the polyclonal/multifocal nature of prostate tumors as well as cell-type heterogeneity between patient samples. Tumor-adjacent stroma (tumor microenvironment) is less affected by genetic alteration and might therefore yield more consistent biomarkers in response to tumor aggressiveness. To this end we compared Affymetrix gene expression profiles in stroma near tumor and identified a set of 115 probe sets for which the expression levels were significantly correlated with time-to-relapse. We also compared patients that chemically relapsed shortly after prostatectomy (<1 year), and patients that did not relapse in the first four years after prostatectomy. We identified 131 differentially expressed microarray probe sets between these two categories. 19 probe sets (15 genes overlapped between the two gene lists with p<0.0001). We developed a PAM-based classifier by training on samples containing stroma near tumor: 9 rapid relapse patient samples and 9 indolent patient samples. We then tested the classifier on 47 different samples, containing 90% or more stroma. The classifier predicted the risk status of patients with an average accuracy of 87%. This is the first general tumor microenvironment-based prognostic classifier. These results indicate that the prostate cancer microenvironment exhibits reproducible changes useful for predicting outcomes for patients.

Management of prostate cancer

Prostate cancer is diagnosed in 37 000 new patients a year, and causes 10 000 deaths each year in the UK (Cancer Research UK, 2011). Diagnoses are increasingly the result of screening using measurement of prostate- specific antigen levels. The natural history of early disease is unclear. Autopsy studies before prostate-specific antigen screening showed an actual latent prevalence (not diagnosed during life) of around 30% at the age of 50 years and 75% at the age of 80 years, and many of these demonstrated local invasion (Franks, 1954). One of the main current challenges in urology is distinguishing indolent prostate cancers from potentially lethal ones. The specificity of the prostate-specific antigen test for clinically significant disease remains disappointingly low and population screening is not encouraged (Ilic et al, 2011). However, prostate-specific antigen testing is often done in good faith, but pre-test counselling is essential. Thus, prostate-specific antigen testing should only be undertaken by the patient's GP or on the advice of a urologist.

Screening for oesophageal cancer

Oesophageal cancer is a global health problem with high mortality due to the advanced nature of the disease at presentation; therefore, detection at an early stage significantly improves outcome. Oesophageal squamous-cell cancer is preceded by dysplasia and oesophageal adenocarcinoma is preceded by Barrett's oesophagus, which progresses to cancer via intermediate dysplastic stages. Screening to detect these preneoplastic lesions has the potential to substantially reduce mortality and morbidity. However, the risks and benefits of such programmes to individuals and to society need to be carefully weighed. Endoscopic screening is invasive, costly and error prone owing to sampling bias and the subjective diagnosis of dysplasia. Non-endoscopic cell-sampling methods are less invasive and more cost effective than endoscopy, but the sensitivity and specificity of cytological assessment of atypia has been disappointing. The use of biomarkers to analyse samples collected using pan-oesophageal cell-collection devices may improve diagnostic accuracy; however, further work is required to confirm this. The psychological and economic implications of screening as well as the feasibility of implementing such programmes must also be considered.

Differentiation of lethal and non lethal prostate cancer: PSA and PSA isoforms and kinetics

Prostate-specific antigen (PSA) testing for the early diagnosis of prostate cancer has led to a decrease in cancer mortality. However, the high prevalence of low-grade prostate cancer and its long natural history, competing causes of death in older men and treatment patterns of prostate cancer, have led to dramatic overtreatment of the disease. Improved markers of prostate cancer lethality are needed to reduce the overtreatment of prostate cancer that leads to a reduced quality of life without extending life for a high proportion of men. The PSA level prior to treatment is routinely used in multivariable models to predict prostate cancer aggressiveness. PSA isoforms and PSA kinetics have been associated with more aggressive phenotypes, but are not routinely employed as part of prediction tools prior to treatment. PSA kinetics is a valuable marker of lethality post treatment and routinely used in determining the need for salvage therapy.