Facteurs de risque génétiques pour le cancer de la prostate

Prostate Cancer among Patients Undergoing Radical Cystoprostatectomy for Bladder Cancer in the Department of Urology in a Tertiary Care Centre

Introduction

Prostate cancer is the most common malignancy in men and remains one of the most prevalent and least understood of all human malignancies. Bladder cancer is the most frequently diagnosed cancer in China. Radical cystectomy remains the gold standard for muscle-invasive, recurrent and multiple bladder cancer. All male patients undergoing radical cystoprostatectomy must be evaluated for prostate cancer before planning surgery. The aim of this study was to find out the prevalence of prostate cancer among patients undergoing radical cystoprostatectomy undergoing surgery for bladder cancer.

Methods

A descriptive cross-sectional study was conducted in a tertiary care centre from 1 August 2023 to 30 August 2023 where data from 1 January 2015 to 30 December 2017 was taken from medical records after obtaining ethical approval from the Ethical Review Board. All patients who underwent radical cystoprostatectomy were included in the study. Whole radical cystoprostatectomy specimens were cut transversely at 3 mm intervals and examined in the same pathological centre. Clinically significant prostate cancer was defined as a tumour with a Gleason pattern ≥4, prostate tumour with clinical stage ≥pT3, lymph node. involvement, positive surgical margin or multifocality of three or more lesions. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval.

Results

Among 210 patients, 52 (24.76%) (18.92-30.60, 95% Confidence Interval) had incidental prostate cancer. The average age of patients with incidental prostate cancer was 65.88±9.54 years.

Conclusions

The prevalence of incidental prostate cancer was found to be lower than the study conducted in a similar setting.

Keywords

bladder cancer; incidental findings; prostate cancer.

Prostate cancer: The main risk and protective factors-Epigenetic modifications

With 13 million new cases worldwide every year, prostate cancer is as a very real public health concern. Prostate cancer is common in over-50s men and the sixth-leading cause of cancer-related death in men worldwide. Like all cancers, prostate cancer is multifactorial - there are non-modifiable risk factors like heredity, ethnicity and geographic location, but also modifiable risk factors such as diet. Diet-cancer linkages have risen to prominence in the last few years, with accruing epidemiological data pointing to between-population incidence differentials in numerous cancers. Indeed, there are correlations between fat-rich diet and risk of hormone-dependent cancers like prostate cancer and breast cancer. Diet is a risk factor for prostate cancer, but certain micronutrients in specific diets are considered protective factors against prostate cancer. Examples include tomato lycopene, green tea epigallocatechin gallate, and soy phytoestrogens. These micronutrients are thought to exert cancer-protective effects via anti-oxidant pathways and inhibition of cell proliferation. Here, we focus in on the effects of phytoestrogens, and chiefly genistein and daidzein, which are the best-researched to date. Soy phytoestrogens are nonsteroid molecules whose structural similarity lends them the ability to mimic the effects of 17ß-estradiol. On top of anti-oxidant effects, there is evidence that soy phytoestrogens can modulate the epigenetic modifications found in prostate cancer. We also studied the impact of phytoestrogens on epigenetic modifications in prostate cancer, with special focus on DNA methylation, miRNA-mediated regulation and histone modifications.

[Constitutional risk factors in prostate cancer]

INTRODUCTION

The aim of this review is to update and divulge the main constitutional risk factors involved in the etiopathology of prostate cancer.

MATERIALS AND METHODS

Bibliographic review of the scientific literature on the constitutional risk factors associated with prostate cancer between 1985 and 2010, obtained from MedLine, CancerLit, Science Citation Index and Embase. The search profiles were Risk Factors, Genetic Factors, Genetic Polymorphisms, Genomics, Etiology, Epidemiology, Hormonal Factors, Endocrinology, Primary Prevention and Prostate Cancer.

RESULTS

The principal constitutional risk factors are: age (before the age of 50 years at least 0.7% of these neoplasms are diagnosed and between 75-85% are diagnosed after the age of 65 years), ethnic-racial and geographic (African Americans present the highest incidence rates, and the lowest are found in South East Asia), genetic, family and hereditary (family syndromes cover 13-26% of all prostate cancers, of which 5% are of autosomal dominant inheritance), hormonal (it is a hormone-dependent tumour), anthropometric (obesity increases the risk), perinatal, arterial hypertension and type 2 diabetes.

CONCLUSIONS

Constitutional risk factors play a very important role in the etiopathology of prostate cancer, especially age, ethnic-racial-geographic factors and genetic-family factors. We cannot know what percentage of these neoplasms are a result of constitutional factors, because our knowledge of these factors is currently lacking.

[RNase L, a crucial mediator of innate immunity and other cell functions]

The 2-5A/RNase L pathway is one of the first cellular defences against viruses. RNase L is an unusual endoribonuclease which activity is strictly regulated by its binding to a small oligonucleotide, 2-5A. 2-5A itself is very unusual, consisting of a series of 5'- triphosphorylated oligoadenylates with 2'-5' bonds. But RNase L activity is not limited to viral RNA cleavage. RNase L plays a central role in innate immunity, apoptosis, cell growth and differentiation by regulating cellular RNA stability and expression. Default in its activity leads to increased susceptibility to virus infections and to tumor development. RNase L gene has been identified as HPC1 (Hereditary Prostate Cancer 1) gene. Study of RNase L variant R462Q in etiology of prostate cancer has led to the identification of the novel human retrovirus closely related to xenotropic murine leukemia viruses (MuLVs) and named XMRV.

Implications of insulin-like growth factor-I for prostate cancer therapies

In the last decade, abundant evidence has suggested that the insulin-like growth factor (IGF) family comprises a multi-component network of molecules involved in the regulation of both physiological and pathological growth processes in the prostate. The IGF axis plays an important role in the tumorigenesis and neoplastic growth of prostate cancer. Epidemiological observations indicate that circulating IGF-I levels are positively associated with increased risk of prostate cancer. Activation of IGF-I receptor (IGF-IR) by IGF-I has mitogenic and anti-apoptotic effects on normal and malignant prostate cells. Therapeutic alternatives in men with progressive prostate cancer after androgen ablation are very limited and more effective therapies are needed for such patients. Inactivation of the IGF-I axis represents a potential target to treat androgen-independent prostate cancer. This review addresses epidemiological studies of IGF-I and therapeutic strategies including reduction of IGF-I levels, inhibition of IGF-IR and the signaling mechanisms involved.

Insulin-Like Growth Factor (IGF) family and prostate cancer

There is abundant in vitro, animal and epidemiologic evidence to suggest that the Insulin-Like Growth Factor (IGF) family is a multi-component network of molecules which is involved in the regulation of both physiological and pathological growth processes in prostate. The IGF family plays a key role in cellular metabolism, differentiation, proliferation, transformation and apoptosis, during normal development and malignant growth. This family also seem essential in prostate cancer bone metastases, angiogenesis and androgen-independent progression. Therapeutic alternatives in men with progressive prostate cancer after androgen ablation are very limited. More effective therapies are needed for these patients. Pharmacologic interventions targeting the IGF family are being devised. Such strategies include reduction of IGF-I levels (growth hormone-releasing hormone antagonists, somatostatin analogs), reduction of functional IGF-I receptor levels (antisense oligonucleotides, small interfering RNA), inhibition of IGF-IR and its signalling (monoclonal antibodies, small-molecule tyrosine kinase inhibitors) and Insulin-Like Growth Factor Binding Proteins.