Definition

 • a malignant epithelial tumour arising in the prostate.

Epidemiology

 • The most common malignant tumour in men, accounting for about 25% of all male cancers.

• about 1 in 8 men will develop prostate cancer in their lifetime.

• Prevalence rising due to longer life expectancy and increased detection rates.

• a less prominent cause of cancer- related deaths, as many cases behave in a relatively indolent fashion.

Aetiology

 • Racial background and genetic factors are important, with a 5- to 10- fold increased risk in men with two or more affected first- degree relatives.

• Dietary association with animal products, particularly red meat.

Carcinogenesis

• arises from a precursor lesion known as prostatic intraepithelial neoplasia (PIN), characterized by neoplastic transformation of the epithelium lining of the prostatic ducts and acini.

• Harbour mutations in a number of genes, including GST-pi, PTEN, AMACR, p27, and E-cadherin (note these are not classical tumour suppressor genes or oncogenes).

Presentation

• The vast majority of prostate cancers are diagnosed early following investigation of a raised serum prostate- specific antigen (PSA) level.

• More advanced localized disease may be present with a suspicious- feeling prostate on digital rectal examination or lower urinary tract symptoms.

• Rarely, patients present with symptoms of metastatic disease.

 Diagnosis

• Patients with raised PSA are usually referred for MRI of the prostate to identify suspicious areas that may be targeted for biopsy.

 • Prostate biopsy may be performed via a transperineal or transrectal route. The transperineal route carries a much lower risk of introducing infection into the prostate gland.

 Histopathology

 • The most common type of prostate cancer is acinar adenocarcinoma, in which the malignant epithelial cells form glandular structures.

• One of the key diagnostic features of prostate cancer is the abnormal architecture of the malignant glands which are crowded and show infiltration between benign glands and ducts.

• Malignant epithelial cells have enlarged nuclei with prominent nucleoli and denser amphophilic cytoplasm.

• Malignant glands often have intraluminal crystalloids (dense crystal- like structures), amorphous pink secretions, or blue- tinged mucin.

Gleason scoring

 • Prostate cancers are graded using the Gleason scoring system.

• Gleason scores are expressed in the format x +y =z and are based on the two most common Gleason patterns present in the tumour.

• Gleason patterns range from 1 to 5 and are based on the architectural growth of the tumour.

 • in practice, patterns 1 and 2 are never diagnosed, and so all prostate cancers have a Gleason score of between 6 and 10.

 • Gleason pattern 3 is composed of well- formed discrete glandular units (Fig. 1).

• Gleason pattern 4 is composed of poorly formed, fused, or cribriform glands (Fig. 2).

 • Gleason pattern 5 is composed of solid sheets, cords, or single cells showing no glandular differentiation.

 Immunohistochemistry

 • Prostate cancer cells are typically positive for PSA and CK7 whilst being negative for CK20.

• Basal cell markers (e.g. p63 or cytokeratin 5, are often used to confirm a morphological diagnosis of prostate cancer by demonstrating absence of basal cells around the cancer glands).

Fig1. Gleason pattern 3 prostate adenocarcinoma composed of individual well- formed glandular acini (see Plate 33).

Fug2. Gleason pattern 4 prostate adenocarcinoma composed of fused poorly formed glands (see Plate 34).

Prognosis

 • The Gleason score is a powerful prognostic indicator, with a higher score associated with a worse outcome.

• Other important factors include the serum PSA level and the stage of the disease.

Prostate cancer screening

• Screening using serum PSA is a controversial subject.

• at present, most countries do not operate an organized prostate screening programme.

• Current evidence suggests that screening would result in overdiagnosis and overtreatment of many men with prostate cancers that are unlikely to behave in an aggressive manner.

مواضيع ذات صلة

العوامل البيئية المسببة للسرطان

الأورام الصماوية للبنكرياس

متلازمة الأورام الغدية الصماوية المتعددة Multiple Endocrine Neoplasia (MEN) Syndrome

خصائص الخلايا السرطانية

Testicular germ cell tumours

Renal cell carcinoma

المسببات الكيميائية للسرطان chemical causes of cancer

الوراثة والسرطان Genes associated with cancer

السرطان اللبي ( النخاعي ) Medullary carcinoma

Hepatocellular carcinoma (liver cell cancer)

تدبير سرطانات الدرق المتمايزة بعد الجراحة

السرطان الحليمي Papillary carcinoma