Facts about prostate cancer

Dr Nirasha Chiranjan gives us a rundown on the facts about prostate cancer.

Prostate cancer is among the most common cancers in men worldwide, with an estimated 1 600 000 cases and 366 000 deaths annually. The incidence generally rising with age; it is more likely to develop in older men, age 65 and older. The overall five-year survival rate is over 98%. 

In developed areas, prostate cancer is increasingly being diagnosed when the tumour is confined to the prostate, due at least in part to screening with prostate-specific antigen (PSA).

Risk factors

• Age: The incidence increases after the age of 40. 
• Ethnicity: More common in black men than Caucasian men.
• Family history and genetic factors: Men with a family history of prostate cancer, especially first-degree relatives are at an increased risk. Also, having a family history of other heritable cancers (e.g. breast-, colorectal-, ovarian- and pancreatic cancer) also increases the risk of prostate cancer.
• Diet: A diet high in animal fat and low in vegetables may be a strong factor in the development. Tomato-based products that are high in lycopene; coffee; and soy intake may be preventative.
• Cigarette smoking: This influences both the risk of developing it and its prognosis. 
• Obesity: This can increase the risk.

Symptoms 

• Asymptomatic 
• Haematuria (blood in the urine)
• Inability to void
• Urinary incontinence
• Erectile dysfunction
• Fatigue
• Haematospermia (blood in the ejaculate) 
• Bone pain

Signs

• Elevated PSA. PSA is a protein made by prostate cells.
• Abnormal prostate findings on digital rectal examination (prostate nodules, induration and asymmetry).

It’s important to note that PSA is not specific for malignancy and can be elevated in certain benign conditions, like prostatitis, perineal trauma and benign prostatic hyperplasia. Additionally, a normal PSA reading doesn’t rule out the possibility of prostate cancer. 

Diagnosis

A prostate biopsy is needed to make the diagnosis of prostate cancer. Architectural features of the cells in the biopsy tissue are used to generate a Gleason Score which correlates with prognosis and determines treatment options. 

The Gleason Score is categorised according to grade groups from 1 to 5 and describes how much the cancer from the biopsy looks like healthy tissue (low score) or abnormal tissue (high score). 

Imaging

Transrectal ultrasound, CT scan, bone scan, MRI scan and PSMA PET CT are all useful tools to assess the loco-regional extent of disease and distant metastases. 

Treatment options

The most important factors in selecting the initial treatment include:

• Anatomic extent of disease (tumour, node, metastasis [TNM] stage).
• Histologic grade (Gleason Score/grade group) and molecular characteristics of the tumour.
• Serum PSA level.
• Estimated outcome with different treatment options.
• Potential complications with each treatment approach.
• The patient’s general medical condition, age, and comorbidity, as well as individual preferences.

1.    Active surveillance 

Serial monitoring of the prostate cancer with PSA levels, digital rectal examinations, repeat prostate biopsies and imaging. There is initiation of definitive treatment if there is evidence of progression. Reserved for patients with low-risk prostate cancer.

2.    Radical prostatectomy 

Removing the entire prostate gland through surgery is a common option for men whose cancer hasn’t spread. It may be carried out with either an open or minimally-invasive approach. Lymph node dissection is optional for those with low-risk disease.

3.   Hormone therapy 

Also known as androgen deprivation therapy (ADT), this blocks testosterone from being produced or blocks it from working on the prostate cancer cells. It’s used in advanced or metastatic prostate cancer. 

4.    Prostate brachytherapy 

Prostate brachytherapy is a form of internal radiation therapy used to treat prostate cancer. It’s an established and effective treatment. It involves placing temporary or permanent radioactive sources into the prostate tissue. This allows high doses of radiation to be delivered to the cancer cells within the prostate gland whilst reducing radiation of normal tissues. 

A major advantage of brachytherapy is that it can be completed within 1-2 days with little time lost from normal activities. Depending on the risk category of the patient, it can be used alone or in combination with external beam radiotherapy. 

New developments in prostate brachytherapy include its use in salvage treatment following relapse in patients who received prior radiotherapy and as a boost to permit dose escalation.

5.    External beam radiation therapy (EBRT)

EBRT uses ionising radiation that focuses on the prostate gland to kill cancer cells from a machine outside the body. 

Imaging to map out the location of the prostate, lymph nodes and surrounding structures is needed prior to commencing radiation. 

EBRT is a non-invasive, highly-effective and well-tolerated modality. Depending on the stage of prostate cancer, it can be used in a curative or palliative setting. 

6.    Systemic therapy 

Chemotherapy or immunotherapy can be used for metastatic prostate cancer. These treatments can extend life, reduce pain and improve quality of life. 

Prevention

• Maintain a heathy weight.
• Adopt a diet that is low in fat and high in fruit and vegetables. 
• Exercise most days of the week.
• Stop smoking.

References:

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