Biology of Disease

be restricted to the more aggressive forms of the disease. Prostatectomy is

the removal of the whole prostate gland and may result in impotence and

incontinence.

External radiation therapy may be given following surgery to ensure that any

remaining cancer cells are destroyed. Radiation therapy is also used as a first

line of treatment and is an equally effective alternative to surgery. Therapeutic

approaches include external beam and brachytherapy (Section 17.6). A form

of external radiotherapy, known as conformational radiotherapy (CRT), allows

the radiation beams to be shaped to match the shape of the prostate itself,

which lowers the side effects caused by irradiation of the surrounding healthy

tissue. Brachytherapy is delivered by the implantation of radioactive iodine

‘seeds’ or iridium wires in the prostate itself. If the cancer has spread to bone,

radiation therapy using^89 Strontium, which is preferentially taken up by bone

tissue, is given by intravenous injection.

Figure 17.34Diagrams (A–D) illustrating the four stages of prostate cancer.

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Stage Description

T1 tumor within the prostate gland too small to be detected during a rectal examination

often no symptoms

PSA test or biopsy is positive

localized prostate cancer

T2 tumor within prostate gland large enough to be detected at rectal examination

often no symptoms

localized prostate cancer

T3/4 tumor has spread into the surrounding tissues

locally advanced prostate cancer

Metastatic

cancer

lymph nodes, bones or other parts of the body affected

advanced prostate cancer

Table 17.9Staging of cancers of the prostate

A) B)

C) D)

T 1 T 2

T 3 T 4

Prostate

gland

Anus

Bladder

Seminal

vesicle

Tumor