31st December 2024

Management of the side effects of prostate cancer treatments

Radiation enteropathy

Radiation to the pelvis, for example when radiating prostate cancer, can damage nearby structures including the bowel or rectum. It is a common phenomenon: of patients who receive abdominal or pelvic radiotherapy, 60-80% will experience bowel toxicity.

In patients with suspected radiation-induced enteropathy, flexible sigmoidoscopy is the first-line investigation to rule out bowel cancer and inflammatory bowel disease, but also analyse the extent of radiation-induced enteropathy if it is ultimately diagnosed.

If symptoms are experienced in the first 3 months following radiating it is considered acute radiation enteropathy. Acute radiation enteropathy symptoms include diarrhoea, abdominal pain, nausea and vomiting. If loperamide does not work, octreotide can be considered.

Beyond the first 3 months, it is considered delayed. Delayed radiation enteropathy symptoms include dysfunctional absorption of nutrients or abnormal peristalsis. The treatment approach is more complex than for acute symptoms, and must be tailored specifically to the individual. It is a chronic and progressive disorder requiring a multidisciplinary team approach.

Both types of radiation enteropathy have high morbidity, affecting quality of life for cancer patients.

Rectal radiation injury (radiation proctopathy) is common when treating prostate cancer. First-line treatment is sucralfate enemas, which can cause dramatic improvement in symptoms. If radiation proctopathy is hemorrhagic, endoscopic intervention may be required to stop the bleeding.

Radiation-induced cystitis

Radiation to the prostate can cause bladder wall inflammation and scarring, which can be short term or chronic, and can result in cystitis. Conservative management includes good oral intake of water. If symptoms persist despite this, specialised options include intravesical injection of medications such as sodium hyaluronate (brand names Cystistat or iAluRil), or hyperbaric oxygen therapy. Rarely, the bladder may need to be surgically removed to help with symptoms.

Androgen-deprivation therapy side effects

There can unfortunately be many side effects to androgen-deprivation therapy. Some examples with their management are:

• Hot flushes: medroxyprogesterone is first line.
• Gynaecomastia: in those starting long-term (planned for at least 6 months) of bicalutamide, prophylactic radiotherapy to the breast buds is first line, and should be offered within the first month of treatment. Second line is tamoxifen.
• Osteoporosis: is also an issue with long-term deprivation therapy as it can result in fragility fractures. A risk assessment for the individual patient should be calculated e.g. FRAX score. Bisphosphonates are first line or denosumab is second line in patients identified as having osteoporosis and on androgen deprivation treatment.