Anti-Cancer Treatments

Radiotherapy

Chemotherapy

Painful adverse effects of radiotherapy and chemotherapy

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Radiotherapy and chemotherapy may be effective for relieving pain and other symptoms (e.g., dyspnoea) associated with cancer. Treatment decisions should take into consideration the patient’s goals, performance status, sensitivity of the tumour and potential toxicities. The goals of therapy and expectations from treatment need to be clearly explained and discussed with patients and their families.²

Radiotherapy

Patients with pain caused by bone metastases or metastatic spinal cord compression should be referred to a clinical oncologist for consideration for external beam radiotherapy or radioisotope treatment.^9,10

Pain associated with metastatic spinal cord compression may be radicular and/or localised to the back or neck. Prognosis is poor in patients with neurologic deficits, and early clinical and radiological diagnosis and referral for radiotherapy are essential. Corticosteroids (e.g., dexamethasone) should be administered immediately on diagnosis.¹⁰

Indications for radiotherapy are listed in Table 1.

Table 1: Indications for Radiotherapy in Management of Cancer Pain17
Pain	Cause
Bone pain	Metastases; pathological fracture (nonsurgical; e.g., rib / pelvis)
Headache	Primary cerebral tumour; brain metastases
Abdominal pain	Hepatomegaly
Pelvic pain	Local tumour infiltration
Chest pain	Primary lung cancer; mesothelioma
Soft tissue pain	Local tumour infiltration

Chemotherapy

Chemotherapy may provide pain relief for patients with widespread metastatic disease and some chemosensitive tumours associated with widespread severe metastatic bone pain (e.g., multiple myeloma and small cell lung cancer). Indications for palliative chemotherapy are listed in Table 2. Chemosensitivity of primary tumours commonly metastasising to bone is listed in Table 3.¹⁷

Table 2: Indications for Chemotherapy in the Management of Cancer Pain17
Pain	Causes	Primary Tumour Types
Bone pain	Bone metastases	- Myeloma - Breast cancer - Lung cancer (small cell and non-small cell)
Headache	Brain metastases	- Germ cell tumours - Lymphoma and leukaemias - [Breast cancer] - [Small cell lung cancer]
Abdominal pain	Ascites Subacute obstruction	- Ovary - Colorectal - Stomach
	Pancreatic pain	- Pancreas
Pelvic pain	Local tumour infiltration	- Colorectal - Ovary - Cervix
Chest pain	Local tumour infiltration	- Lung cancer (small cell and non-small cell) - Metastases from chemosensitive sites, e.g., breast, colorectal, [mesothelioma]
[] indicates tumours with only modest (<50%) response rates when other modalities, such as radiotherapy may be preferred.

 

Table 3: Chemosensitivity of Primary Tumours Commonly Metastasising to Bone17
High (>50% Response Rate)	Mid (25-50% Response Rate)	Low (<25% Response Rate)
Myeloma Bronchus Breast	Rectum Oesophagus* *Mid/low	Oesophagus* Prostate Thyroid Kidney

Painful adverse effects of radiotherapy and chemotherapy

It is important to note that anticancer treatments themselves may be associated with painful syndromes, sometimes leading to chronic pain in cancer survivors. These include peripheral neuropathy due to chemotherapy, radiation-induced plexopathy, chronic pelvic pain secondary to radiation, and postsurgical pain. Pain may interfere with function and quality of life. Management should include patient education and psychological support. 

A multidisciplinary approach including physiotherapy and occupational therapy is necessary and patients require early referral to specialist care.^10,67 

Treatment-related side effects associated with radiation therapy are directly related to the region that has received treatment. By definition, acute side effects are those occurring within 90 days from the start of treatment, whereas late effects occur after 90 days. Table 4 lists potential side effects and advice for management.

Table 4: Side Effects of Radiation Therapy
Treated Region	Acute Side Effects	Management
Head and neck	Oral mucositis Grade 3-4	Analgesics, mouth gargles, intraoral applications such as triamcinolone acetonide (Kenalog® in Orabase®) cream, oral corticosteroids
Oesophagus	Oesophagitis	Mucaine® gel (oxethazaine, aluminium hydroxide, magnesium hydroxide) 10 ml 5 minutes before meals, analgesics (paracetamol)
Pelvic region	Cystitis, proctitis	Oral fluids, urinary antiseptics, local application (lignocaine jelly)
Skin	Wet desquamation, bleeding	Hydrocolloid dressings, antibiotic cream if infection is present

Late effects can occur due to radiation fibrosis of the brachial plexus and lumbar plexus, radiation myelopathy, radiation necrosis of bones and soft tissue, and radiation-induced second primary cancers.

Other late effects include mucosal ulceration of the oesophagus and rectum with associated pain and bleeding. These should be treated using sucralfate, either orally or as an enema, as well as with corticosteroids and analgesics.