How To Treat Cough In Cancer Patients

All about cancer

Cancer is a complex group of diseases characterized by the uncontrollable growth of some body cells and has the ability to spread to and destroy other normal body cells.  

Normally, our body cells follow an order, they grow and multiply to form new cells through a process called cell division. When the cells grow old and die, they are replaced by new ones. This order can however be disturbed by some factors; cells that are meant to die, continue growing and multiply to form a lump of tissues called tumors. These tumors can be benign (mild) or malignant (harmful). Cancer can spread to other parts of the body (metastasis).

Cancer is one of the major causes of death in the world. But thanks to the advancement in early detection, treatment, and prevention there has been a decline in the overall mortality rate for most cancers.

Causes of cancer

Cancer has no single cause, rather the interaction of many factors such as genetic (inherited from parents) and environmental factors lead to cancer. Fundamentally, cancer is caused by changes to the way our gene functions, these changes can be driven by different external agents/carcinogens or by genetic factors (inherited mutations).

Three main types of genes are usually affected in cancer, when these genes are altered in some ways, they lead to cancer. They are of the following:

• Proto-oncogenes: are associated with cell growth and division
• Tumor suppressor genes: control cell growth and division, detect abnormal cells, and stop them from being cancerous by destroying them
• DNA- repair genes: these fix damaged DNA

There are three main external factors or carcinogens that can trigger genetic changes

1. Physical carcinogens: this includes radiation such as x-rays, gamma rays and ultraviolet rays
2. Chemical carcinogens: asbestos, benzene, arsenic, perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and related chemicals, components of tobacco smoke, aflatoxin
3. Biological carcinogens:
   • viruses such as human papilloma virus that can cause cervical cancer, hepatitis B and C virus that can cause liver cancer
   • bacteria such as helicobacter pylori can cause stomach cancer
   • parasites such as liver fluke has been linked to cancer of the bile ducts, schistosoma that has been linked to bladder cancer

Types

There are numerous types of cancer. They can be named by the organ or tissue they originate from, (e.g brain cancer, ovarian cancer) or by the specific type of cell that form them, for instance,carcinoma (epithelial cells), epidermoid carcinoma (squamous cells), sarcoma (bone and soft tissue), leukemia (bone marrow), lymphoma (lymphocytes), melanoma (melanocytes).

Common cancers are;

• Bladder Cancer
• Breast Cancer
• Lung Cancer
• Colon and Rectal Cancer
• Endometrial Cancer
• Kidney Cancer
• Leukemia

You can get resources for specific types of cancer here.

Signs and symptoms

Cancer symptoms vary widely, more common symptoms are;

• severe and chronic fatigue
• fever or night sweats
• neurological problems (seizures, headaches, etc.)
• lumps
• weight loss
• changes in the breast or skin
• bladder changes (painful urination, bloody urine)
• bowel habit changes
• eating problems

However, the symptoms listed above are not all inclusive, as they are not particular to cancer and can be signs of other disorders. If you notice major and disturbing changes in how you feel or how your body works that worsen or lasts for a long time, visit your healthcare provider for an adequate diagnosis.

About cough in cancer patients

Cough is a natural reflex experienced by everyone. It is a basic mechanism by which we clear up our airways and protect our lungs. In respiratory diseases such as bronchitis and pneumonia, coughing is necessary to expel excess mucus. In cancer patients, cough is usually observed in cancers arising from the lungs and the airways. When cancer from other body parts metastasizes to the chest region, cough can also be observed. Some cancer treatments can also be a potent cause of cough. Cancer patients are already burdened by various symptoms associated with the malignancy, andcoughing symptoms can pose additional discomfort and can be bothersome.

These coughs can be dry or productive (associated with sputum). It can also be persistent and associated with other symptoms such as vomiting, headaches, muscle strains, loss of bladder control, and even rib fractures, particularly in cancers that have extended to the bone. Treatment of cancer-related  cough is therefore important and you should inform your healthcare provider if you develop a cough. Your healthcare team will add cough treatment to your palliative care to prevent it from further affecting your quality of life.

Causes

Cough can be caused by the following in cancer patients:

1. Specific types of cancer
   • lung cancer; has cough as one of its most common symptoms and it can worsen breathlessness. The frequency is high in non-small cell lung cancer (NSCLC) and small cell lung cancer(SCLC), however not all lung cancers are associated with cough
   • cancers that affect the airways; they are tumors that affect the airways and windpipe (trachea), they include adenoid cystic carcinomas, mucoepidermoid carcinomas, and tracheal carcinoid tumors
   • metastasis of other cancer types; this is the advanced stage of cancer. When cancer fails to respond to treatment, the tumor can spread to other parts of the body. When this progression includes the lungs or the chest area, a cough can develop

2. Cancer therapy -unfortunately, some cancer treatments can be the cause of the cough itself.  These include:
   • radiation therapy to the chest which can be used for some lung cancer and breast cancer patients
   • some chemotherapy drugs such as irinotecan, bleomycin, and methotrexate
   • some immunotherapy drugs. They are used to treat the immunosuppressant effect of chemotherapy drugs. However, some of these drugs cause inflammation of the lungs and tend to cause cough e.g pembrolizumab

It is important to note that in some patients, there can be more than one cause of cough

Is cough a usual symptom for all cancer patients? 

No, cough is not a general symptom of cancer, therefore not all cancer patients cough. Cough in cancer patients can be due to some lung cancers, treatment-related, or due to complications (lung metastasis). If you are experiencing a persistent cough, inform your cancer care team for necessary interventions.

Treating cough in cancer patients

Persistent cough in cancer patients is distressing, and treatment is necessary to help improve patients' quality of life. 

Treatment of cough in cancer patients depends on the cause. For example, a cough caused by a tumor can be treated by different cancer therapy options (radiation therapy, chemotherapy or surgery. Your health care provider will decide the suitable option for you), and infection such as pneumonia can be treated with antibiotics. Your cough might also be unrelated to cancer and can be due to other causes such as cigarette smoke, asthma, pleural or pericardial effusion, infections, postnasal drip etc.

Furthermore, in some cases treating the cause of the cough will not provide relief of the cough, in these cases, your doctor will recommend medications.

Natural Remedies

• Acupuncture
• Menthol
• Eucalyptus
• Honey and lemon drink

Medications

When treatment of cough will not provide relief, your doctor can prescribe drugs such as;

1. Mucolytics; are expectorants that loosen up mucus and make it easier to cough up e.g guaifenesin

2. Demulcents; such as butamirate syrup, or simple or glycerin-based syrup. They coat and soothe mucous membranes

3. Antitussives; these are drugs that suppress the cough reflex and they include opioids like codeine and non-opioids like dextromethorphan. If your cough is not responsive to demulcents, your doctor can recommend opioid antitussives or non-opioid antitussives if you have opioid-resistant cough

4. Nebulized local anesthesia; this can be helpful if you have lung cancer and a cough that is not relieved by opioids and other antitussives. They include local anesthetics as well as nebulized anesthetics such as lidocaine or bupivacaine

5. Antihistamines; These drugs will decrease mucus production 

6. Corticosteroids; Although these are not widely used, high doses can be beneficial when the cough reflex is caused by inflammation

Other Ways

Other methods different from medicinal interventions can also be recommended for you. They can be invasive or non-invasive, they include the following:

• drainage of pleural effusions (thoracentesis); when a cough is due to the presence of fluids around the lungs, a procedure called thoracentesis can be carried out to drain the fluid

• endobronchial brachytherapy; a type of radiation treatment where the radiation is directed at the tissue being treated. This can be recommended for you if your cough is due to cancer localized in your airways and surgery, chemotherapy isn't suitable for you

• photodynamic therapy; this type of treatment uses light to kill cancer cells

•  physiotherapy, cough suppression exercises

When to seek medical attention

It is advisable to see your doctor when you notice you are coughing up blood or have a chronic cough that lasts up to 8 weeks Your doctor will perform a series of medical tests to determine the cause. Early detection of lung cancer increases your chance of recovery.

Summary

Cough is a symptom of some diseases such as pneumonia, and bronchitis and can also be a symptom of lung cancer. Other cancers can be associated with cough due to treatment options or metastasis. Cough in cancer patient can be very