Treatment Of Throat Cancer

Overview of Throat Cancer

The throat is a tube-like structure in the neck that joins the latter part of the nose and mouth with the initial part of the food pipe (oesophagus) and windpipe (trachea).¹ 

It is the common pathway through which the air, food, and liquid pass. The air enters the lungs through the windpipe where as the food and liquid enter the stomach through the food pipe. 

An abnormal growth of mass in the throat is called Throat Cancer. In this article, we’ll focus on the treatment options for throat cancer, along with its types, symptoms, diagnosis, and likely course (prognosis) of throat cancer.

Types of Throat Cancer: 

Parts of the Throat 

Before we learn the types of throat cancer, we must know the parts of the throat. They are:

• Tonsils
• Adenoid
• Pharynx
• Larynx

Pharyngeal Cancer

Pharyngeal cancer affects the pharynx. There are 3 sub-types, named after the 3 parts of the pharynx. They are:

• Nasopharyngeal cancer: It affects the nasopharynx, the top part of the pharynx located just behind the nose
  • The symptoms involve the nose, throat, and ears. Along with a lump in the neck, the patient may also complain of a sore throat, bloody saliva, nosebleeds, stuffy nose, ringing in the ear (tinnitus), ear infections, hearing loss, and unexplained weight loss. Advanced cases may also involve the eyes causing headaches and double vision.
  • The cause of Nasopharyngeal cancer is often associated with Epstein-Barr Virus (EBV).
• Oropharyngeal cancer: Also referred to as Pharyngeal cancer sometimes^2,3
  • It affects the middle part of the pharynx, behind the mouth called the oropharynx.
    The symptoms are similar to those of Nasopharyngeal cancer. A painless lump in the neck accompanied by a sore throat, difficulty in swallowing, mouth bleeding, ear pain, and a lock jaw.
  • The causes can be smoking, alcohol consumption, and Human papillomavirus (HPV). 
• Hypopharyngeal cancer: It affects the lowermost part of the pharynx called the hypopharynx. It is an uncommon cancer. 
  • The symptoms include a lump in the neck, sore throat, difficulty in swallowing, bad breath, and voice changes.
  • Tobacco, alcohol, and HPV are major risk factors. 

Laryngeal Cancer

• According to the National Library of Medicine (NLM), about one-third of head and neck cancers are Laryngeal cancer.⁴ It affects the larynx or the voice box
• The most common symptom is a change in voice. The person affected by this condition may complain of a hoarse voice for more than 3 weeks.⁵ Other symptoms include a lump in the neck, difficulty in breathing and swallowing, wheezing, cough, sore throat, and ear pain
• The major risk factors are smoking and alcohol consumption. In a person who consumes both tobacco and alcohol, the risk of laryngeal cancer increases significantly. People assigned male at birth (AMAB) and aged 55 years or more are five times more prone to laryngeal cancer⁶

Diagnosis of Throat Cancer

Physical Examination

After asking a series of questions regarding family medical history and habits such as smoking, alcohol, and sexual contact, your doctor may physically examine the lump in your throat externally and internally by wearing gloves. This is to evaluate the physical characteristics of the tumour. 

Nasendoscopy

Nasendoscopy is a procedure for examining the nose, throat, and ear. It consists of a thin, flexible tube with a camera that is passed through your nostril. It is a safe procedure with little to no discomfort.

Pharyngoscopy and Laryngoscopy

As the name suggests, Pharyngoscopy and Laryngoscopy are the procedures used to examine the pharynx and larynx respectively. Depending on the approach, the procedure can be direct or indirect: 

Direct Laryngoscopy 

The Larynx is examined by directly inserting the metal blade of the laryngoscope into the throat. It allows direct vision of the larynx and vocal cords in a straight line.⁷ 

Indirect Laryngoscopy 

It involves the insertion of a flexible fibreoptic tube with a camera into the larynx through the nose or mouth. The images taken by the camera are seen on the monitor.⁷

Biopsy

Biopsy or removal of a piece of tissue for examination under a microscope is done to confirm the diagnosis. 

Diagnostic Imaging

Several image testing procedures involving different forms of energy such as x-rays, ultrasound, radiowaves, and radioactive substances can be done to evaluate the internal structures and the tumour.

For throat cancer, Computed Tomography (CT scan), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET Scan), and Ultrasound can be done. 

HPV Testing

Since throat cancer is widely associated with the Human Papilloma Virus (HPV), an HPV test must be done for an appropriate treatment plan. 

Stages of Cancer

After the diagnosis is confirmed, your doctor will determine the stage of cancer to evaluate the extent, before planning the treatment. 

The staging system most commonly used is the TNM staging system, where:

• T stands for Tumour size
• N stands for Lymph Node involvement
• M stands for Metastasis (spread of cancer cells from one site to the other)

To denote the stage of cancer, Roman numerals are used. 

• Stage 0- Abnormal cells found but not cancer. It is also called Carcinoma in situ
• Stage I- Early stage of cancer. The tumour is less than or equal to 2 cm in size. Lymph nodes are not involved
• Stage II- Tumour is 2 to 4 cm in size. Lymph nodes are not involved
• Stage III- Tumour is more than 4 cm in size and has involved lymph nodes on the same side as the tumour
• Stage IV- The end stage, where the tumour has also spread to other sites. The size may be small or large and many lymph nodes may be involved

(Read more here: Cancer Staging)

Treatment Options for Throat Cancer

Surgery

Early Stage 

Transoral Robotic Surgery (TORS) is a minimally invasive procedure first developed to treat head and neck cancers. It is performed using a 3D High-definition camera and  Robotic assistance under general anesthesia. It is beneficial in cases where the tumour is hard to reach and the patient does not want open surgery. 

Advanced Stage 

In advanced cases, a part of the throat, larynx, or pharynx containing the tumour is removed:

• Total laryngectomy- Removal of the entire larynx
• Pharyngectomy- Removal of a part or all of the pharynx
• Neck Dissection- Removal of affected lymph nodes
• Tracheostomy- The process of surgically creating a hole (stoma) in the trachea to enable airflow to the lungs when the windpipe is obstructed by a tumour

Support after Surgery

The patient may need speech and swallowing therapy, nutritional support, and reconstructive surgery following surgical intervention.

Radiation Therapy

Standard Radiation

High-beam radiations are used to destroy the cancer cells by damaging the DNA. It may be done alone or with chemotherapy.
It is beneficial for patients who are too sick or are unwilling to undergo surgery. Small tumours can be effectively destroyed by radiation therapy. 

De-escalated Radiation Therapy (DART)

DART was introduced to reduce the long treatment-induced side effects of heavy doses of radiation to treat HPV-related cases of Oropharyngeal Squamous Cell Carcinoma (OPSCC). 

By lowering the dose of radiation and/or chemotherapy, the side effects were reduced without compromising the high cure and survival rate of the patient. 

Proton Therapy

Proton Therapy is an effective way to precisely target cancer cells and minimize damage to surrounding tissue by 50-70%.⁸ It is a non-invasive and painless approach that delivers a beam of protons directly to the diseased tissue. 

The benefits include reduced side effects, the ability to treat cancer in difficult areas, precision, and accuracy. 

Side Effects of Radiation Therapy

Short-term side effects include sore throat, mouth sores, dry mouth, hoarseness, difficulty swallowing, and weakness.

Long-term side effects include speech difficulties, swallowing problems, dental caries, and osteoradionecrosis. 

Chemotherapy

Chemotherapy refers to the drug treatment of cancer. It is often combined with radiation (chemoradiation therapy) for advanced stages or cases where surgery is not possible.

It can be used as neoadjuvant (before surgery) or adjuvant (after surgery) therapy to shrink the tumor and prevent recurrence. 

The drugs that can be used for head and neck chemotherapy are:^9,10

• Cisplatin
• Fluorouracil
• Capecitabine
• Carboplatin
• Paclitaxel (Taxol)
• Docetaxel (Taxotere)
• Methotrexate
• Hydroxyurea
• Pembrolizumab
• Nivolumab

Targeted Therapy

Targeted Therapy uses drugs that attack specific proteins or genes involved in the cancer’s growth.
EGFR-targeted therapy is one such example. Epidermal Growth Factor Receptor or EGFR is a protein found on some cancer cells. Drugs like Cetuximab target EGFR and inhibit abnormal cell growth and its multiplication. 

Immunotherapy

Immunotherapy boosts the immune system to recognize and attack cancer cells, used mainly in cases where cancer has spread or recurred​. 

According to the Cancer Research Institute, 4 drugs are approved for immunotherapy of head and neck cancer. They are:¹¹

• Cetuximab (Erbitux)
• Dostarlimab (Jemperli)
• Nivolumab (Opdivo)
• Pembrolizumab (Keytruda)

Side effects of these drugs can include nausea, diarrhea, fatigue, cough, skin rash, loss of appetite, constipation, joint pain, and itching.

Palliative Care

The symptoms of cancer can be daunting, painful, and depressing for the person affected by it. Palliative care focuses on improving such symptoms and the quality of life. 

It is usually done alongside the curative therapies. However, in certain incurable cases, palliative therapy provides symptomatic relief to the patient. 

It involves a specialist caregiver team that provides:

• Physical support to relieve pain, fatigue, nausea, and vomiting
• Emotional support to cope with the emotional stress and depression of the patient and family
• Practical support to assist with financial and legal matters

Prognosis and Follow-Up

The prognosis depends upon the cancer stage and the time of detection. HPV-positive cancer cases generally have a better prognosis with higher cure rates and lower recurrence risk​. The 5-year survival rate is about 85-90%.¹²

For other types of throat cancer, the 5-year survival rate ranges anywhere between 40-80% approximately.¹³

(Read more here: Survival for Laryngeal Cancer)

Survivorship

Regular follow-ups for monitoring, early detection of recurrence, and rehabilitation therapy for speech and swallowing functions are critical for long-term recovery.

Summary

Abnormal growth of cells in the throat is called Throat cancer. It may affect the pharynx or larynx. The symptoms include a lump in the neck accompanied by a sore throat, difficulty in swallowing, change in voice, bloody saliva, ear infection, and unexplained weight loss.

Diagnosis can be done by physical examination, imaging, and visualization diagnostic methods. It is confirmed by biopsy. Treatment modalities include surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy. 

Engaging with cancer support groups and mental health services to manage emotional challenges and improve overall well-being during and after treatment​ can improve the quality of life of the affected person.