What is the Hypopharynx?
The hypopharynx is a triangular tube in the throat, at the bottom of the pharynx. It is the primary passage for food as we swallow. Food moves from the mouth, through the hypopharynx (around the larynx), into the esophagus and to the stomach.
The pharynx is a hollow tube. It starts behind the nose, goes down the neck and leads air to the trachea (windpipe) and food to the esophagus (which leads to the stomach). If cancer forms in bottom part, the hypopharynx, it can form a tumor that squeezes this tube and makes it hard to swallow.
What is Hypopharyngeal Cancer?
Hypopharyngeal cancer is a type of head and neck cancer that begins in the hypopharynx. It often begins because abnormal (malignant) squamous cells form in the lining of this area. Other throat cancers have different names, based on where they begin.
This cancer is rare. It can grow in the hypopharynx mainly because of tobacco use and/or excessive alcohol use. Hypopharyngeal cancer can spread past the throat to nearby lymph nodes, tissue, and into the chest cavity, lungs or bones.
Squamous Cell Carcinomas
Almost all cancers in the hypopharynx develop from the thin, flat cells called squamous cells, which are in the epithelium, the inner layer lining the hypopharynx. Cancer beginning in this layer of cells is called squamous cell carcinoma or squamous cell cancer.
Most squamous cell cancers of the hypopharynx begin as pre-cancerous conditions called dysplasia. Most of the time, dysplasia doesn't turn into actual cancer. It often goes away without any treatment.
Some cases of dysplasia will progress into a condition called carcinoma in situ. In this stage, cancer cells are only seen in the epithelium lining. They have not grown into deeper layers or spread to other parts of the body. It is the earliest form of cancer.
Other rare types of cancer can also start in the hypopharynx.
- Minor Salivary Gland Cancers - Some areas of the hypopharynx have tiny glands known as minor salivary glands beneath the lining layer. These glands produce mucus and saliva to lubricate and moisten the area.
- Sarcomas - The shape of the hypopharynx depends on a framework of connective tissues and cartilage. Cancers like chondrosarcomas or synovial sarcomas can develop from connective tissues of the hypopharynx. This is extremely rare.
- Melanomas - Although, these cancers usually start in the skin, in rare cases they can start on inner (mucosal) surfaces of the body such as the hypopharynx.
Risk Factors & Symptoms
The primary risk factors for hypopharyngeal cancer include:
- Smoking/Chewing tobacco
- Heavy alcohol use
Other risks include:
- Eating a diet without enough nutrients
- Having Plummer-Vinson Syndrome, a condition in people with long-term iron deficiency or anemia. People with this condition can't swallow well due to small, thin growths of tissue that can block the esophagus
- Past exposure to radiation
- Human Papillomavirus (HPV)
The most common symptoms of hypopharyngeal cancer are:
- A sore throat that does not go away
- Ear pain
- A lump in the neck
- Pain or difficulty when swallowing
- A change in your voice
Other conditions may cause the same symptoms. It is important to talk with your doctor if you experience any of these.
If you are diagnosed with hypopharyngeal cancer, the doctor needs to know the stage of the disease to plan for treatment. Staging is a careful attempt to define exactly where the cancer is found, whether it has spread, and how aggressive the cancer cells are. If your cancer spreads to the bone, visit our bone metastases page.
Stages of Hypopharyngeal Cancer
Hypopharyngeal cancer, like other head and neck cancers, are staged with the AJCC (American Joint Committee on Cancer) system. This is a rating system that assigns a measurement for TNM:
· T = Tumor characteristics, based on imaging tests. This describes how big the tumor is and how far into the hypopharynx cancer has grown.
· N = Lymph Nodes involved. This defines if and how cancer has spread to lymph nodes in the neck.
· M = Metastases. This explains if and where cancer has spread beyond the neck (including into organs in the chest, liver or bones).
Each of these factors are defined with a number ranging from 0 (or x – meaning it’s very early disease) to 4 a, b, c (meaning the disease is very advanced). After this, the cancer’s Stage is defined with a scale from “Stage 0” (for very early signs of cancer), to Stage IV a, b or c (for very advanced cancers).
In general, the stages are described as:
Stage 0 (Carcinoma in Situ) - Abnormal cells are in the lining of the hypopharynx. The cells have not spread and they may not have formed a tumor (Tis). No lymph nodes are affected (N0), nor are other parts of the body (M0).
Stage I - Cancer has grown in one area of the hypopharynx only. The tumor is two centimeters or smaller (T1). No lymph nodes are affected (N0), nor are other parts of the body (M0)
Stage II - The tumor is between two and four centimeters large (T2), or abnormal cells are found in more than one are of the hypopharynx. It has not spread past one area of the hypopharynx. No lymph nodes are affected (N0), and it has not spread to the larynx or other parts of the body (M0).
Stage III – Either the tumor is larger than four centimeters or it has spread to the larynx (affecting the voice box) or esophagus (T3), but it has not spread to the lymph nodes (N0, M0). Or, the tumor isn’t that big, but the cancer may have spread to one lymph node and the lymph node is three centimeters or smaller (N1). No other parts of the body are affected (M0).
Stage IV - Stage IV is divided into stage IVA, IVB, and IVC.
- Stage IVA - The cancer has spread to the thyroid, cricoid cartilage, larynx, the bone under the tongue, or nearby soft tissue (T4a). Cancer may not have spread to nearby lymph nodes (N0); or it has spread to one lymph node on the same side of the neck as the tumor that is smaller than 3 centimeters (N1). OR, the tumor isn’t very big (ranging from T1-T4a) but it has spread to lymph nodes more aggressively (N2). No other parts of the body are affected (M0).
- Stage IVB - The tumor has spread into muscles of the upper spinal column, the carotid artery, or the lining of the between the lungs (T4b). Lymph nodes may be affected (any N). No other parts of the body are affected (M0)
- Stage IVC - The tumor may be any size and it may or may not have affected the larynx (any T). Lymph nodes may be affected (any N). The cancer has spread beyond the hypopharynx to places such as the lung, liver or bone. (M1).
Surgery is a common treatment for all stages of hypopharyngeal cancer. The following surgical procedures may be used:
- Laryngopharyngectomy - Surgery to remove the larynx (voice box) and part of the pharynx (throat).
- Partial laryngopharyngectomy - Surgery to remove part of the larynx and part of the pharynx. A partial laryngopharyngectomy prevents loss of the voice.
- Neck dissection - Surgery to remove lymph nodes and other tissues in the neck.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, called adjuvant therapy, lowers the risk that the cancer will come back.
If your larynx is removed, you will need to learn a new way to speak because your voice box will be removed. Your nose and mouth will be permanently separated from your windpipe and lungs, and you will be breathing through a new opening in your neck called a stoma. Having a laryngectomy changes lung function, including increased mucus and coughing.
The most common side effects of any neck dissection are numbness of the ear, weakness when raising the arm above the head, and weakness of the lower lip. These side effects are caused by injury during the operation to certain nerves that supply these areas.