What is Tonsil Cancer?
Tonsil cancer is the most common type of mouth and throat cancer, and it’s becoming more common due to the rising rates of cancers caused by the human papillomavirus (HPV). The presence of HPV can greatly change how serious tonsil cancer can be. Because of this, there have been key changes to how the disease is classified and staged by the World Health Organization (WHO) and the TNM cancer staging system. Treatments for tonsil cancer can include surgery and cancer-specific therapies, but the best treatment plan is still being researched.
What Causes Tonsil Cancer?
In the past, cancers of the throat and tonsils were mainly linked to smoking and heavy drinking, with smoking identified as a major risk for a bad outcome. However, in recent times, there’s been a big increase in the number of these cancers caused by HPV (Human Papillomavirus). In fact, up to 93% of new throat cancer cases in Western Europe are now related to HPV.
There’s also growing research that suggests that if your partner has a cancer related to HPV, you may have a slightly higher risk of developing throat and anogenital cancers (cancers of the anus and genitals). So it’s important to understand how lifestyle and relationship factors could potentially impact your cancer risks.
Risk Factors and Frequency for Tonsil Cancer
Tonsil cancer – a type of oropharyngeal cancer – is surprisingly common. It accounts for almost a quarter of all cancer types in the mouth and throat region. On average, there are about 8.4 cases of tonsil cancer out of every 100,000 people. Alarmingly, tonsil cancer rates have been on the rise over the past 40 years. This spike is largely due to what many call the “viral epidemic” of HPV (Human Papillomavirus). In fact, western countries have seen a jump in the percentage of cancers linked to HPV. This percentage jumped from 42.5% before 2000 to 72.2% between 2005 and 2009. On the flip side, rates of oropharyngeal cancers not tied to HPV did not significantly increase during that time.
- Tonsil cancer is the most common type of oropharyngeal cancer, making up about 23.1% of these cancers.
- Around 8.4 out of 100,000 people are diagnosed with tonsil cancer.
- The rate of tonsil cancer has dramatically increased over the last 40 years.
- This increase is largely linked to a rise in HPV-related cases.
- There has been a rise in the share of HPV-linked cancers; from 42.5% before 2000 to 72.2% between 2005 and 2009.
- There hasn’t been a significant increase in the rate of non-HPV oropharyngeal cancers within the same period.
Signs and Symptoms of Tonsil Cancer
Tonsil cancer can present in many different ways. Patients might experience a sore throat, ear pain on one side, or a feeling like there’s a lump in their throat. Some people might even feel like they can’t open their mouth very wide, a condition known as trismus. It’s not uncommon for some people to have no symptoms at all and only discover they have tonsil cancer when a doctor notices that one tonsil is larger than the other.
Because the tonsils have a rich supply of lymphatic nodes, many tumors can present as hidden lesions with enlarged neck nodes, especially in the area known as the jugulodigastric region. Doctors need to ask about any concerning symptoms, like weight loss, painful swallowing, difficulty swallowing, and ongoing hoarseness. A thorough medical history and discussion of risk factors like smoking, heavy alcohol use, and risky behaviours such as intravenous drug use may help identify a possible cause.
HPV-positive tumors usually appear in younger patients who don’t smoke, regardless of their gender. However, HPV-negative tumors typically arise in older male smokers with various health issues, and have overall poorer outcomes.
Patients should undergo a complete exam of the ear, nose, and throat by a qualified ear, nose, and throat specialist, which should include checking the neck for enlarged lymph nodes and a detailed examination of the throat, or oropharynx. In particular, the doctor should inspect the area where the tonsils are located (the tonsil beds), as primary cancers can be concealed within the tonsil crypts. A flexible nasal endoscope, a device used to view a person’s nasal and sinus passages, should be used to conduct a thorough examination of the oropharynx, which includes a look at the tonsils, the base of the tongue, the bowl-shaped area at the back of the tongue known as the vallecula, and the sidewall of the throat to check for signs of cancer spreading.
Testing for Tonsil Cancer
Imaging technologies are incredibly important in the diagnosis and treatment planning of tonsil cancer. A type of scan called a contrast-enhanced MRI is typically utilized as it provides the most detailed view of the specific area affected by cancer and its local spread. Sometimes, a CT scan is also used to assess the disease, but its effectiveness can be hindered if you have undergone any adjacent dental treatments.
CT scans are popular for staging all head and neck cancers, including tonsil cancer. Staging refers to determining the size and extent of cancer within your body. The CT scans look for associated nodal and lung diseases by imaging from the base of your skull to your diaphragm. Besides, PET-CT scans, another imaging technology, can assist in diagnosing and staging difficult-to-detect cancers, and are often used after treatment as a surveillance measure.
However, PET-CT scans do have their limitations; they can often display false-positive findings. This means they often show uptake in surrounding areas like the opposite tonsil, the base of the tongue, and Waldeyer’s ring (a ring of lymphoid tissue in the throat), even when there’s no sign of cancer.
In addition to imaging, if your doctor suspects tonsil cancer, it’s highly recommended you undergo an examination using a process called panendoscopy. Panendoscopy is a procedure where a flexible scope examines your upper aerodigestive tract (the part of the body that includes the nose, mouth, throat, and esophagus). This is done under anesthesia and allows doctors to closely assess and biopsy the potentially cancerous tonsil area. It’s also used in planning the surgical approach to remove the cancer and to look for any additional cancers in the upper airway and esophagus which can accompany tonsil cancer.
One more procedure, called Fine-Needle Aspiration (FNA) biopsy, can be utilized in patients who are not fit for surgery. In an FNA biopsy, a thin needle is used to remove a small sample of cells for testing. However, the reliability of HPV testing—the test used to assess the presence of the human papillomavirus that often plays a role in tonsil cancer—in these samples has been disputed.
Treatment Options for Tonsil Cancer
Early-stage tonsil cancer is often treated with a single method of treatment. Two types of surgery, transoral robotic surgery (TORS) and transoral laser microsurgery (TLM), are among the most popular choices, and both have proven to be effective. TORS is becoming more popular because it takes less time, requires shorter hospital stay, and recovery of swallowing is often quicker compared to traditional surgeries. However, severe difficulties in swallowing can occur after the surgery. TLM, on the other hand, is less commonly used. This surgery involves the removal of the tumor in several pieces, which can make it more difficult for doctors to examine the tumor under a microscope to ensure all cancer was removed.
Whether using TORS or TLM, it is recommended that both tonsils are removed during the surgery. This is because there is a small chance that both tonsils might have cancer.
In cases of more advanced tonsil cancer, TLM or TORS can still be used to treat tumors at an early stage of the severe type (T3 tumors). For very severe types (T4 tumors), these surgeries might not be possible. Instead, most of these patients will receive a combination of chemotherapy and radiation therapy. This is because surgery in these cases may require cutting the jawbone and extensive reconstruction after the procedure, which can lead to poor after-surgery results involving functions like swallowing and speaking.
Since tonsil cancer often spreads to the nearby lymph nodes, it is usually recommended that patients also undergo a surgery to remove the lymph nodes in the neck.
Using radiation alone as primary treatment for early tonsil cancer has shown good results in terms of cancer control and survival. For cancers that are not spreading toward one side, a treatment approach called unilateral radiotherapy can be used. This approach treats only one side of the neck, which has a low rate of the cancer coming back on the other side, and it leads to less negative side effects from radiation. For patients with cancer spread to both sides, it’s recommended to treat both sides of the neck with radiation.
For more advanced tonsil and throat cancers, combination of chemotherapy and radiation (chemoradiotherapy) is preferred treatment method as per one review study. This helps to avoid extensive surgery which has high risk of long-term side effects. Most commonly used treatment plan includes radiation with a platinum-based medication called cisplatin. If a patient can’t tolerate cisplatin due to kidney problems or hearing loss, then a similar treatment with a drug called cetuximab can be used as an alternative.
What else can Tonsil Cancer be?
When a doctor thinks a patient may have tonsil cancer, they don’t only test for this one type of cancer. They also consider some other types that might be causing similar symptoms. Some of these alternatives include:
- Squamous cell carcinoma (a type of skin cancer)
- Lymphoma (cancer of the lymph nodes)
- Small cell carcinoma (a rare and very fast-spreading type of cancer)
- Other rare cancers that can sometimes spread to the tonsil, such as Merkel cell carcinoma, renal cell (kidney) carcinoma, rectal adenocarcinoma, and small cell lung cancer
What to expect with Tonsil Cancer
The chances of surviving tonsil cancer depend on a few things. One of them is whether the tumor is HPV positive. If the tumor is HPV positive, then the five-year survival rate is 71%. That contrasts sharply with the five-year survival rate of those with HPV negative tonsil cancer, which is just 46% according to one study.
However, having HPV positive tonsil cancer does not guarantee a better survival outcome if the patient is a smoker. In fact, the mortality rates in patients with HPV positive tonsil cancer who smoke are significantly higher than those who don’t.
Other factors affect the prognosis of tonsil cancer positively. These include having small tumors, no disease in the lymph nodes, being younger in age, having fewer other health issues, and when the tumor is invaded by special cells called lymphocytes that help fight off disease.
Presently, there are no studies directly comparing survival outcomes between patients whose tonsil cancers were managed solely through surgical treatment and those whose disease was managed through cancer-focused treatments.
Possible Complications When Diagnosed with Tonsil Cancer
If tonsillar cancer is not treated, the cancerous cells will continue to grow gradually and can invade local structures in the throat and nasal area. This includes structures like the lateral pterygoid muscle and plates, skull base and even reach as far as main arteries like the carotid. This is a sign of a very advanced cancer state, known as T4b disease. Additional consequences of this can include the cancerous invasion interfering with nerves emerging from the skull and vertebrae. This could lead to conditions such as Horner’s syndrome and palsies, which involve weakening of certain nerves. Furthermore, if the cancerous invasion encases the carotid artery, it could lead to a very serious and life-threatening condition where the artery ruptures.
- Cancer growth and invasion into surrounding areas
- Problems with nerves, causing conditions like Horner’s syndrome and palsies
- Potential threat to life if serious artery is encased
Treatment options for tonsil cancer can also come with significant side effects. One surgical procedure, TORS, can cause severe pain and difficulty swallowing after the operation, especially in advanced cases. Radiotherapy often causes inflammation and sores in the mouth, dry mouth, and skin reactions. These issues can greatly affect swallowing, and can be even more pronounced in patients who have a combination of TORS and post-operative chemo-radiotherapy. These combined treatments have been reported to significantly impact swallowing ability and overall quality of life.
- Severe postoperative pain and difficulty swallowing from TORS treatment
- Inflammation and sores in the mouth, dry mouth, and skin reactions from radiotherapy
- Worsened swallowing and quality of life when TORS and chemo-radiotherapy treatments are combined
Preventing Tonsil Cancer
Doctors typically give advice to all their patients about the importance of quitting smoking and alcohol, given that these habits play a significant role in causing and determining the progress of various diseases. Vaccination for Human papillomavirus (HPV, a group of more than 200 related viruses) is a topic of debate in non-scientific media. While there’s proven success of these vaccines in preventing women’s genital cancers, there’s not much proof that they can prevent tonsil cancers.
A couple of factors contribute to this. Firstly, unlike cervical cancers, there are no identified stages in tonsil cancers that can warn us before the cancer fully develops. Secondly, differences exist in how HPV is connected to different types of cancers, potentially affecting how useful the vaccine may be.
Despite these uncertainties, countries such as the United Kingdom, United States, Canada, and Australia are vaccinating both boys and girls with the hope that it may reduce the chances of oral cancers in the long run.
