Oral Cancer: Symptoms, Diagnosis and Treatments

Smoking and Drinking Substantially Increase Risk of Oral Cancer

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In the United States and around the world, the frequency of oral cancer, or cancer that affects the lips, oral cavity, and throat, is high in part because many people both drink and smoke. This combined risk factor, drinking and smoking, serves to substantially increase a person's risk of developing oral cancer—more so than either risk factor does individually.

The most obvious way of preventing oral cancer is to abstain from drinking and smoking; however, we all know that cessation is challenging for many people who are dependent on drugs and alcohol or misuse drugs and alcohol.

Oral Cancer Statistics

About 85 percent of head and neck cancers are oral cancers. (Head and neck cancers are distinct from brain cancers.) Moreover in the United States, 3 percent of all malignant cancers in men and 2 percent of all malignant caners in women are oral cancers.

Oral cancer affects more men than women, and African-American men are more likely than are white men to develop oral cancer. Finally, oral cancer is far more common in people aged 40 and older.

In Southeast Asia, a whopping 40 percent of all cancers are oral cancers. In developed nations, the percentage of cancers that are oral cancers hovers around 4 percent.

The chance that any individual person will develop oral cancer during the course of his lifetime is about 1.1 percent. Each year, oral cancer kills about 8000 people in the United States. Furthermore, about 42,000 people in the United States are diagnosed with this type of cancer every year.

In 2012, nearly 300,000 people across the United States had oral cancer. To put this number in perspective, the population of Cincinnati is about 300,000 people.

Despite advances in diagnostic and surgical techniques, the number of people alive 5 years after initial diagnosis of oral cancer, or the 5-year survival rate, has been the same for about 4 decades: between 50 and 55 percent.

In other words, about half the people who are diagnosed today with oral cancer will die within the next 5 years. This guarded survival rate occurs because even though we can catch oral cancer early, people with this disease usually present for treatment later, with more advanced and severe disease.

Anatomy of Oral Cancer

Most oral cancers affect the first two-thirds of the tongue. Specifically, these cancers grow from the bottom (dorsal) and (lateral) sides of the tongue. The top (dorsal) part of your tongue is rough with taste buds. The bottom part of your tongue is smooth.

Very rarely, oral cancer can affect either the lips or parts of the oral cavity including the following:

  • inside the cheeks (buccal mucosa)
  • roof of the mouth (hard palate)
  • the small area located behind the wisdom teeth (retromolar trigone)
  • the gums (gingiva)

Oral cancers occasionally can grow from the back of the throat or pharynx. More specifically, the cancers can grow from the oropharynx and hypopharynx.

The oropharynx consists of the following:

  • soft palate
  • side and back walls of the throat
  • back one-third of the tongue
  • tonsils

The hypopharynx is the bottom part of the throat. The pharynx is a 5-inch long tube that connects the real estate between the nose and entrance of the esophagus and larynx (windpipe). Food and air pass through the hypopharynx on their way to the stomach and lungs, respectively.

The location of a malignant (cancerous) tumor in the oral cavity or pharynx is important because location can affect disease behavior (pathology) and treatment.

Ultimately, oral cancer can affect any part of the mouth, oral cavity and pharynx.

What Are Oral Cancers Made of?

Most oral cancers are squamous cell cancers. Squamous cells are the thin, flat cells that line the oral cavity and pharynx.

Squamous cell cancers begin to form after alteration transpires at the molecular level. Once the squamous cells get messed up on a molecular level, the appearance of these cells changes. As more cells change in appearance, oral cancer becomes observable, or clinically evident, and symptoms begin to manifest.

Nonsquamous oral cancers are rare and can include salivary gland tumors, sarcomas, and melanoma.

What Are the Risk Factors for Oral Cancer?

Risk factors are defined as any characteristic or exposure that increases the likelihood (risk) of developing disease.

Here are some oral cancer risk factors:

  • alcohol
  • tobacco
  • HPV16 (human papilloma virus type 16 which is linked to increasing frequency of tonsillar cancers)
  • diet deficient in fruits and vegetables
  • excess sun exposure (increases risk for lip cancer)
  • immunosuppression (weakened immune system)
  • betel quid chewing (a stimulant  drug found in the Indian subcontinent which is ingested like chewing tobacco and often mixed with tobacco)
  • mate drinking (a traditional South American beverage that's rich in caffeine and made of yerba mate)

What Are the Symptoms of Oral Cancer?

Here are some possible signs and symptoms of oral cancer. (FYI: A sign is any observable effect of disease; whereas, a symptom is something that a patient complains about and is thus subjective.)

  • white patches on the inside of the mouth (leukoplakia)
  • sore throat that doesn't go away
  • scab (on the lip) or ulcer that doesn't go away
  • lump on the inside of the mouth
  • pain on chewing
  • pain on swallowing
  • swollen glands (lymph nodes)
  • jaw pain
  • tongue pain
  • loose teeth
  • loose dentures

More advanced symptoms of oral cancer include the following:

  • weight loss
  • bloody cough
  • trouble eating (dysphagia)
  • hoarseness
  • trouble breathing

Typically, people with oral cancers attribute early signs and symptoms of the disease to other causes. Consequently, these people present with this cancer late during the course of illness when the illness is more severe. Additionally, primary care physicians (family medicine physicians or internists) can sometimes overlook the significance of early-stage oral cancer signs and symptoms.

Unfortunately, lack of early detection is a major reason oral cancer kills nearly half of the people it burdens. Disease caught early is much more treatable.

How Is Oral Cancer Diagnosed?

If a physician or dentist sees a suspicious lesion, or abnormality, in your mouth or throat after performing a physical exam, a biopsy is done to figure out what this lesion is. With a biopsy, a small tissue sample is cut from the source and analyzed using a microscope in the lab.

In addition to biopsy, other diagnostic modalities can be used to help diagnose oral cancer or figure out whether it has spread (metastasized). These tests include the following:

  • MRI
  • CT scan
  • PET scan (good at detecting metastases or spread)
  • chest and dental x-rays
  • endoscopy (a flexible tube with a camera and light at the end used to visualize the inside of your body)
  • barium swallow (gastrointestinal series of x-rays of the esophagus and stomach)

How Is Oral Cancer Staged?

The stage, or severity, of an oral cancer is based on TNM staging criteria.

The T in TNM refers the anatomic extent of the primary tumor. In other words, T refers to the extent to which the primary oral cancer tumor grows into surrounding structures.

Then N in TNM stands for lymph node spread or the extent to which the oral cancer invades the regional lymph nodes. (The lymph nodes can disseminate the tumor throughout the body by means of the lymph system.)

Finally, the M in TNM stands for metastases or the presence of secondary malignant growths in anatomical sites distant from the original tumor location.

There are 5 main stages of oral cancer: Stage 0, I, II, III and IV. Of note, Stage IV is further divided into 3 sub-stages—IVA, IVB and IVC—which we won't specifically discuss to keep things a bit more simple.

Staging can get tricky. Nevertheless here are brief descriptions of oral cancers that fall into each of the 5 main stages.

  • Stage 0 oral cancer refers to carcinoma in situ, or cancer that has not yet spread and has stayed exactly where it began. Stage 0 cancers are highly treatable.
  • Stage I oral cancer refers to a tumor that hasn't spread to lymph nodes or distant anatomical sites and is sized at 2 cm or less along its greatest dimension.
  • Stage II oral cancer refers to a tumor that hasn't spread and is sized between 2 and 4 cm along its greatest dimension.
  • Stage III oral cancer can refer to any size primary tumor that may or may not have spread to the lymph nodes.
  • Depending on sub-stage, Stage IV cancers can refer to any size tumor with lymph node and distant metastases.

When determining proper treatment, staging a tumor using diagnostic modalities is key. Staging can also be used to predict prognosis, or outlook, for those with cancer.

Treatment of Oral Cancers

Depending on size, stage and location, oral cancer can be treated using surgery, radiotherapy and chemotherapy.

Oncology teams responsible for treating patients with oral cancer include various health professionals who provide additional services such as dental care, psychological counseling, social support and nutrition counseling.

When the primary oral cancer tumor is well-circumscribed, or well-defined, and accessible, an ENT (ear, nose and throat specialist or otolaryngologist) will surgically remove it.

Sometimes, either it's hard to get at a tumor or the tumor has spread, or metastasized, to the lymph nodes and beyond. In these cases, chemotherapy and radiotherapy can be used. Furthermore, chemotherapy and radiotherapy can be used as adjunct, or additional, treatments that complement surgery and thus minimize spread of the cancer.

People who receive treatment for oral cancer must vigilantly follow up for comprehensive check-ups every 6 months. The chance that an oral cancer will return is between 3 percent and 7 percent each year.

Prognosis of Oral Cancers

Stage I and Stage II oral cancers are highly treatable with 5-year survival rates greater than 90 percent. In other words, the number of people alive 5 years after initial diagnosis with Stage I and Stage II oral cancer is greater than 90 percent.

Stage III and Stage IV cancers have lower five-year survival rates: between 23 and 58 percent.

In conclusion, if you or a loved one suspect oral cancer for whatever reason, it's imperative that you make an appointment with your physician as soon as possible. Because initial signs and symptoms of oral cancer are nonspecific, you must share your specific concerns about oral cancer with your physician. You can also ask to be referred to a specialist, or ENT, for further evaluation. Oral cancer is a serious disease which should be treated early on to ensure survival.

Sources

Kim ES, Gunn G, William W, Jr., Kies MS. Chapter 16. Head and Neck Cancer. In: Kantarjian HM, Wolff RA, Koller CA. eds. The MD Anderson Manual of Medical Oncology, 2e. New York, NY: McGraw-Hill; 2011. Accessed March 17, 2016.

Article titled "TNM Staging of Cancers of the Head and Neck: Striving for Uniformity Among Diversity" by SG Patel and JP Shah published in CA: A Cancer Journal for Clinicians in 2005

Usatine RP, Smith MA, Chumley HS, Mayeaux EJ, Jr.. Chapter 43. Oropharyngeal Cancer. In: Usatine RP, Smith MA, Chumley HS, Mayeaux EJ, Jr.. eds. The Color Atlas of Family Medicine, 2e. New York, NY: McGraw-Hill; 2013. Accessed March 16, 2016.

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