Soft palate cancer is a type of oropharyngeal cancer. The oropharynx is the area at the back of the mouth and top of the throat. Soft palate cancer grows on the roof of the mouth.

Soft palate cancers account for about 5–12% of all oropharynx cancers, according to a 10-year study at a single institute published in 2020.

This article explains what soft palate cancer is, including the symptoms, treatments, and causes. It also details the outlook once receiving a diagnosis and whether the cancer is preventable.

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The soft palate is the muscular area at the roof of the mouth, toward the back of the throat. It includes the uvula that hangs at the back of the throat and five muscles that serve key roles in breathing, speech, and swallowing.

The soft palate sits behind the hard palate, which is the bony front two-thirds of the roof of the mouth.

Soft palate cancer develops when cells in the soft palate divide uncontrollably and do not die at the normal stage in their life cycle. Instead, they risk spreading to other parts of the body.

Several types of cancers commonly affect the soft palate. A type of cancer called squamous cell carcinoma (SCC) makes up nearly 70% of all soft palate cancers, according to a 2018 review.

Other cancers of the soft palate include:

  • mucoepidermoid carcinoma
  • adenoid cystic carcinoma
  • polymorphous low-grade adenocarcinoma
  • low-grade papillary adenocarcinoma
  • acinic cell carcinoma
  • mucosal melanoma
  • Kaposi sarcoma
  • non-Hodgkin’s lymphoma

Symptoms of soft palate cancer depend on the type of cancer that develops. Symptoms might include:

  • a sore on the palate that will not heal
  • foul-smelling breath, which is called halitosis
  • bleeding in the mouth
  • difficulty swallowing
  • pain when swallowing
  • changes to speech
  • hoarseness when speaking
  • loose teeth
  • dentures no longer fit like they used to
  • extreme tiredness
  • unexplained weight loss

Most often, palate cancers appear as a lump that may or may not cause pain and bleeding. Some cancers, such as Kaposi sarcoma, present as patches instead of lumps.

It is important to contact a doctor upon noticing any unusual or persistent changes in speech or swallowing. Detecting cancer as early as possible can help a improve a person’s outlook.

Regular dental checkups that examine the whole mouth can help people identify cancers that are not causing symptoms.

People with a higher risk of oropharyngeal cancer, such as people who use tobacco or regularly consume alcohol, can seek routine dental visits to monitor their oral health.

The main causes of oropharyngeal cancer are smoking and alcohol use, especially at the same time.

Smoking and drinking damage cells in the mouth and throat lining. Because cancers often develop from cells’ mistakes when copying DNA, this damage may increase the risk of cells’ mistakes when copying themselves, potentially leading to cancer.

Tobacco contains many chemicals that damage DNA. Alcohol may help these chemicals enter cells more easily.

Human papillomavirus (HPV) is a sexually transmitted infection (STI) that can also cause oropharyngeal cancer. It can be transmitted to the back of the mouth through oral sex.

HPV may cause 70% of all oropharyngeal cancers in the United States. However, HPV usually causes tonsil cancer or cancer of the tongue base, rather than soft palate cancer.

HPV makes proteins called E6 and E7 that can switch off some genes in cells that suppress the growth of tumors. The cells in the throat make too many of these proteins, potentially leading to cancer growth.

Risk factors

According to the American Cancer Society, people most at risk of oropharynx cancer include:

  • Males: Around 1 in 60 men develop oral and oropharyngeal cancers, compared to 1 in 141 women.
  • Older adults: The average age of onset for oral and oropharyngeal cancers is 64 years. However, more than 1 in 5 people with oral cancer diagnoses are under age 55.
  • White people: Oral and oropharyngeal cancers are a little more common in white people than in people of other races.

Treatment options for soft palate cancer depend on several factors, such as:

  • the type of cancer
  • the stage of cancer
  • how far the cancer has spread
  • how well the person is likely to tolerate certain treatments

Surgery

Many doctors recommend a wide local excision to treat soft palate cancer. The procedure involves surgically removing the palate.

If the cancer is aggressive or has spread, a surgeon may also remove lymph nodes or tissues in the neck.

After this type of surgery, the surgical team may perform a reconstructive procedure. This may help restore as much speech and swallowing function as possible and preserve appearance.

Reconstruction may involve local tissue rearrangement, a skin graft, or a free flap tissue transfer. A surgeon may also use dental devices, such as an obturator. An obturator is a prosthesis that replaces the surgically removed roof of the mouth.

Chemotherapy and radiation therapy

Doctors use chemotherapy, radiation therapy, or a combination of the two, known as chemoradiation, to treat some cases of soft palate cancer.

Chemotherapy involves a qualified healthcare professional administering cancer-killing medications through an intravenous (IV) drip.

In radiation therapy, a qualified healthcare professional uses radiation to target and kill cancer cells. This may be done with an external radiation beam or tiny, implanted pellets of radioactive material.

Doctors may recommend radiation therapy for early stage oropharyngeal cancer. Surgery might also be necessary to remove the tumor.

A doctor may recommend radiation, chemotherapy, or chemoradiation after surgery, particularly for people with aggressive cancer or cancer that has spread.

A cancer care team may treat soft palate cancer that has advanced into deeper tissue or nearby lymph nodes using chemoradiation.

A multidisciplinary care team typically manages these advanced cancers. The team may comprise the following specialists:

  • otolaryngologists
  • radiation oncologists
  • medical oncologists

Immunotherapy

If soft palate cancer spreads to other areas, a doctor may recommend chemotherapy or immunotherapy.

Immunotherapy involves a qualified healthcare professional administering drugs called PD-1 inhibitors. They encourage the immune system to target cancer cells, which can trick the immune system into avoiding or even protecting them.

Sometimes, doctors recommend immunotherapy and chemotherapy for cancer that has reached other parts of the body.

A 5-year relative survival rate of cancer compares the chances of a person who has a specific cancer surviving for 5 years after diagnosis with the chances of someone who does not have cancer.

According to the American Cancer Society, the 5-year relative survival rates of oropharyngeal cancers are as follows:

  • Localized: If the cancer stays in one area, the survival rate is 59%.
  • Regional: If the cancer has spread to nearby tissues, the survival rate is 62%. It’s not clear why this is the case for oropharyngeal cancer.
  • Distant: If the cancer has spread to distant organs, such as the lungs, the survival rate is 29%.

The numbers may not tell the whole story, however. For example, they do not account for improvement after treatment or the cancer spreading to other areas.

A doctor will explain the outlook for each individual with cancer based on their health, age, and the progress of their treatment.

It is not possible to prevent soft palate cancer. However, it is possible to reduce the risk of all oropharyngeal cancers with the following measures:

  • avoiding or quitting tobacco use, which can reduce cancer risk even in people who have used it for many years
  • reducing the risk of exposure to HPV by taking a vaccine called Gardasil 9
  • limiting alcohol consumption

The Centers for Disease Control and Prevention (CDC) recommends Gardasil 9 for everyone up to 26 years old. People ages 27–45 years can speak with a doctor about their own risk of HPV and the benefits of vaccination. Condoms and dental dams may also reduce the risk of HPV transmission.

Soft palate cancer can develop from tobacco and alcohol use as well as HPV infection. It can cause lumps and lesions to develop in the back of the mouth, affecting speech and swallowing.

After diagnosis, treatment can involve surgery, chemotherapy, and radiation therapy.

It is possible to reduce the risk of soft palate cancer by avoiding tobacco and limiting the risk of exposure to HPV.