Oral Complications of Cancer Treatment: What the Dental Team Can Do

With over 1.4 million new cases of cancer diagnosed each year and a shift to outpatient management, you will likely see some of these patients in your practice. Because cancer treatment can affect the oral tissues, you need to know about potential oral side effects. Preexisting or untreated oral disease can also complicate cancer treatment. Your role in patient management can extend benefits beyond the oral cavity.

Oral complications from radiation to the head and neck or chemotherapy for any malignancy can compromise patients’ health and quality of life, and affect their ability to complete planned cancer treatment. For some patients, the complications can be so debilitating that they may tolerate only lower doses of therapy, postpone scheduled treatments, or discontinue treatment entirely. Oral complications can also lead to serious systemic infections. Medically necessary oral care before, during, and after cancer treatment can prevent or reduce the incidence and severity of oral complications, enhancing both patient survival and quality of life.

Other complications of chemotherapy

• Neurotoxicity: persistent, deep aching and burning pain that mimics a toothache, but for which no dental or mucosal source can be found. This complication is a side effect of certain classes of drugs, such as the vinca alkaloids.

• Bleeding: oral bleeding from the decreased platelets and clotting factors associated with the effects of therapy on bone marrow.

Other complications of radiation therapy

• Radiation caries: lifelong risk of rampant dental decay that may begin within 3 months of completing radiation treatment if changes in either the quality or quantity of saliva persist.

• Trismus/tissue fibrosis: loss of elasticity of masticatory muscles that restricts normal ability to open the mouth.

• Osteonecrosis: blood vessel compromise and necrosis of bone exposed to high-dose radiation therapy; results in decreased ability to heal if traumatized.

Who Has Oral Complications?

Oral complications occur in virtually all patients receiving radiation for head and neck malignancies, in approximately 80 percent of hematopoietic (blood-forming) stem cell transplant recipients, and in nearly 40 percent of patients receiving chemotherapy. Risk for oral complications can be classified as low or high:

• Lower risk: Patients receiving minimally myelosuppressive or nonmyelosuppressive chemotherapy.

• Higher risk: Patients receiving stomatotoxic chemotherapy resulting in prolonged myelosuppression, including patients undergoing hematopoietic stem cell transplantation; and patients undergoing head and neck radiation for oral, pharyngeal, and laryngeal cancer.

Some complications occur only during treatment; others, such as xerostomia, may persist for years. Unfortunately, patients with cancer do not always receive oral care until serious complications develop.

Evaluation

Ideally, a comprehensive oral evaluation should take place 1 month before cancer treatment starts to allow adequate time for recovery from any required invasive dental procedures. The pretreatment evaluation includes a thorough examination of hard and soft tissues, as well as appropriate radiographs to detect possible sources of infection and pathology. Also take the following steps before cancer treatment begins:

• Identify and treat existing infections, carious and other compromised teeth, and tissue injury or trauma.

• Stabilize or eliminate potential sites of infection.

• Extract teeth in the radiation field that are nonrestorable or may pose a future problem to prevent later extraction-induced osteonecrosis.

• Conduct a prosthodontic evaluation if indicated. If a removable prosthesis is worn, make sure that it is clean and well adapted to the tissue. Instruct the patient not to wear the prosthesis during treatment, if possible; or at the least, not to wear it at night.

• Perform oral prophylaxis if indicated.

• Time oral surgery to allow at least 2 weeks for healing before radiation therapy begins. For patients receiving radiation treatment, this is the best time to consider surgical procedures. Oral surgery should be performed at least 7 to 10 days before the patient receives myelosuppressive chemotherapy. Medical consultation is indicated before invasive procedures.

• Remove orthodontic bands and brackets if highly stomatotoxic chemotherapy is planned or if the appliances will be in the radiation field.

• Consider extracting highly mobile primary teeth in children, and teeth that are expected to exfoliate during treatment.

• Prescribe an individualized oral hygiene regimen to minimize oral complications. Patients undergoing head and neck radiation therapy should be instructed on the use of supplemental fluoride.

Education

Patient education is an integral part of the pretreatment evaluation and should include a discussion of potential oral complications. It is very important that the dental team impress on the patient that optimal oral hygiene during treatment, adequate nutrition, and avoiding tobacco and alcohol can prevent or minimize oral complications. To ensure that the patient fully understands what is required, provide detailed instructions on specific oral care practices, such as how and when to brush and floss, how to recognize signs of complications, and other instructions appropriate for the individual. Patients should understand that good oral care during cancer treatment contributes to its success.

Advise patients to

• Brush teeth, gums, and tongue gently with an extra-soft toothbrush and fluoride toothpaste after every meal and before bed. If brushing hurts, soften the bristles in warm water.

• Floss teeth gently every day. If gums are sore or bleeding, avoid those areas but keep flossing other teeth.

• Follow instructions for using fluoride gel.

• Avoid mouthwashes containing alcohol.

• Rinse the mouth with a baking soda and salt solution, followed by a plain water rinse several times a day. (Use 1/4 teaspoon each of baking soda and salt in 1 quart of warm water.) Omit salt during mucositis.

• Exercise the jaw muscles three times a day to prevent and treat jaw stiffness from radiation. Open and close the mouth as far as possible without causing pain; repeat 20 times.

• Avoid candy, gum, and soda unless they are sugar-free.

• Avoid spicy or acidic foods, toothpicks, tobacco products, and alcohol.

• Keep the appointment schedule recommended by the dentist.

Other factors to remember

Schedule dental work carefully. If oral surgery is required, allow at least 7 to 10 days of healing before the patient receives myelosuppressive chemotherapy. Elective oral surgery should not be performed for the duration of radiation treatment.

Determine hematologic status. If the patient is receiving chemotherapy, have the oncology team conduct blood work 24 hours before dental treatment to determine whether the patient’s platelet count, clotting factors, and absolute neutrophil count are sufficient to recommend oral treatment. Postpone oral surgery or other oral invasive procedures if:

• platelet count is less than 75,000/mm ³ or abnormal clotting factors are present.

• absolute neutrophil count is less than 1,000/mm ³ (or consider prophylactic antibiotics).

Consider oral causes of fever. Fever of unknown origin may be related to an oral infection. Remember that oral signs of infection or other complications may be altered by immunosuppression related to chemotherapy.

Evaluate need for antibiotic prophylaxis. If the patient has a central venous catheter, consult the oncologist to determine if antibiotics are needed before any dental treatment to prevent endocarditis.

Follow-up Oral Care

Chemotherapy

Once all complications of chemotherapy have resolved, patients may be able to resume their normal dental care schedule. However, if immune function continues to be compromised, determine the patient’s hematologic status before initiating any dental treatment or surgery. This is particularly important to remember for patients who have undergone stem cell transplantation. Ask if the patient has received intravenous bisphosphonate therapy.

Radiation therapy

Once the patient has completed head and neck radiation therapy and acute oral complications have abated, evaluate the patient regularly (every 4 to 8 weeks, for example) for the first 6 months. Thereafter, you can determine a schedule based on the patient’s needs. However, keep in mind that oral complications can continue or emerge long after radiation therapy has ended.

Points to remember

• High-dose radiation treatment carries a lifelong risk of xerostomia, dental caries, and osteonecrosis.

• Because of the risk of osteonecrosis, principally in the mandible, patients should avoid invasive surgical procedures, including extractions that involve irradiated bone. If an invasive procedure is required, use of antibiotics and hyperbaric oxygen therapy before and after surgery should be considered.

• Lifelong daily fluoride application, good nutrition, and conscientious oral hygiene are especially important for patients with salivary gland dysfunction.

• Dentures may need to be reconstructed if treatment altered oral tissues. Some people can never wear dentures again because of friable tissues and xerostomia.

• Dentists should closely monitor children who have received radiation to craniofacial and dental structures for abnormal growth and development.

• Dentists should be mindful about the recurrence of malignancies in patients with oral and head and neck cancers, and thoroughly examine all oral mucosal tissues at recall appointments.

Special Considerations for Hematopoietic Stem Cell Transplant Patients

The intensive conditioning regimens of transplantation can result in pronounced immunosuppression, greatly increasing a patient’s risk of mucositis, ulceration, hemorrhage, infection, and xerostomia. The complications begin to resolve when hematologic status improves. Although the complete blood count and differential may be normal, immunosuppression may last for up to a year after the transplant, along with the risk of infections. Also, the oral cavity and salivary glands are commonly involved in graft-versus-host disease in allograft recipients. This can result in mucosal inflammation, ulceration, and xerostomia, so continued monitoring is necessary. Careful attention to oral care in the immediate and long-term post-transplant period is important to patients’ overall health.

For information on this subject please contact Dr Eva A. Douvara DMD PhD, owner and principle of the Dental Clinic Dr Douvaras.

Tel: +30 210 7224224 - Mob: +30 6932 486648