Navigating Treatment After Oral Cancer

  • by Jennifer Gibson
  • Apr 13, 2020
Approximately 53,000 people will be diagnosed with oral cancer this year, according to the American Cancer Society (ACS). While the overall death rate for oral cancers has been decreasing over the last 30 years, the ACS estimates that 10,750 patients will die from the disease in 2020.1 The increased survival rate is related to the increase in oral and oropharyngeal cancers caused by the human papillomavirus (HPV), which is more responsive to existing treatments. However, oral cancer is frequently not discovered until a later stage when it has metastasized to another location, resulting in a worse prognosis.2 Patients who have undergone treatment for oral cancer generally have chemotherapy and radiation to destroy the cancer cells. Such treatments cause significant side effects, and general dentists must be aware of these in order to provide prompt and comprehensive management and treatment.

Oral Cancer Risks

Major risk factors for developing oral cancer include tobacco and alcohol use, but HPV-caused cancer has increased significantly in recent years and is becoming more common in younger people with no history of tobacco use or alcohol abuse. According to the ACS, HPV DNA is found in two out of three oropharyngeal cancers.3 The risk of oral HPV infection increases in those who engage in oral sex with multiple partners, so HPV vaccination at a younger age — before someone is sexually active — could lower the risk of developing oral cancer. Additionally, one study found that people with poor-to-fair oral health are 56% more likely to develop an oral HPV infection than those with good or excellent oral health.4 While more research is needed to examine the link between oral cancer and oral health, maintaining a healthy oral cavity with proper brushing and flossing and regular dental visits will undoubtedly benefit patients.

Oral Cancer Detection

Oral cancer is difficult to detect, and patients may have no symptoms or pain. Often this cancer is found during routine screenings by the patient’s dentist. Karen Pitman, MD, FACS, medical director of the Greater Baltimore Medical Center’s Head and Neck Center and associate professor of otolaryngology at Johns Hopkins Medicine, said dentists are integral to the process.

“No one looks in the mouth of a patient as much as his or her dentist,” said Pitman. “They have the most regular opportunities with patients to do a full mouth and neck exam. Any routine dental exam should include screening for oral cancer by looking for suspicious lesions in the mouth or lumps in the neck. Any patients with findings should be referred to an oral surgeon or ear, nose and throat specialist for biopsy and further evaluation.”

Alexander T. Pearson, MD, PhD, an assistant professor of medicine and medical oncologist specializing in head and neck cancer at the University of Chicago Medical Center, agrees that dentists play a particularly important role in detecting oral cancer.

“Oral cancers arising from dysplasia or other premalignancies of the oral mucosa are often first detected by dentists who can monitor the area,” said Pearson. “Finding oral cancer during a screening is very preferable to finding a neck mass once it’s spread to the lymph nodes. Not all oral cancers are detectable, but some are clearly visible with asymmetry in the mouth, which should then be referred for biopsy and evaluation.”

Oral Cancer Treatment

As with any cancer treatment, the process varies based on many factors, and oral cancer patients may undergo surgery, chemotherapy, radiation therapy or a combination. Dental preparation is important for patients about to undergo treatment for oral cancer. Prior to the start of treatment, the patient should visit his or her general dentist for an evaluation of his or her overall dental health and to address any existing issues.

Pearson said it’s not uncommon for oral cancer patients to have been neglecting their dental care, and it’s especially important to complete invasive procedures and address areas of infection prior to starting cancer treatment to minimize the risk of infections spreading and allow time for healing. The cancer care team should work closely with the patient’s general dentist to ensure dental care is performed in a timely manner so as not to delay cancer treatment.

“We typically ask for dental clearance before initiating oral cancer therapy,” said Pearson. “It’s a really important time — particularly if they’ve been putting off preventive maintenance — for us to ensure we get patients’ mouths in a good place.”

The National Institute of Dental and Craniofacial Research (NIDCR) publishes a guide to aid dentists in the prevention and management of oral complications in cancer patients. According to the NIDCR, dentists should see patients one month before cancer treatment begins to evaluate their oral health; complete any invasive procedures; manage areas of caries, endodontic and periodontal disease; eliminate any sources of oral trauma; treat any problems in the oral radiation field; and provide patient education on oral hygiene.5

If radiation is part of the patient’s treatment plan, added Pitman, the patient will get fluoride trays in advance for daily use to prevent demineralization and radiation caries during the radiation treatment.

Oral Cancer Treatment Complications and Side Effects

In addition to the typical side effects of cancer treatment, such as nausea, fatigue and hair loss, patients may experience oral mucositis, xerostomia, osteoradionecrosis, trismus and secondary infection.6 These conditions are not limited to patients with oral cancer, though they can be exacerbated in those patients and therefore more difficult to manage. 

Damage to teeth and jaw bones from radiation also makes patients more susceptible to dental side effects.

“The balancing act is a lot more delicate for oral cancer patients,” Pearson said. “During cancer treatment, the oral microbiome is different, and the mouth’s ability to flush is altered, so it’s a perfect setup for dental-related issues to develop.”

Oral mucositis is one of the most common side effects of cancer treatment but generally goes away once treatment is completed.

In severe cases, oral sores may develop, and swelling could make it difficult for patients to talk or swallow. Several options are available for management of oral mucositis, including rinses, gels and medications.6 Patients should examine their mouths daily for signs of complications from oral mucositis. Additionally, oral candidiasis is a common secondary infection during oral cancer radiation treatment and can be treated with nystatin.

Longer-term complications that oral cancer patients may deal with for the rest of their lives include xerostomia, or dry mouth. Xerostomia occurs when the salivary glands sustain damage during oral cancer treatment, particularly when they’re in the path of radiation.6 The damage can be recoverable or permanent. Oftentimes, patients with oral cancer stop producing saliva altogether.

Pearson said xerostomia is very common in oral cancer patients who undergo radiation treatment because the salivary glands are more susceptible to chronic changes related to radiation treatment. 

Renuka Malik, MD, a radiation oncologist and assistant professor of radiation and cellular oncology at the University of Chicago, recommends mouthwashes such as Biotène®, which are artificial types of mucous secretions that can help lubricate the mouth.

“Additionally, baking soda rinses or aggressive swishing after eating can help remove loose particles for patients who have difficulty flossing,” said Malik.

Though it is an uncomfortable and difficult condition, Pearson said patients have to adapt to dry mouth, noting that mouthwashes don’t solve the underlying problem. Managing patient expectations is key, he said, and he’s hopeful that research into tissue engineering eventually could make this long-term complication a thing of the past. Meanwhile, dentists should closely examine patients for any sign of radiation caries — which can progress rapidly if not treated — due to changes in efficacy and amount of saliva.

A rare side effect, osteoradionecrosis (ORN) — bone death due to radiation — sometimes develops, and 75% of ORN cases occur within three years of radiation treatment. Jaw trauma can increase the risk of ORN, with tooth extractions accounting for up to 50% of cases. If possible, dentists should avoid extractions and invasive periodontal procedures once radiation therapy begins.6

If tooth extractions are needed after radiation, dentists should discuss with physicians the potential need for hyperbaric oxygen therapy to aid in wound healing, said Malik. “This is important especially if a patient is deemed high risk.”

Some oral cancer patients develop trismus following treatment with both surgery and radiation therapy in an area affecting the temporomandibular joint and the muscles of mastication. After treatment in this area, radiation-induced fibrosis and postsurgical scar formation may hinder the patient’s ability to open his or her mouth as wide as before treatment.6 Early identification is important.

“Stretching to prevent tightening of the muscles surrounding the jaw can help prevent trismus,” said Malik.

The Dentist and the Treatment Team

Cancer treatment requires a multidisciplinary approach. From oncologists to psychologists, social workers to surgeons, all of a cancer patient’s providers meet regularly in what is typically referred to as a “tumor conference.” Pitman encourages dentists to participate in these meetings if they are treating oral cancer patients and said it can go a long way in relieving patient frustrations if dentists take a big-picture view of their patients’ health.

“Dentists nationwide need to know how important they are in screening for oral cancer and getting patients to the right resources,” she said. “One of the frustrations patients have is that, if they had a neck mass, they saw their primary care provider and got antibiotics. Then, six months later, they’re showing up in the oncologist’s office. If the patient had seen a dentist, they would have recognized the suspicious neck mass and referred the patient to a head and neck or oral surgeon right away.”

General dentists often have a lifelong relationship with their patients, and this continuity of care makes them integral in managing long-term complications and side effects after oral cancer treatment. Dentists should embrace their role by educating themselves and their patients to promote optimal oral health and quality of life before, during and after oral cancer treatment. 

Jennifer Gibson is a freelance writer based in the Chicago area. To comment on this article, email impact@agd.org.

References 
1. “Key Statistics for Oral Cavity and Oropharyngeal Cancers.” American Cancer Society, 8 Jan. 2020, https://www.cancer.org/cancer/oral-cavity-and-oropharyngeal-cancer/about/key-statistics.html. Accessed 2 Feb. 2020. 
2. “Oral Cancer Facts.” The Oral Cancer Foundation, 27 Feb. 2019, www.oralcancerfoundation.org/facts/. Accessed 2 Feb. 2020. 
3. “Risk Factors for Oral Cavity and Oropharyngeal Cancers,” American Cancer Society, 9 March 2019, www.cancer.org/cancer/oral-cavity-and-oropharyngeal-cancer/causes-risks-prevention/risk-factors.html. Accessed 2 Feb. 2020. 
4. Bui, Thanh Cong, et al. “Examining the Association Between Oral Health and Oral HPV Infection,” Cancer Prevention Research, vol. 6, no. 9, 2013, pp. 917-924. 
5. “Dental Providers Oncology Pocket Guide.” National Institute of Dental and Craniofacial Research, Sept. 2009, www.nidcr.nih.gov/sites/default/files/2017-09/oncologyguide-dental-provider_0.pdf. Accessed 2 Feb. 2020. 
6. Kim, Reuben Han-Kyu, et al. “Managing Intraoral Lesions in Oral Cancer Patients in a General Dental Practice: An Overview.” Journal of the California Dental Association, vol. 44, no. 2, 2016, pp. 85-92.