Cancer is a highly prevalent disease in the UK, with 367,167 new cases being diagnosed across the UK from 2015-2017... but how does a cancer diagnosis affect dental care?
Of these patients with cancer, 38,000 are people are living with head and neck cancers. 5 year survival rates are 50%, with risk factors including:
- Age
- Male sex
- Smoking
- Increased alcohol use
Pre-cancer treatment
While many patients who are diagnosed with cancer may not prioritise a dental assessment prior to their treatment, it is essential, particularly with some types of cancer or treatment proposed.
Starting a patient on treatment for their cancer may be of urgency and therefore not allow for dental assessment; but in patients who are going to be exposed to radiotherapy of the head and neck, or chemotherapy treatment with antiresorptive drugs such as denosumab or zoledronic acid, a dental assessment should be prioritised due to the risks of osteoradionecrosis or Medication related osteonecrosis of the Jaw (MRONJ).
It is recommended that before the start of the therapy, or as soon as possible thereafter, the aim is to get a patient as dentally fit as feasible as well as delivering preventative care such as high fluoride toothpaste prescription and diet/oral hygiene advice. This may result in the extraction of teeth of poor prognosis, or those in line with the beam of radiotherapy. The aim of this is to avoid having to do invasive dental treatment following exposure to radiotherapy/antiresorptive drugs which carries the risk of ORN or MRONJ.
As a result, patients could have multiple teeth extracted without much time to process this decision. This can have a psychological effect on the patient who will need ongoing support from their MDT. The overall prognosis of the patient needs to be taken into account - if their overall treatment is palliative, this would influence how drastic a dental treatment plan is. These patients should be managed with an input from specialists to make these challenging decisions which could be an oral surgeon or special care dentist. It should be emphasised to the patient the importance of regular visits to a general dental practitioner to pick up issues early and deliver prevention advice.
During Cancer Treatment
Cancer is generally treated by three different methods, or a combination of methods:
- Chemotherapy
- Radiotherapy
- Surgery
During cancer treatment, oral health may be a low priority for patients. They may be feeling unwell from their treatments and neglect their oral health at this time. Also depending on their treatment plan for their cancer, finding time to attend dental appointments could be a challenge.
1. Radiotherapy
Radiotherapy uses radiation to damage the DNA of the tumour cells, causing cell death. It can be targeted, palliative to relieve symptoms, or used in combination with other treatments.
A common oral side effect is mucositis where the lining of the mouth becomes inflamed, ulcerated and very sore. If the patient cannot eat during this time, they may become PEG or NG fed. Dentists will need to recommend products to help with patient comfort which can include analgesic sprays or mouthrinses such as Difflam, the use of mild SLS-free toothpaste such as Oranurse and advised to avoid spicy food, smoking or alcohol.
2. Chemotherapy
8-61% of head and neck cancers are treated with chemotherapy. Cytotoxic medications are used to target the cancer cells and kill them in 2-4 week cycles. The drugs not only target the cancer cells, but they also affect other rapidly dividing cells such as hair, bone marrow, reproductive cells and peripheral nerves. This can lead to anaemia, hair loss, fertility issues and peripheral neuropathy.
Patients who have anaemia and other blood effects can feel fatigued, are at risk of infection e.g. neutropenic sepsis and can have low platelets which increases the bleeding risk, which could be problematic if dental extractions are required.
If dental treatment is required during chemotherapy, care should be taken to planning and liaison with their oncology team is advised to avoid the Nadir point. This occurs 14 days after a round of chemotherapy and is the point where the patient’s immune system is at its lowest; therefore patients are at very high risk of infections. Preoperative blood tests on the day of treatment to check patient platelets and neutrophils assesses their risk of infection and bleeding. Should these be out of range, treatment may be deferred or antibiotic cover will be required or platelet infusion prior to treatment. Local haemostatic measures could be advised for extractions. The patient may also take longer to heal than normal because they are immunosuppressed.
Similar to radiotherapy, mucositis can occur. This occurs 3-5 days after chemotherapy and should be managed as described above. A patient’s taste may be affected following chemotherapy, or the mouth becomes susceptible to infections such as candida or herpes as a result of dry mouth and immunosuppression.
3. Surgery
If surgery is planned, this could be an opportunity for dental extractions should they be required if there are teeth of poor prognosis; especially if they will be in the way of surgery, radiotherapy beam or would be at high risk of ORN if they were extracted post-treatment.
Post-op Cancer Treatment
As already mentioned, some chemotherapy drugs carry the risk of development of MRONJ, hence the importance of pre-assessment.
Trismus and dysphagia can also be a problem post-radiotherapy and post-surgery. This can result in difficulty achieving good oral hygiene, impaired access if dental treatment is required, and higher risk of caries due to reduced oral clearance. Patients may also be prescribed high calorie fortisip drinks that can increase caries risk if they have swallowing difficulties.
ORN of the jaw or MRONJ can occur either spontaneously or if there is trauma in the site e.g. a rubbing denture or more likely following tooth extraction. This can be a life-debilitating condition which is challenging to treat.
Saliva flow may be reduced following radiotherapy and therefore caries risk increases and radiation caries can occur. Saliva flow does however tend to improve 2 years after radiotherapy treatment.
A diagnosis of cancer can affect the dental management of a patient; from before they start their cancer treatment, to during the treatment, to afterwards and dealing with the side-effects of their treatment. Pre-assessment with a dentist is vital in many cancer patients, with engagement of specialists to contribute to their wider MDT management.
To find out more about the dental management, please refer to BSDH updated oncology guidelines.
