11.5
Leukaemias
Section I: Clinical Scenario and Dental Considerations
Clinical Scenario
A 47‐year‐old male is referred for urgent dental assessment by his haemato‐oncology specialist. The patient complains of recurrent pain from a tooth in the upper left quadrant which is typically present 1 week after chemotherapy and then subsides.
Medical History
- Chronic myeloid leukaemia (CML)
- Diagnosed 2 months ago
- Already commenced 3 cycles of chemotherapy
- Due to have cycle 4 in 7 days’ time
- Diabetes mellitus type 2
Medications
- Imatinib (3 cycles)
- Vitamin D
- Calcium supplementation
- Metformin
- Long‐acting insulin
Dental History
- Irregular dental attender; only attends when in pain due to limited financial resources and lack of access
- Brushes his teeth once a day
- Diet – due to discomfort from his mouth during chemotherapy, can only eat soft food; also has 4 nutritional supplements drinks as advised by his clinical nurse specialist
Social History
- Originally from Bangladesh – has been living and working overseas for 10 years
- Lives with his cousin
- Married; wife and children live in Bangladesh
- Works as a construction worker
- Tobacco consumption: 10 cigarettes daily for 10 years; smokeless tobacco – chews paan 4 times daily for 20 years
- Alcohol consumption: nil
Oral Examination
- Dry lips, mild xerostomia
- Generalised dental plaque, calculus (particularly lingual to lower anterior teeth), staining (Figure 11.5.1)
- Interdental food packing posterior quadrants
- Paan remnants in the lower left buccal vestibule; adjacent white patch on the buccal mucosa; stiffening/banding of the tissue
- Caries in #13, #26 and #27
Radiological Examination
- Orthopantomogram undertaken – demonstrates generalised mild bone loss
- Bilateral bite‐wing radiographs – extensive caries with likely pulpal involvement #26 (distal) and #27 (mesial) (Figure 11.5.2)
Structured Learning
- What is the significance of the patient taking imatinib?
- Imatinib is a targeted cancer therapy drug (biological therapy)
- It acts as a tyrosine kinase inhibitor, thereby blocking the growth of cancer cells
- It is taken orally once or twice a day
- In addition to the general side‐effects of cancer therapy, it has been implicated in the development of medication‐related osteonecrosis of the jaw (MROJ)
- What could be the cause of the lesion in the left buccal mucosa?
- The patient chews paan which is typically composed of areca nut, slaked lime (from limestone or coral) and tobacco wrapped within a betel leaf
- This is known to be associated with yellow‐brown staining of the teeth and mucosal surfaces, the development of white patches (leucoplakia) and oral submucous fibrosis (associated with the areca nut)
- You advise the patient to stop chewing the paan due to the negative impact on his oral health and the risk of oral cancer. He advises you that it helps him to cope with his chemotherapy and manage his diabetes. What could be the perceived benefits he is referring to?
- Paan is perceived as a cure for halitosis
- It is also used by some patients to manage symptoms such as nausea and vomiting associated with chemotherapy
- Some patients with diabetes also believe that paan helps control the disease
- However, the perceived health benefits are not proven
- The risks of continued paan use, particularly when it contains areca nut and tobacco, outweigh any possible benefits
- Sensibility testing is undertaken on #26 and #27. Both teeth are confirmed to be non‐vital. The patient requests root canal treatment as he does not want to lose more teeth. What would you discuss?
- If the teeth are restorable, endodontic treatment followed by restoration and a full‐coverage restoration at a later stage is an option
- However, consideration should be given to the fact that the patient is receiving active chemotherapy to control his CML
- Completion of multiroot endodontic treatment and restoration is likely to cause further delays to chemotherapy
- Furthermore, although the success rate of root canal treatment is 90–95%, a risk of reinfection remains which can cause further delays
- As the patient is immunocompromised due to both CML and cancer therapy, the success rate is likely to be lower
- This can pose a further risk during chemotherapy and delay treatment further due to the potential for bacteraemia
- Following discussion with the haemato‐oncologist, dental extraction of #26 and #27 is advised. What factors would you need to take into account?
- It is ideal to wait at least 10 days post dental extractions before recommencing chemotherapy (to allow for primary healing); hence the next cycle of chemotherapy may need to be delayed (risks and benefits of this should be discussed with the haemato‐oncologist)
- Increased risk of bleeding, infection and delayed wound healing
- This would then need to be followed by further close reviews due to the risk of MRONJ
- Preoperative blood tests confirm the Hb level is 100 g/dL, platelets 65 × 109/L and neutrophil count 0.5 × 109/L. What are the implications for dental extractions given these blood counts (see Chapter 12.2)?
- The Hb count is reduced, indicating that the patient is anaemic; this is associated with hypoxia, lethargy and fatigue; supplemental nasal oxygen at 2–3 L/min should be considered during dental extractions
- Although the platelet levels are low, they are sufficient to proceed with dental extractions under local anaesthesia without platelet supplementation; local haemostatic measures should be used, including sutures and haemostatic agents (sponges and tranexamic acid mouthwash)
- The neutrophil count is significantly reduced; this is associated with a significant risk of infection; perioperative antibiotic prophylaxis and granulocyte‐colony stimulating factor (G‐CSF) subcutaneous injections typically given for 5 days prior to surgery, may be advised by the haemato‐oncologist; G‐CSF stimulates the bone marrow to produce more white blood cells, although it is used with caution as it may stimulate some leukaemic processes; it is currently considered as a safe and effective way to stimulate myelopoiesis and allows for continued imatinib therapy in CML patients at risk for disease progression
- What other factors do you need to consider in your risk assessment?
- Social
- Patient is likely to be fatigued due to CML and chemotherapy
- An escort is desirable
- When scheduling dental appointments, need to consider the timing and impact of the cancer therapy hospital visits
- Medical
- Anaemia, thrombocytopenia and neutropenia are common side‐effects of CML treatment
- Caution when interpreting the haemoglobin A1c levels as anaemia in relation to chemotherapy and/or cancer therapy (anaemia may exaggerate the glycaemic status of the patient)
- Dental
- Acute and chronic side‐effects of chemotherapy
- Risk of MROJ
- Calorific supplement drinks and soft diet increase caries risk
- Suboptimal oral hygiene habits
- Compliance issues in daily life
- Lack of perceived need
- Irregular dental attender
- Xerostomia due to chemotherapy and diabetes
- Increased risk of periodontal disease due to diabetes (bidirectional relationship)
- Food packing
- Paan‐associated risk of oral submucous fibrosis
General Dental Considerations
Oral Findings
- Oropharyngeal lesions can be the presenting complaint in >10% of cases of acute leukaemia
- Oral bleeding and petechiae/ecchymoses are typical manifestations
- Gingival swelling secondary to infiltration of gingival tissue with leukaemia cells (Figure 11.5.3); this is most commonly seen with acute myeloid leukaemia subtypes (~67% acute monocytic leukaemia, ~18% acute myelomonocytic leukaemia, ~4% acute myelocytic leukaemia). Instances of gingival or palatal enlargement have also been reported in chronic lymphocytic leukaemia
- Herpetic oral and perioral infections are common and troublesome (viruses can also cause encephalitis or pneumonia)
- Candidiasis is particularly common in oral cavity and paranasal sinuses; usually caused by Candida albicans
- Aspergillosis and mucormycosis can involve the maxillary antrum and be invasive
- Bacterial infections more common, including Pseudomonas spp., Serratia spp., Klebsiella spp., Enterobacter spp., Proteus spp. and Escherichia spp.; Gram‐negative species occasionally cause oral lesions which become a major source of septicaemia or metastatic infections
- In severely immunocompromised patients, over 50% of systemic infections result from oropharyngeal micro‐organisms
- Other oral/perioral findings
- Mucosal pallor
- Mucosal or gingival ulceration
- Pericoronitis
- Cervical lymphadenopathy
- Tonsillar swelling
- Paraesthesia (particularly of lower lip)
- Extrusion of teeth
- Painful swelling of major salivary glands (Mikulicz syndrome)
- Radiographic changes
- May be reversible with chemotherapy
- Destruction of crypts of developing teeth
- Thinning or disappearance of lamina dura (especially premolar and molar regions)
- Loss of alveolar crestal bone, and bone destruction near apices of mandibular posterior teeth
- Side‐effects of cancer therapy may also be observed (see Chapter 12.2); commonly include mucositis, sometimes with ulceration
Dental Management
- Dental treatment modification depends on the severity of the underlying disease, the intensity and stage of cancer therapy, and the urgency/invasiveness of the proposed dental intervention (Tables 11.5.1 and 11.5.2