The risks of delayed oral cancer detection in primary care

Case report

We discuss the case of a 46-year-old male who presented to the Oral and Maxillofacial Surgery Department at Bedford General Hospital. He had previously attended the local dental access centre with a 2-month history of upper right quadrant jaw pain, unexplained tooth mobility and right-sided nasal congestion. He described the pain as a poorly localized dull ache, not sensitive to hot or cold, with no disturbance to his sleep. A periapical radiograph showed no evidence of caries nor any significant bone loss. He was provisionally diagnosed with sinusitis and prescribed antibiotics by the general dental practitioner. The patient re-presented two weeks later with further symptom progression. He now experienced a sensation of ‘bruising and fullness’ over his right cheek. The upper right second molar tooth was extracted as it was identified as the potential cause of his symptoms. He subsequently developed a gradual loss of sensation over the right upper lip, cheek, and side of the nose, coupled with mobility of the adjacent molar teeth. The facial swelling had rapidly progressed.

An urgent referral was made to the hospital, now seven weeks after initial presentation. Clinical examination revealed a firm swelling underlying the right cheek with a reduction in sensation in the right infra-orbital nerve distribution. Intra-orally, a tender, firm, submucosal mass was palpable in the right posterior buccal sulcus measuring approximately 3 x 2 cm (Figure 1). The first and third molar teeth were grade III mobile and he had no trismus. Decreased air entry through the right nostril was noted. There was no evidence of proptosis nor any diplopia. The patient denied any symptoms of dysphagia, dysphonia, fever or weight loss.

Review of the OPG radiograph taken two weeks earlier at the dental access centre showed evidence of an apparent reduction in bone density of the alveolus adjacent to the upper right molar teeth (Figure 2). This had not been identified by the referring dental practitioner.

An urgent CT scan revealed gross bone destruction of the right maxilla and a mass within the maxillary antrum extending to the posterior orbital floor (Figure 3). There was no obvious intranasal component, nor any posterior extension into the pterygoid or infratemporal fossae.

An incisional biopsy confirmed histological features consistent with an odontogenic carcinoma arisen from within an ameloblastoma; a type 2 ameloblastic carcinoma. The patient underwent tumour resection, selective neck dissection with microvascular free flap reconstruction and adjunctive radiotherapy. He is disease free at 5 years and remains under close clinical and radiographic surveillance.

Ameloblastic carcinoma is an extremely rare, malignant, epithelial odontogenic tumour occurring most commonly in the posterior mandible. Fewer than 50 cases of maxillary ameloblastic carcinoma have been reported in the literature over the last 60 years.⁵ This neoplasm is aggressive in nature, usually exhibiting rapid growth with a propensity for extensive local destruction and metastatic spread. It typically presents as a slow growing and often painless swelling of the jaws. Appearances can range from a small cystic-type lesion with typically benign clinical features, to a large, indurated mass with extensive bony resorption. Variation in clinical presentation may create diagnostic difficulty, thus prompt radiological and histological investigations are key.

Discussion

The incidence of oral cancer has increased by over a quarter in the last 10 years and prognosis has improved significantly via swift diagnosis and referral.⁶ Over 6500 new cases of oral cancer are diagnosed in the UK each year.⁷ Worldwide, 25% of all oral cancers are attributable to tobacco usage, 7–19% to alcohol consumption, 10–15% to micronutrient deficiency and more than 50% to betel quid chewing in certain populations. Carcinogenicity is dose-dependent and magnified by multiple exposures.⁸

Dental practitioners play a critical role in the early detection of oral malignancy and should be able to recognize the sinister signs and symptoms of a potential oral cancer diagnosis. A study by Kondori et al⁹ investigated 976 biopsy reports of specimens sent to a single pathology centre and compared them to the submitting clinician's presumptive clinical diagnoses. They found that 43% of clinical diagnoses made by the submitting dentists were incorrect. Further still, fewer than 40% of the dentists completed a full oral cavity examination, including soft tissues, and only 30% were found to educate their patients regarding smoking cessation programmes, where appropriate.

It has been estimated that, with early detection, 90% of oral cancer patients could be cured.¹ It is a well-known fact that early diagnosis and effective treatment of oral malignancy improves survival, but the poor overall 5-year survival rate (50%) has been attributed to advanced stage at presentation to an appropriate referral centre.¹⁰

The dental practitioner has a crucial role in raising patient awareness of the signs and symptoms of oral cancer. Commonly reported presentations of oral cancer to the dental practitioner include a mouth ulcer (32%), a lump in the face or neck (28%), and pain or soreness in the mouth or throat (27%).¹¹ Other symptoms which should trigger concern include unexplained tooth mobility, sensory or motor nerve dysfunction, prolonged trismus, dysphagia and dysphonia. Rhinorrhea, nasal congestion, referred otalgia and loss of taste (ageusia) should also raise suspicion. Such ‘red flag’ clinical findings have been summarized by the BDA in the ‘Early Detection and Prevention of Oral Cancer’ paper published in 2010 (Table 1).¹²

The dental examination must involve a full assessment of the dentition and surrounding soft tissues as well as the cervical lymph nodes. The neck node assessment is critical, as the primary site of an oral malignancy is not always readily detectable, and malignancy may present as a secondary deposit within a neck lymph node. Studies performed assessing the sensitivity of dentists in diagnosing malignancy have shown that over 90% of dentists pick up cancers in accessible areas, such as the lip, buccal mucosa and dorsal surface of the tongue. This dropped significantly to under 50% for cancerous lesions in less visible areas, including the floor of the mouth, posterior tongue, buccal sulcus and bony tumours of the jaws.^10,13 Some authors suggest a requirement for mandatory, periodic re-training for all dentists in the recognition of oral cancer and of the appropriate referral pathway in their local area.¹⁴

Maxillary sinus tumours often present late with non-specific symptoms and can mimic dental pain. Later symptoms can include tooth mobility, facial swelling with or without sensory disturbance, soft tissue ulceration and epiphora. Nasal and orbital signs may also indicate advanced disease progression. It is important to note that only 10–12% of cases of maxillary sinusitis can be attributed to an odontogenic aetiology.¹⁵ General dental practitioners suspecting a diagnosis of sinusitis should consider a referral to an ENT specialist with access to diagnostic aids, such as naso-endoscopy and CT imaging. In the aforementioned case, the symptoms at initial presentation warranted urgent referral to secondary care for further investigation.

Conclusion

Dental practitioners have a key role in oral health promotion and oral cancer screening. They are best placed to detect oral malignancy, so must be aware of key signs and symptoms suggestive of sinister pathology to ensure prompt referral; thereby enhancing patient prognosis.

Dental practitioners must be knowledgeable of what constitutes a suspected cancer pathway referral (Table 2).¹⁶ Familiarization of the local pathway for such referals should form part of mandatory induction training to ensure prompt and efficient referral to prevent delay in diagnosis.