ReviewDiagnostic clinical aids in oral cancer
Introduction
Early diagnosis of oral cancer is a priority public health objective, in which oral health professionals should play a leading role. Early detection of cancer should lead to less damage from cancer treatments and to a better prognosis.
Early detection of cancer distinguishes “screening” (application of a test to evaluate presence of the disease in asymptomatic individuals who apparently do not suffer from it) from “detection of cases” (application of a particular procedure to patients with an identified lesion). Conventional oral exploration (visual and palpation examination) constitutes the gold standard screening study for oral precancer and cancer; the relevant study for the detection of cases is the biopsy and histopathological diagnosis. There are also a number of techniques that may variously contribute to the diagnosis of oral cancer1 (Table 1).
Section snippets
Toluidine blue (TB)
The use of toluidine blue (tolonium chloride) as a diagnostic aid for the detection of oral cancer (Fig. 1) has been evaluated in a large number of studies over many decades.[2], [3] It has also been suggested that TB may provide information on lesion margins, accelerate the decision to biopsy, and guide biopsy site selection and the treatment of oral potentially malignant and malignant lesions.4 Based on data available up to 1989, a meta-analysis assessing the effectiveness of TB for
Light-based detection systems
Light-based detection systems are based on the assumption that the structural and metabolic changes that take place in the mucosa during carcinogenesis give rise to distinct profiles of absorption and refraction when exposed to different types of light or energy4 (Table 2). There have been remarkably few reliable studies on many of these devices before their release for clinical use.
Exfoliative cytology
Exfoliative oral cytology is the study and interpretation of the characteristics of cells that flake off, whether naturally or artificially, from the oral mucosa14 (Fig. 2). Oral cytology is useful for monitoring several sites for a large lesion and can guide the choice of sites for incisional biopsies.[14], [15]
OralCDx® brush biopsy (OralCDx® Laboratories Inc., Suffern, NY, USA) is an oral transepithelial “biopsy” system that uses computer-assisted brushing.16 This technique was designed to
Biopsy and histopathology
Suspected malignant lesions must be biopsied in order to establish a definitive diagnosis.23 The accurate diagnosis of potentially malignant and malignant oral lesions depends on the quality of the biopsy, adequate clinical information, and correct interpretation of the biopsy results (Fig. 3). Oral biopsy specimens can be affected by a number of artefacts resulting from crushing, fulguration, injection, or incorrect fixation and freezing.24 There is controversy regarding selection both of the
Blood
Immunological and biochemical alterations in the serum have been sought to help in the early diagnosis of oral cancer.36 For example, circulating immune complexes have been detected in 75% of patients with head and neck carcinoma. In patients with OSCC, significantly lower iron and selenium levels have been found than in healthy controls. In contrast, serum copper levels were higher in patients with OSCC or precancerous lesions than in healthy controls.36 Serum tumour markers for OSCC have
Saliva
Saliva analysis could in the future prove to be an efficient, non-invasive, patient-friendly tool for the diagnosis of OSCC.39 The diagnostic capacity is based on the permanent and intimate contact between saliva and the mucosa where this cancer evolves. Patients with OSCC have a global alteration of salivary composition. Salivary levels of total sugar, protein-bound sialic acid, free sialic acid, sodium, calcium, immunoglobulin G, albumin, and lactate dehydrogenase are significantly raised
Imaging
Dental panoramic tomography (DPT), computed tomography (CT), and magnetic resonance imaging (MRI) are frequently used to supplement the clinical evaluation and staging of the primary tumour and regional lymph nodes. CT is the technique of choice to evaluate bone invasion by the tumour. The introduction of cone beam computed tomography (CBCT) provides and alternative for the preoperative study of patients with oral cancer to determine the degree of invasion and extension of the lesion towards
Conflict of interest statement
None declared.
References (45)
- et al.
Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue
Oral Oncol
(2008) - et al.
Use of meta-analysis to evaluate tolonium chloride in oral cancer screening
Oral Surg Oral Med Oral Pathol
(1989) - et al.
Critical evaluation of diagnostic aids for the detection of oral cancer
Oral Oncol
(2008) - et al.
A pilot case control study on the efficacy of acetic acid wash and chemiluminescence illumination (ViziLite) in the visualisation of oral mucosa White lesions
Oral Oncol
(2007) - et al.
Efficacy of the ViziLite system in the identification of oral lesions
J Oral Maxillofac Surg
(2007) - et al.
The application of acetic acid in the detection of oral squamous cell carcinoma
Oral Surg Oral Med Oral Pahol Oral Radiol Endod
(2008) - et al.
The status of in vivo autofluorescence spectroscopy and imaging for oral oncology
Oral Oncol
(2005) Improving detection of precancerous and cancerous oral lesions. Computer-assisted analysis of the oral brush biopsy. US Collaborative OralCDx Study Group
J Am Dent Assoc
(1999)- et al.
An audit of the efficacy of the oral brush biopsy technique in a specialist oral medicine unit
Oral Oncol
(2004) - et al.
Histologic evaluation of width of soft tissue necrosis adjacent to carbon dioxide incisions
Oral Surg Oral Med Oral Pathol
(1990)