Tumour thickness in oral cancer using an intra-oral ultrasound probe

Abstract

ObjectivesTo investigate tumour-thickness measurement with an intra-operative ultrasound (US) probe.MethodsA retrospective data analysis was undertaken for a total of 65 patients with a T1-2 oral cavity cancer, who were seen at a tertiary referral centre between 2004 and 2010. The correspondence between tumour thickness measured by ultrasonography and histopathology was assessed by Pearson’s correlation coefficient, and also between tumour thickness and the development of neck metastasis.ResultsIn 11 cases, intra-oral measurement was not optimal due to limited mouth opening (n = 2) or impossibility to depict the lesion (n = 9). Tumour thickness measured by US correlated well with histopathology (n = 23, R = 0.93). Tumour thickness of ≤7 mm carries a risk of lymph node metastasis of 12%, whereas in tumours exceeding 7 mm this risk is 57% (p = 0.001). Twenty-five percent developed neck metastasis and 19% had local recurrence.ConclusionTumour thickness is an important predictive marker for lymph node metastases. As such, it can help in decision-making with regard to management of the primary tumour and neck. Based upon our findings, a wait-and-see policy is only warranted for superficial lesions with tumour thickness of less than 7 mm, but only if regular follow-up using US-guided aspiration of the neck is ensured.

The relationship between primary tumour thicknesses in cancers of the oral cavity to subsequent lymph node metastasis

“…It was concluded that for clinically N0 oral cancer, elective neck dissection was indicated in patients with depth invasion of more than 2 mm because in these tumors the risk of metastases reached 40%. 3,18 On the other hand, study did by Fukano et al, showed that tongue tumours exceeding 5 mm carried a risk of 65% for neck metastases, whereas those infiltrating 5 mm or less had a risk of only 6%. 22 Yuen et al, showed in their study that tumour thickness is prognostic for both nodal and local recurrence in oral carcinomas.…”

“…20 They found this method to be superior to conventional US for this region and more accurate for the estimation of tumour thickness. 3,19 US thus seem to be the optimal technique in patients with no limited mouth opening or base of tongue involvement. US measurement is more reliable than MRI for the measurement of tumour thickness, especially in superficial lesions.…”

“…2 So the need to predict the risk of lymph node metastases in clinically N0 patients with oral cancer is very important in treatment planning for the neck. 3 The risk for cervical node metastases is influenced by characteristics of the primary tumor such as location, size, histological grading and surgical margins which showed a significant association with Lympho-vascular and peri-/endoneural invasion, nodal involvement, status of the surgical margins, and therefor the overall prognosis and survival. 4 Worse prognosis is expected in patients with nodal disease this worsens with the presence of extra-capsular spread.…”

“…6,7 Tumor thickness has been shown with growing evidence to be one of the most important and reliable features in predicting regional node involvement and patient survival in oral cavity cancers. 3,8 It is now widely accepted that thickness is more accurate predictor of sub-clinical nodal metastasis, local recurrence and survival than tumor size. 9 Depth of invasion is defined as distance between normal mucosal surface and the deepest point of invasion.…”

The use of intraoral ultrasound in the characterization of minor salivary gland malignancy: report of two cases

“…This has significance for carcinoma in situ, as the risk of microscopic lymph node metastasis increases significantly above 7 mm. 9 Bone invasion of the jaws can be detected, and sonographic appearances distinguishing invasion or remodelling of the palate have been previously described. 10 Here, we described the diagnostic efficacy of ultrasound for pre-biopsy characterization of two cases of minor salivary gland malignancy.…”