Early tongue carcinomas (clinical stage I and II): echo-guided three-dimensional diode laser mini-invasive surgery with evaluation of histological prognostic parameters. A study of 85 cases with prolonged follow-up.

Abstract

The management of patients with early stage (cT1-T2) tongue squamous cell carcinoma without clinicoradiologic evidence of neck node metastasis (cN0) has been widely debated over the last 3 decades and still remains controversial. Nevertheless, the identification of patients with low-stage tumours at high-risk for occult cervical metastases is imperative before planning treatments of primary tumours, as well as that of prognostic markers which may possibly select those patients who may benefit of additional workup after surgery in view of the high metastatic potential of the primary tumour. The pre-surgical evaluation of tongue malignant primary tumour (for assessing lateral and deep margins) along with diode laser surgery (with accurate incision, bleeding-free and with reduced/absent post-surgical complications) may lead to a more conservative but equally decisive surgical treatment, also with a greater patient compliance. We studied 85 consecutive cases of cT1-T2 N0 tongue squamous cell carcinoma who had been managed by the following diagnostic/therapeutic protocol: pre-operative high definition ultrasound examination for the evaluation of size and depth, followed by three-dimensional surgical excision by diode laser (wavelength of 800 ± 10 nm, output power of 8 W in continuous wave, flexible optic fibre of 320 μm in contact mode) and detailed histological analyses of well-established prognostic parameters (tumour grade, thickness, depth, front of infiltration and surgical margins) with statistical analysis. No post-surgical photobiomodulation was performed. Overall, 58.82% of patients were stage I, 18% stage II, and the most frequent histotype was squamous cell carcinoma (97.64%). Large nests invasion pattern was observed in 64 cases, expansive pattern in 9, invasion in single cells in 12; front of invasion involved the muscle in 62 cases, vessels in 6, nerves in 15; peritumoural vascular invasion was assessed in 6 patients and perineural invasion in 15. Selective neck lymphadenectomy was performed in 9 cases, and clinically occult node metastases were detected in two cases. At follow-up, 78 patients (98.73%) were alive and free of disease, one patient experienced tumour-related death, while the remaining 6 died for non-disease-related causes. All the histological prognostic parameters were statistically significant (χ2 test; p = 0.05), thus leading to a prognostic weight classification with a three-tiered stratification. On the bases of these results, the authors maintain that the reported diagnostic/therapeutic protocol, including the pre-operative echo-guided three-dimensional evaluation, the following diode laser mini-invasive surgery for tumour excision and the histological examination along with the proposed three-tiered stratification of histological prognostic parameters may allow proper management of clinical stage I and II early tongue carcinomas.