Marco Piovesana

Is NBI-Guided Resection a Breakthrough for Achieving Adequate Resection Margins in Oral and Oropharyngeal Squamous Cell Carcinoma?

Objectives: Obtaining free resection margins is the main goal of oncological surgeons. Narrow-band imaging (NBI) has been recently used to help define resection margins in transoral laser microsurgery for laryngeal carcinoma. The aim of this study was to evaluate the effect of intraoperative NBI in defining the surgical resection margins of oral and oropharyngeal cancers. Methods: Between January 2014 and March 2015, NBI was used intraoperatively after an initial definition of resection margins with white light in 26 patients (group A). The rate of superficial positive margins at definitive histology was compared with that of a historical cohort of 44 patients (group B) previously managed without the use of intraoperative NBI. Results: A statistically significant reduction in the rate of positive superficial margins was observed at definitive histology in group A (P = .028). NBI helped to identify the presence of dysplasia and cancer around the visible tumor not otherwise detectable with visual examination alone. Conclusions: NBI could be a useful tool for obtaining free resection margins in oral and oropharyngeal carcinoma.

Open questions and novel concepts in oral cancer surgery

The persistence of cancerous cells after surgery in oral squamous cell carcinoma (OSCC) represents a major challenge, as it often leads to local recurrences and secondary primary tumors, which are eventually responsible for a large proportion of deaths. This persistence is currently evaluated by histological analyses. In this review we discuss some important pitfalls of the histopathological analysis, such as margin evaluation, specimen shrinkage and T staging. In addition, we critically analyze the appropriateness of current surgical techniques in relation to the concept of field cancerization. Finally, we describe some novel imaging and molecular approaches, which might be useful in tailoring surgical resections and encourage the use of OSCC animal models to explore and provide proof of concept of the feasibility and potential clinical utility of innovative surgical protocols.

NBI utility in the pre-operative and intra-operative assessment of oral cavity and oropharyngeal carcinoma ☆ ☆☆

PURPOSE Despite advances in the surgical management of head and neck squamous cell carcinoma, the identification of synchronous lesions, precancerous lesions around the main tumor, or the unknown primary in the case of neck metastasis remains a problem, as these lesions may be invisible to the naked eye or with standard white light (WL) endoscopy. However, the advent of tools such as narrow-band imaging (NBI) could help the clinician. The purpose of this study was to assess the impact of NBI during the pre-operative and intra-operative stages of management of oral and oropharyngeal cancers. MATERIALS AND METHODS NBI was used pre-operatively in 47 patients with oral or oropharyngeal squamous cell carcinoma to identify the involvement of adjacent subsites, multifocality, synchronous lesions or an unknown primary. NBI was used intra-operatively in 30 patients to better define the tumor limits and guide the resection. The advantage of NBI versus WL endoscopy was analyzed by calculating the true and false positive rate pre-operatively, and the need for resection enlargements, histology of the enlargement, and the rate of clear margins at definitive histology, intra-operatively. RESULTS Pre-operatively, the diagnostic gain of NBI was 8.5%, allowing identification of three synchronous tumors and one unknown primary. Intra-operatively, NBI improved the definition of tumor limits in 67.7% of cases, with resection enlargements showing dysplasia and carcinoma in 8 and 12 patients, respectively; we obtained 74.2% negative margins at histology. CONCLUSIONS NBI could represent an added value in the pre-operative and intra-operative assessment of oral cavity and oropharyngeal carcinoma.

Follow-up of oral and oropharyngeal cancer using narrow-band imaging and high-definition television with rigid endoscope to obtain an early diagnosis of second primary tumors: a prospective study

Narrow-band imaging (NBI) is an optical technique enhancing mucosal vasculature. The aim of this study is to assess the effectiveness of rigid NBI endoscopy in the early detection of second primaries or local recurrences after treatment for oral (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC), its advantage over standard white-light (WL) endoscopy, and the influence of previous radiotherapy, the learning curve, and lesion site. Between January 2013 and June 2015, 195 patients treated for OSCC or OPSCC with surgery alone (group A) or radiotherapy with or without surgery and/or chemotherapy (group B) underwent additional follow-up assessments using NBI. Sensitivity, specificity, positive/negative predictive values (PPV and NPV), and accuracy for detecting second primaries or local recurrences were calculated for patients with at least two NBI assessments. The effect of previous radiotherapy was determined by test of proportions and that of the learning curve and lesion site with Fisher’s exact test. 138/195 patients were included in the analysis. NBI sensitivity, specificity, PPV, NPV, and accuracy for groups A and B were 89.5 vs 100%, 85.2 vs 81.5%, 65.4 vs 69.7%, 96.3 vs 100%, and 86.3 vs 87%, respectively. The diagnostic gain of NBI was 88.2% in group A and 69.6% in group B. The learning curve was the main source of false positives (p = 0.025), whereas radiotherapy and lesion site were uninfluential (p = NS). NBI appears useful for follow-up after treatment for OSCC or OPSCC, its performance being affected only by the learning curve and not by previous treatment or lesion site.

Will the mininvasive approach challenge the old paradigms in oral cancer surgery

In the genome era, the achievement of a safe and complete resection of oral cancers remains a challenge for surgeons. Margin length at histopathological examination is still considered the main indicator of oncological radicality. However, this parameter is fraught by major limitations. Cancer aggressiveness, and in particular its ability to spread in the surrounding tissue, most probably influences loco-regional control and prognosis more than margin length. Unfortunately, no molecular markers are currently available to predict tumor aggressiveness pre-operatively. However, additional histopathological parameters, beside margin length, could be considered to better stratify oral tumors, including depth of invasion (DOI), perineural invasion or composite scores. Recent advances in laser technology have established a novel surgical trend toward a minimalist approach, named transoral laser microsurgery (TLM). TLM provides a local control rate comparable to the one achieved by larger resections if the margin appears disease free, independent from its length. In addition, the clinical availability of innovative optical technologies, such as narrow band imaging (NBI) or autofluorescence, allows more precise and tailored resections, not simply based on clinical observation and ruler measurement. This review will propose the possible implementation of novel procedures toward a mini-invasive surgical approach, providing a satisfactory control rate but significantly improving the quality of life of the patients compared to conventional surgery.

Intraoperative Margin Control in Transoral Approach for Oral and Oropharyngeal Cancer: Intraoperative Margin Control

Piecemeal resection provides an innovative conceptual tool for margins surveillance because it entails the intraoperative evaluation of the whole resection margins and not just sample points, which should result in a better control of deep margins compared to en bloc resection. Although it is recognized that the intraoperative use of narrow band imaging (NBI) results in a better control of superficial margins, in this exploratory study we investigated whether NBI and piecemeal resection could be used in combination to improve margin control at both superficial and deep levels. Because piecemeal resection is based on frozen section analysis, we wanted to verify its reliability compared to definitive histological examination.