Indications and extent of elective neck dissection in patients with early stage oral and oropharyngeal carcinoma: nationwide survey in The Netherlands

Abnormal p53 Immunohistochemical Patterns Are Associated with Regional Lymph Node Metastasis in Oral Cavity Squamous Cell Carcinoma at Time of Surgery

INTRODUCTION

Sixty to eighty percent of oral cavity invasive squamous cell carcinoma (OSCC) demonstrate molecular alterations in TP53. The presence of TP53 mutations in multiple organ systems has been associated with a more aggressive clinical course. The purpose of this study was to classify OSCC into p53 wild-type OSCC and p53-abnormal OSCC using p53 immunohistochemistry and to determine if abnormal p53 status correlates with higher risk of lymph node metastasis at the time of surgery.

MATERIALS AND METHODS

A total of 101 patients with OSCC resection and cervical lymph node dissection were identified. p53 immunohistochemistry was performed for all cases and scored into p53 wild-type (p53-HPV: mid-epithelial/basal sparing, markedly reduced [null-like]/basal sparing; p53-conventional: scattered basal, patchy basal/parabasal) and p53-abnormal (overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, null, cytoplasmic) patterns. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization were used to confirm the HPV status in cases showing mid-epithelial/basal sparing or markedly reduced (null-like)/basal sparing pattern. Logistic regression analysis was performed to investigate the association of p53 status, tumor size, depth of invasion, and pT stage against lymph node status.

RESULTS

We identified 22 cases with p53 wild-type patterns (16 p53-conventional, 6 p53-HPV) and 79 cases with p53-abnormal patterns. Two of 22 p53 wild-type cases had positive lymph nodes (1 p53-conventional, 1 p53-HPV), while 40 of 79 p53-abnormal cases had positive lymph nodes (p<0.001). Multivariate analysis showed that p53-abnormal pattern was an independent risk factor associated with positive node(s) with an odds ratio of 8.12 (95% CI, 2.10-53.78; p=0.008).

CONCLUSION

p53-abnormal OSCCs were significantly more likely to be associated with positive lymph node status compared to p53 wild-type OSCCs at time of surgery. Further investigation with long-term follow-up is required to determine its clinical application prior to surgery planning.

What is the role of sentinel lymph node biopsy in the management of oral cancer in 2020?

Approximately 70–80% of patients with cT1-2N0 oral squamous cell carcinoma (OSCC) ultimately prove to have no cancer in the cervical lymphatics on final pathology after selective neck dissection. As a result, sentinel lymph node biopsy (SLNB) has been adopted during the last decade as a diagnostic staging method to intelligently identify patients who would benefit from formal selective lymphadenectomy or neck irradiation. While not yet universally accepted, SLNB is now incorporated in many national guidelines. SLNB offers a less invasive alternative to elective neck dissection (END), and has some advantages and disadvantages. SLNB can assess the individual drainage pattern and, with step serial sectioning and immunohistochemistry (IHC), can enable the accurate detection of micrometastases and isolated tumor cells (ITCs). Staging of the neck is improved relative to END with routine histopathological examination. The improvements in staging are particularly notable for the contralateral neck and the pretreated neck. However, for floor of mouth (FOM) tumors, occult metastases are frequently missed by SLNB due to the proximity of activity from the primary site to the lymphatics (the shine through phenomenon). For FOM cancers, it is advised to perform either elective neck dissection or superselective neck dissection of the preglandular triangle of level I. New tracers and techniques under development may improve the diagnostic accuracy of SLNB for early-stage OSCC, particularly for FOM tumors. Treatment of the neck (either neck dissection or radiotherapy), although limited to levels I–IV, remains mandatory for any positive category of metastasis (macrometastasis, micrometastasis, or ITCs). Recently, the updated EANM practical guidelines for SLN localization in OSCC and the surgical consensus guidelines on SLNB in patients with OSCC were published. In this review, the current evidence and results of SLNB in early OSCC are presented.

Tumor depth of invasion and prognosis of early-stage oral squamous cell carcinoma: A meta-analysis

OBJECTIVES

To assess the prognosis for early-stage oral squamous cell carcinoma according to tumor depth of invasion (DOI).

METHODS

This study was logged in the PROSPERO database under protocol # CRD42017059976. The search was conducted in six electronic databases up to May 2019. Fixed-effects meta-analysis was performed for the calculation of the odds ratio (OR) and respective 95% CI. Primary outcomes were lymph node metastasis, recurrence, and survival. Heterogeneity was calculated by the I² test. The certainty of evidence was assessed by Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Twenty-seven studies were included (19 in the meta-analysis) with 2,404 patients with a mean of 60 years of age. High tumor DOI is associated with a greater chance of presenting lymph node metastasis, regardless of the cutoff point for DOI (13 meta-analysis; OR 1.69-53.08), recurrence (five meta-analysis; OR 1.22-3.83), and lower chance of survival (1 meta-analysis; OR 0.49). The certainty of evidence varied from very low to low.

CONCLUSIONS

Tumor DOI is a good prognosticator for early-stage OSCC. The findings of the current meta-analysis highlight the clinical relevance of DOI and corroborate its incorporation for staging OSCC.

Elective neck dissection in oral squamous cell carcinoma: Past, present and future

In 1994 a decision analysis, based on the literature and utility ratings for outcome by a panel of experienced head and neck physicians, was presented which showed a threshold probability of occult metastases of 20% to recommend elective treatment of the neck. It was stated that recommendations for the management of the cN0 neck are not immutable and should be reconfigured to determine the optimal management based on different sets of underlying assumptions. Although much has changed and is published in the almost 25 years after its publication, up to date this figure is still mentioned in the context of decisions on treatment of the clinically negative (cN0) neck. Therefore, we critically reviewed the developments in diagnostics and therapy and modeling approaches in the context of decisions on treatment of the cN0 neck. However, the results of studies on treatment of the cN0 neck cannot be translated to other settings due to significant differences in relevant variables such as population, culture, diagnostic work-up, follow-up, costs, institutional preferences and other factors. Moreover, patients may have personal preferences and may weigh oncologic outcomes versus morbidity and quality of life differently. Therefore, instead of trying to establish "the" best strategy for the cN0 neck or "the" optimal cut-off point for elective neck treatment, the approach to optimize the management of the cN0 neck would be to develop and implement models and decision support systems that can serve to optimize choices depending on individual, institutional, population and other relevant variables.

An international comparison of the management of the neck in early oral squamous cell carcinoma in the Netherlands, UK, and USA

BACKGROUND

Early oral cavity squamous cell carcinoma (OCSCC) management appears to vary both within and between countries. Variation in practice can be an indicator of absence of evidence-based management and may negatively influence survival and morbidity. The exact variation and the relationship to differences in guidelines are unknown. This study aimed to report on these variations in the Netherlands, UK, and USA, and to evaluate them.

METHODS

Information regarding the variation in OCSCC management strategies was obtained from a questionnaire sent to representatives of head and neck cancer centers in the Netherlands, UK, and USA. Within-country and between-country variations were also assessed in light of the different guidelines.

RESULTS

In total, representatives of 45 centers completed the questionnaire; 10 from the Netherlands, 26 from the UK and 9 from the USA. Our results demonstrate a distinct variation in the diagnoses, treatment and follow-up of OCSCC, both within and between countries. Only a small amount of variation between countries could be linked to differences in guidelines.

CONCLUSIONS

There is high variation in the management of the neck in OCSCC. There seem to be a need for direct evidence about optimal management decisions to establish more evidence-based management and uniform practice.

Complete pathologic response as a prognostic factor for squamous cell carcinoma of the oropharynx post-chemoradiotherapy

Introduction

Chemoradiotherapy for squamous cell carcinoma of the oropharynx (SCCO) provides good results for locoregional disease control, with high rates of complete clinical and pathologic responses, mainly in the neck.

Objective

To determine whether complete pathologic response after chemoradiotherapy is related to the prognosis of patients with SCCO.

Methods

Data were prospectively extracted from clinical records of N2 and N3 SCCO patients submitted to a planned neck dissection after chemoradiotherapy.

Results

A total of 19 patients were evaluated. Half of patients obtained complete pathologic response in the neck. Distant or locoregional recurrence occurred in approximately 42% of patients, and 26% died. Statistical analysis showed an association between complete pathologic response and lower disease recurrence rate (77.8% vs. 20.8%; p = 0.017) and greater overall survival (88.9% vs. 23.3%; p = 0.049).

Conclusion

The presence of a complete pathologic response after chemoradiotherapy positively influences the prognosis of patients with SCCO.

Sentinel lymph node biopsy in clinically N0 T1-T2 staged oral cancer: the Dutch multicenter trial

OBJECTIVES

Results of the Dutch multi-institutional trial on sentinel lymph node (SLN) biopsy in oral cancer.

PATIENTS AND METHODS

Patients were consecutively enrolled from 4 institutions, with T1/T2 oral cancer and cN0 neck based on palpation and ultrasound guided fine needle aspiration cytology. Lymphatic mapping consisted of preoperative lymphoscintigraphy. For intraoperative SLN detection a gamma-probe was used and in some patients additional blue dye. SLN negative patients were carefully observed, SLN positive patients were treated by neck dissection, radiotherapy or a combination of both. Endpoints of the study were risk of occult lymp node metastases, neck control, accuracy, 5-year disease-free survival (DFS), overall survival (OS) and disease-specific survival (DSS).

RESULTS

Twenty of 62 patients (32%) had positive SLNs. Macrometastases were found in 9 patients, micrometastases in 8, and isolated tumour cells in 3 patients. Median follow-up was 52.5 months. Of the 42 SLN negative patients, 5 developed a regional recurrence of whom 4 patients could be successfully salvaged. DFS, OS and DSS of SLN negative patients were 72.0%, 92.7% and 97.4%, and for SLN positive patients these numbers were 73.7%, 79.7%, 85.0%, respectively (DFS: p=0.916, OS: p=0.134, DSS: p=0.059, respectively). Neck control rate was 97% in SLN negative and 95% in SLN positive patients. Sensitivity was 80% and negative predictive value 88%.

CONCLUSION

SLN biopsy is able to reduce the risk of occult lymph node metastases in T1/T2 oral cancer patients from 40% to 8%, and enables excellent control of the neck.