Elective neck dissection for the management of the N0 neck in early cancer of the oral tongue: need for a randomized controlled trial

Application value of a hybrid tracer during sentinel lymph node biopsy for head and neck malignancies: A systematic review and meta-analysis

To address the limitations of conventional sentinel lymph node biopsy (SLNB), a novel hybrid tracer (indocyanine green [ICG]-99mTc-nanocolloid) has been developed. This meta-analysis aimed to compare the differences between the novel hybrid tracer and conventional methods using ICG or radioisotope (RI) for SLNB in head and neck malignancies. This study was registered in the International Prospective Register of Systematic Reviews (CRD42023409127). PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched. This study included raw data on the number of sentinel lymph nodes (SLNs) identified using different modalities during surgery for head and neck malignancies. The identification rate of SLNs was the main outcome of interest. Prognostic data and complication rate cannot be deduced from this article. The heterogeneity test (I2) determined the use of a fixed- or random-effects model for the pooled risk ratio (RR). Overall, 1275 studies were screened, of which 11 met the inclusion criteria for the meta-analysis. In SLN identification of head and neck malignancies, ICG-99mTc-nanocolloid was superior to ICG or RI. In the subgroup analyses, the detection rates of ICG and RI tracers in SLNB were comparable, regardless of the device, tumor type, or tumor stage. In conclusion, in SLN identification of head and neck malignancies, the use of ICG-99mTc-nanocolloid is superior to the single technique of ICG or RI. This study suggests that Hospitals using ICG or RI may find it beneficial to change their practice to ICG-99mTc-nanocolloid, especially in the head and neck area, owing to its superior effectiveness.

N0 neck trial: Does intensification of follow-up (Ultrasound + Physical Examination) influence outcomes in early-stage oral cancer?

AIM OF THE STUDY

We previously reported a survival benefit of elective neck dissection (END) over therapeutic neck dissection (TND) in patients with clinically node-negative early-stage oral cancer. We now report the results of the second question in the same study addressing the impact of adding neck ultrasound to physical examination during follow-up on outcomes.

METHODS

Patients with lateralized T1/T2 oral squamous cell carcinoma (SCC) were randomized to END or TND and to follow-up with physical-examination plus neck ultrasound (PE+US) versus physical-examination (PE). The primary endpoint was overall survival (OS).

RESULTS

Between January 2004 and June 2014, 596 patients were enrolled. This is an intention to treat analysis of 592 analysable patients, of whom 295 were allocated to PE+US and 297 to PE with a median follow-up of 77.47 months (interquartile range (IQR) 54.51-126.48). There was no significant difference (unadjusted hazard ratio [HR], 0.92, 95% CI, 0.71-1.20, p = 0.54) in 5-year OS between PE+US (70.8%, 95% CI, 65.51-76.09) and PE (67.3%, 95% CI, 61.81-72.79). Among 131 patients with neck node relapse as the first event, the median time to relapse detection was 4.85 (IQR 2.33-9.60) and 7.62 (IQR 3.22-9.86) months in PE+US and PE arms, respectively. The N stage in the PE+US arm was N1 33.8%, N2a 7.4%, N2b/c 44.1% and N3 14.7% while in PE was N1 28.6%, N2a 9.5%, N2b/c 39.7%, N3 20.6% and unknown 1.6%.

CONCLUSION

Adding neck ultrasound to physical examination during follow-up detects nodal relapses earlier but does not improve overall survival.

Contralateral Nodal Relapse in Well-lateralised Oral Cavity Cancers Treated Uniformly with Ipsilateral Surgery and Adjuvant Radiotherapy With or Without Concurrent Chemotherapy: a Retrospective Study

AIMS

To evaluate the incidence and pattern of contralateral nodal relapse (CLNR), contralateral nodal relapse-free survival (CLNRFS) and risk factors predicting CLNR in well-lateralised oral cavity cancers (OCC) treated with unilateral surgery and adjuvant ipsilateral radiotherapy with or without concurrent chemotherapy.

MATERIALS AND METHODS

Consecutive patients of well-lateralised OCC treated between 2012 and 2017 were included. The primary endpoint was incidence of CLNR and CLNRFS. Univariable and multivariable analyses were carried out to identify potential factors predicting CLNR.

RESULTS

Of the 208 eligible patients, 21 (10%) developed isolated CLNR at a median follow-up of 45 months. The incidence of CLNR was 21.3% in node-positive patients. CLNR was most common at level IB (61.9%) followed by level II. The 5-year CLNRFS and overall survival were 82.5% and 57.7%, respectively. Any positive ipsilateral lymph node (P = 0.001), two or more positive lymph nodes (P < 0.001), involvement of ipsilateral level IB (P = 0.002) or level II lymph node (P < 0.001), presence of extranodal extension (P < 0.001), lymphatic invasion (P = 0.015) and perineural invasion (P = 0.021) were significant factors for CLNR on univariable analysis. The presence of two or more positive lymph nodes (P < 0.001) was an independent prognostic factor for CLNR on multivariable analysis. CLNR increased significantly with each increasing lymph node number beyond two compared with node-negative patients.

CONCLUSION

The overall incidence of isolated CLNR is low in well-lateralised OCC. Patients with two or more positive lymph nodes have a higher risk of CLNR and may be considered for elective treatment of contralateral neck.

Role of 18F-FDG PET/CT in Guiding Surgical Management of Clinically Node Negative Neck (cN0) in Carcinoma Oral Cavity

Conventional staging paradigm with clinical examination or imaging invariably leads to underestimation of occult metastatic neck disease in oral cavity carcinoma. The advantage of 18F-FDG PET/CT is in its ability to identify lymph nodes without morphological changes yet harboring occult metastases. We present findings of our study to evaluate diagnostic accuracy of 18F-FDG PET/CT, in detecting occult cervical lymph node metastasis in carcinoma oral cavity. In a single institution prospective study, 51 consecutive patients with histologically proven (cT1/T2) oral cavity carcinoma and clinically node negative neck (cNo), underwent 18F-FDG PET/CT before elective neck dissection of 58 neck sides. 18F-FDG PET/CT findings were compared with histopathology of dissected nodes, to calculate diagnostic accuracy. 18F-FDG PET/CT correctly characterized the occult lymph node metastasis status (true positive + true negative) in 51 of 58 neck sides, yielding diagnostic accuracy of 87.93%. Sensitivity of 18F-FDG PET/CT was 90% and specificity was 87.5%. While a positive 18F-FDG PET/CT accurately predicted the disease in only 60% (positive predictive value), a negative 18F-FDG PET/CT reasonably ruled out occult metastases in 97.67% (negative predictive value). If a decision regarding the need for neck dissection had been based solely on 18F-FDG PET/CT, the number of neck dissections would have been reduced by 74.13%. Based on diagnostic accuracy and high negative predictive value, incorporating 18F-FDG PET/CT in preoperative staging paradigm of cT1/T2 carcinoma oral cavity will guide in selection of patients in which cN0 neck can be safely observed.

Pattern and localization of perineural invasion predict poor survival in oral tongue carcinoma

BACKGROUND

Survival rate for oral tongue squamous cell carcinoma (OTSCC) is still poor and, despite Tumor-Node-Metastasis staging system has been recently updated, patients included under the same stage still show difference in prognosis. Perineural invasion (PNI) emerged to be an indicator of tumor aggressive behavior and unfortunate events. In this study, we investigate the clinic and prognostic value of PNI in a cohort of OTSCC patients.

METHODS

About 200 patients with OTSCC were retrospectively evaluated the presence of PNI. PNI was furtherly descripted as uni-/multifocal and as intra-/peritumoral. Disease-Specific and Relapse-Free Survival (DSS; RFS) were estimated; moreover, we included PNI in the current AJCC 8th Staging System, improving the prognostication model.

RESULTS

Perineural invasion was found in 40.5% of patients. Intratumoral PNI predicted patients at high risk of being diagnosed with lymph-node metastasis. Tumors with positive PNI reported a worse DSS (Hazard Ratio=1.878, p-value = 0.008). Moreover, patients exhibiting both multifocal intra- and peritumoral PNI reported poorest DSS (Hazard Ratio = 2.409, p-value = 0.010). Patients were reclassified in a new staging system in case of multifocal PNI, providing better stratification capacity.

CONCLUSIONS

Perineural invasion might serve as an additional prognostic factor in OTSCC, and by integrating PNI in the staging system, further improvements in prognostication might be reached.

The Emerging Impact of Tumor Budding in Oral Squamous Cell Carcinoma: Main Issues and Clinical Relevance of a New Prognostic Marker

Tumor Budding (TB) represents a single cancer cell or a small cluster of less than five cancer cells on the infiltrative tumor front. Accumulating evidence suggests TB is an independent prognostic factor in oral squamous cell carcinoma (OSCC). However, its exact role is not yet elucidated, and a standardized scoring system is still necessary. The study aims to extensively review the literature data regarding the prognostic role of TB in OSCC. The results of TB are an independent prognostic factor of poor survival outcomes in OSCC. To date, the manual detection of hematoxylin and eosin-staining or pancytokeratin-immunostaining sections are the most commonly used methods. Between the several cut-offs, the two-tier system with five buds/field cut-offs provides better risk stratification. The prognostic role of the BD model in predicting survival outcomes was extensively validated; however, the inclusion of DOI, which is already a staging parameter, encouraged other authors to propose other models, integrating TB count with other adverse risk factors, such as the tumor–stroma ratio and tumor-infiltrated lymphocytes. The prognostic relevance of TB in OSCC highlights its evaluation in daily pathological practice. Therefore, the TB detection method and the TB scoring system should be validated based on tumor stage and site.

Prognostic significance of tumor budding thresholds in oral tongue squamous cell carcinoma

Oral tongue squamous cell carcinoma (OTSCC) represents the most common malignancy of the oral cavity. Tumor budding (TB) is a reliable prognostic factor in OTSCC; however, a standardized scoring system is not still validated. The study aims to evaluate the prognostic role of TB in 211 OTSCC patients treated between 1997-2018. TB was evaluated on haematoxylin and eosin-stained sections in the hotspot area of the infiltrative front (×200-magnification). It was scored using a two-tier, a three-tier system, and according to BD-model and revised-Grading system. Univariate and multivariate Cox regression analyses of disease-specific survival (DSS) and disease-free survival (DFS) were performed. A p-values<0.05 was considered as statistically significant. The two-tier and three-tier system resulted an independent prognostic factor of DSS. High-risk patients had a 2.21 and 3.08 times-increased probability of poor DSS compared to low-risk group. It is significantly increased even for intermediate-risk group. No significant differences emerged classifying patients according to BD-model and revised-Grading. These data confirm the prognostic value of TB in predicting DSS in OTSCC. Classifying patients in two groups using the 5-buds cut-off significantly discriminates their outcomes. Since the established role of DOI and the poor prognostic value of grading, TB could be considered an independent prognostic marker.

Treating the N0 neck in early stage oral cancer: a pause for re-assessment?

The incidence of metastases following neck dissection in the apparent lymph node negative neck in oral cancer is between 7% and 33%; early resection of cervical metastases may well increase survival. Modern imaging techniques can reduce the yield of previously undiagnosed metastatic nodes in elective neck dissection (END). An audit of 112 consecutive cases was conducted to determine the proportion of undiagnosed nodal metastases, after END. There were neck metastases in 10 cases (9%), which were mainly (but not all) micrometastic. The 20% likelihood of nodal metastases was only apparent in primary tumours greater than 6 mm thick. The length of inpatient stay was increased from 3.7 to 16.5 days with free vascularised transfer. There were complications including cranial nerve damage. There were two peri-operative deaths. No ipsilateral neck failures occurred, median follow up was 937 days. To reduce unnecessary END, resection can be undertaken as a prior procedure, subsequently only carrying out END on tumours greater than 6 mm, or with unfavourable tumour characteristics.

Novel double injection technique for sentinel lymph node biopsy in oral cancer

The development of new lymphatic tracers and the advancement of hybrid tracers, such as indocyanine green (ICG)-Nanocoll (GE Healthcare), represent an exciting step in the future of sentinel lymph node biopsy (SLNB). These tracers aim to improve our ability to detect sentinel lymph nodes by enhancing their localisation. The aim of this study was to assess the performance of a novel dual tracer, double injection technique of ICG-'cold'-Nanocoll and radiolabelled Nanocoll, in SLNB for early-stage oral cancer. A double injection technique was performed first using ^99mTc-Nancoll prior to sentinel node imaging followed by ICG-'cold'-Nanocoll injection in theatre. Analysis involved examination of the number, labelling, and location of the nodes harvested, sentinel node status, survival analysis, false negative rate, and complications associated with use of the technique. ICG 'cold' Nanocoll results showed concordance of fluorescence and radioactivity detection in 74 nodes in 24 patients. Most importantly, all nodes found positive for metastasis (6 nodes) were discovered to be both 'hot' and fluorescent; 74 nodes removed were both 'hot' and fluorescent, eight fluorescent only and six 'hot' only. Our results indicate that two sets of tracer injections given at two different time points will flow to the same sentinel nodes. This double labelling increased our confidence that the retrieved node was a sentinel node.

Relationships between intraoral ultrasonographic and histopathological findings in patients with tongue cancer

BACKGROUND

In this study, we aimed to investigate the relationships between histopathological and intraoral ultrasonographic (IUS) findings in patients with tongue cancer.

METHODS

IUS and histopathological findings in 46 patients with tongue cancer were considered for this study. We assessed the relationships between IUS findings regarding tumor thickness, margin type, border type, and internal echo intensity; internal/peripheral Doppler findings; and muscle invasion and histopathological findings regarding tumor thickness, differentiation, Yamamoto-Kohama (YK)-classification grade, blood vessel invasion, lymphatic invasion, perineural invasion, and muscle invasion.

RESULTS

Statistical associations were found between the following findings: between thickness determined through IUS measurement and that determined through histopathological measurement, between the IUS findings regarding tumor margin and border types and the histopathologically determined YK-classifications grades, and between a Doppler image of the internal area of tongue lesions and lymphatic invasion.

CONCLUSIONS

IUS findings may be used to predict histopathological findings about tumor thickness and YK-classification grades.

Elective node dissection versus observation for management of patients with early-stage cT1/T2N0 tongue carcinoma: A systematic review and meta-analysis of prospective studies

OBJECTIVE

To carry out a meta-analysis of prospective literature comparing the clinical efficacy of elective neck dissection (END) vs observation (OBS) in patients with early-stage cT1/T2N0 tongue carcinoma.

DESIGN/SETTING/PARTICIPANTS/OUTCOME MEASURES

We systematically reviewed four databases from inception to 30-October-2020. We considered all studies meeting the following PICOS conditions: (a) Patients: early-stage cT1/T2N0 tongue carcinoma, (b) Intervention: END, (c) Comparator: OBS, (d) Outcomes: local tongue recurrence, cervical nodal recurrence, disease-specific survival (DSS) rate, and disease-free survival (DFS) rate and (e) Study design: prospective reports. We pooled dichotomous data as relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

Four studies (one case-control study and three randomised controlled trials) met our inclusion criteria. There were 448 eligible patients (225 and 223 patients were treated with END and OBS, respectively). END significantly correlated with improved DSS rate (RR = 1.15, 95% CI: 1.04-1.27, P = .007). Nonetheless, there were no significant differences between END and OBS groups regarding the rates of local tongue recurrence (RR = 1.23, 95% CI: 0.50-3.03, P = .65), cervical nodal recurrence (RR = 0.45, 95% CI: 0.16-1.27, P = .13) and DFS rate (RR = 1.08, 95% CI: 0.91-1.27, P = .38). Pooled analysis for cervical nodal recurrence was heterogeneous, and sensitivity analysis revealed a significantly lower cervical nodal recurrence rate in favour of END group (RR = 0.30, 95% CI: 0.13-0.67, P = .004).

CONCLUSION

END correlated with a significant decrease in cervical nodal recurrence and improved DSS rate. END might be superior to OBS in patients with early-stage cT1/T2N0 tongue cancer.

History of dysplasia and primary site associated with recurrence in T1N0 oral squamous cell carcinoma

OBJECTIVE

Recurrent disease occurs in a significant proportion of early-stage oral squamous cell carcinoma (OSCC) despite removal of the entire tumor with clear surgical margins. Our study sought to identify clinicopathologic factors that increase the risk of locoregional recurrence in T1N0 OSCC.

STUDY DESIGN

We conducted an observational retrospective analysis of 65 cases of T1N0 OSCC over a period of 13 years. For each case, we examined the clinical presentation, histopathologic appearance, and treatment characteristics of interest to evaluate the association between these variables and locoregional recurrence.

RESULTS

The 5-year and 10-year locoregional recurrence rates were 29.2% and 33.8%, respectively. Individuals with prior oral dysplasia had significantly higher odds for locoregional recurrence (P < .01) and reduced 5-year disease-free survival rates (P < .01). OSCC of the tongue and floor of the mouth had lower recurrence odds than carcinomas of the gingiva, buccal mucosa, and palate (P < .05). Histologic grade (P = .80), depth of invasion (P = .82), and elective neck dissection (P = .80) did not appear to influence locoregional recurrence for T1N0 tumors.

CONCLUSIONS

Given the morbidity and mortality associated with OSCC, understanding of the clinicopathologic factors associated with recurrent disease may lead to improved treatment and follow-up protocols for a subset of early-stage patients.

Elective neck dissection versus positron emission tomography-computed tomography-guided management of the neck in clinically node-negative early oral cavity cancer: A cost-utility analysis

BACKGROUND

In early oral cavity cancer, elective neck dissection (END) for the clinically node-negative (cN0) neck improves survival compared with observation. This paradigm has been challenged recently by the use of positron emission tomography-computed tomography (PET-CT) imaging in the cN0 neck. To inform this debate, we performed an economic evaluation comparing PET-CT-guided therapy with routine END in the cN0 neck.

METHODS

Patients with T1-2N0 lateralized oral tongue cancer were analyzed. A Markov model over a 40-year time horizon simulated treatment, disease recurrence, and survival from a US health care payer perspective. Model parameters were derived from a review of the literature.

RESULTS

The END strategy was dominant, with a cost savings of $1576.30 USD, an increase of 0.055 quality-adjusted life years (QALYs), a net monetary benefit of $4303 USD, and a 0.22 life-year advantage. END was sensitive to variation in cost and utilities in deterministic and probabilistic sensitivity analyses. PET-CT became the preferred strategy when decreasing occult nodal disease to 18% and increasing the negative predictive value (NPV) of PET-CT to 89% in 1-way sensitivity analyses. In probabilistic sensitivity analysis, assuming a cost effectiveness threshold of $50,000 USD/QALY, END was dominant in 64% of simulations and cost effective in 69.8%.

CONCLUSION

END is a cost-effective strategy compared with PET-CT in patients who have node-negative oral cancer. Although lower PET standardized uptake value thresholds would result in fewer false negatives and improved NPV, it is still uncertain that PET-CT would be cost effective, as this would likely result in more false positive tests.

The occult nodal metastasis rate of early tongue cancer (T1-T2): A protocol for a systematic review and meta-analysis

OBJECTIVES

In this study, a meta-analysis was conducted to evaluate the occult lymph node metastasis rate in patients with early-stage (T1-T2) oral tongue squamous cell carcinoma. Also, the correlation between occult lymph node metastasis rate and T2 ratio among T1-T2 or the reported year of each study was analyzed to adjust other confound variables.

STUDY DESIGN

Literature search.

METHODS

A systematic computerized search of the electronic databases was carried out for articles published between January 1, 1980, and December 31, 2018, which reported occult nodal metastasis rate in T1 and T2 (separately) tongue cancer patients. Statistical analysis was performed using Comprehensive Meta Analysis version 3.3.070. Publication bias was assessed by the Egger test and Begg funnel plot method. The correlation between occult nodal metastasis rate and T2 ratio or reported year, respectively, was assessed by meta-regression analysis.

RESULTS

From 19 studies, a total of 1567 cases were included in the meta-analysis. By random effects model, the mean occult cervical lymph node metastasis was 24.4% (95% confidence interval; 0.205-0.248). The meta-regression revealed that the T2 ratio and the reported year of the studies did not have a significant effect on the occult metastasis rate (correlation coefficient = 0.531 and 0.002, respectively, and P = .426 and 0.921, respectively).

CONCLUSION

The meta-analysis revealed that the early-stage oral tongue squamous cell carcinoma had a rate of 24.4% for occult nodal metastasis. The occult nodal metastasis rate was not significantly affected by neither T2 ratio among T1-T2 nor reported year of the studies.

Assessment of Quality of Life of Free Anterolateral Thigh Flap for Reconstruction of Tissue Defects of Total or Near-Total Glossectomy

Background

The aim of this study was to evaluate quality of life of free anterolateral thigh flap (ALTFF) for reconstruction of tissue defects of total or near-total glossectomy.

Methods

Quality of life was assessed by means of the University of Washington Quality of Life (UW-QOL) and the 14-item Oral Health Impact Profile (OHIP-14), after 12 months postoperatively.

Results

65 of 79 questionnaires were returned (82.27%). In the UW-QOL, the best-scoring domain was “shoulder,” whereas the lowest scores were for “chewing” and “pain.” In the OHIP-14, the lowest-scoring domain was “handicap,” followed by “Social disability” and “Psychological disability.”

Conclusion

Free anterolateral thigh perforator flaps for reconstruction of total or near-total glossectomy defects after cancer resection would have significantly influenced the patients' oral functions and quality of life.

The expression and prognostic relevance of programmed cell death protein 1 in tongue squamous cell carcinoma

Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor which plays an important role in a patient's immune responses to microbial and cancer antigens. It is expressed in tumor-infiltrating lymphocytes (TILs) with many different malignancies. The aim of the study was to evaluate PD-1 expression and its prognostic value in tongue cancer. The data of tongue squamous cell carcinoma (TSCC) patients (N = 81) treated in Tampere University Hospital between 1999 and 2013 were used. Control data consisted of patients with non-malignant tongue mucous membrane lesions (N = 48). The formalin-fixed paraffin-embedded samples were stained immunohistochemically and scanned via digital microscope. The staining of PD-1 was examined semi-quantitatively. The density and intensity of PD-1 + cells were significantly higher in TSCC than in control samples. The expression of PD-1 correlated with better survival. The expression of PD-1 could be a potential prognostic marker in TSCC. Further research using larger sample size is needed.

Perineural and lymphovascular invasion in squamous cell carcinoma of the tongue

BACKGROUND

Perineural invasion (PNI) and lymphovascular invasion (LVI) may be adverse prognostic indicators in squamous cell carcinoma (SCC) of the tongue.

METHODS

The percentages of histological PNI and LVI were determined in 335 patients with tongue SCC. Sixty tumours originally reported as negative for these features were tested to determine how many more were positive with "immunohistochemical enhancement."

RESULTS

PNI was found in 141 (42.1%) and LVI in 51 (15.2%) patients. 79.4% of the 141 patients who had PNI and 72.6% of the 51 with LVI had a T3 or T4 tumour. Lymph node metastasis was identified in 145 (51.2%) of the 280 patients who had undergone neck dissection; 58.2% of the 141 patients with PNI and 80.4% of the 51 patients with LVI had lymph node metastasis. There was a highly statistically significant correlation between PNI with increasing pT (P < .00001) and pN (P < .0001) stage, and a statistically significant correlation between LVI and pT stage (P < .001), the association of LVI with pN status could not be reliably tested statistically. Immunohistochemistry for S100 identified five further cases of PNI, but review of the original H&E showed the feature was present in four and had been missed at original reporting. CD31 identified three further possible cases of LVI and D2-40 none. The endothelium of some vascular channels was positive for both CD31 and D2-40 and cross-reactivity with other cells compromised interpretation.

CONCLUSIONS

Histological identification of PNI and LVI per se remains of uncertain prognostic significance. "Immunohistochemical enhancement" offered little benefit.

Depth of invasion determined by magnetic resonance imaging in tongue cancer can be a predictor of cervical lymph node metastasis

OBJECTIVES

We evaluated the relationships between depth of invasion (DOI) of tongue cancer, as measured with preoperative T1- and T2-weighted magnetic resonance imaging (MRI) and postoperative histopathologic (Path) specimens, with cervical lymph node metastasis (CLNM) and tumor stage. We also calculated the correlation of MRI and Path DOI measurements.

STUDY DESIGN

This retrospective study included 101 patients who had squamous cell carcinoma of the tongue and were treated surgically. Two observers measured DOI on all 3 modalities.

RESULTS

DOI thresholds for predicting CLNM with high diagnostic efficacy were 6.99 mm and 8.32 mm for MRI and 5 mm for Path. DOI values from all modalities were significantly different for tumors with and without CLNM (P < .01) and for the 4 TNM stages (P ≤ .05), with increasing values corresponding to advancement in tumor stage. Addition of DOI changed the T level of many tumors based on the new TNM (tumor-node-metastasis) classification. The correlation coefficient between DOI calculated on each MRI sequence and Path was 0.90.

CONCLUSIONS

MRI-derived DOI accurately reflected the subsequent metastatic status and degree of progression of tumor stages, with a strong positive correlation to Path values, and may be considered a predictor of tumor stage and CLNM.

Elective neck dissection in T1/T2 oral squamous cell carcinoma with N0 neck: essential or not? A systematic review and meta-analysis

INTRODUCTION

Oral squamous cell carcinoma (SCC) is characterized by a high risk of cervical lymph node metastasis with a high incidence of occult metastasis. A strong debate is still present regarding the best treatment for early oral cavity cancer with N0 neck.

OBJECTIVE

The aim of the present study was to compare between the results of elective neck dissection (END) and watchful waiting (observation or therapeutic neck dissection) in patients with early-stage (T1/T2) oral squamous cell carcinoma with N0 neck.

DATA SOURCES

Medline database (https://www.pubmed.com), Google Scholar and Scopus.

PATIENTS AND METHODS

A systematic review and meta-analysis for the evaluation of regional recurrence rate and 5-year survival rate after elective neck dissection (END) or watchful waiting in early oral cancers were conducted. This study included published English medical articles (which met our predetermined inclusion criteria) in the last 30 years, concerning early oral SCC with N0 neck. 24 articles were included (4 randomized studies and 20 observational "retrospective" studies) with a total number of 2190 of patients who underwent END and 1619 who underwent watchful waiting. Regarding the 5-year survival rate, (10) studies were included with a total number of 1211 patients who underwent END and 948 who underwent watchful waiting.

RESULTS

Regarding the regional recurrence rate, (END) was associated with significantly lower risk of recurrence when compared with observation. Regarding the 5-year survival rate, END was associated with a better survival rate than the observational group.

CONCLUSIONS

Elective neck dissection is better than watchful waiting in early (T1/T2) stage oral cavity squamous cell carcinoma with N0 neck, regarding regional recurrence and 5-year survival rate.

Nerve-tumour interaction enhances the aggressiveness of oral squamous cell carcinoma

OBJECTIVES

Perineural invasion (PNI) is a poor prognostic pathologic feature of oral squamous cell carcinoma (OSCC). The mechanisms of PNI remain poorly understood, and nerve-tumour interactions have been implicated for its pathogenesis.

DESIGN AND SETTING

Systematic investigation of nerve-tumour interactions was performed using fresh human peripheral nerve. In vitro and in vivo models were used to determine the ability of human peripheral nerves to enhance OSCC migration/invasion. Retrospective cohort study was also carried out in one medical centre from 2001 to 2009.

PARTICIPANTS

314 T1-2 OSCC patients.

MAIN OUTCOME MEASURES

In the transwell migration/invasion assay, the cells in five representative fields were counted. In the nerve implantation model, tumour size was estimated. PNI quantification by PNI focus number was carried out in the OSCC patients to correlate with cervical lymph node metastasis and oncologic outcomes.

RESULTS

The transwell migration/invasion assay demonstrated that human peripheral nerves, compared with subcutaneous soft tissue, significantly enhanced the migration/invasion abilities of OSCC. Moreover, the enhanced migration was dose-dependent with increased length or number of peripheral nerve segments. The nerve implantation model showed that human peripheral nerve also enhanced OSCC growth in vivo. Finally, increased PNI focus number was found dose-dependently associated with increased cervical lymph node metastasis and decreased 5-year disease-specific survival rates.

CONCLUSIONS

These results clearly indicated the presence of nerve-tumour interaction that involved paracrine influences leading to aggressiveness of OSCC. Further investigations are required to explore key cell types and molecules involved in nerve-tumour interactions for future therapeutic targeting of PNI in OSCC.

Nationwide randomised trial evaluating elective neck dissection for early stage oral cancer (SEND study) with meta-analysis and concurrent real-world cohort

BACKGROUND

Guidelines remain unclear over whether patients with early stage oral cancer without overt neck disease benefit from upfront elective neck dissection (END), particularly those with the smallest tumours.

METHODS

We conducted a randomised trial of patients with stage T1/T2 N0 disease, who had their mouth tumour resected either with or without END. Data were also collected from a concurrent cohort of patients who had their preferred surgery. Endpoints included overall survival (OS) and disease-free survival (DFS). We conducted a meta-analysis of all six randomised trials.

RESULTS

Two hundred fifty randomised and 346 observational cohort patients were studied (27 hospitals). Occult neck disease was found in 19.1% (T1) and 34.7% (T2) patients respectively. Five-year intention-to-treat hazard ratios (HR) were: OS HR = 0.71 (p = 0.18), and DFS HR = 0.66 (p = 0.04). Corresponding per-protocol results were: OS HR = 0.59 (p = 0.054), and DFS HR = 0.56 (p = 0.007). END was effective for small tumours. END patients experienced more facial/neck nerve damage; QoL was largely unaffected. The observational cohort supported the randomised findings. The meta-analysis produced HR OS 0.64 and DFS 0.54 (p < 0.001).

CONCLUSION

SEND and the cumulative evidence show that within a generalisable setting oral cancer patients who have an upfront END have a lower risk of death/recurrence, even with small tumours.

CLINICAL TRIAL REGISTRATION

NIHR UK Clinical Research Network database ID number: UKCRN 2069 (registered on 17/02/2006), ISCRTN number: 65018995, ClinicalTrials.gov Identifier: NCT00571883.

Elective Neck Dissection Versus Observation in Early-Stage (cT1/T2N0) Oral Squamous Cell Carcinoma

Objectives

Whether to perform elective neck dissection (END) or apply the observation (OBS) policy in patients with early‐stage oral squamous cell carcinoma (OSCC) without clinical evidence of cervical lymph node metastasis (cT1/T2N0) remains uncertain. The two most recent meta‐analyses include many studies published before the widespread availability of CT scanning in the 1990s. With the rapid advancement in imaging studies since 1990, the early clinical detection of cervical node metastasis has become more reliable without the need for END or pathological staging. Thus, we conducted a systematic review and meta‐analysis of studies comparing survival outcomes between END and OBS in patients with cT1/T2N0 OSCC.

Methods

We performed a systematic search of MEDLINE, PubMed, and Scopus for retrospective and prospective studies published between January 1, 1990, and January 1, 2018, comparing clinical outcomes between END and OBS in patients with cT1/T2N0 OSCC. Information on population characteristics, study design, overall survival (OS), disease‐specific survival (DSS), and disease‐free survival (DFS) was extracted and estimated. Effect measures for outcomes were hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Thirteen retrospective and two prospective randomized studies (3,158 patients) met the inclusion criteria. Compared to OBS, END failed to significantly improve OS (HR, 1.02; 95% CI, 0.95–1.09; P = .77; fixed‐effects model), DSS (HR, 1.07; CI, 1.02–1.13; P = .31; fixed‐effects model), and DFS (HR, 0.86; CI, 0.72–1.01; P = .12; random‐effects model).

Conclusions

Our findings indicate that in patients with cT1T2N0 OSCC, the OBS policy can yield markedly similar OS, DSS, and DFS to those resulting from END.

Level of Evidence

2

Elective Neck Dissection Versus Wait-and-Watch Policy for Oral Cavity Squamous Cell Carcinoma in Early Stage: A Systematic Review and Meta-Analysis Based on Survival Data

PURPOSE

Whether elective neck dissection (END) should be adopted for patients with clinically early-stage (cT1-2N0M0) oral cavity squamous cell carcinoma (OCSCC) remains debated. The aim of this systematic review was to compare the survival benefit of END with that of the wait-and-watch policy (WW) for patients with early-stage OCSCC based on survival data.

MATERIALS AND METHODS

According to the inclusion criteria, an exhaustive search for eligible studies was conducted. The study inclusion and data extraction were performed by 2 reviewers independently. The risk of bias was assessed in duplicate using the Risk Of Bias In Nonrandomized Studies of Interventions instrument. The hazard ratio (HR) of the time-to-event data was extracted or estimated. RevMan 5.3 and STATA 15.1 were adopted for data synthesis.

RESULTS

Of the 35 studies that were included, only 5 were assessed as having a low risk of bias. Results of the meta-analyses showed END could significantly decrease neck recurrence (relative risk = 0.45; confidence interval [CI], 0.35-0.59; P < .00001) and improve disease-free survival (HR = 0.55; CI, 0.42-0.71; P < .00001), overall survival (HR = 0.75; CI, 0.64-0.86; P < .0001), and disease-specific survival (HR = 0.76; CI, 0.61-0.94; P = .01) compared with WW for patients with cT1-2N0. The subgroup analysis showed that END could decrease neck recurrence (P < .00001) and improve disease-free survival (P = .001) for patients with early-stage tongue cancer and that supraomohyoid neck dissection could decrease neck recurrence (P = .02). For patients with cT1N0, END could significantly decrease the proportion with neck recurrence (P = .0008) and improve disease-free survival (P = .0003), but the difference between overall survival and disease-specific survival did not achieve significance.

CONCLUSIONS

END can decrease recurrence and improve survival time for patients with early-stage OCSCC. More high-quality studies are needed to make a solid conclusion, especially for patients with cT1N0M0.

Management of the Neck in Squamous Cell Carcinoma of the Oral Cavity and Oropharynx: ASCO Clinical Practice Guideline

PURPOSE

The aim of the current work is to provide evidence-based recommendations to practicing physicians and others on the management of the neck in patients with squamous cell carcinoma of the oral cavity and oropharynx.

METHODS

ASCO convened an Expert Panel of medical oncology, surgery, radiation oncology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2018. Outcomes of interest included survival, regional disease control, neck recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 124 relevant studies to inform the evidence base for this guideline. Six clinical scenarios were devised; three for oral cavity cancer and three for oropharynx cancer, and recommendations were generated for each one.

RECOMMENDATIONS

For oral cavity cancers, clinical scenarios focused on the indications for and the hallmarks of a high-quality neck dissection, indications for postoperative radiotherapy or chemoradiotherapy, and whether radiotherapy alone is sufficient elective treatment of an undissected neck compared with high-quality neck dissection. For oropharynx cancers, clinical scenarios focused on hallmarks of a high-quality neck dissection, factors that would favor operative versus nonoperative primary management, and clarifying criteria for an incomplete response to definitive chemoradiation for which salvage neck dissection would be recommended. Consensus was reached and recommendations were made for all six clinical scenarios. Additional information is available at www.asco.org/head-neck-cancer-guidelines .

Discrete Perineural Invasion Focus Number in Quantification for T1-T2 Oral Squamous Cell Carcinoma

Objective

Perineural invasion (PNI) has been an established poor prognostic feature for T1-T2 oral squamous cell carcinoma (OSCC). Different presentations and amounts of PNI are commonly observed, but PNI is currently recorded as being present or absent. This study asked whether the quantification of PNI provides additional information for early OSCC.

Study Design

Retrospective cohort study.

Setting

Tertiary referral medical center.

Subjects and Methods

Pathologic reevaluations were performed for 314 patients with T1-T2 OSCC who underwent curative surgery from June 2001 to August 2009. A novel parameter, PNI focus number, was defined for PNI quantification. With 5 PNI foci as the cutoff, patients were categorized into 3 groups: no PNI (0 PNI foci), low PNI (PNI foci, 1-5), and high PNI (PNI foci >5). Rate of cervical lymph node metastasis (LN+), 5-year disease-specific survival (DSS), and 5-year overall survival (OS) were analyzed among these groups.

Results

PNI focus number independently predicted for LN+, poor DSS, and poor OS in multivariate analysis after controlling for T classification, lymphovascular invasion, differentiation, margin, and tumor thickness. The 5-year DSS demonstrated a dose-dependent decrease among the 3 groups (no PNI, 88.6%; low PNI, 75.2%; high PNI, 33.8%; P < .001). Moreover, the 5-year DSS of the high PNI group was significantly worse than that of the low PNI group.

Conclusion

PNI focus number can be a novel parameter for PNI quantification in early OSCC. Although optimal quantification methods still require further investigation, this study offers clear clinical support for the nerve-tumor interaction hypothesis and advocates further mechanistic research for the exploration of PNI-related treatment concepts for OSCC.

Association of neck dissection with survival for early stage N0 tongue cancer: A SEER population-based study

The management of the node negative neck in patients with tongue cancer remains a complex and controversial issue, especially in those with early stage tumors. Patients with negative cervical lymph nodes generally have a good prognosis. However, in patients without neck dissection, neck recurrences may occur after excision of the primary tumor due to occult cervical metastases. It often results in poor salvage therapy options and short survival. We used Surveillance, Epidemiology, and End Results data from 2004 to 2013 to investigate the association of neck dissection with survival among early stage tongue cancer patients with negative lymph node metastasis. A total of 4274 eligible patients were subdivided into 2 groups according to their neck management strategies: neck dissection and observation. Univariate and multivariate Cox proportional hazards regression models were used to determine the independent factors of survival. The Kaplan-Meier method was employed for survival analysis. In the overall cohort, patients who underwent neck dissection had better survival than those who were managed with observation in both tongue cancer specific survival and overall survival. After adjusting for confounding variables, neck dissection strategy remains an independent prognostic factor for better survival. When stratifying the patients according to age, gender, race, marital status, histologic grade, stage and radiotherapy, patients in the neck dissection group had significantly better survival than those in the observation group. Neck dissection may improve survival for early stage tongue cancer patients with negative lymph node metastasis. These results may assist clinicians in selecting the most appropriate neck management strategy for individual patients.

Elective Neck Dissection Versus Observation in Squamous Cell Carcinoma of Oral Cavity With Clinically N0 Neck: A Systematic Review and Meta-Analysis of Prospective Studies

PURPOSE

To assess the possible benefits of elective neck dissection (END) in patients with squamous cell carcinoma (SCC) of the oral cavity and clinically N0 neck.

MATERIALS AND METHODS

Medline, Embase, the China National Knowledge Infrastructure, and the Wan Fang Database were systematically searched. A meta-analysis was performed to evaluate the possible benefits of END to such patients.

RESULTS

Six prospective studies involving 865 patients fulfilled the inclusion criteria. Meta-analysis of all included studies showed that END substantially lowered the risk of regional recurrences (risk ratio [RR] = 0.27; 95% confidence interval [CI], 0.21-0.36) in the fixed-effect model compared with observation only. Three of the 6 included studies showed that the specific death rate related to regional recurrences was lower in the END group than in the observation group in the fixed-effect model (RR = 0.35; 95% CI, 0.19-0.65). The mean metastasis rate of occult cervical lymph node was 30.27% (standard deviation, 9.42%). When the fixed-effect model was applied, 4 of the 6 included studies showed less recurrence in the END group compared with the observation group (RR = 0.53; 95% CI, 0.44-0.64).

CONCLUSIONS

END substantially decreases recurrences and deaths related to regional recurrences in early-stage SCC of the oral cavity with clinically N0 neck, especially SCC of the oral tongue and floor of the mouth, which is necessary for such patients.

Correlation between the malignancy and prognosis of oral squamous cell carcinoma in the maximum standardized uptake value

Positron emission tomography/computed tomography (PET/CT) examinations are indispensable in determining the stage, evaluating the treatment response, and diagnosing recurrence and metastasis during oral cancer treatment. In this study, we examined the correlation between the maximum standardized uptake value (SUVmax) for ¹⁸F-FDG PET/CT and the progressive factors, biological characteristics, and prognosis of oral cancer. We included 52 cases of oral squamous cell carcinoma with surgery as the initial treatment. Inclusion criteria included tumor diameter of ≥ 1 cm excluding superficial cancer. We performed 18F-FDG PET/CT examinations before surgery and determined the correlation between SUVmax and clinicopathological factors, such as histological grade, Ki-67 expression, as well as progress factors. SUVmax was significantly correlated with clinical T stage, vascular invasion, lymphatic invasion, Ki-67 expression, and postoperative event (recurrence or metastasis) in Student's t test. Using a cut-off SUVmax of 8.0, clinical T stage, lymph node metastasis, vascular invasion, infiltrative pattern, and Ki-67 expression significantly correlated in chi-squared test. Although observed and expected 3-year overall survival rates were not significantly different, observed and expected 3-year disease-free survival rates were significantly different. Analyzing each clinicopathological factor using various data obtained from ¹⁸F-FDG PET/CT scans may be useful to determine prognosis during oral cancer treatment.

Redefining Perineural Invasion: Integration of Biology With Clinical Outcome

A diagnosis of perineural invasion (PNI), defined as cancer within or surrounding at least 33% of the nerve, leads to selection of aggressive treatment in squamous cell carcinoma (SCC). Recent mechanistic studies show that cancer and nerves interact prior to physical contact. The purpose of this study was to explore cancer-nerve interactions relative to clinical outcome. Biopsy specimens from 71 patients with oral cavity SCC were stained with hematoxylin and eosin and immunohistochemical (IHC; cytokeratin, S100, GAP43, Tuj1) stains. Using current criteria, PNI detection was increased with IHC. Overall survival (OS) tended to be poor for patients with PNI (P = .098). OS was significantly lower for patients with minimum tumor-nerve distance smaller than 5 μm (P = .011). The estimated relative death rate decreased as the nerve-tumor distance increased; there was a gradual drop off in death rate from distance equal to zero that stabilized around 500 μm. In PNI-negative patients, nerve diameter was significantly related to OS (HR 2.88, 95%CI[1.11,7.49]). Among PNI-negative nerves, larger nerve-tumor distance and smaller nerve diameter were significantly related to better OS, even when adjusting for T-stage and age (HR 0.82, 95% CI[0.72,0.92]; HR 1.27, 95% CI[1.00,1.62], respectively). GAP43, a marker for neuronal outgrowth, stained less than Tuj1 in nerves at greater distances from tumor (OR 0.76, 95% CI[0.73,0.79]); more GAP43 staining was associated with PNI. Findings from a small group of patients suggest that nerve parameters other than presence of PNI can influence outcome and that current criteria of PNI need to be re-evaluated to integrate recent biological discoveries.

Perineural Invasion in Head and Neck Cancer

Perineural invasion (PNI) is a mechanism of tumor dissemination that can provide a challenge to tumor eradication and that is correlated with poor survival. Squamous cell carcinoma, the most common type of head and neck cancer, has a high prevalence of PNI. This review provides an overview of clinical studies on the outcomes and factors associated with PNI in head and neck cancer and on findings on cancer-nerve crosstalk.

Upregulation of proline rich 11 is an independent unfavorable prognostic factor for survival of tongue squamous cell carcinoma patients

Proline rich 11 (PRR11) serves an important role in the development and progression of a number of types of human cancer. However, the clinical role of PRR11 in tongue squamous cell carcinoma (TSCC) remains unknown. The present study aimed to investigate the expression and clinicopathological significance of PRR11 in TSCC. The Cancer Genome Atlas analysis demonstrated that the upregulation of PRR11 in TSCC correlated with poor prognosis. The data of the present study revealed that PRR11 mRNA and protein expression was markedly upregulated in human TSCC tissues. Immunohistochemistry on 72 archived paraffin-embedded TSCC specimens suggested that high levels of PRR11 expression were significantly associated with clinical stage (P<0.001), T classification (P=0.009), N classification (P=0.017) and vital status (P=0.010). In addition, patients with TSCC with higher PRR11 expression exhibited substantially shorter survival times compared with patients with lower PRR11 expression (P<0.001). Univariate and multivariate analyses indicated that PRR11 upregulation may be an independent prognostic factor for patients with TSCC (P=0.001). Taken together, and to the best of our knowledge, the results of the present study demonstrated for the first time that PRR11 is involved in the development and progression of TSCC, and may serve as a useful prognostic marker and an effective target for treating TSCC.

Regional recurrence in early stage I-II oral tongue cancer: a single institutional study and review of the literature

CONCLUSIONS

There is a high propensity for locoregional and isolated regional failure in stage II patients, even though treated with combined therapy. In stage I patients the risk of isolated regional failure was moderate, at levels below 10%.

BACKGROUND

The neck treatment of early stages of oral tongue squamous cell carcinoma (OTSCC) are still debatable, considering that previous studies have produced diverting results. The purpose of this study is to report on the outcome of patients with stages I-II, with special respect to regional outcome.

MATERIALS AND METHODS

All patients treated for OTSCC at Karolinska University Hospital between 2008-2014 were included. Patient demographics, intention of treatment, treatment modality, time of follow-up and status at follow-up, recurrence, and place of recurrence were recorded.

RESULTS

Of 230 patients, 149 presented within stages I and II. Of those, 105 were electively treated to the neck. In stage I, the risk of presence of disease in the neck specimen was four out of 63 (6%), whereas 17 out of 41 (41%) were positive in stage II patients. The overall risk of isolated regional failure at any time in stage I patients was six out of 89 and in stage II 25 out of 60.

Cytoplasmic neuropilin 2 is associated with metastasis and a poor prognosis in early tongue cancer patients

Neuropilin 2 (Nrp2) plays an important role in regulating lymphangiogenesis. Nrp2 expression in early tongue cancer was investigated to predict lymph node metastasis and the long-term prognosis. The relationships between clinicopathological variables of cT1-T2N0 tongue squamous cell carcinoma (SCC) and overexpression of Nrp2, vascular endothelial growth factor C (VEGFC), vascular endothelial growth factor receptor 3 (VEGFR3), and semaphorin 3F (Sema3F) were analyzed. Expression levels were compared using oral SCC cell lines. The Nrp2 gene was silenced to determine the impact of Nrp2. Cytoplasmic Nrp2 overexpression predicted regional metastasis with sensitivity and specificity of 90.3% and 42.1%, respectively. Cytoplasmic Nrp2 overexpression (P<0.001) and VEGFC overexpression (P=0.006) were significantly related to regional metastasis (Student t-test). However, only cytoplasmic Nrp2 overexpression was an independent prognostic factor for both disease-free survival (DFS; P=0.008) and overall survival (OS; P=0.016) (Cox regression); the risk of recurrence was 12-times higher (P=0.015) and risk of mortality was 8-times higher (P=0.016). Co-localization of Nrp2 and VEGFC was greater within the cytoplasm of aggressive cell lines (HN12 and RCa-T). Nrp2 plays a role in tumourigenesis; VEGFC supplementation cannot rescue the biological function of Nrp2 in Nrp2-depleted cell lines. Cytoplasmic Nrp2 overexpression is associated with decreased OS and DFS. Cytoplasmic Nrp2 overexpression may be a reliable diagnostic and prognostic marker for early tongue SCC.

Survival in Head and Neck Cancers - Results of A Multi- Institution Study

BACKGROUND

The prime output of Hospital Based Cancer Registries is stage and treatment based survival to evaluate patient care, but because of challenges of obtaining follow-up details a separate study on Patterns of Care and Survival for selected sites was initiated under the National Cancer Registry Programme of India. The results of stage and treatment based survival for head and neck cancers by individual organ sites are presented.

MATERIALS AND METHODS

A standardized Patient Information Form recorded the details and entered on-line at www.hbccrindia.org to a central repository - National Centre for Disease Informatics and Research. Cases from 12 institutions diagnosed between 1 January 2006 and 31 December 2008 comprised the study subjects. The patterns of treatment were examined for 14053 and survival for 4773 patients from five institutions who reported at least 70% follow-up as of 31 December 2012.

RESULTS

Surgical treatment with radiation for cancer tongue and mouth showed five year cumulative survival (FCS) of 67.5% and 60.4% respectively for locally advanced stage. Chemo-radiation compared to radiation alone showed better survival benefit of around 15% in both oro and hypo-pharyngeal cancers and their FCS was 40.0%; Hazard Ratio (HR):1.5;CI=1.2-1.9) and 38.7%; (HR):1.7; CI=1.3-2.2).

CONCLUSIONS

The awareness about the requirement of concurrent chemo-radiation in specifically cancers of the oro and hypopharynx has to be promoted in developing countries. The annual (2014) estimate number of new Head and Neck cancers with locally advanced disease in India is around 140,000 and 91,000 (65%) patients do not receive the benefit of optimal treatment with ensuing poorer survival.

Efficacy of Elective Neck Dissection in T1/T2N0M0 Oral Tongue Squamous Cell Carcinoma

Objective/Hypothesis

The aim of this population-based study is to analyze the survival benefits of elective neck dissection (END) over neck observation in T1/T2N0M0 oral tongue squamous cell carcinoma (OT-SCC) cases.

Study Design

Retrospective administrative database analysis.

Subjects and Methods

The SEER database (Surveillance, Epidemiology, and End Results) was queried for patients diagnosed with T1/T2N0M0 OT-SCC from 1998 to 2011. Data included patient demographics, initial treatment, and survival outcomes. The Kaplan-Meier model and the Cox proportional hazards model were utilized for survival analysis.

Results

Out of 7010 T1/T2N0M0 cases, END was performed in 1770 T1 and 950 T2 cases, and the neck was observed in 3278 T1 and 1001 T2 cases. Significantly poorer 5-year disease-specific survival (DSS) rates were noted for the neck observation group when compared with the END group for tumors with moderately differentiated (72.1% vs 86%, P < .0001) and poorly differentiated or undifferentiated (55.6% vs 71.5%, P = .0001) histologic grades. No significant survival benefit was seen between the END group and the neck observation group when tumor size was <1 cm, regardless of histology grade. However, those with tumors >1 cm had a significantly better 5-year DSS with END, except for the well-differentiated tumor cohort, which showed improved survival only when the tumors were >2 cm (5-year DSS: END vs neck observation, 83.5% vs 65.7%, P = .0002).

Conclusion

END improves DSS versus neck observation in T1/T2N0M0 OT-SCC patients with moderately differentiated, poorly differentiated, or undifferentiated histologic grade tumors >1 cm. Those with well-differentiated tumors benefited from END only when tumor size was >2 cm.

Perineural Invasion in Squamous Cell Carcinoma of the Oral Cavity: Histology, Tumor Stage, and Outcome

OBJECTIVES/HYPOTHESIS

To analyze the impact of different types of perineural invasion (PNI) in squamous cell carcinoma (SCC) of the oral cavity on overall survival and recurrence rate, with a special focus on histologic subtypes and tumor stage.

STUDY DESIGN

Retrospective case-control study with clinicopathological analysis.

METHODS

Seventeen patients who received primary surgical treatment for SCC of the oral cavity with PNI were matched to a control group. In a histologic review, PNI was classified into subtypes according to an adapted Liebig classification. The term type A was used to describe tumor invasion into the nerve, whereas type B was used to describe circumferential growth around the nerve. Clinical charts were reviewed, and a Kaplan-Meier survival analysis was performed.

RESULTS

The recurrence-free survival rates were 47.1% versus 80.4% (PNI vs. matched control group, P < 0.05), 60.0% versus 94.1% (PNI in stage I and II disease vs. matched control group, P < 0.05) and 41.7% versus 73.5% (PNI in stage III and IV disease vs. matched control group, P < 0.05). In most cases (n = 9) of PNI, both histologic subtypes (type A and type B) were present. Five cases exclusively showed type A, and three cases exclusively showed type B.

CONCLUSIONS

Perineural invasion in early disease oral carcinoma has a particularly high impact on survival. Both histologic subtypes showed a significantly worse recurrence-free survival rate when compared to the control group.

LEVEL OF EVIDENCE

3.