Sentinel node biopsy versus elective neck dissection. Which is more cost-effective? A prospective observational study

Nomogram to Predict Nodal Recurrence-Free Survival in Early Oral Squamous Cell Carcinoma

OBJECTIVE

This study aimed to develop and internally validate a prognostic nomogram for predicting nodal recurrence-free survival (NRFS) in patients with early-stage oral squamous cell carcinoma (OSCC) with clinically negative neck lymph nodes.

MATERIALS AND METHODS

The management of early-stage oral cancer patients with clinically negative neck lymph nodes (cN0) remains controversial, especially concerning the need for elective neck dissection. Data from a single institution spanning 2010 to 2020 were utilized to develop and evaluate the nomogram. The nomogram was constructed using multivariable Cox regression and LASSO regression analyses to identify independent risk factors for lymph node metastasis. Internal validation was performed using bootstrap resampling to assess the nomogram's predictive accuracy.

RESULTS

A total of 930 cN0 patients with T1 and T2 stage OSCC were randomly divided into training and validation cohorts (8:2 ratio). Independent risk factors for lymph node metastasis included tumor pathological grade (well: reference, moderate/poor: OR 1.69), cT (cT1: reference, cT2: OR 2.01), history of drinking (never: reference, current/former: OR 1.72), and depth of invasion (0 mm < DOI ≤ 5 mm: reference, 5 mm < DOI ≤ 10 mm: OR 1.31). The nomogram, incorporating these variables, demonstrated good predictive accuracy with a C-index of 0.67 (95% CI: 0.58-0.76) in the validation set. In both training and validation groups, the nomogram effectively stratified patients into low-risk and high-risk groups for occult cervical nodal metastases (p < 0.05).

CONCLUSIONS

The nomogram enables risk stratification and improved identification of occult cervical nodal metastases in clinically node-negative OSCC patients by incorporating tumor-specific and patient-specific risk factors.

Feasibility and diagnostic performance of sentinel node biopsy for staging cN0 oral squamous cell carcinoma in a previously treated neck

Objectives

Staging of the cN0 neck with sentinel node biopsy (SNB) in early-stage oral squamous cell carcinoma (OSCC) is validated in patients with a previously untreated neck. We aimed to investigate the feasibility and diagnostic accuracy of SNB and unexpected drainage patterns in patients with cT1-T2N0 OSCC and a history of previous head and neck cancer comprising treatment of the neck, that is, surgery, radiotherapy, or both.

Methods

Fifty patients with a previously treated neck diagnosed with a new primary or recurrent cN0 OSCC between 2014 and 2021 were included and retrospectively analyzed. Feasibility was assessed by the rate of successfully performed SNB neck staging procedures. Based on follow-up data, the diagnostic performance of SNB was evaluated by calculation of negative predictive value (NPV) and false omission rate (FOR).

Results

A SNB staging procedure was successfully performed in 76% (38/50) of the patients. Technical failures were due to the lack of drainage preoperatively or failure in intraoperative SN detection. In patients successfully staged with SNB, the rate of a positive SN was 13% (5/38). In the SNB-negative group, no patients were diagnosed with a regional node recurrence during follow-up, and the NPV and FOR were 100% and 0%, respectively. Unexpected lymphatic drainage occurred in 32% (12/38) of the patients.

Conclusion

SNB is technically feasible in cT1-2N0 OSCC patients with a previously treated neck with a high diagnostic accuracy. Importantly, SNB enables the detection of individual and unexpected lymphatic drainage patterns.

Sentinel lymph node biopsy in early-stage oral squamous cell carcinoma: A retrospective single-center analysis

Sentinel lymph node biopsy (SLNB) is increasingly incorporated in European national guidelines for the management of the clinically node-negative neck (cN0) in early-stage oral squamous cell carcinoma (OSCC). In Germany, SLNB in OSCCs is not yet routinely performed. This study aimed to evaluate the clinical outcome of SLNB in a German cohort. Patients with primary early-stage OSCC who underwent tumor resection and SLNB were retrospectively analyzed. Clinical-pathological characteristics were documented. Primary endpoints were sensitivity and the negative predictive value (NPV). A total of 46 patients with a mean age of 62.3 (±14.5) years met the inclusion criteria. Most tumors were located in the tongue (63.0%). Bilateral drainage from a lateral tumor was observed in three cases (6.5%), and sentinel lymph node metastasis was detected in three patients (6.5%). Mean follow-up for all patients was 13.8 months (±9.6). One patient developed regional recurrence following a negative SLNB during the observation period, leading to an NPV of 0.98 and a sensitivity of 75.0%. The 2-year neck-specific relapse-free survival was 92.8%. SLNB in early-stage OSCC is a reliable diagnostic tool of the cN0 neck, ensuring a high NPV and RFS. SLNB can be advantageous in comparison to elective neck dissection due to the detection of contralateral lymph drainage.

Cost-Effectiveness of [99mTc]Tilmanocept Relative to [99mTc]Sulfur Colloid for Sentinel Lymph Node Biopsy in Early Stage Oral Cavity Cancer

BACKGROUND

Several studies have demonstrated varying rates of efficacy, reliability, and sensitivity of sentinel lymph node biopsy (SLNB) in identifying occult nodal disease for early stage oral cavity squamous cell carcinoma (OCSCC) depending on the radionuclide agent utilized. No head-to-head comparison of cost or clinical outcomes of SLNB when utilizing [99mTc]tilmanocept versus [99mTc]sulfur colloid has been performed. The goal of this study was to develop a decision model to compare the cost-effectiveness of [99mTc]tilmanocept versus [99mTc]sulfur colloid in early stage OCSCC.

PATIENTS AND METHODS

A decision model of disease and treatment as a function of SLNB was created. Patients with a negative SLNB entered a Markov model of the natural history of OCSCC parameterized with published data to simulate five states of health and iterated over a 30-year time horizon. Treatment costs and quality-adjusted life-years (QALYs) for each health state were included. The incremental cost-effectiveness ratio (ICER) was then estimated using $100,000 per additional QALY as the threshold for determining cost-effectiveness.

RESULTS

The base case cost-effectiveness analysis suggested [99mTc]tilmanocept was more effective than [99mTc]sulfur colloid by 0.12 QALYs (7.06 versus 6.94 QALYs). [99mTc]Tilmanocept was more costly, with a lifetime cost of $84,961 in comparison with $84,264 for sulfur colloid, however, the overall base case ICER was $5859 per additional QALY, well under the threshold for cost-effectiveness. Multiple one-way sensitivity analyses were performed, and demonstrated the model was robust to alternative parameter values.

CONCLUSION

Our analysis showed that while [99mTc]tilmanocept is more costly upfront, these costs are worth the additional QALYs gained by the use of [99mTc]tilmanocept.

Indications for sentinel lymph node biopsy in node-negative oral cancers

BACKGROUND

We aimed to define the indications for sentinel lymph node biopsy (SLNB), the third option for cervical treatment in oral cancer with negative cervical lymph nodes.

METHODS

The greatest depth of invasion (DOI) and long diameter (LD) of the primary site were used as exposures. SLN metastasis was considered the outcome.

RESULTS

In three trials conducted between 2009 and 2016, 158 patients were eligible and reassigned to this study group. The scatterplot based on the respective values of DOI and LD would eventually be divided into three sections. In cases of sections T1, T2, and T3, the proportions of SLN metastasis positivity were 21.3%, 35.3%, and 51.2%, respectively. In certain cases of T1 with 2 mm < DOI ≤ 5 mm and 8 mm < LD ≤ 20 mm, the proportion of SLN metastasis positivity was 40.9%.

CONCLUSIONS

SLNB-navigated or assisted neck dissection can be added as an effective procedure for N0 neck control.

Current Treatment Strategies and Risk Stratification for Oral Carcinoma

Management of oral cavity squamous cell carcinoma (OSCC) involves a multidisciplinary team approach. Surgery is ideally the primary treatment option for nonmetastatic OSCC, and less invasive curative surgical approaches are preferred in early-stage disease to minimize surgical-related morbidity. For patients at high risk of recurrence, adjuvant treatment using radiation therapy or chemoradiation is often used. Systemic therapy may also be used in the neoadjuvant setting (for advanced-stage disease with the intent of mandibular preservation) or in the palliative setting (for nonsalvageable locoregional recurrence and/or distant metastases). Patient involvement in treatment decision is the key for patient-driven management, particularly in clinical situation with poor prognosis, for example, early postoperative recurrence before planned adjuvant therapy.

Role of sentinel lymph node biopsy for oral squamous cell carcinoma: Current evidence and future challenges

Sentinel lymph node biopsy (SLNB) has been used across oncological specialties for prognostication, staging, and identification of occult nodal metastasis. Recent studies demonstrated the potential clinical utility of SLNB in oral cavity squamous cell carcinoma (OCSCC). Elective neck dissection is the current standard of care in early management of OCSCC with depth of invasion greater than 2-4 mm; however, majority of patients ultimately do not have nodal disease on final pathology. SLNB is an alternative procedure widely adopted in early cancer management in many oncological subspecialities. Several considerations such as depth of invasion, nodal mapping, histopathology methods, operator variability, postoperative complications, and advancement in preoperative and intraoperative imaging technology can guide the appropriate application to SLNB in OCSCC. The aim of this review is to discuss the current evidence for SLNB in the treatment of early stage OCSCC, imaging technologies that support SLNB procedures, and studies that are currently underway.

Efficacy of different sentinel lymph node biopsy protocols in oral squamous cell carcinoma: Systematic review and meta-analysis

The sentinel node biopsy (SNB) is highly protocolized in other cancers, however, this is not the case for oral squamous cell carcinoma patients, hence our objective was to evaluate the different protocols published. A specific study protocol was designed and subsequently registered on PROSPERO (Ref. CRD42021279217). Twenty‐three articles were included in the meta‐analysis. The grouped sensitivity of the SNB was 82% (95% CI: 0.74–0.88), and the grouped specificity was 100% (95% CI: 0.99–1.00). The use of other radiotracers other than pre‐operative lopamidol showed higher values of sensitivity of 82.80% (95% CI: 76.90%–87.50%; p < 0.001). The use of the blue dye stain showed higher sensitivity values of 85.60% (95% CI: 71.90%–93.20%), compared to sensitivity values of 77.50% when it was not used (95% CI: 69.10%–84.20%) (p < 0.001). Diagnostic rates are variable and they were significantly better when 99mTc was used in all its variations and accompanied by the blue dye staining.

Critical Review of the Current Evidence on Sentinel Node Biopsy in Oral Cancer

PURPOSE OF REVIEW

With contemporary surgery of the cN0 neck in early oral cancer becoming more selective, sentinel node biopsy (SNB) is gaining popularity as a possible alternate option to elective neck dissection (END). This review attempts to critically appraise the current evidence and highlight pertinent arguments for the use of SNB in early oral cancers.

RECENT FINDINGS

Based on the recent randomized trials, it is imperative to perform an END at the time of primary resection in cN0 oral cancers. The much criticized false negative rate of SNB can be argued to be equal to the regional failure rate after END for pN0 necks, possibly making a case for SNB due to the reduction in number of neck dissections. There still lies ambiguity on the technique, protocols, and benefit of SNB over END. The role of extended histopathological techniques and the implications of micrometastasis and isolated tumor cells for treatment intensification remain questionable. Currently, SNB is an intermediary between routine imaging and END that needs to evolve before it can become a practice changing alternative to END itself. More efforts are needed in standardizing the protocols for SNB.

Sentinel Lymph Node Biopsy Versus Elective Node Dissection in Stage cT1-2N0 Oral Cavity Cancer

OBJECTIVE

To compare overall survival (OS) and disease-free survival (DFS) between sentinel lymph node biopsy (SNB) and elective neck dissection (END) in the surgical management of cT1-2N0 oral cavity squamous cell carcinoma (OCSCC).

METHODS

English full-text articles were searched in PubMed and Embase on May 9, 2021. Articles had to compare SNB with END in cT1-T2N0 OCSCC patients; report hazard ratios (HRs), Kaplan-Meier curves, or P-values with total number of events for survival outcomes; be from a clinical trial, cohort, or case-control study. Two reviewers reviewed articles and a third settled disagreements. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Risk of Bias in Non-randomized Studies of Interventions tool and revised Cochrane risk-of-bias tool for randomized trials were used. The generic inverse variance method with a random-effect model was used for meta-analysis.

RESULTS

Ten studies, five retrospective, three prospective, and two randomized controlled trials, were included (total number of patients [n] = 10,498, END n = 9102, SNB n = 1396). No significant differences were found in OS (HR = 0.92; 95% confidence interval [CI]: 0.65-1.31) or DFS (HR = 0.70; 95% CI: 0.41-1.20). Heterogeneity was not detected in pooled OS analysis (P = .18; I²  = 30%), but was in pooled DFS analysis (P = .003; I²  = 66%).

CONCLUSIONS

No statistically significant differences in OS or DFS were observed between SNB and END in cT1-2N0 OCSCC, suggesting that SNB might be an alternative to END in the management of early-stage, clinically node-negative OCSCC. Laryngoscope, 2021.

Sentinel lymph node biopsy versus elective neck dissection in squamous cell carcinoma of the oral cavity with a clinically N0 neck: Systematic review and meta-analysis of prospective studies

Sentinel lymph node biopsy (SLNB) is an emerging strategy for managing early-stage oral squamous cell carcinoma (SCC) with a clinically N0 (cN0) neck. However, the role of SLNB in this scenario is debatable. Herein, relevant literature was systematically reviewed, and a meta-analysis was performed to evaluate the potential dividends of SLNB compared to elective neck dissection (END) for these patients. The meta-analysis, including six prospective studies, showed comparable results of the two management strategies in terms of regional recurrence (risk ratio [RR] = 0.99; 95% confidence interval [CI], 0.58-1.70), 5-year disease-free survival (RR = 0.99; 95% CI, 0.87-1.11), and 5-year overall survival (RR = 1.01; 95% CI, 0.90-1.13). Fewer adverse events occurred in the SLNB arm than in the END arm (RR = 0.12; 95% CI, 0.02-0.70). Overall, SLNB results in as favorable an oncologic prognosis for patients with cN0 oral SCC as END, while significantly lessening side effects and unnecessary surgeries.

Sentinel lymph node biopsy versus selective neck dissection in patients with early oral squamous cell carcinoma: A cost analysis

OBJECTIVE

Sentinel lymph node biopsy (SLNB) has been proved to be as efficient as selective neck dissection (SND) for the treatment of occult metastases in T1-T2cN0 oral squamous cell carcinoma (OSCC). The aim of our study was to assess and compare the cost of these two surgical procedures.

PATIENTS AND METHODS

This retrospective cost analysis includes consecutive patients treated between 2012 and 2017 in two French hospitals either by SLNB or SND. Hospital cost (hospital stay for initial surgery and re-hospitalizations over a period of 60 days after the initial surgery), the length of hospital stay for the initial surgery and the perioperative management were described and compared between the two techniques. The propensity score regression adjustment method was used to address selection bias.

RESULTS

Ninety-four patients underwent SLNB procedure and seventy-seven patients underwent SND. The length of hospital stay for initial surgery was lower in SLNB group: 5.8 days (SD: 3.8) versus 9.2 days (SD: 5) in the SND group. Hospital costs were lower in SLNB group: €7 489 (standard deviation: €3 691) versus €8 886 (standard deviation: €4 381) but this difference was not significant after propensity score regression adjustment. The rate of complication, the delay of full oral feeding and postoperative drainage were lower in SLNB group.

CONCLUSION

SLNB in T1-T2cN0 OSCC is less invasive than SND with fewer complications, a shorter length of hospital stay and favorable perioperative management. This study shows that this technique could be also less expensive than SND.

Neck failure following pathologically node-negative neck dissection (pN0) in oral squamous cell carcinoma: a systematic review and meta-analysis

Due to the risk of occult cervical metastasis, elective neck dissection (END) is recommended in the management of patients with early oral cavity squamous cell carcinoma (OSCC) and a clinically node-negative (cN0) neck. This paper presents a systematic review and meta-analysis of studies that recorded isolated regional recurrence (RR) in the pathologically node-negative neck dissection (pN0) neck following END in order to quantify the failure rate. Pubmed and Ovid databases were systematically searched for relevant articles published between January 2009 and January 2019. Studies reporting RR following END in patients with OSCC who had no pathological evidence of lymph node metastasis were eligible for inclusion in this meta-analysis. In addition, a selection of large head and neck units were invited to submit unpublished data. Search criteria produced a list of 5448 papers, of which 18 studies met the inclusion criteria. Three institutions contributed unpublished data. This included a total of 4824 patients with median follow-up of 34 months (2.8 years). Eight datasets included patients staged T1-T4 with RR 17.3% (469/2711), 13 datasets included patients staged T1-T2 with RR 7.5% (158/2113). Overall across all 21 studies, isolated neck recurrence was identified in 627 cases giving a RR of 13.0% (627/4824) on meta-analysis. Understanding the therapeutic effectiveness of END provides context for evaluation of clinical management of the cN0 in these patients. A pathologically negative neck does not guarantee against future recurrence.

Diagnostic yield of sentinel lymph node biopsy in oral squamous cell carcinoma T1/T2-N0: systematic review and meta-analysis

The objective of this study was to conduct a systematic review and meta-analysis on the efficacy of sentinel lymph node biopsy (SLNB) in T1/T2-N0 oral squamous cell carcinoma (OSCC). A systematic review of the literature on SLNB until March 2019 was conducted. The review was organized according to the PRISMA protocol, considering the following PICO (population, intervention, comparison, outcome) question: What is the sensitivity of sentinel lymph node biopsy in OSCC? 'P' was patients with head and neck squamous cell carcinoma T1/2-N0; 'I' was SLNB; 'C' was neck treated with elective neck dissection and haematoxylin-eosin histopathology; 'O' was sensitivity and specificity. A meta-analysis and meta-regression were performed on the selected studies. The sensitivity of SLNB was up to 88% (95% confidence interval (CI) 72-96%) and specificity was up to 99% (95% CI 96-100%). The area under the summary receiver operating characteristic curve was 0.99 (95% CI 0.98-1.00). In the four studies where immunohistochemistry was performed, both the sensitivity and specificity were higher than in the studies without immunohistochemistry: 93% (95% CI 88-97%) and 98% (95% CI 96-100%), respectively. In conclusion, SLNB is an effective technique for treating patients with some types of stage T1/2-N0 OSCC. Some parameters such as immunohistochemistry could determine the level of diagnostic accuracy.

Novel Diagnostic Approaches for Assessment of the Clinically Negative Neck in Head and Neck Cancer Patients

In head and neck cancer, the presence of nodal disease is a strong determinant of prognosis and treatment. Despite the use of modern multimodality diagnostic imaging, the prevalence of occult nodal metastases is relatively high. This is why in clinically node negative head and neck cancer the lymphatics are treated “electively” to eradicate subclinical tumor deposits. As a consequence, many true node negative patients undergo surgery or irradiation of the neck and suffer from the associated and unnecessary early and long-term morbidity. Safely tailoring head and neck cancer treatment to individual patients requires a more accurate pre-treatment assessment of nodal status. In this review, we discuss the potential of several innovative diagnostic approaches to guide customized management of the clinically negative neck in head and neck cancer patients.

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.

Variability in Recommendations for Cervical Lymph Node Pathology for Staging of Canine Oral Neoplasia: A Survey Study

There is no clear guideline regarding the indication for routine lymph node extirpation and pathologic evaluation during staging of canine oral tumors, despite a relatively high reported nodal metastatic rate for select tumor types. It is particularly unclear if clinicians recommend removal of lymph nodes only when there is confirmation of metastasis, defined as the N+ neck, or if elective neck dissection (END) is routinely recommended to confirm the true pathologic metastatic status of lymph nodes in the clinical N0 neck (no evidence of metastasis on clinical staging with diagnostic imaging or cytology). When clinicians are recommending END as a staging tool to confirm nodal status, there is also ambiguity regarding the surgical extent for subsequent histopathologic evaluation. The objective of this cross-sectional survey study was to determine the current recommendations given by practicing specialists regarding lymph node removal for dogs with oral tumors. Overall, 87 responses were obtained from 49 private practices (56%) and 38 academic institutions (44%). Respondents identified as oncologists (44%, N = 38), soft tissue surgeons (40%, N = 35), and dentists (16%, N = 14). Regardless of tumor type and stage, extirpation and histopathology were most commonly recommended in the clinical N+ neck only. The recommendation to routinely perform END in the N0 neck was significantly associated with tumor type. Bilateral removal of the mandibular and retropharyngeal lymph nodes was recommended more often for oral malignant melanoma (OMM) than for oral squamous cell carcinoma (OSCC; p ≤ 0.0039) or for oral fibrosarcoma (OFSA; p ≤ 0.0007). The likelihood of recommending END increased with increasing tumor size. Academic clinicians were significantly (p < 0.01) more likely to recommend END compared to private practitioners for canine T1-T3 OMM, T3 OSCC, T2 OFSA, and MCT. This study highlights the variability in recommendations for lymph node pathology for dogs with oral tumors. While tumor type and size influenced the decision to pursue END, it was not routinely recommended, even for tumor types with a known propensity for metastasis. Prospective studies are warranted to determine the potential diagnostic and therapeutic value of END in the N0 neck in veterinary patients such that a consensus approach can be made.

Elective Neck Dissection or Sentinel Lymph Node Biopsy in Early Stage Oral Cavity Cancer Patients: The Dutch Experience

Background: Sentinel lymph node biopsy (SLNB) has been introduced as a diagnostic staging modality for detection of occult metastases in patients with early stage oral cancer. Comparisons regarding accuracy to the routinely used elective neck dissection (END) are lacking in literature. Methods: A retrospective, multicenter cohort study included 390 patients staged by END and 488 by SLNB. Results: The overall sensitivity (84% vs. 81%, p = 0.612) and negative predictive value (NPV) (93%, p = 1.000) were comparable between END and SLNB patients. The END cohort contained more pT2 tumours (51%) compared to the SLNB cohort (23%) (p < 0.001). No differences were found for sensitivity and NPV between SLNB and END divided by pT stage. In floor-of-mouth (FOM) tumours, SLNB had a lower sensitivity (63% vs. 92%, p = 0.006) and NPV (90% vs. 97%, p = 0.057) compared to END. Higher disease-specific survival (DSS) rates were found for pT1 SLNB patients compared to pT1 END patients (96% vs. 90%, p = 0.048). Conclusion: In the absence of randomized clinical trials, this study provides the highest available evidence that, in oral cancer, SLNB is as accurate as END in detecting occult lymph node metastases, except for floor-of-mouth tumours.

Management of the clinically N0 neck in early-stage oral squamous cell carcinoma (OSCC). An EACMFS position paper

Metastasis of oral squamous cell carcinoma (OSCC) to the cervical lymph nodes has a significant impact on prognosis. Accurate staging of the neck is important in order to deliver appropriate treatment for locoregional control of the disease and for prognosis. The management of the neck in early, low volume disease (clinically T₁/T₂ oral cavity tumours) has long been debated. The risk of occult nodal involvement in cT₁/T₂ OSCC is estimated around 20-30%. We describe the natural evolutionary history of OSCC and its patterns of spread and metastasis to the local lymphatic basins. We discuss most published literature and studies on management of the clinically negative neck (cN₀). Particular focus is given to prospective randomized trials comparing the outcomes of upfront elective neck dissection against the observational stance, and we summarize the results of the sentinel node biopsy studies. The paper discusses the significance of the primary tumour histological characteristics and specifically the tumour's depth of invasion (DOI) and its impact on predicting nodal metastasis. The DOI has been incorporated in the TNM staging highlighting its significance in aiding the treatment decision making and this is reflected in world-wide oncological guidelines. The critical analysis of all available literature amalgamates the existing evidence in early OSCC and provides recommendations in the management of the clinically N₀ neck.

Usefulness of Sentinel Lymph Node Biopsy for Oral Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

We assessed the diagnostic accuracy of sentinel lymph node biopsy (SLNB) for detecting neck nodal metastasis in early oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection.

STUDY DESIGN

A systematic search for relevant literature was conducted in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane databases.

METHODS

Two reviewers individually searched the five databases up to November 2019. For studies that met inclusion criteria, data on patient diagnoses were pooled, including true positives, true negatives, false positives, and false negatives. Methodological quality was checked with the Quality Assessment of Diagnostic Accuracy Studies (version 2) tool.

RESULTS

In total, 98 observational or retrospective studies were included. The diagnostic odds ratio of SLNB was 326.165 (95% confidence interval [CI]: 231.477-459.587; I²  = 0%). The area under the summary receiver operating characteristic curve was 0.982. Sensitivity was 0.827 (95% CI: 0.804-0.848), and specificity was 0.981 (95% CI: 0.975-0.986). The correlation between sensitivity and the false positive rate was -0.076, which indicates that heterogeneity did not exist. Subgroup analyses were performed with the subgroups reference test type, publication year, and study type. No significant difference was found within the reference test type subgroup. However, differences within the publication year and study type subgroups were significant, where the retrospective study subgroup was significantly more sensitive and specific than the prospective study subgroup.

CONCLUSION

Results of this meta-analysis imply that the high specificity of SLNB supports its role as a diagnostic tool for patients with clinical tumor stage (CT)1-2 clinically negative (N0) OSCC. More studies should be done to further verify the results of this study.

LEVEL OF EVIDENCE

2a Laryngoscope, 131:E459-E465, 2021.

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.

[Sentinel lymph node biopsy in head and neck oncology]

Sentinel lymph node biopsy (SLNB) has been initially developed for melanoma and breast cancers. Its application in head and neck cancers is recent, probably due to the complexity of the lymphatic drainage, the proximity between the primary tumor and the lymph nodes and the critical anatomical structures (such as the facial nerve). In onco-dermatology, SLNB is validated in head and neck surgery for melanoma with Breslow thickness up to 1mm or ulceration, Merkel carcinoma and high-risk squamous cell carcinoma. Considering the malignancies of the upper aerodigestive tract, the feasibility and oncologic safety of SLNB are now established for T1-T2N0 oral and oropharyngeal squamous cell carcinomas. Thus, it could allow patients with negative sentinel nodes to avoid an unnecessary neck dissection, leading to a decrease of morbidity with an quality of life improvement. For some primary locations (e.g., anterior floor of the mouth) with high proximity between tumor and lymph nodes, it is recommended to remove the tumor before the SLNB so as to improve the detection. New techniques of detection are currently being developed with intra-operative procedures and new tracers (such as tilmanocept), leading to a better accuracy of detection and, probably, new indications.

The economic burden of oral squamous cell carcinoma in Australia

OBJECTIVES

The financial burden of treatment for oral squamous cell carcinoma in Australia has never been reported, and there is a paucity of international data. Here, we report the direct costs of treatment of surgically resectable oral cancer in a tertiary public hospital in Australia over a 15-year period.

MATERIALS AND METHODS

Pathology department records, records of hospital attendance and hospital finance department records were interrogated to determine the direct costs of inpatient and outpatient treatment. Costs were adjusted using the total health price index so that all costs were equivalent to costings for the 2016/2017 financial year.

RESULTS

A total of 113 cases were identified as suitable for inclusion. Complete inpatient and outpatient hospital attendance and costing data for treatment and subsequent 2-year follow-up was available for 29 cases. The average total cost over the 2-year period was $92 958AUD (median $102 722, range $11 662-$181 512). On average, 92.8% of costs were incurred in the first year post-diagnosis. Inpatient costs, outpatient costs and total costs increased with increasing pathological cancer stage. Both 1- and 2-year post-diagnosis overall cost for patients with Stage 4 oral cavity cancer were more than two times greater than for patients with Stage 1 oral cancer.

CONCLUSION

It is well documented that patients diagnosed at an earlier stage will have better survival outcomes, and it is assumed that the economic burden of their treatment will be less. We have shown that there is a direct correlation between cancer stage and cancer treatment cost. The findings provide clear economic support for oral cancer screening initiatives to detect earlier stage cancers, and the need to investigate novel techniques and technologies to detect oral squamous cell carcinoma early and reduce recurrence and mortality rates.

Sentinel lymph node biopsy for management of the N0 neck in oral cavity squamous cell carcinoma

BACKGROUND AND OBJECTIVES

The management of the clinically N0 (cN0) neck is controversial for early stage squamous cell carcinoma of the oral cavity (OSCC). This paper represents a single institution series analyzing the efficacy of sentinel lymph node biopsy (SNB) for early stage oral cavity cancers.

METHODS

From 2005 to 2017, 108 patients with cN0 OSCC were treated with primary resection and SNB. Patients with positive biopsy results proceeded to neck dissection with or without adjuvant chemoradiotherapy. Mean follow-up for the entire cohort was 50.8 months (range: 8-147 months). Clinically, 56 patients were T1N0, 49 patients were T2N0, and three patients were T3N0 or greater.

RESULTS

Disease-specific survival was 93% within the entire cohort. Sentinel lymph nodes were identified in 95.4% of patients. Twenty one patients had a positive biopsy. There were seven false-negative biopsies. The overall rate of nodal disease was 26%. Accuracy of node biopsy was 93%, with sensitivity of 75%, and negative predictive value of 91%. Recurrence rate was 19% (20/108), with an overall survival of 60% in this subgroup.

CONCLUSION

SNB is a safe, effective, and well tolerated method for staging cN0 OSCC.

Diagnostic Efficacy of Sentinel Lymph Node Biopsy in Early Oral Squamous Cell Carcinoma: A Meta-Analysis of 66 Studies

OBJECTIVES

The diagnostic efficacy of sentinel lymph node biopsy(SLNB) in early oral squamous cell carcinoma(OSCC) still remains controversial. This meta-analysis was conducted to assess the diagnostic value of SLNB in clinically neck-negative T1-2 OSCC.

METHODS

A systematic literature search for relevant literature published up to September 11, 2016 was conducted in PubMed, Embase, Web of Science, Cochrane Library and ClinicalTrials, and the reference lists of eligible studies were examined. Data from different studies were pooled to estimate the summary sentinel lymph node(SLN) identification rate, sensitivity, negative predictive value. Summary receiver operator characteristic curve(SROC) was plotted and area under the SROC curve (AUC) was calculated to evaluate the overall diagnostic efficacy. Threshold effect was assessed with use of the spearman correlation coefficient. Between-study heterogeneity was tested using the Q tests and the I2 statistics. Subgroup analyses were conducted in view of the greater effect of different study characteristics on diagnostic efficacy of SLN. Deeks' funnel plot asymmetry test was performed to evaluate publication bias. Sensitivity analysis was evaluated through omitting studies one by one and comparing the pooled results of random-effects model and fixed-effects model. All analyses were performed using Review Manager (version 5.3.5), Meta-DiSc (version 1.4), Comprehensive Meta Analysis (version 2.0) and STATA (version 12).

RESULTS

66 studies comprising 3566 patients with cT1-2N0 OSCC were included in this meta-analysis. The pooled SLN identification rate was 96.3%(95% CI: 95.3%-97.0%). The pooled sensitivity was 0.87 (95% CI: 0.85-0.89), pooled negative predictive value was 0.94 (95% CI: 0.93-0.95), and AUC was 0.98 (95% CI: 0.97-0.99). Subgroup analyses indicated that SLN assessment with immunohistochemistry(IHC) achieved a significantly higher sensitivity than without IHC.

CONCLUSIONS

This meta-analysis suggests that SLNB has a high diagnostic accuracy in cT1-2N0 oral squamous cell carcinoma, and is an ideal alternative to elective neck dissection. Furthermore, the use of IHC can significantly improve SLNB diagnostic sensitivity for early OSCC.