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

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Transcriptional expression of SLC16A7 as a biomarker of occult lymph node metastases in patients with head and neck squamous cell carcinoma

PURPOSE

Glucose is the main energy substrate of tumor cells. This study aims to assess whether the transcriptional expression of glucose metabolism-related genes is associated with occult lymph node metastases in head and neck squamous cell carcinoma (HNSCC) patients.

METHODS

We examined the transcriptional expression of a panel of glucose metabolism-related genes in a cohort of 53 patients with HNSCC without cervical lymph node involvement at the time of diagnosis (cN0) and subsequently treated with elective neck dissection.

RESULTS

Occult lymph node metastases were found in 37.7% (n = 20) of the patients. Among the analyzed genes, SLC16A7 exhibited the strongest association with the presence of occult lymph node metastases. Patients with occult lymph node metastases (cN0/pN +) had significantly lower SLC16A7 expression values (p = 0.001). Patients with low SLC16A7 expression (n = 17, 32.1%) had a frequency of occult lymph node metastases of 76.5%, while for patients with high SLCA16A7 expression (n = 36, 67.9%) it was 19.4% (P = 0.0001). A multivariable analysis showed that patients with low expression of SLC16A7 had a 12.6 times higher risk of developing occult lymph node metastases.

CONCLUSION

cN0 HNSCC patients with low SLC16A7 expression had a higher risk of occult lymph node metastases.

A Prospective Cohort Study on Neck Lymph Node Mapping in Oral Cancers Using Methylene Blue Dye

In the current scenario, the management of N0 neck in early-stage oral cancer is debatable, whether or not they should undergo elective neck dissection. Most of the time these patients are either over-treated or under-treated. Sentinel lymph node (SLN) biopsy is a good option to identify occult LN in this cohort of patients for guiding neck dissection. With a focus on SLN biopsy using methylene blue dye, this study aims to evaluate its feasibility and accuracy in node-negative oral squamous cell carcinoma. A prospective observational study was conducted involving operable squamous cell carcinoma patients with clinically and radiologically node-negative neck. Methylene blue was injected in the peritumoral area and after that SLN was identified and then neck dissection was completed. Of 47 patients, SLN was identified in 82.98%, with 53.85% having more than two SLN. Common locations were in levels IB, IA and IIA. Occult metastasis was observed in 12.82% of cases, predominantly in T2 patients. Sensitivity, specificity and NPV were 50%, 100% and 88.89% respectively. The study affirms the feasibility and accuracy of methylene blue-assisted SLN biopsy in oral cancer. Despite a high detection rate, methylene blue dye alone should not be used for SLN identification in oral cavity cancer. However, it can be used as an adjunct of lymphoscintigraphy to increase the yield of the procedure. Multi-institutional trials with larger cohorts may provide valuable insights and more information for comprehensively addressing the limitations of this technique and its broader applicability in decision-making, particularly in resource-constrained countries like India where lymphoscintigraphy is not readily accessible.

Oncological Outcome of Node-Positive Oral Squamous Cell Carcinomas Treated With Selective and Comprehensive Neck Dissection

Selective neck dissection (SND) is the treatment of choice in patients with oral squamous cell carcinomas (OSCCs) and clinically node-negative necks (cN0). The treatment of patients with positive-staged necks (cN+) includes SND as well as comprehensive neck dissection (CND). The clear benefit of one or the other remains under debate. We aim to address this lack of clarity by analysing patients with OSCC staged with clinically node-positive necks, treated with either CND or SND using a level-by-level approach. This retrospective study included patients diagnosed with OSCC with clinically (cN+) and pathologically (pN+) positive cervical lymph nodes (LNs) with clear neck level categorization during the years 2010-2019. In total, 74 patients were analysed. Cox regression analysis found no significance for the type of ND being an independent risk factor, neither for overall survival (OS) nor for disease-free survival (DFS). Regional recurrence of CND cases (5.77%) was comparable to SND cases (9.09%). For OS, extracapsular spread (ECS) and male sex were identified as independent risk factors with poorer outcome. pT-stage and ECS were found to be independent risk factors for DFS. The results of this study suggest that both CND and SND may be viable treatment options for certain patients with OSCC pN+.

Histopathological predictors of lymph node metastasis in oral cavity squamous cell carcinoma: a systematic review and meta-analysis

Objectives

Lymph node metastasis (LNM) is the most significant parameter affecting overall survival in patients with oral cavity squamous cell carcinomas (OCSCC). Elective neck dissection (END) is the standard of care in the early management of OCSCC with a depth of invasion (DOI) greater than 2-4 mm. However, most patients show no LNM in the final pathologic report, indicating overtreatment. Thus, more detailed indicators are needed to predict LNM in patients with OCSCC. In this study, we critically evaluate the existing literature about the risk of different histological parameters in estimating LNM.

Methods

A systematic review was conducted using PRISMA guidelines. PubMed, Web of Science, Cochrane, and Scopus were searched from inception to December 2023 to collect all relevant studies. Eligibility screening of records was performed, and data extraction from the selected studies was carried out independently. Inclusion in our systematic review necessitated the following prerequisites: Involvement of patients diagnosed with OCSCC, and examination of histological parameters related to lymph node metastasis in these studies. Exclusion criteria included animal studies, non-English articles, non-availability of full text, and unpublished data.

Results

We included 217 studies in our systematic review, of which 142 were eligible for the meta-analysis. DOI exceeding 4 mm exhibited higher risk for LNM [Risk ratio (RR) 2.18 (1.91-2.48), p<0.00001], as did perineural invasion (PNI) [RR 2.04 (1.77-2.34), p<0.00001], poorly differentiated tumors [RR 1.97 (1.61-2.42), p<0.00001], lymphovascular invasion (LVI) [RR 2.43 (2.12-2.78), p<0.00001], groups and single pattern of invasion [RR 2.47 (2.11-2.89), p<0.00001], high tumor budding [RR 2.65 (1.99-3.52), p<0.00001], tumor size over 4 cm [RR 1.76 (1.43-2.18), p<0.00001], tumor thickness beyond 4 mm [RR 2.72 (1.91-3.87), p<0.00001], involved or close margin [RR 1.73 (1.29-2.33), p = 0.0003], and T3 and T4 disease [RR 1.98 (1.62-2.41), p <0.00001].

Conclusion

Our results confirm the potential usefulness of many histopathological features in predicting LNM and highlight the promising results of others. Many of these parameters are not routinely incorporated into pathologic reports. Future studies must focus on applying these parameters to examine their validity in predicting the need for elective neck treatment.

Predictors of Occult Metastasis and Prognostic Factors in Patients with cN0 Oral Cancer Who Underwent Elective Neck Dissection

Elective neck dissection (END) is recommended for the management of patients with oral squamous cell carcinoma (OSCC) because of the risk of occult metastasis (OM). We hypothesized that some factors predict poor prognosis regardless of a cN0 END. This study aimed to investigate the predictors of OM and prognostic factors in patients with cN0 OSCC who underwent supraomohyoid neck dissection (SOHND). A retrospective cohort study design was created and implemented. The primary predictive variables in this study were OM and risk factors for poor prognosis after SOHND. A Cox proportional hazard model was used to adjust for the effects of potential confounders on the risk factors for poor prognoses. Among 86 patients with OSCC, OMs were observed in 9 (10.5%). The neutrophil-to-lymphocyte ratio (NLR) and vascular invasion are good markers for detecting OM. A Cox multivariable analysis identified two independent predictors of overall survival: pathologic node (pN) and laterality of END. An independent predictive factor for disease-free survival, the surgical margin, was also identified in this study. According to the pN classification, pN1 patients had a worse survival rate than pN2 patients. Therefore, in the case of pN1, regardless of being cN0, additional adjuvant therapy may be necessary.

Sentinel lymph node biopsy versus elective neck dissection in management of the clinically negative (cN0) neck in patients with oral squamous cell carcinoma: A systematic review and meta-analysis

Oral squamous cell carcinoma (OSCC) is the most prevalent type of head and neck cancer, and lymph node metastasis is a crucial prognostic factor that has a direct correlation with the survival rate. The standard procedure for managing clinically negative (cN0) neck in OSCC patients is elective neck dissection (END), but it can lead to various complications that affect the patient's quality of life. Therefore, medical professionals are exploring the use of the sentinel lymph node biopsy (SLNB) to manage cN0 neck in OSCC patients. The aim of this systematic review and meta-analysis was to compare the overall survival (OS) and disease-free survival (DFS) of patients undergoing SLNB and END in the surgical management of early cN0 neck in OSCC patients. To conduct this study, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to report the systematic reviews. The study included all comparative clinical studies, including randomized clinical trials (RCTs), clinical perspective studies, and retrospective studies that compared END to SLNB for early cN0 neck in OSCC patients. The hazard ratio (HR) and risk ratio (RR) with 95% confidence interval (CI) were calculated using comprehensive meta-analysis. The primary outcome variables were OS, DFS, and disease-specific survival (DSS). The secondary outcome variable was the nodal recurrence rate without local or distant metastasis. The GRADE system was used to assess the evidence's certainty. The meta-analysis included 12 clinical studies, comprising three RCTs and seven non-RCTs. The results showed no statistically significant difference between END and SLNB concerning OS (HR = 0.993, CI: 0.814 to 1.211, P = 0.947, low-quality evidence), DFS (HR = 0.705, CI: 0.408 to 1.29, P = 0.21, low-quality evidence), and nodal recurrence (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). Additionally, SLNB was non-inferior to END regarding DSS (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). In conclusion, this research affirms the safety and precision of SLNB as a means to stage cN0 OSCC patients, with outcomes that are comparable to END in terms of survival and nodal recurrence. Nevertheless, it's crucial to acknowledge that the quality of evidence in this study was relatively low. Therefore, additional RCTs comparing END to SLNB are warranted to validate these results and offer more robust guidance for managing cN0 OSCC patients.

Do patients with cN0 oral squamous cell carcinoma benefit from elective neck dissection? A large-scale population-based study

BACKGROUND

The neck management of clinical-nodal negative (cN0) oral squamous cell carcinoma (OSCC) remains controversial. Elective neck dissection (END) and observation are the main strategies, but it is still not clear who could benefit the most from END. The purpose of this study was to clarify the potential clinical factors that affect the therapeutic value of END and to explore the actual characteristics associated with benefit from END.

METHODS

Patients with cN0 OSCC were identified in the SEER database from 2000 to 2019. 5-year Overall survival (OS) and disease-specific survival (DSS) were analyzed using the Kaplan‒Meier method, and the hazard ratios (HRs) for survival were estimated using the Cox regression model. Multiple subgroup analyses of DSS and OS among different factors, comparing END and No END, were performed.

RESULTS

A total of 17,019 patients with cN0 OSCC were included. The basic survival analysis and Cox regression model showed that END increased the probability of 5-year DSS and OS and was an independent prognostic factor. However, among patients who underwent only primary tumor surgery, no significant differences were found between the END and No END groups in 5-year DSS (P = 0. 585) and OS (P = 0.465). Further subgroup analysis showed that primary sites and T stage, but not other factors, might influence the benefit of END. Significant differences were found for T1 (P < 0.001 for OS) and T2 (P = 0.001 for DSS and < 0.001 for OS) tongue squamous cell carcinoma (TSCC) but not for other primary tumor sites.

CONCLUSION

This large-scale retrospective population-based cohort study suggests that not all patients with cN0 OSCC could benefit from END. Patients with cN0 TSCC are recommended to undergo END, especially with early-stage tumors.

Surgical Management of the Neck in Oral Cavity Squamous Cell Carcinoma

Oral cavity cancer remains a significant cause of morbidity and mortality globally, with a poor prognosis once the disease has metastasized to cervical lymph nodes. The anatomy of lymphatic drainage in the neck gives us a roadmap to follow when assessing for metastasis, although the predictive factors are still not well understood. The mainstay of treatment continues to be neck dissection. However, there is much debate on the management of the clinically negative neck. The necessity of elective neck dissection has been questioned in recent years, with other options such as sentinel lymph node biopsy gaining popularity. This review will explore the aspects of surgical management of the neck in oral cavity cancer and highlights the further research that needs to be done.

Submandibular gland involvement in oral cavity squamous cell carcinoma: a retrospective multicenter study

BACKGROUND

The submandibular gland (SMG) is routinely excised during neck dissection. Given the importance of the SMG in saliva production, it is important to understand its involvement rate by cancer tissue and the feasibility of its preservation.

METHODS

Retrospective data were collected from five academic centers in Europe. The study involved adult patients affected by primary oral cavity carcinoma (OCC) undergoing tumor excision and neck dissection. The main outcome analyzed was the SMG involvement rate. A systematic review and a meta-analysis were also conducted to provide an updated synthesis of the topic.

RESULTS

A total of 642 patients were enrolled. The SMG involvement rate was 12/642 (1.9%; 95% CI 1.0-3.2) when considered per patient, and 12/852 (1.4%; 95% CI 0.6-2.1) when considered per gland. All the glands involved were ipsilateral to the tumor. Statistical analysis showed that predictive factors for gland invasion were: advanced pT status, advanced nodal involvement, presence of extracapsular spread and perivascular invasion. The involvement of level I lymph nodes was associated with gland invasion in 9 out of 12 cases. pN0 cases were correlated with a reduced risk of SMG involvement. The review of the literature and the meta-analysis confirmed the rare involvement of the SMG: on the 4458 patients and 5037 glands analyzed, the involvement rate was 1.8% (99% CI 1.1-2.7) and 1.6% (99% CI 1.0-2.4), respectively.

CONCLUSIONS

The incidence of SMG involvement in primary OCC is rare. Therefore, exploring gland preservation as an option in selected cases would be reasonable. Future prospective studies are needed to investigate the oncological safety and the real impact on quality of life of SMG preservation.

A Clinicopathological Evaluation of the Correlation of Carcinoma Oral Tongue (Anterior Two Thirds) with Cervical Nodal Metastasis to Assess the Level of Neck Dissection: A Hospital Based Prospective Study

Aims

Being an important prognostic predictor in carcinoma oral tongue, neck metastasis poses an adverse impact on prognosis.The management of neck is still controversial. Neck metastasis depends on features like tumor thickness, depth of invasion, lymphovascular invasion and perineural invasion. Thus by correlating these features with the level of nodal metastasis and by correlating clinical and pathological staging, a preoperative assumption for a more conservative neck dissection may be done.

Objectives

To correlate clinical staging, pathological staging and depth of invasion (DOI) of tumor with cervical nodal metastasis, for a preoperative assumption of a more conservative neck dissection.To study the correlation of additional prognostic features like lymphovascular invasion, perineural invasion, positive resection margin, worst pattern of invasion, lymphocytic infiltration and presence of necrosis with that of cervical nodal metastasis.

Materials and Methods

The study was conducted on 24 patients of carcinoma oral tongue who underwent resection of the primary with an appropriate neck dissection and their clinical, imaging, and postoperative histopathological findings were correlated.

Results

We found a significant association of the CC (craniocaudal) dimension and radiologically determined DOI (depth of invasion) with the pN also significant association of clinical and radiological DOI with histological DOI. The probability of occult metastasis was found to be more when the MRI-DOI is > 5 mm. The sensitivity and specificity of cN staging were 66.67% and 73.33% respectively. The accuracy of cN was 70.8%.

Conclusion

In the present study a good sensitivity, specificity and accuracy of cN (clinical nodal stage) was found. Craniocaudal (CC) dimension and DOI of the primary tumor measured by MRI is a strong predictor of the disease extension and nodal metastasis. MRI-DOI > 5 mm warrants an elective neck dissection of level I-III. For tumors MRI DOI < 5 mm observation can be recommended with adherence to a strict follow-up.

The incidence of occult level IV nodal metastasis in tongue squamous cell carcinoma: a 20 year review

BACKGROUND

The extent of neck dissection for tongue SCC is unclear owing to the potential presence of occult level IV metastasis. We aim to assess the incidence of occult level IV nodal metastasis for tongue SCC patients treated in our centre over a 20 year period.

METHODS

A retrospective analysis of data collected from 1999 to 2019 was performed. Patients diagnosed with oral tongue SCC treated primarily with surgery and a neck dissection fulfilled the inclusion criteria.

RESULTS

A total of 124 patients were included in our study. Sixty-one patients were N0 with no occult level IV metastasis. About 17.3% of clinically node positive patients had level IV metastasis. Length of hospital stay and complication rates were comparable for patients who received levels I-III and I-IV neck dissections.

CONCLUSION

Occult level IV metastasis in N0 tongue SCC patients are exceedingly rare, we would therefore suggest consideration for a level I-III neck dissection. In patients who are clinically node positive, a level I-IV neck dissection would be recommended.

Sentinel node biopsy in node negative early oral cancers: Solution to the conundrum!

Ideal management of the node-negative neck in early oral cancers is a debated issue. Elective neck dissection (END) is recommended in these patients as it offers a survival benefit. However, about 50-70% of patients who do not harbor occult metastasis are overtreated with this approach. Surgery is associated with morbidity, predominantly shoulder dysfunction. Numerous attempts have been made to identify true node-negative patients through imaging and prediction models but none have high diagnostic accuracy to safely spare the neck dissection. The recent publications of 2 large randomized controlled trials comparing the outcomes of sentinel node biopsy (SNB) and END have spurred interest in SNB. Both the trials reported SNB to be an oncologically safe procedure and spared unnecessary neck dissections. The functional outcomes of the trials showed that SNB limits the morbidity compared to END, which albeit evens out at the end of one-year post-surgery. Despite its benefits, SNB has failed to gain widespread acceptability due to various limitations including the need for infrastructure, equipment costs, staff, and multidisciplinary collaboration of nuclear medicine, surgical, and pathology fraternity. The labor-intensive pathology protocol with serial step sectioning and immunohistochemistry poses a challenge to the feasibility at a high-volume center. This perspective discusses these limitations and propose plausible solutions to the conundrum. To make it widely applicable and feasible across the globe efforts should be directed to understand biology better, find novel solutions, and implement the lessons learned over decades from other sites.

Identification of occult metastatic disease via lymphoscintigraphy-guided neck dissection in N0 oral squamous cell carcinoma

BACKGROUND

The purpose of this study is to assess the efficacy of lymphoscintigraphy-guided neck dissection (LSG-ND) in the treatment of N0 oral squamous cell carcinoma.

METHODS

A retrospective cohort study of patients with N0 oral squamous cell carcinoma (SCC) who had either LSG-ND or neck dissection (ND) at our institution between 2008 and 2020.

RESULTS

Eighty-seven patients met criteria with N0 oral squamous cell carcinoma with no previous treatment or neck surgery (27 LSG-ND, 60 ND). Sentinel lymph nodes were identified on the contralateral side in 14.8% of patients with unilateral tumors in the LSG-ND group, with 22.2% of cases with unexpected lymphatic drainage outside ipsilateral levels I-III. No recurrences to date have occurred in the LSG-ND cohort, while 13.3% of patients with ND had regional recurrence (p = 0.04).

CONCLUSIONS

LSG-ND provides a greater ability to identify occult metastatic disease with a significant reduction in regional recurrence in N0 oral SCC.

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.

Elective neck dissection improves the survival of patients with T2N0M0 oral squamous cell carcinoma: a study of the SEER database

Background

Treatment of clinical N0 neck tumours is controversial in early-stage oral squamous cell carcinoma (OSCC), possibly because T1N0M0 and T2N0M0 merge together at early stages. The purposes of this study were to compare survival outcomes only for T2N0M0 cases based upon treatment elective neck dissection versus neck observation.

Methods

T2N0M0 OSCC cases were identified in the Surveillance, Epidemiology, and End Results database of the United States National Cancer Institute between 2004 and 2015. Survival curves for different variable values were generated using Kaplan-Meier estimates and compared using the log-rank test. Variables that achieved significance at P < 0.05 were entered into multivariable analyses via the Cox proportional hazards multivariate regression.

Results

A total of 2857 patients were selected, and 2313 cases were available for disease specific survival (DSS). The 5-year and 10-year overall survival (OS) were 66.7 and 46% for patients receiving elective neck dissection (END), respectively, and 56.4 and 37.2% for patients with neck observation (P < 0.0001). The 5-year and 10-year DSS were 73.6 and 64% for the END group, respectively, versus 64.5 and 54.5% for the neck observation group (P < 0.0001). More importantly, performing END was independently associated with favourable DSS and OS for patients with T2N0M0 OSCC [hazard ratio (HR) = 0.769, P = 0.0069 for DSS; HR = 0.829, P = 0.0031 for OS, neck observation group as reference] according to multivariate survival analysis.

Conclusion

END is recommended for T2N0M0 OSCC cases and it is associated with improved DSS and OS.

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.

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.

The Indications for Elective Neck Dissection in T1N0M0 Oral Cavity Squamous Cell Carcinoma

PURPOSE

The management of the clinically node-negative neck in T1 oral cavity squamous cell carcinoma (SCC) is controversial. The purpose of this study was to investigate tumor characteristics of surgically managed patients with T1N0 oral cavity SCC and determine the possible benefits of elective neck dissection (END).

MATERIALS AND METHODS

A retrospective cohort study was conducted assessing outcomes for patients with stage I oral SCC at Waikato Hospital, New Zealand, between 2008 and 2018. Clinical staging was based on the American Joint Committee on Cancer Cancer Staging Manual, 8^th Edition. Patients with T1N0 SCC either had an END or had the neck observed. These data were used to determine the rate of occult nodal disease, recurrence rate, and survival. Data collected included patient demographics, location, tumor characteristics including differentiation, depth of invasion (DOI), perineural invasion (PNI), lymphovascular invasion, closest histologic margin, management of the neck, the number of pathologic lymph nodes, adjuvant treatment, recurrence, and survival.

RESULTS

A total of 70 patients were included in the study (40 male, 30 female; age range 30 to 91; mean age 65 years). Twenty-seven (38.6%) patients underwent END, whereas 43 patients (61.4%) were observed. Occult nodal metastases were diagnosed in 6 of 27 (22.2%) patients who underwent END. Regional relapse occurred in 7 of 43 (16.3%) patients who were observed. Risk factors for nodal disease included increasing DOI ≥ 3 mm (P = .049), poor tumor differentiation (P = .003), and presence of PNI (P = .002). Negative prognostic factors for overall survival included male gender (P = .02, hr = 3.55, CI for HR (1.18, 10.65)), presence of PNI (P = .001, hr = 4.52, CI for HR (1.77, 11.57)), and locoregional recurrence (P < .005, hr = 6.55, CI for HR (2.69, 15.98)). Six of the 7 tumors that relapsed in the neck after observation had a primary tumor DOI < 3 mm.

CONCLUSIONS

There is little data published for management outcomes of the node-negative neck in stage I oral squamous cell carcinoma. Given salvage neck dissection carries a poorer prognosis, END should be recommended for all T1N0 oral SCC with DOI ≥ 3 mm. In cases of DOI < 3 mm undergoing primary ablation only, a staging neck dissection as a second procedure should be considered in the presence of poor tumor differentiation or PNI on final histology.

Nodal yield and topography of nodal metastases from oral cavity squamous cell carcinoma - An audit of 1004 cases undergoing primary surgical resection

OBJECTIVES

Nodal metastasis is an important prognostic factor in oral squamous cell carcinoma (OSCC). Detailed topographic study of metastasis can guide surgical and adjuvant radiation treatment protocols.

METHODS

Retrospective analysis of distribution of nodal spread was done by auditing pathology records of 1004 patients who underwent primary surgical management at our center.

RESULTS

The median nodal yield was 41 (range of 9-166) nodes, per patient. Metastasis was present in 42.9% patients, of which 52.3% demonstrated extranodal extension. Reclassification by AJCC8 criteria resulted in up-staging in 35.6% patients (pN1, pN2a, pN2b, pN2c, pN3a and pN3b in 13.1%, 3.7%, 6.9%, 0.9%, 0%, 18.1% respectively). Ipsilateral levels Ib and IIa were involved in a quarter of patients each, while IIb, IV and V were involved in < 4%, 3% and 1% of patients, respectively. Contralateral nodal metastasis was present in 5.4%. Skip metastases to level IV were 2.2% and 1.2% for tongue and gingivobuccal primaries. Tongue primaries had a lower likelihood of involving level Ib, but higher of level IIa and III, compared to gingivobuccal primaries, and a lower likelihood of extranodal extension. Primary site did not influence nodal metastasis to levels IIb, IV or V, but other factors like lymphovascular invasion, pT stage and margin status had an influence.

CONCLUSION

This large series with high nodal yield, shows low level of metastasis to level IIb, IV and V, which can help modify future guidelines for extent of surgery and avoid targeted adjuvant radiation to specific levels.

Occult Nodal Metastasis in Oral Cavity Cancers

Introduction: In squamous cell carcinoma (SCC) of the oral cavity, there is always a risk of occult metastasis to neck nodes in the clinically and radiologically negative neck (N0). Therefore, elective neck dissection (END) has ever been under discussion since the beginning of their routine use for the management of neck for oral carcinomas. The purpose of the current study is to identify the percentage of occult nodal metastasis to neck levels I-V in the cases of oral carcinoma who were treated for the N0 with END.

Methods: Patients who were treated between June 2005 and May 2010 with END from neck levels I to V for the management of N0 with oral SCC had been identified from the database of Aga Khan University Hospital. Those who met the inclusion and exclusion criteria were included in the study. Data were analyzed using SPSS 16 software. Using descriptive statistics, the mean was computed for the quantitative variable (age). Frequencies and percentages were calculated for gender, site, tumor grade, and lymph node involvement for each neck level.

Results: A total of 50 patients were included in the study. There were 38 males and 12 females. The mean age was 47 (range 25-72). The most common site of the tumor was buccal mucosa in 50% of the cases followed by tongue 20%, then floor of mouth 14%, dentoalveolar ridge 8%, retromolar area 4%, lip 2%, and hard palate 2%. Histopathological grading of tumors showed well-differentiated 28%, moderately differentiated 33%, and poorly differentiated 6%. Twenty-seven out of 50 patients were found positive for nodal metastasis on final postoperative histopathology. Neck node metastasis at level I was found in 22 patients, at level II in 16 patients, at level III in seven patients, and at level IV in two patients. The level V was found free of metastasis in all of the cases.

Conclusion: The rate of occult metastatic disease to the neck nodes was similar to that found in the literature. Both early and advanced local disease is associated with a risk of occult metastasis. END for neck levels I-V is, therefore, recommended for the management of the N0 in all cases of oral SCCs. Spread to levels IV and V is rare and these levels should not be a part of routine END.

Oral Microbiota and Cancer Development

Oral microbiota are among the most diverse in the human body. More than 700 species have been identified in the mouth, and new sequencing methods are allowing us to discover even more species. The anatomy of the oral cavity is different from that of other body sites. The oral cavity has mucosal surfaces (the tongue, the buccal mucosa, the gingiva, and the palate), hard tissues (the teeth), and exocrine gland tissue (major and minor salivary glands), all of which present unique features for microbiota composition. The connection between oral microbiota and diseases of the human body has been under intensive research in the past years. Furthermore, oral microbiota have been associated with cancer development. Patients suffering from periodontitis, a common advanced gingival disease caused by bacterial dysbiosis, have a 2-5 times higher risk of acquiring any cancer compared to healthy individuals. Some oral taxa, especially Porphyromonas gingivalis and Fusobacterium nucleatum, have been shown to have carcinogenic potential by several different mechanisms. They can inhibit apoptosis, activate cell proliferation, promote cellular invasion, induce chronic inflammation, and directly produce carcinogens. These microbiota changes can already be seen with potentially malignant lesions of the oral cavity. The causal relationship between microbiota and cancer is complex. It is difficult to accurately study the impact of specific bacteria on carcinoma development in humans. This review focuses on the elucidating the interactions between oral cavity bacterial microbiota and cancer. We gather literature on the current knowledge of the bacterial contribution to cancer development and the mechanisms behind it.

Challenges and outcomes in establishing a sentinel lymph node biopsy service for oral squamous cell carcinoma in a regional district specialist hospital

UK national guidelines in 2016 recommended that sentinel lymph node biopsy (SLNB) should be offered to patients with early oral squamous cell carcinoma (OSCC). We review the establishment of an OSCC SLNB service with specific consideration to resources, service implications and patient outcomes. A review of processes was performed to identify key stages in establishing the service, and subsequently a retrospective cohort study consisting of 46 consecutive patients with T1/T2 N0 OSCC was undertaken. The key stages identified were: coordinating a nuclear medicine pathway and reliable cost-appropriate pathology service, constructing a Trust business case, and gaining approval of a new interventional service policy. A median (range) of 3.3 (1-8) sentinel nodes (SLN) were removed, with 17 patients having a positive SLN. The negative predictive value of SLNB was 100%, with 12 having a SLN outside the field if elective neck dissection (END) was planned. There was a significantly increased risk of a positive SLN with increasing depth of invasion (DOI) (p=0.007) and increased diameter (p=0.036). We also identified a longer-than-ideal time to completion neck dissection and inadequate ultrasound follow up of negative SLNB patients. Establishment of a service requires careful planning. Our results were in keeping with those reported in the literature, and showed that SLNB for OSCC has a high negative predictive value and can identify at-risk SLN outside the traditional END levels, even in well-lateralised tumours. Our findings show that DOI and size of SLN were significantly associated with a positive SLN, and also identified areas requiring improvement.

Comparison of contrast-enhanced ultrasound and contrast-enhanced computed tomography for the diagnosis of cervical lymph node metastasis in squamous cell carcinoma of the oral cavity

Early detection of cervical lymph node metastasis (CLNM) from squamous cell carcinoma (SCC) of the oral cavity remains challenging. This prospective study was performed to evaluate the ability of contrast-enhanced ultrasound (CEUS) to detect CLNM from oral cavity SCC. Additionally, its diagnostic value was compared with that of contrast-enhanced computed tomography (CECT). Forty-eight consecutive patients with SCC of the oral cavity were enrolled. All subjects were examined preoperatively with both CEUS and CECT. Subsequently, neck dissections were performed for these patients, and cervical lymph nodes separated from the surgical specimens were assessed histologically. The diagnostic performance of these two examinations was compared based on the results of histopathology. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and Youden index for CEUS and CECT were 69.39% vs. 44.90%, 94.71% vs. 97.12%, 89.88%% vs. 87.16%, 75.56% vs. 78.57%, 92.92% vs. 88.21%, and 64.10% vs. 42.02%, respectively. A significant difference was observed in terms of sensitivity (P=0.024) and Youden index (rate difference 22.08%, 95% confidence interval 2.72-41.44%). Therefore, CEUS appears to be a promising diagnostic tool that is superior to CECT for detecting CLNM from SCC of the oral cavity, with a higher sensitivity.

Sentinel lymph node biopsies in early stage oral and oropharyngeal carcinoma: a retrospective single-centre experience

The aim of this retrospective study was to analyse a consecutive series of patients with oral and oropharyngeal carcinoma who had had sentinel lymph node biopsy (SLNB) at our hospital during 2008-2017. A total of 70 patients with clinically and radiologically confirmed primary oral (n=67) or oropharyngeal (n=3) carcinoma, with no signs of metastatic lymph nodes preoperatively (clinically N0) were included. Patients' clinical and personal data, characteristics of the tumours, sentinel lymph node (SLN) status and outcomes were recorded. Eight patients had invaded SLN. Two patients with clear sentinel lymph node biopsies had recurrences in the cervical lymph nodes with no new primary tumour as origin. The negative predictive value (NPV) and sensitivity for SLNB were 97% and 80%, respectively. The depth of invasion was an individual predictor for cervical lymph node metastasis (p=0.043). Single photo emission computed tomography (SPECT) detected fewer SLN in patients with invaded lymph nodes than in patients with clear lymph nodes (p=0.018). Our data support the use of SLNB as a minimally invasive method for staging the cervical lymph nodes among patients with cN0 oral and oropharyngeal carcinoma. Our results further confirm that greater depth of invasion is associated with cervical lymph node metastases.

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

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

Evidence mapping and quality assessment of systematic reviews on therapeutic interventions for oral cancer

Purpose

This evidence mapping aims to describe and assess the quality of available evidence in systematic reviews (SRs) on treatments for oral cancer.

Materials and methods

We followed the methodology of Global Evidence Mapping. Searches in MEDLINE, EMBASE, Epistemonikos and The Cochrane Library were conducted to identify SRs on treatments for oral cancer. The methodological quality of SRs was assessed using the Assessing the Methodological Quality of Systematic Reviews-2 tool. We organized the results according to identified Population–Intervention–Comparison–Outcome (PICO) questions and presented the evidence mapping in tables and a bubble plot.

Results

Fifteen SRs met the eligibility criteria, including 118 individual reports, of which 55.1% were randomized controlled clinical trials. Ten SRs scored “Critically low” methodological quality. We extracted 30 PICOs focusing on interventions such as surgery, radiotherapy, chemotherapy, targeted therapy and immunotherapy; 18 PICOs were for resectable oral cancer, of which 8 were reported as beneficial. There were 12 PICOs for unresectable oral cancer, of which only 2 interventions were reported as beneficial.

Conclusion

There is limited available evidence on treatments for oral cancer. The methodological quality of most included SRs scored “Critically low”. The main beneficial treatment reported by authors for patients with resectable oral cancer is surgery alone or in combination with radiotherapy or chemotherapy. Evidence about the benefits of the treatments for unresectable oral cancer is lacking. These findings highlight the need to address future research focused on new treatments and knowledge gaps in this field, and increased efforts are required to improve the methodology quality and reporting process of SRs on treatments for oral cancer.