Tumour infiltration depth ⩾4mm is an indication for an elective neck dissection in pT1cN0 oral squamous cell carcinoma

Evaluating Depth of Invasion as a Continuous Prognostic Factor in Oral Squamous Cell Carcinoma

BACKGROUND

Depth of invasion (DOI) has a significant clinical impact on the staging system of oral squamous cell carcinoma (OSCC). We aimed to compare the prognostic impact of treating DOI as a continuous variable rather than a categorical one.

METHODS

A retrospective review of 277 OSCC patients surgically treated in a tertiary care center from 2000 to 2020, with a minimum 2-year follow-up. The analyses were performed using Cox and logistic regression.

RESULTS

DOI as a continuous variable significantly predicted mortality in both univariate (p < 0.001) and multivariate (p < 0.001) analyses. It was also a significant predictor of locoregional recurrence (multivariate p = 0.039) and occult lymph node metastasis (univariate p = 0.005, multivariate p = 0.04). Categorical analysis failed to demonstrate the same significance.

CONCLUSIONS

DOI as a continuous factor rather than a categorical one is significantly associated with mortality, locoregional recurrence, and occult lymph node metastasis. This innovative approach promotes personalized risk stratification and better decision-making.

Three-dimensional measurement of the depth of invasion in oral squamous cell carcinoma samples using Lugol's iodine-enhanced micro-computed tomography: an original study

OBJECTIVES

Depth of invasion (DOI) in oral squamous cell carcinoma (OSCC) guides treatment and prognosis but lacks three-dimensional (3D) insight. Thus, this study aimed to investigate the feasibility and accuracy of Lugol's iodine-enhanced micro-computed tomography (CT) for the 3D measurement of DOI in OSCC samples.

METHODOLOGY

In total, 50 in vitro OSCC samples from Nanjing Stomatological Hospital (July 2022 to January 2024) were subjected to micro-CT imaging with a slice thickness of 50 μm following 3% Lugol iodine staining for 12 h, followed by pathological examination and staining. The panoramic diagnostic scanner digitally measured pathological DOI. The micro-CT DOI was measured by evaluating the voxel value of the boundary of the tumor lesion and comparing it with the pathological examination results. Experienced physicians analyzed both measurements, and statistical analyses were performed to determine their correlation.

RESULTS

Lugol iodine-enhanced micro-CT imaging distinguishes various tissue structures, such as tumor tissue, epithelial tissue, muscle tissue, blood vessel structure, and other major tissue structures in 3D space. This imaging technique found and localized micro-tumor lesions (1.82×1.5×1 mm3) when in conjunction with pathological sections. Statistical analysis indicated a strong correlation between pathological DOI and micro-CT DOI (P<.001; r=0.986). During DOI measurement, Lugol iodine-enhanced micro-CT imaging effectively compensated for the loss of 3D space information in the pathological measurements, improving the accuracy of the DOI measurement.

CONCLUSIONS

Lugol iodine-enhanced micro-CT improves OSCC DOI 3D measurements, enhances pathological staging accuracy, and aids treatment decisions and prognosis.

Punch Biopsy for Preoperative Depth of Invasion Assessment in Early Oral Tongue Squamous Cell Carcinoma: A Prospective Pilot Study

ImportanceThe inclusion of depth of invasion (DOI) in the American Joint Committee on Cancer's staging system for oral tongue squamous cell carcinoma (OTSCC) has major clinical implications. Few studies have evaluated the accuracy of preoperative biopsy to predict DOI.ObjectiveTo evaluate the reliability of preoperative punch biopsy for measuring DOI in early OTSCC and compare it to evaluation by digital palpation. Secondarily, to assess the punch biopsy's ability to differentiate between carcinoma in situ (Tis) and invasive carcinoma.DesignA prospective single-center cohort study.SettingCenter Hospitalier de l'Université de Montréal, a tertiary center in Canada.ParticipantsPatients with suspected early stage OTSCC.InterventionPunch biopsy was used to sample the deepest part of tumors to measure biopsy-derived DOI (bDOI). In addition, DOI was estimated via digital palpation: clinical DOI (cDOI) by surgeons.Main Outcome MeasuresPathologic DOI (pDOI) from final histopathology reports was the gold standard. Spearman's correlations were calculated between cDOI, bDOI, and pDOI. Diagnostic performance metrics were calculated for the ability to distinguish pDOI of ≥2 mm, and to differentiate Tis from invasive carcinoma.ResultsAmong 27 patients, correlation coefficients between bDOI and pDOI, and cDOI and pDOI were 0.603 (95% CI: 0.202-0.884) and 0.894 (95% CI: 0.749-0.955), respectively. Punch biopsy sensitivity and specificity were 0.88 (95% CI: 0.62-0.98) and 0.91 (95% CI: 0.59-0.99) to detect pDOI ≥ 2 mm, and 0.89 (95% CI: 0.65-0.99) and 0.86 (95% CI: 0.42-1.00) for distinguishing Tis from invasive carcinoma. Digital palpation sensitivity and specificity for pDOI ≥ 2 mm were 0.86 (95% CI: 0.57-0.98) and 1.00 (95% CI: 0.63-1.00).ConclusionsPunch biopsy and clinical palpation demonstrate high diagnostic yield for identifying lesions with pDOI ≥ 2 mm. Punch biopsy appears to be reliable to distinguish Tis from invasive carcinoma.RelevanceLarger studies are needed to corroborate these findings and assess the role of punch biopsy in guiding elective neck dissection decisions.

Neoteric Predictors for Lymph Node Metastasis in Early Oral Squamous Cell Carcinoma: Tumor Budding and Worst Pattern of Invasion

Oral cancer is one of the most common cancers seen in the Indian subcontinent. Its primary treatment is surgery with or without adjuvant treatment. Despite advances in science, prognosis and overall survival has not yet chanced over the past two decades. Pathologically proven regional lymph node metastasis adversely affects the prognosis. This study was conducted to evaluate the predictive factors for lymph node metastasis in Stage I and II oral squamous cell carcinoma (OSCC) with distinct emphasis on tumor budding and worst pattern of invasion. This is a prospective observational study was done at a tertiary care center, Prince Aly Khan Hospital, Mumbai, over a period of 22 months (March, 2020 to December, 2021). We analyzed 237 patients of early OSCC for clinicopathological parameters (age, trismus, differentiation, depth of invasion, tumor budding, worst pattern of invasion). Chi Square test and logistic regression model were used for data evaluation. Statistical Package for Social Sciences, version 21.0 IBM Corporation USA for Microsoft Windows, was used for data analysis. This study reported statistically significant predictive factors for lymph node metastasis viz. tumor budding (OR 30.8 95% CI 12.365-76.731 p < 0.001), worst pattern of invasion (OR 4.5 95% CI 1.853-11.305 p = 0.001) and age (OR 0.149 95% CI 0.043-0.0516 p < 0.003) on logistic regression model. On Chi square test, along with the above factors- tumor differentiation (p = 0.008) and depth of invasion (p = 0.001) were also found statistically significant in prediction for lymph node metastasis in early OSCC. Strong predictive association exists between lymph node metastasis and tumor budding, worst pattern of invasion and higher age group in early OSCC. These factors can be adapted as a routinely assessed predictive marker and mentioned in histopathology reports with its prognostic implications, thus can be considered for further planning and management. These predictive factors can be used to formulate a risk score to incorporate various clinicopathological factors including tumor budding, worst pattern of invasion, depth of invasion, tumor differentiation and T stage which can be used in patients diagnosed with early stage I & II OSCC where neck dissection can be avoided.

Prognostic significance of anatomic site-specific depth of invasion in oral squamous cell carcinoma - An eastern Indian multi-center study

A crucial parameter in determining the prognosis of oral cavity cancer is depth of invasion (DOI). This research aimed to correlate pathological DOI at different intra-oral anatomical sites for oral squamous cell carcinoma (OSCC) with the risk of regional lymph node metastasis (LNM). This study also investigated the correlation of 3-year overall survival (OS) and disease-specific survival (DSS) with tumor depth. DOI measurement of the primary tumor at different intra-oral anatomic sites of clinically node negative patients who underwent curative surgery with elective neck dissection (END) was carried out as per AJCC 8th Edition staging guidelines in 3 DOI groups of ≤5 mm(A), >5 to ≤10 mm(B) and >10 mm(C). Association of groupwise DOI values with histopathological parameters including LNM and 3 years survival was evaluated. Univariate and multivariate logistic regression analysis (Odds ratio (OR) = 1.1 95 % CI: 1.0-1.2, p < 0.05) showed DOI to be a significant predictor for sub-clinical nodal metastasis observed in 136/382 OSCC patients. Receiver operating curve suggested that at 5 mm DOI (4 mm for early-stage OSCC), the risk of occult LNM was >20 % for all intra-oral sites combined. DOI <5 mm group demonstrated a superior 3-year OS (OR = 19.8 % CI: 7.8-49.9) and DSS (OR = 14.7 % CI: 5.9-37.0). Thus, DOI is an independent predictor of nodal metastasis and has significant association with LNM, OS and DSS. Our findings suggest that a DOI of ≥4 mm is an accurate cut-off value for performing END in early-stage OSCC and > 5 mm for advanced cases across all evaluated oral anatomic sites.

Depth of Invasion in Early Oral Cancer: Is 4MM a Threshold for Elective Neck Dissection?

Lymph node metastasis is one of the most important prognostic factors in oral squamous cell carcinoma. In early stage oral cancers, Depth of invasion (DOI) is a predictor for lymph node metastasis. The aim of this study was to evaluate if DOI 4 mm can be considered as a threshold for clinical decision making on elective neck dissection (END) in early oral cancer, by assessing the association of DOI and the risk of occult lymph node metastasis in early Oral squamous cell carcinoma (OSCC). A retrospective study was conducted on 319 patients with early pT1-2 OSCC who were clinically N negative. All patients underwent primary resection and END. The patients were divided into two groups based on DOI: < 4 mm and ≥ 4 mm. Nodal metastases were then noted for each group. The rate of nodal metastasis in respect to tumor size was also observed. Out of 111 patients having DOI < 4 mm only 15 (4.7%) had lymph node metastasis, whereas out of 208 patients having DOI ≥ 4 mm, 81 patients (25.4%) had neck node metastasis, with p value < 0.05. Tumors having DOI ≥ 4 mm has higher chances of occult metastasis and also increased probability of other prognostic factors like PNI and LVI, suggesting that DOI ≥ 4 mm can be considered a cut - off value for performing END.

Intraoral ultrasonography: an adjunct in oral onco-surgery

OBJECTIVE

To determine the precision and accuracy of intraoral sonography in assessing the depth of invasion in oral cancer.

MATERIAL AND METHODS

A prospective study was conducted in 30 cases of oral cancer. Subjects were subjected to computerised tomography and intraoral sonography before surgery. The depth of invasion assessed through clinical palpation and radiological tools was compared with surgical histopathology.

RESULTS

The depth of invasion assessed on clinical palpation and computerized tomography had statistically significant difference with histopathology whereas intraoral sonography didn't show any difference. The intraoral sonography and computerised tomography had comparable precision and accuracy, with a slight dominance of the computerised tomography in assessing the tumor's depth of invasion greater than 4 mm. However, intraoral sonography was more precise and accurate than computerised tomography in assessing the depth of invasion beyond 10 mm.

CONCLUSION

Intraoral sonography was found to be a reliable tool in the assessment of the depth of invasion in oral cancer. It can prove beneficial during surgery in achieving tumour-free surgical margins.

Prediction of nodal disease in oral squamous cell carcinoma of the tongue: histopathological risk assessment with the focus on depth of invasion

OBJECTIVE

Cervical lymph node metastasis (CLNM) is one of the most relevant influencing factors for the oncological outcome of patients with oral squamous cell carcinoma (OSCC). Several studies showed that the tumors depth of invasion (DOI) influences the risk for CLNM, however varying across the oral subsites. The aim of this study is to investigate the role of DOI and other risk factors in OSCC of the tongue in relation to the occurrence of occult CLNM.

MATERIALS AND METHODS

In this retrospective study, n = 139 patients with primary OSCC of the tongue, treated by complete surgical resection (R0) with curative intention between 2013 and 2021, were included. For data analysis, epidemiologic data as well as preoperative tumor staging, surgical therapy including neck management, histopathological tumor data and follow-up were considered. Uni- and multivariate logistic regression were used to determine association between histopathological risk factors and the occurrence of occult CLNM.

RESULTS

The rate of occult cervical metastasis was 19.4%. T-staging, cervical nodal disease (pN+) and lymphatic invasion were significantly associated with reduced OS and RFS. While DOI had no relevant influence on the OS and RFS (p = 0.88 and p = 0.91 respectively), there was significant correlation between DOI and the occurrence of occult CLNM (OR: 1.17, 95%CI: 1.05-1.30; p < 0.01). The optimal cutoff in predicting occult CLNM was 6 mm (Sensitivity: 84.2%, Specificity: 73.5%, AUC: 0.75).

CONCLUSIONS

The DOI is a helpful risk parameter to predict the occurrence of occult nodal disease in OSCC of the tongue. Given the critical decision cutoff between 2 and 4 mm DOI for performing elective neck dissection in the current guidelines, our data suggests that in these cases, surgical de-escalation could be feasible with close follow-up.

CLINICAL RELEVANCE

This study highlights the relevance of DOI as a risk parameter in the prediction of CLNM with the aim to specify the individual patient risk and to deescalate surgical therapy in order to decrease comorbidities while improving the oncological prognosis.

Impact of histopathological parameters in prognosis of oral squamous cell carcinoma

OBJECTIVE

Squamous cell carcinomas comprise approximately 90% of all oral malignancies. There is a wide geographical variation in the incidence of oral cancer, with South and South East Asia (SSEA) accounting for almost two third of new cases. The prognosis of oral cancer is influenced by a vast array of factors including demographic, clinical, histopathological and molecular factors. The objective this review is to analyse the impact of histopathological features assessed in hematoxylin and eosin stained sections on the prognosis of OSCC.

MATERIALS AND METHODS

Medline and Scopus data base search was performed in order to identify related articles on histopathological parameters in predicting prognosis of oral squamous cell carcinoma. The primary emphasis is on the studies conducted in SSEA, with an accompanying comparison of their findings with those from research conducted in other parts of the world.

RESULTS

It has been shown that the number of studies conducted in SSEA is not proportionate to the high prevalence of Oral Cancer in the region. There is no significant difference between the findings from SSEA compared to the rest of the world. It is clearly shown that most histopathological parameters can be accurately used to predict nodal metastasis and prognosis.

CONCLUSIONS

Histopathological parameters can be used reliably in planning treatment of Oral cancer. Clinicians should combine clinical and histopathological parameters in drawing treatment plan for Oral Cancer.

Proposals for the delineation of neck clinical target volume for definitive Radiation therapy in patients with oral/ oropharyngeal squamous cell cancer based on lymph node distribution

PURPOSE/OBJECTIVE(S)

To establish the distribution pattern of cervical lymph node metastasis (LNM) and propose optimized clinical target volume (CTV) boundaries specific to oral/ oropharyngeal squamous cell cancer (OSCC/OPSCC).

MATERIALS/METHODS

531 patients with pathologically confirmed OSCC/OPSCC were enrolled from January 2013 to June 2022. Patients were stratified into two groups based on the minimal distance from the lesion's edge to the body's midline: ≤1 cm or > 1 cm. The geometric center of cervical metastatic LN was marked on a template CT. LN distribution probability maps were established. The relationships between the LN distribution and consensus guidelines were analyzed to propose modifications for CTV boundaries specific to OSCC/OPSCC.

RESULTS

A total of 1962 positive LNs were enrolled. Compared with the > 1 cm group, the ≤ 1 cm group has following feature tendencies: male smokers, younger, median organs, large gross lesion, infiltrative growth pattern, contralateral LNM. The most frequently involved level of LNM was ipsilateral II, but ipsilateral Ib had the highest involvement rate in the > 1 cm OSCC group. In addition, tongue cancer had a higher incidence of LN extranodal extension (ENE), which mainly distributes in ipsilateral level II. The skip metastasis was prone to from level III to Vb (3.5 %) in LN(+)/ENE (-), and level Ib to VIa (3.7 %) in LN(+)/ENE (+). Accordingly, we proposed the following modifications: 1. only including lateral and posterior margin of submandibular gland within 5 mm; 2. retracting posterior boundary of level II to front edge of levator scapula muscle, and descending the upper boundary to transverse process of C2 vertebra only for OSCC; 3. including posterior third of thyroglossal muscle or anterior edge of sternocleidomastoid muscle; 4. sparing level Va in case of only level II involvement; 5. including upper area of the thyroid cartilage plate in case of level Ib LN(+)/ENE (+); 6. sparing level VIIa is considered.

CONCLUSION

This is the first description of LN topographic spread patterns for OSCC/OPSCC. Modified CTV for prophylactic irradiation was proposed to spare the organs at risk and minimize adverse effects.

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.

Management of the neck in T1 and T2 buccal squamous cell carcinoma

Buccal squamous cell carcinoma (SCC) appears to behave more aggressively than other oral subsites, in particular with regards to regional disease at presentation and regional recurrence. Adequate management of the neck is of the utmost importance but is still the subject of debate. An international multicentre retrospective review of 101 patients treated for T1-T2 buccal SCC was performed. Twenty-four were staged clinical node positive (cN+) and underwent therapeutic neck dissection, while 77 were node negative (cN0), with 32 undergoing elective neck dissection (END), with an occult nodal metastasis rate of 28.1%. Depth of invasion (DOI) < 4 mm was associated with a significantly lower rate of cervical nodal metastasis (87.5% versus 12.5%; P = 0.033). END demonstrated a non-significantly lower regional recurrence rate compared to observation (6.3% versus 8.9%, P = 0.670). Regional recurrence was more common in pN+ (24%) and undissected cases (8.9%) than in pN0 patients (0%) (P = 0.011) and was associated with DOI > 5 mm (P = 0.002). Regional recurrence resulted in a reduction in survival (24 versus 93 months, P < 0.001). In the pT2cN0 group, END improved survival (123 versus 26 months, P = 0.009). It is suggested that END be performed in cT2N0 buccal SCC, particularly for tumours with DOI > 4 mm.

Global research trends in tongue cancer from 2000 to 2022: bibliometric and visualized analysis

OBJECTIVES

This study conducts a systematic bibliometric analysis of tongue cancer publications to identify key topics, hotspots, and research distribution.

METHODS

We analyzed tongue cancer publications in the Web of Science core collection database, assessing their quantity and quality. We investigated contributors, including countries, affiliations, journals, authors, and categories, within collaborative networks. Additionally, we synthesized key research findings using various analytical techniques, such as alluvial flow, burstness analysis, cluster analysis, co-occurrence network of associations, and network layer overlay.

RESULTS

From 2000 to 2022, this bibliometric study covers 2205 articles and reviews across 617 journals, involving 72 countries, 2233 institutions, and 11,266 authors. It shows consistent growth, particularly in 2016. Key contributors include China (499 publications), Karolinska Institute (84 publications), Oral Oncology (144 publications), and Tuula Salo (47 publications). Other notable contributors are the USA (16,747 citations), the National Cancer Institute (NCI) (2597 citations), and the Memorial Sloan-Kettering Cancer Center (MSK) (2231 citations). Additionally, there are significant teams led by Tuula Salo and Dalianis. We have identified six primary clusters: #0 apoptosis, #1 depth of invasion, #2 radiotherapy, #3 hpv, #4 tongue cancer, #5 oral cancer. The top ten highly cited documents primarily pertain to epidemiology, prognostic indicators in early-stage oral tongue cancer, and HPV. Additionally, we observed 16 reference clusters, with depth of invasion (#3), young patients (#4), and tumor budding (#6) gaining prominence since 2012, indicating sustained research interests.

CONCLUSIONS

This analysis emphasizes the increasing scholarly interest in tongue cancer research. The bibliometric evaluation highlights pivotal recent research themes such as HPV, depth of invasion, tumor budding, and surgical margins.

CLINICAL RELEVANCE

The bibliometric analysis highlights the key topics and studies which have shaped the understanding and management of tongue cancer.

Depth of Invasion in Carcinoma Tongue: Evaluation of Clinical and Imaging Techniques

BACKGROUND

"Depth of invasion" is an additional index incorporated in 8th AJCC staging system for oral cavity squamous cell carcinoma based on its prognostic significance. Pre-operative assessment by clinical palpation and imaging modalities has been used with limitations. The aim of the study is to compare different techniques including clinical palpation, ultrasound, and magnetic resonance imaging with histopathology for assessment of depth of tumor invasion.

MATERIALS

Fifty patients of carcinoma tongue (T1-T3) were enrolled. Clinical palpation, Ultrasound tongue, and Magnetic resonance imaging were used to assess depth of tumor invasion. Microscopic depth of invasion was considered as reference. Statistical analysis was done to assess the level of agreement, reliability, and internal consistency. ROC analysis was done to find the "Area Under Curve" for microscopic depth versus ultrasound, MRI, and gross histopathological "depth of invasion".

RESULTS

Ultrasound tongue showed highest "area under curve", Intra class correlation (ICC:0.786) with a good consistency (Cronbach's Alpha:0.880) with histological reference compared to MRI(ICC:0.689;CA:0.816). Clinical palpation showed weak agreement (Kappa:0.43) for assessing depth. To observe the concordance between ultrasound and microscopic depth, Lin's Concordance Correlation Coefficient (CCC = 0.782) was calculated with 95% limits of agreement. Lin's concordance correlation between ultrasound and microscopic depth showed a good agreement.

CONCLUSIONS

Ultrasound tongue is a reliable imaging modality for pre-operative T staging by assessing tumor "depth of invasion" in carcinoma tongue patients with good internal consistency as per 8th AJCC staging system.

LEVEL OF EVIDENCE

2 (CEBM-Level of Evidence-2.1) Laryngoscope, 134:215-221, 2024.

Depth of Invasion: Influence of the Latest TNM Classification on the Prognosis of Clinical Early Stages of Oral Tongue Squamous Cell Carcinoma and Its Association with Other Histological Risk Factors

BACKGROUND

The American Joint Committee on Cancer (AJCC), in its 8th edition, introduces modifications to the previous TNM classification, incorporating tumour depth of invasion (DOI). The aim of this research is to analyse the prognosis (in terms of disease-free survival and overall survival) of clinical early stage (I and II) squamous cell carcinomas of the oral tongue according to the DOI levels established by the AJCC in its latest TNM classification to assess changes to the T category and global staging system and to evaluate the association between DOI and other histological risk factors.

METHODS

A retrospective longitudinal observational study of a series of cases was designed. All patients were treated with upfront surgery at our institution between 2010 and 2019. The variables of interest were defined and classified into four groups: demographic, clinical, histological and evolutive control. Univariate and multivariate analyses were carried out and survival functions were calculated using the Kaplan-Meier method. Statistical significance was established for p values below 0.05.

RESULTS

Sixty-one patients were included. The average follow-up time was 47.42 months. Fifteen patients presented a loco-regional relapse (24.59%) and five developed distant disease (8.19%). Twelve patients died (19.67%). Statistically significant differences were observed, with respect to disease-free survival (p = 0.043), but not with respect to overall survival (p = 0.139). A total of 49.1% of the sample upstaged their T category and 29.5% underwent modifications of their global stage. The analysis of the relationship between DOI with other histological variables showed a significant association with the presence of pathological cervical nodes (p = 0.012), perineural invasion (p = 0.004) and tumour differentiation grade (p = 0.034). Multivariate analysis showed association between depth of invasion and perineural invasion.

CONCLUSIONS

Depth of invasion is a histological risk factor in early clinical stages of oral tongue squamous cell carcinoma. Depth of invasion impacts negatively on patient prognosis, is capable per se of modifying the T category and the global tumour staging, and is associated with the presence of cervical metastatic disease, perineural invasion and tumoural differentiation grade.

Marginal versus Segmental Mandibulectomy in the Treatment of Oral Cavity Cancer: A Systematic Review and Meta-analysis

Introduction  Oral cavity squamous cell carcinoma (OCSCC) is the most common malignancy in the oral cavity. Two types of mandibular resections have been described: the segmental mandibulectomy and the marginal mandibulectomy. Both may have a different impact over the quality of life, oncological prognosis, and functional or aesthetic result. Objectives  The aim of this study was to systematically explore the literature to determine the survival outcomes and disease control rates in patients who underwent segmental or marginal mandibulectomy for OCSCC with histological evidence of cortical and medullary bone invasion. Data Synthesis  This review involved a systematic search of the electronic databases MEDLINE/PUBMED, Google Scholar, Ovid Medline, Embase, and Scopus including articles from 1985 to 2019. Fifteen articles were included for qualitative analysis and 11 articles were considered for meta-analysis calculations. All of them correspond to retrospective cohort studies. Conclusion  This systematic review reveals the low-level evidence regarding the impact over local control or survival according to the type of mandibulectomy. Our results need to be considered with precaution according to the limited evidence available. We just found difference regarding the 5-year disease-free survival, and a tendency in favor of segmental mandibulectomy was confirmed when medullary invasion was evident.

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.

The pattern and spread of invasion can predict late cervical lymph node metastasis in early tongue squamous cell carcinoma

To determine the predictive indexes of late cervical lymph node metastasis in early tongue squamous cell carcinoma (TSCC). We retrospectively analyzed the cases of 25 patients with stage I/II TSCC who had undergone surgical treatment without elective neck dissection. We evaluated the relationships between clinicopathologic factors and the occurrence of late cervical lymph node metastasis. Of the 25 cases, metastasis to the cervical lymph nodes was observed in nine cases (36.0%). The clinicopathological factors associated with late cervical lymph node metastasis were the mode of invasion (MOI, p = 0.032), depth of invasion (DOI, p = 0.004), and perineural invasion (PNI, p = 0.040). A multivariate analysis revealed that only the DOI was an independent predictor of late cervical lymph node metastasis. The combination of the DOI and MOI or the PNI and MOI was significantly correlated with late cervical lymph node metastasis (p = 0.004 and p = 0.012, respectively). Our findings suggest that combinations of the MOI, DOI, and PNI could be used as an index for predicting late cervical lymph node metastasis in early TSCC.

Re-examining predictors of pathologic lymph node positivity in clinically node negative oral cavity cancer

BACKGROUND

Elective lymph node dissection (ELND) is performed for many early-stage oral cavity squamous cell carcinomas (OCSCC) with clinically negative necks (cN0), often guided by depth of invasion (DOI). However, DOI is less validated in non-tongue OC sites, and often correlates with other adverse features. We sought to evaluate the utility of DOI versus other factors for independently predicting pathologic lymph node positivity (pN+) in patients with cN0 OCSCC.

METHODS

Patients with cN0 OCSCC diagnosed from 2010 to 2015 undergoing primary surgery were identified in the National Cancer Data Base.

RESULTS

5060 cN0 OCSCC patients met inclusion criteria. The presence of lymphovascular invasion (LVI) was the strongest independent predictor of pN+ (odds ratio [OR] = 4.27, 95% confidence interval [CI] 3.36-5.42, P < 0.001). High histologic grade also strongly predicted pN+ (OR 3.33, 95% CI 2.20-4.60, P < 0.001). DOI had no association with the likelihood of pN+ among all OCSCC patients, but was predictive among patients within the oral tongue subset (OR 2.01, 95% CI 1.08-3.73, P = 0.03 for DOI > 20 mm vs. DOI: 2.0-3.99 mm).

CONCLUSION

LVI and grade are the strongest independent predictors of pN+ in cN0 OCSCC. Contrary to prior studies, DOI was not found to be a predictor of pN+ among patients with cN0 OCSCC. However, DOI was a predictor of pN+ or the oral tongue subset, albeit still less strongly than LVI or grade. These findings could potentially be used to better identify a subset of cN0 OCSCC patients who could be considered for omission of ELND in future studies.

WPOI-5: Accurately Identified at Intraoperative Consultation and Predictive of Occult Cervical Metastases

BACKGROUND

Frozen section analysis of oral cancer specimens is ideal for assessing margin distances and depth of invasion (DOI); the latter impacts intraoperative decisions regarding elective neck dissection (END). Here, we show that intraoperative determination of worst pattern of invasion (WPOI), specifically WPOI-5, has a high level of accuracy. This relates to our demonstration herein that WPOI-5 predicts occult cervical metastases (OCM) for pT1 oral squamous carcinoma (OSC).

METHODS

The presence of OCM was correlated with WPOI in 228 patients with primary T1/T2/cN0 OSC undergoing resection and END. Concordance between intraoperative and final pathology WPOI determination was assessed on 51 cases of OSC.

RESULTS

WPOI-5 predicts OCM in pT1 patients, compared with WPOI-4/WPOI-3 (p < 0.0001). Most pT1 WPOI-5 tumors had DOI of 4-5 mm (24/59 or 40.7%). Only two pT1 WPOI-5 tumors had DOI < 4 mm (3.0 and 3.5 mm). If END were performed in this pT1 cohort for all WPOI-5 OSC patients regardless of DOI, OR all OSC patients with DOI ≥ 4 mm regardless of WPOI, then no OCM would be missed (p = 0.017, 100% sensitivity, 29% specificity, 77% positive predictive value, 23% negative predictive value). With respect to intraoperative WPOI-5 determination, the accuracy, sensitivity, and specificity was 92.16, 73.33, and 100.0%, respectively.

CONCLUSIONS

DOI ≥ 4 mm is the dominant predictor of OCM. For the rare WPOI-5 OSC with DOI < 4 mm, it is reasonable to suggest that surgeons perform END. WPOI-5 may be accurately determined intraoperatively. As microscopic instruction is needed to accurately assess WPOI-5, a teaching link is included in this manuscript.

A prediction model of nodal metastasis in cN0 oral squamous cell carcinoma using metabolic and pathological variables

BACKGROUND

The efficacy of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) Positron Emission Tomography/Computed Tomography(PET/CT) in evaluating the neck status in clinically node-negative (cN0) oral squamous cell carcinoma(OSCC) patients was still unsatisfying. We tried to develop a prediction model for nodal metastasis in cN0 OSCC patients by using metabolic and pathological variables.

METHODS

Consecutive cN0 OSCC patients with preoperative ¹⁸F-FDG PET/CT, subsequent surgical resection of primary tumor and neck dissection were included. Ninety-five patients who underwent PET/CT scanning in Shanghai ninth people's hospital were identified as training cohort, and another 46 patients who imaged in Shanghai Universal Medical Imaging Diagnostic Center were selected as validation cohort. Nodal-status-related variables in the training cohort were selected by multivariable regression after using the least absolute shrinkage and selection operator (LASSO). A nomogram was constructed with significant variables for the risk prediction of nodal metastasis. Finally, nomogram performance was determined by its discrimination, calibration, and clinical usefulness.

RESULTS

Nodal maximum standardized uptake value(nodal SUVmax) and pathological T stage were selected as significant variables. A prediction model incorporating the two variables was used to plot a nomogram. The area under the curve was 0.871(Standard Error [SE], 0.035; 95% Confidence Interval [CI], 0.787-0.931) in the training cohort, and 0.809(SE, 0.069; 95% CI, 0.666-0.910) in the validation cohort, with good calibration demonstrated.

CONCLUSIONS

A prediction model incorporates metabolic and pathological variables has good performance for predicting nodal metastasis in cN0 OSCC patients. However, further studies with large populations are needed to verify our findings.

Preoperative evaluation of depth of invasion in oral tongue squamous cell carcinoma: A systematic review and meta-analysis

The inclusion of depth of invasion (DOI) in the American Joint Committee on Cancer's staging system for oral cavity squamous cell carcinoma (SCC) has major clinical impacts. Recent studies have evaluated the reliability of imaging modalities and biopsy techniques to measure DOI preoperatively. The objective of this systematic review and meta-analysis was to comprehensively include all previously described methods to measure preoperative DOI in oral tongue SCC (OTSCC) and to compare their reliability. A systematic review was conducted on PubMed, Embase and Cochrane according to the PRISMA guidelines. Studies that evaluated the reliability of DOI measured on biopsy or imaging (rDOI) by comparing it to DOI on histopathology (pDOI) were included for extraction. A meta-analysis was conducted to obtain pooled correlation coefficients for each imaging modality. The pooled correlation coefficients between rDOI and pDOI were 0.86 (CI_95% = [0.82-0.88]) and 0.80 (CI_95% = [0.70-0.87]) for magnetic resonance imaging (MRI) studies and computed tomography (CT) studies, respectively. For ultrasound (US), the correlation coefficient could only be measured by including studies which measured not only DOI but also tumor thickness. It was 0.89 (CI_95%= [0.82-0.94]). Overall, MRI is the better studied modality. It has a good reliability to measure preoperative rDOI in OTSCC. CT is less studied but appears to be less reliable. US cannot be compared to these imaging modality as it has been used more often to measure TT than DOI.

Incorporating the epidermal growth factor receptor expression and histopathological parameters in a mathematical model to predict the prognosis of oral squamous cell carcinoma: a prospective observational cohort study

Background

Oral squamous cell carcinomas (OSCC) are the most common type of variant causing oral cancers, contributing for around 90%. The overall survival of these patients is below 50%. The postoperative overall survival (OS) has not improved over years much despite of advanced surgical techniques and invention of various anticancer drugs. There was always a requirement for a non-invasive molecular marker to predict the prognosis of these patients. The epidermal growth factor and their receptors are not only thought to play a critical but also an influential role in growth of the cell and differentiation in normal/ healthy tissues. They also play an important role in malignant progression of disease and tumorigenesis. A better and sound understanding of mechanisms at molecular level and identification of potential oncogenes in OSCC may provide innovative therapeutic decisions such as targeted therapy in management of these cancer patients.

Aim & objectives

The aim of this study is to check whether epidermal growth factor expression is a prognosticator in oral squamous cell carcinoma and also to propose a mathematical model to find the prognosis of the patients which have not been done so far in the literature.

Materials & methods

The study was a prospective cohort study with 25 patients who had biopsy proven OSCC who reported to our hospital from July 2017 to June 2019. The data collected from their histopathological report for this prospective study and model were: surgical margins (superior, inferior, anterior and posterior), depth of tumor, lymph nodal metastasis, lymphovascular invasion and scoring of epidermal growth factor receptor (EGFR) expression done by immunohistochemistry (IHC) on wax blocks.

Results

EGFR expression on surgical margins was found to have a p-value of 0.023 which was significant statistically. EGFR expression showed a statistically significant p value 0.002 as independent marker in prognosis with sensitivity of 97.7% and specificity of 61.2%. The tumor depth of infiltration showed an insignificant correlation with pathological Tumor, Node, Metastasis (TNM) staging with a p value of 0.860. A mathematical model linear regression equation was proposed which predicted a cutoff value above 16, the prognosis of the patient being bad (Stages III and IV), and below 16, the prognosis of the patient being good (Stages I and II).

Conclusion

This study put forward a proposed mathematical model by incorporating all important parameters to predict the prognosis of the patients. EGFR expression is one such important parameter to be considered to develop anti-EGFR agents to improve the OS of the patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12663-022-01797-0.

Comparison of Intra-Operative Depth of Invasion Measurement by Frozen Section with Post-Operative Histopathology in Patient of Oral Cavity Squamous Cell Carcinoma

Depth of Invasion (DOI) is an important and independent predictor for occult metastasis and recurrence. AJCC staging system (8th edition) has incorporated DOI in the staging of oral cancers. It is an essential parameter in deciding elective neck dissection. We hereby conducted a study to determine the accuracy of DOI in the frozen section as compared to the histological section in patients with T1N0 oral squamous cell carcinoma. This study was conducted over a period of 45 months in a tertiary care hospital. 31 patients with diagnosed Oral SCC and with T1N0 were enrolled. The intra-operative frozen section was done DOI was measured as per Cap protocol and compared with the DOI in the histopathological section. Strong correlation was found between DOI measured by frozen section and permanent section (r = 0.998; 95% CI, 0.999-0.997). The paired t test showed a mean difference of 0.0066 mm (95% CI, - 0.0103-0.02346 mm; P = 0.096) between frozen section and permanent section. DOI measured was slightly higher in frozen section however this difference was neither statically nor clinically significant.This study shows the accuracy of frozen specimens in determining tumor DOI in T1N0M0 in oral cavity squamous cell carcinoma. Intraoperative DOI along with other factors may be used to determine the need for END (elective neck dissection) in early-stage oral cavity squamous cell carcinoma and thus avoid a staged operation or over- or under-treatment of the neck.

Comparative study on Classifications of AJCC 8th and 7th in the patients with tongue squamous cell carcinoma

OBJECTIVES

Depth of invasion (DOI) is the most important predictor for lymph node metastasis in early-stage oral cancer. This study aims to investigate the effects of the different classifications of AJCC 7th and 8th on predicting lymph node metastasis and the optimal cutoff point for DOI predicting the lymph node metastasis in patients with tongue squamous cell carcinoma (TSCC).

MATERIALS AND METHODS

We performed a retrospective study in 208 TSCC patients in early T-stage without clinical or radiological signs of lymph node metastasis. Those patients were treated with elective neck dissection (END) between April 2019 and December 2020. And the relation between DOI and lymph node metastasis was analyzed.

RESULTS

Metastases were found in 58 of 208 patients (27.88%). Of those 58 patients, the mean DOI was 8.311 mm compared to 5.425 mm in patients without metastases (P < 0.0001). The receiver operating characteristic curve (ROC-curve) showed an area under the curve of 0.7066 with the most optimal cutoff point on a DOI of 4.050 mm (sensitivity 86.21%, specificity 52%). Linear regression analysis (1 mm≤DOI≤6 mm) revealed that a DOI ≥ 3.211 mm predicated an incidence of occult lymph node metastasis greater than 20%. Regional metastases were found in 12.82% of patients with DOI ≤ 4.0 mm. Within the entire cohort, 60 cases (28.85%) got upgraded with respect to T-stage. No tumor underwent downstaging.

CONCLUSION

The 8th edition provides better lymph node metastasis prediction for TSCC than the 7th. And DOI is a poor predictor for regional metastasis in patients with early T-stage clinically node-negative TSCC. END in patients with early-stage TSCC should be performed in patients with DOI ≥ 3.211 mm.

Depth of Invasion as a Predictor of Cervical Nodal Metastasis of Oral Tongue Squamous Cell Carcinoma: Findings From a Tertiary Care Center in Pakistan

Background and objective

Cervical lymph node metastasis has a significant impact on the survival of patients with oral cavity tumors. The rate of occult neck node metastasis is reported to range from 20 to 40%. The depth of invasion (DOI) has been incorporated in the eighth edition of the American Joint Commission on Cancer (AJCC) staging manual and is an important predictor of cervical lymph node metastasis. In this study, we aimed to identify the occult neck node metastasis rate in early oral tongue squamous cell carcinoma (OTSCC) and correlate it with the DOI.

Methods

A retrospective review of all patients presenting to our facility with early-stage OTSCC was performed. Patients with tumor size of ≤4 cm and who underwent elective neck dissection at the time of surgery were included. The study outcomes were the rates of occult neck metastases in T1 and T2 OTSCC and their correlation with the DOI.

Results

There were 80 patients in total. Occult neck node metastases were seen in 29 (36.25%) patients. Patients with a DOI >5 mm were 1.41 times more likely to have occult neck node metastasis than those with a DOI ≤5 mm.

Conclusion

Occult neck node metastasis is significantly associated with the DOI. The risk of neck metastasis is higher in patients with a DOI >5 mm.

Prognostic factors for lymph node metastasis from upper gingival carcinomas

Objectives

This study sought to identify tumor characteristics that associate with regional lymph node metastases in squamous cell carcinomas originating in the upper gingiva.

Materials and methods

Data from 113 patients from Osaka University Dental Hospital were included. We measured each primary tumor’s width, length, depth, and the extent of bone invasion. Additionally, tumor signal intensity for T1 and T2-weighted images as well as the center of the tumor’s location and T classification was assessed, and a histopathological analysis was performed.

Results

Tumor signal intensity was not found to be a significant prognostic factor. However, bucco-lingual width, histopathological classification as well as the tumor’s location were significantly different between metastatic and non-metastatic groups in both univariate and multivariate analysis. Superior–inferior depth and T classification were significant only in the univariate (and not the multivariate) analysis.

Conclusions

Bucco-lingual width, histopathological grading as well as the tumor’s location are likely to be important predictors for the occurrence of LN metastasis in upper gingival carcinoma patients and should be considered when managing care for these patients.

Pretreatment Blood Markers in the Prediction of Occult Neck Metastasis: A 10-Year Retrospective Study

Introduction

The purpose of this study was to clarify the role of inflammatory blood markers in the management of early-stage (T1-T2) oral squamous cell carcinoma (OSCC) of the tongue in patients with a clinically negative neck. 

Materials and methods

We undertook a retrospective chart review of 102 patients with early-stage OSCC of the tongue, subjected to tumor resection and elective neck dissection. Based on postsurgical histopathological examination results, we divided our cohort into pN+ and pN0 groups. Afterwards, we analyzed the role of pretreatment inflammatory blood markers in predicting occult neck metastasis. We also evaluated neutrophil-lymphocyte ratio (NLR) association with the depth of invasion (DOI) of the primary tumor.

Results

We found a significant association of NLR (p=0.001) and monocyte-lymphocyte ratio (p=0.011) with neck status on univariate analysis. Multivariate analysis showed that only NLR (p=0.02) was an independent risk factor for occult metastasis among inflammatory blood markers. Receiver Operating Characteristic curve analysis and Younden’s Index determined the NLR value of 2.96 as the most adequate cut-off value for neck status prediction. NLR values of pretreatment workup also had a significant association with the DOI of the primary tumor (p=0.018).

Conclusion

Our study supports the role of pretreatment NLR in predicting occult neck metastasis in early-stage OSCC of the tongue. It also sheds some light over the potential of NLR as a predictor of the primary tumor’s DOI.

Cortactin expression assessment improves patient selection for a watchful waiting strategy in pT1cN0-staged oral squamous cell carcinomas with a tumor infiltration depth below 4 mm

BACKGROUND

In this feasibility study we aimed to evaluate the value of previously reported molecular tumor biomarkers associated with lymph node metastasis in oral squamous cell carcinoma (OSCC) to optimize neck strategy selection criteria.

METHODS

The association between expression of cortactin, cyclin D1, FADD, RAB25, and S100A9 and sentinel lymph node status was evaluated in a series of 87 (cT1-2N0) patients with OSCC treated with primary resection and SLNB procedure.

RESULTS

Tumor infiltration depth and tumor pattern of invasion were independent prognostic markers for SLN status, while none of the tumor makers showed a better prognostic value to replace SLNB as neck staging technique in the total cohort. However, in the subgroup of patients with pT1N0 OSCC, cortactin expression (OR 16.0, 95%CI 2.0-127.9) was associated with SLN classification.

CONCLUSIONS

Expression of cortactin is a promising immunohistochemical tumor marker to identify patients at low risk that may not benefit from SLNB or END.

The Potential of MET Immunoreactivity for Prediction of Lymph Node Metastasis in Early Oral Tongue Squamous Cell Carcinoma

Objective

MET positivity is independently associated with survival in oral squamous cell carcinoma (OSCC). Since MET is a known orchestrator of invasive tumor growth, we investigated its association with LNM in early oral tongue squamous cell carcinoma (OTSCC). As it is recommended by the NCCN to use tumor depth of invasion (DOI) in making decisions on elective neck dissection (END), the results obtained for MET positivity were aligned with those for DOI > 4 mm. The cutoff value used in our institution.

Methods

Tumor samples from patients who underwent primary tumor resection and neck dissection between 1995 and 2013, were collected from the archives of the Leiden and Erasmus University Medical Center. Immunohistochemistry with D1C2 was performed to identify MET negative (< 10% uniform positivity) and MET positive (≥ 10% uniform positivity) cancers. ROC curve analysis and the Chi-squared test were used to investigate the association of MET positivity with LNM (pN+ and occult). Binary logistic regression was used to investigate the association of MET positivity with LNM.

Results

Forty-five (44.1%) of the 102 cancers were MET positive. Ninety were cN0 of which 20 were pN+ (occult metastasis). The remaining 12 cancers were cN+, of which 10 were proven pN+ and 2 were pN0. MET positivity was associated with LNM with a positive predictive value (PPV) of 44.4% and a negative predictive value (NPV) of 82.5% for pN+. For the occult group, the PPV was 36.8% and the NPV was 88.5%. Regression analysis showed that MET positivity is associated with pN+ and occult LNM (p-value < 0.05).

Conclusion

MET positivity is significantly associated with LNM in early OTSCC, outperforming DOI. The added value of MET positivity could be in the preoperative setting when END is being considered during the initial surgery. For cases with DOI ≤ 4 mm, MET positivity could aid in the clinical decision whether regular follow-up, watchful waiting, or END is more appropriate. Realizing that these preliminary results need to be independently validated in a larger patient cohort, we believe that MET positivity could be of added value in the decision making on END in early OTSCC.

High-risk early-stage oral tongue squamous cell carcinoma, when free margins are not enough: Critical review

Oral tongue squamous cell carcinoma (OTSCC) is a quite peculiar disease from an anatomical and biological standpoint. An increasing amount of literature highlights the existence of a small subset of T1-T2N0 OTSCC, properly resected on a margin-dependent basis, which conversely proved higher than expected rates of loco-regional/distant failure and disease-specific mortality. These specific high-risk tumors might not have a margin-dependent disease and could possibly benefit from a more aggressive upfront loco-regional treatment, especially addressing the so-called T-N tract. Widespread adoption of a histopathological risk model would allow early recognition of these high-risk diseases and, consequently, intensification of the traditional treatment strategies in that specific niche. We reviewed the available knowledge trying to shed light on the potential determinants of the dismal prognosis of these high-risk OTSCC, with special reference to the role of overlooked T-N tract involvement and possible alternatives in terms of elective neck management and risk stratification.

Lymphovascular invasion as a prognostic tool for oral squamous cell carcinoma: a comprehensive review

Oral cancer is the most common malignancy of the head and neck region, characterized by a poor prognosis. Novel prognostic markers are needed to better stratify these patients. Lymphovascular invasion (LVI) has been included in the eighth edition of the AJCC Cancer Staging Manual as an additional prognostic factor, but its influence on the recurrence risk and lymph node metastasis is relatively understudied. This is a comprehensive review of the literature on the clinical and prognostic role of LVI in oral cancer. A relevant search of the PubMed, Scopus, and Web of Science databases yielded 29 articles that satisfied the inclusion criteria. Findings indicated that LVI is an independent negative prognostic factor in oral cancer patients and appears to be associated with cervical lymph node metastasis and loco-regional recurrence. Notably, in oral tongue cancer, survival outcomes progressively worsen when LVI is associated with other adverse pathological features, especially in the early stages. Therefore, these patients could benefit from elective neck dissection and/or adjuvant therapy. The high variability of LVI prevalence hinders the comparison of literature results. Several methodological limitations were found to be present in the collected articles, including the lack of a rigorous definition for LVI, the difficult detection in routine histological section, the presence of potential confounders, the retrospective nature, and an inadequate sample size in most studies. Therefore, it is necessary to conduct prognostic studies using standardized methods to define and quantify LVI.

Is the Depth of Invasion a Marker for Elective Neck Dissection in Early Oral Squamous Cell Carcinoma?

Objective

The depth of invasion (DOI) is considered an independent risk factor for occult lymph node metastasis in oral cavity squamous cell carcinoma (OCSCC). It is used to decide whether an elective neck dissection (END) is indicated in the case of a clinically negative neck for early stage carcinoma (pT1/pT2). However, there is no consensus on the cut-off value of the DOI for performing an END. The aim of this study was to determine a cut-off value for clinical decision making on END, by assessing the association of the DOI and the risk of occult lymph node metastasis in early OCSCC.

Methods

A retrospective cohort study was conducted at the Erasmus MC, University Medical Centre Rotterdam, The Netherlands. Patients surgically treated for pT1/pT2 OCSCC between 2006 and 2012 were included. For all cases, the DOI was measured according to the 8^th edition of the American Joint Committee on Cancer guideline. Patient characteristics, tumor characteristics (pTN, differentiation grade, perineural invasion, and lymphovascular invasion), treatment modality (END or watchful waiting), and 5-year follow-up (local recurrence, regional recurrence, and distant metastasis) were obtained from patient files.

Results

A total of 222 patients were included, 117 pT1 and 105 pT2. Occult lymph node metastasis was found in 39 of the 166 patients who received END. Univariate logistic regression analysis showed DOI to be a significant predictor for occult lymph node metastasis (odds ratio (OR) = 1.3 per mm DOI; 95% CI: 1.1-1.5, p = 0.001). At a DOI of 4.3 mm the risk of occult lymph node metastasis was >20% (all subsites combined).

Conclusion

The DOI is a significant predictor for occult lymph node metastasis in early stage oral carcinoma. A NPV of 81% was found at a DOI cut-off value of 4 mm. Therefore, an END should be performed if the DOI is >4 mm.

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.

Prognostic outcomes of treatment naïve oral tongue squamous cell carcinoma (OTSCC): a comprehensive analysis of 14 years

OBJECTIVES

To analyze the factors predicting survival outcomes in treatment naïve oral tongue squamous cell carcinoma (OTSCC).

MATERIALS AND METHODS

A comprehensive review of 531 oral tongue carcinoma patients treated with upfront surgery followed by adjuvant radiotherapy or chemoradiotherapy was conducted from 2004-2018.

RESULTS

The mean age of presentation was 53 years (11-86) with a male to female ratio of 1.3:1. The associated risk factors were smoking (21%), betel nut (16%), naswar (9%) and alcohol (1%). Most of the cases were either well (45.1%) or moderately (46.2%) differentiated. Surgery was performed in 164 patients alone while 368 were treated with surgery in combination with adjuvant modalities. Overall (OS) and disease free survival (DFS) were 66 and 71%, respectively, with a median follow up of 2.5 years. Cox regression analysis showed nodal positivity, increased depth of invasion (DOI) and higher lymph node ratio (LNR) as significant prognosticators impacting OS and DSS.

CONCLUSION

Nodal volume, DOI and LNR are the most consistent predictors of poor outcome in OTSCC. Nodal positivity, depth of invasion > 5 mm and lymph node ratio > 0.04 adversely affect OS and DSS.

Intraoral ultrasonography in the assessment of DOI in oral cavity squamous cell carcinoma: a comparison with magnetic resonance and histopathology

Objective

The first-line therapeutic approach for oral cavity squamous cell carcinoma (OCSCC) is complete surgical resection. Preoperative assessment of depth of invasion (cDOI) is crucial to plan the surgery. Magnetic resonance (MR) and intraoral ultrasonography (IOUS) have been shown to be useful tools for assessment of DOI. The present analysis investigates the accuracy of MR and IOUS in evaluating DOI in OCSCC compared to histological evaluation (pDOI).

Materials and methods

Forty-nine previously untreated patients with cT1-T3 OCSCC were reviewed. Nine patients were staged with MR alone, 10 with IOUS alone, and 30 with both MR and IOUS.

Results

Mean difference between cDOI_MR and pDOI values of 0.2 mm (95% CI − 1.0–1.3 mm) and between cDOI_IOUS and pDOI of 0.3 mm (95% CI − 1.0–1.6 mm). Spearman R between cDOI_MR and pDOI was R = 0.83 and between cDOI_IOUS and pDOI was R = 0.76. Both radiological techniques showed high performance for the correct identification, with the optimum cut-off of 5 mm, of patients with a pDOI ≥ 4 mm and amenable to a neck dissection, with an AUC of 0.92 and 0.82 for MR and IOUS, respectively.

Conclusion

Both examinations were valid approaches for preoperative determination of DOI in OCSCC, although with different cost-effectiveness profiles and indications.

Electronic supplementary material

The online version of this article (10.1007/s00405-020-06421-w) contains supplementary material, which is available to authorized users.

Comparison of Early Oral Cancer Depth of Invasion From the American Joint Committe on Cancer 7th to 8th Edition Criteria. Does the Difference Impact the Accuracy of Clinical Decision Making?

PURPOSE

Depth of invasion (DOI) is an independent predictor of regional metastasis in oral squamous cell carcinoma. Measurement criteria for DOI were modified in the American Joint Committee on Cancer (AJCC) eighth edition. The purpose of this study was to compare DOI AJCC seventh (DOI7) and eighth (DOI8) edition criteria on frozen section accuracy for decisions regarding elective neck dissection (END) in cT1N0 oral squamous cell carcinoma.

PATIENTS AND METHODS

A blinded, retrospective, comparative study of patients who underwent ablative surgery at the University of Michigan was completed. The predictor variable was criteria for DOI measurement. The outcome variables were concordance between DOI7 and DOI8 measurements and accuracy using thresholds for END. Effect of tumor growth pattern and worst pattern of invasion, and the difference between DOI8 on frozen and permanent specimen were assessed.

RESULTS

A total of 30 specimens of T1N0 oral squamous cell carcinoma (16 tongue, 5 alveolus, 5 floor of mouth, 4 buccal mucosa) were included. DOI7 versus DOI8 on frozen and permanent specimen were significantly different (P < .05) but clinically insignificant and highly correlated (r > 0.99, P < .001). One hundred percent concordance between DOI7 and DOI8 was noted on frozen specimen in predicting the need for END when compared with permanent pathology DOI. There was no significant impact of tumor growth pattern or worst pattern of invasion on measurements and no significant difference in DOI on frozen and permanent specimen for DOI8 (P = .68). Excellent agreement between pathologists for all measurements was observed (ICC>0.99, P < 0001).

CONCLUSIONS

High concordance between DOI measurements by AJCC seventh and eighth edition criteria suggests that guidelines for DOI thresholds for END in patients with T1N0 tumors developed using the AJCC seventh edition can be safely applied using AJCC eighth edition criteria. DOI measurement by AJCC 8 criteria on frozen specimen can be used to guide decision-making regarding END, given the high correlation to AJCC 8 permanent DOI measurement.

Lymph node characteristics and their prognostic significance in oral squamous cell carcinoma

BACKGROUND

The prognostic significance of various histopathologic lymph node-based biomarkers in oral squamous cell carcinoma (OSCC) needs further evaluation.

METHODS

Retrospective analysis of 212 OSCC patients with regional metastasis to determine the association of extranodal extension (ENE), extent of ENE, size of metastatic deposit, lymph node yield (LNY), lymph node ratio (LNR), and topography of involvement with survival outcomes.

RESULTS

The presence of ENE, larger nodal deposit, higher pN stage, lymph nodes in the lower levels, and patients who did not receive adjuvant treatment had poor disease-free survival (DFS). In addition, more positive nodes and high LNR showed worse overall survival (OS). ENE beyond 5 mm resulted in poorer outcomes. Larger sizes of metastatic deposit predisposed to ENE. Multivariate analyses showed only lower level of neck involvement to affect both DFS and OS.

CONCLUSIONS

Lymph node metastasis to lower levels and other lymph node characteristics affect prognosis and must be considered in the evolution of staging systems for OSCC.

RNA-Binding Proteins as Regulators of Migration, Invasion and Metastasis in Oral Squamous Cell Carcinoma

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.

Validation of the UICC 8th edition staging of oral cavity squamous cell carcinoma in a UK cohort

The eighth edition of the Union for International Cancer Control (UICC) staging manual was recently introduced. The staging of oral cavity squamous cell carcinoma saw changes in relation to depth of invasion and extra-nodal extension. We aimed to evaluate this system and its prognostic ability in a UK cohort. A retrospective review was undertaken of patients diagnosed with squamous cell carcinoma (SCC) of the oral cavity between January 2009 and December 2013. Data were collected on demographics, histology, and recurrence-free (RFS) and five-year overall survival (OS). Patients were staged using both the seventh and eighth editions of the UICC staging manual. Stage-specific survival analysis was performed using the Kaplan-Meier method. A total of 191 records were reviewed and 87 were included in the analysis. The mean (range) age was 60 (37-88) years, and 53% were male. The tongue was the most common site (51%). Using the seventh edition patients were staged as stage I=30, II=14, III=7, IVa=35, and IVb=1. Applying the eighth edition, 26 patients (30%) were upstaged (I=24, II=15, III=14, IVa=17, IVb=17). Ten were upstaged based on pT and 16 on pN status. Both staging manuals showed statistically significant discrimination between stages for both OS and RFS. Patients upstaged from stage IVa in the seventh edition had significantly worse OS in the new system (p=0.043). Both staging systems discriminated accurately between stages. Patients upstaged in stage IVa showed significantly worse OS suggesting improved prognostication with the eighth edition and the changes introduced.

Assessing the magnetic resonance imaging in determining the depth of invasion of tongue cancer

OBJECTIVES

To assess the magnetic resonance imaging (MRI) in predicting tumour's depth of invasion (DOI) of tongue cancer by comparing to pathology and to determine the cut-off value of MRI-derived DOI for lymph node metastasis.

PATIENTS AND METHODS

In a retrospective analysis, 156 patients with newly diagnosed tongue cancer were included. Tumour's DOI was compared between MRI measurement and pathology by Pearson correlation coefficient and paired t test. The accuracy of MRI-derived DOI was compared to the pathological DOI. The relationship between MRI-derived DOI and cervical lymph node metastasis was calculated by receiver operating characteristic curve.

RESULTS

Tumour's DOI was well correlated between MRI measurement and pathology with correlation coefficients of 0.77. MRI-derived DOI was 3.4 mm (28%) larger than pathology. The accuracy of MRI in deciding pathological DOI was 67.9%. The cut-off value of MRI-derived DOI was 10.5 mm for lymph node metastasis of tongue cancer.

CONCLUSION

Magnetic resonance imaging can be used as a reference to determine tumour's DOI of tongue cancer. Tumour with MRI-derived DOI larger than 10.5 mm deserves simultaneous neck dissection at initial surgery.

Depth of invasion in early stage oral cavity squamous cell carcinoma: The optimal cut-off value for elective neck dissection

OBJECTIVES

Depth of invasion (DOI) is the most important predictor for lymph node metastasis (LNM) in early stage (T1-T2) oral cancer. The aim of this study is to validate the cut-off value of 4 mm on which the decision to perform an Elective Neck Dissection (END) is made.

MATERIALS AND METHODS

We performed a retrospective study in patients with pathologically proven early stage oral cavity squamous cell carcinoma (OCSCC) without clinical or radiological signs of LNM, who were treated between 2013 and 2018. An END was performed when DOI was ≥ 4 mm and a watchful waiting protocol was applied in patients with DOI < 4 mm.

RESULTS

Three hundred patients were included. END was performed in 77% of patients with DOI ≥ 4 mm, of which 36% had occult LNM (pN+). Patients in the watchful waiting group (48%) developed a regional recurrence in 5.2% for DOI < 4 mm and 24.1% for DOI ≥ 4 mm. For DOI ≥ 4 mm, regional recurrence free survival was higher for patients who were treated with END compared to watchful waiting (p = 0.002). A Receiver-Operator-Curve -analysis showed that a DOI cut-off value of 4.0 mm was the optimal threshold for the prediction of occult LNM (95.1% sensitivity, 52.9% specificity).

CONCLUSION

A DOI of ≥ 4 mm is an accurate cut-off value for performing an END in early stage OCSCC. END results in higher survival rates and lower regional recurrence rates in patients with DOI ≥ 4 mm.

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.

Assessment of tumour depth in early tongue cancer: Accuracy of MRI and intraoral ultrasound

OBJECTIVES

Complete resection of tongue cancer is necessary to achieve local control. Unfortunately, deep resection margins are frequently inadequate. To improve deep margin control, accurate knowledge of tumour thickness is pivotal. Magnetic resonance imaging (MRI) and intraoral ultrasound (ioUS) are frequently applied for tumour staging. This study explores the accuracy of these techniques to estimate depth of invasion.

MATERIALS AND METHODS

The data of patients with a T1-2 tongue cancer that had been treated surgically between 2014 and 2018 were retrospectively analysed. Measurements that had been taken by either MRI or ioUS were compared with those taken during histopathology.

RESULTS

A total of 83 patients with tongue cancer had undergone a pre-operative MRI and 107 had been studied through an ioUS. Tumour thickness measured by MRI (r = 0.72) and ioUS (r = 0.78) correlated significantly (p < 0.001) with histopathological depth of invasion (DOI). In tumours with a DOI of 0-10 mm, MRI has a mean absolute difference with histopathology of 3.1 mm (SD 3.2 mm) and ioUS of 1.6 mm (SD 1.3 mm). In tumours with a DOI greater than 10 mm, MRI has a mean absolute difference of 3.5 mm (SD 3.0 mm) and ioUS of 4.7 mm (SD 3.5 mm).

CONCLUSION

Estimation of histopathological DOI in tongue cancers with DOI till 10 mm is very accurate through use of ioUS. ioUS tends to underestimate DOI in tumors exceeding 10 mm DOI. MRI tends to overestimate DOI in both thin and thick tumours. Since ultrasound measurements can be performed during surgery, ioUS could potentially guide the surgeon in the achievement of adequate resection margins.

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.

Magnetic Resonance vs. Intraoral Ultrasonography in the Preoperative Assessment of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: Preoperative assessment is critical to decide the most adequate surgical strategy for oral squamous cell carcinoma (SCC). Magnetic resonance (MR) and intraoral ultrasonography (US) have been reported to be of great value for preoperative estimation of depth of invasion (DOI) and/or tumor thickness (TT). This review aims to analyze the accuracy of MR and intraoral US in determining DOI/TT in oral SCC, by assuming histological evaluation as the reference method.

Methods: The procedure was conducted following the modified 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We performed a systematic search of papers on PubMed, Scopus, Web of Science, and Cochrane Library databases until July 31st, 2019. For quantitative synthesis, we included nine studies (487 patients) focused on MR, and 12 (520 patients) focused on intraoral US. The Pearson correlation coefficient (r) between DOI/TT evaluated with MR or intraoral US was assumed as effect size. A meta-analysis (MA) for each study group (MR and US) was performed by using the random-effects models with the DerSimonian–Laird estimator and r-to-z transformation.

Results: In the MA for MR studies, a high heterogeneity was found (I² = 94.84%; Q = 154.915, P < 0.001). No significant risk of bias occurred by evaluating funnel plot asymmetry (P = 0.563). The pooled (overall) r of the MR studies was 0.87 (95% CI from 0.82 to 0.92), whereas the pooled r-to-z transformed was 1.44 (95% CI from 1.02 to 1.85). In the MA for US studies a high heterogeneity was found (I² = 93.56%; Q = 170.884, P < 0.001). However, no significant risk of bias occurred (P = 0.779). The pooled r of the US studies was 0.96 (95% CI from 0.94 to 0.97), whereas the pooled r-to-z transformed was 1.76 (95% CI from 1.39 to 2.13). These outputs were confirmed in additional MA performed by enrolling only MR (n = 8) and US (n = 11) studies that evaluated TT.

Conclusions: MR and intraoral US seem to be promising approaches for preoperative assessment of DOI/TT in oral SCC. Remarkably, a higher pooled r and r-to-z transformed were observed in the intraoral US studies, suggesting that this approach could be more closely related to histopathological findings.

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

Addition of tumour infiltration depth and extranodal extension improves the prognostic value of the pathological TNM classification for early-stage oral squamous cell carcinoma

AIMS

In the 8th edition of the American Joint Committee on Cancer TNM staging manual, tumour infiltration depth and extranodal extension are added to the pathological classification for oral squamous cell carcinoma. The currently available 8th TNM validation studies lack patients with conservative neck treatment, and changes in the classification especially affect patients with small tumours. The aim of this study was to determine the potential impact of the changes in the 8th edition pTNM classification on the prognosis and treatment strategy for oral squamous cell carcinoma in a well-defined series of pT1-T2 patients with long-term follow-up.

METHODS AND RESULTS

Two hundred and eleven first primary pT1-T2 oral squamous cell carcinoma patients, with surgical resection as primary treatment, were analysed retrospectively. One hundred and seventy-three patients underwent a neck dissection, and 38 patients had frequent clinical neck assessments. Long-term follow-up (median 64 months) and reassessed tumour infiltration depth were available. Classification according to the 8th edition criteria resulted in 36% total upstaging with the T classification and 16% total upstaging with the N classification. T3-restaged patients (n = 30, 14%) had lower 5-year disease-specific survival rates than T2-staged patients (81% versus 67%, P = 0.042). Postoperative (chemo)radiotherapy could have been considered in another seven (3%) patients on the basis of the 8th edition criteria.

CONCLUSIONS

Addition of tumour infiltration depth and extranodal extension in the 8th TNM classification leads to the identification of oral squamous cell carcinoma patients with a worse prognosis who might benefit from an improved postoperative treatment strategy.