Pathologic staging changes in oral cavity squamous cell carcinoma: Stage migration and implications for adjuvant treatment

Controversies in the treatment of early-stage oral squamous cell carcinoma

The treatment of early-stage oral squamous cell carcinoma (OSCC) is still a controversial issue. Thanks to the 8th edition of TNM by AJCC there is a better distinction between the stages of OSCC. However, Stages I and II still share the same treatment protocol, even if the prognosis is radically different. A retrospective study has been conducted including 70 previously untreated patients with Stage I or II OSCC, treated with tumorectomy and selective neck dissection. The study focuses on the link between pT1/2 and various other factors, particularly histological grading, vascular and perineural invasion, local and cervical recurrence, surgical margins and overall survival. These data reveal significant differences between pT1 and pT2 in histological grade, perineural invasion, cervical recurrence, surgical margins, and overall survival, emphasizing the necessity of different treatment protocols for T1 and T2 OSCC. Distinct strategies should be proposed to treat Stage I and II OSCC, with Stage II patients possibly benefitting from more aggressive treatments: following these data, a wait-and-see strategy should only be considered in Stage I, while certain treatments at the cervical level - such as prophylactic neck dissection and sentinel node biopsy - should always be considered for Stage II tumors.

Evolution of TNM Classification for Clinical Staging of Oral Cancer: The Past, Present and the Future

Purpose

The AJCC (American Joint Committee on Cancer) Cancer Staging Manual, 1st Edition, was published in 1977 which focused on the TNM classification and staging of cancer to allow easy communication, formulation of a treatment plan and predict the prognosis, among the medical fraternity.

Methods

Ever since the beginning, various modifications of the classification were introduced and released by the joint collaboration of AJCC and UICC (International Union Against Cancer) in various editions of cancer staging manuals.

Results

The present review article was kept focused onto the changes introduced in the clinical staging of cancers of oral cavity. These changes came a long way since 1st edition 1944, to the eighth edition which was published in 2017.

Conclusions

This article is a critical review on the past and present perspectives of the TNM classification of the oral cavity that were addressed and changed, adding a light on the future trends or necessary inclusions that would formulate a much easily acceptable and useful classification system.

AIRO GORTEC consensus on postoperative radiotherapy (PORT) in low-intermediate risk early stages oral squamous cell cancers (OSCC)

Evidence on the efficacy of postoperative radiotherapy (PORT) in low-intermediate risk squamous cell carcinoma of the oral cavity (OSCC) remains inconclusive. Members of a task force from two national radio-oncology Associations (AIRO and GORTEC) defined 14 clinically relevant questions to identify "gray areas" pertinent to the indication for PORT in this clinical setting. Consequently, a literature review was performed on the topic. The resulting statements were then rated by an Expert Panel (EP) using a modified Delphi method. Only radiation oncologists were part of the discussion and voting on the scenarios. There was agreement on the 14 statements at the first round of voting. The task force then decided to propose clinical cases for the two more controversial statements that had received a lower agreement to better capture the Experts' attitudes. The clinical cases highlighted a more significant decisional heterogeneity. However, the good level of consensus reached among the two Associations gives relevant support in informing clinical choices while acknowledging general indications cannot fit all clinical situations and do not replace multidisciplinary discussion.

Lymph Node Ratio as a Prognostic Factor in Neck Dissection in Oral Cancer Patients: A Systematic Review and Meta-Analysis

Simple Summary

Lymph node ratio (LNR) is a well-studied prognostic factor in colorectal and breast cancer, and it has been recently evaluated as a clinically relevant biomarker in oral squamous cell carcinoma. LNR represents the ratio of positive lymph nodes extracted in a neck dissection to the total number of nodes harvested (lymph node yield, LNY). Many single-center cohort studies and a few multicenter have assessed the significance of LNR as a prognostic factor in oral cancer. In this systematic review and meta-analysis of 32 studies and 20,994 oral cancer patients, we demonstrate that LNR is an independent prognostic indicator in patients with oral squamous cell carcinoma.

Abstract

Many studies have evaluated the clinical implications of lymph node ratio (LNR) as a prognostic factor in patients with oral squamous cell carcinoma (OSCC). The main purpose of this systematic review and meta-analysis was to address LNR as a prognosticator in patients with OSCC. A systematic search was conducted in the following databases: PubMed, EMBASE, Google Scholar, OpenGrey, Cochrane library, and ClinicalTrials.gov, and studies between 2009 and 2020 were sought. The pooled relative risk was calculated along with 95% confidence intervals for the following endpoints: overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), distant metastasis-free survival (DMFS), locoregional disease-free survival (LRDFS), local recurrence-free survival (LRFS), and recurrence-free survival (RFS) according to the random-effects model (Der Simonian–Laird approach). Subgroup and meta-regression analyses were performed as well. Finally, 32 cohort studies were eligible, which included 20,994 patients with OSCC. Patients were subdivided into two categories, group YES (studies that included in their analysis only patients with positive lymph nodes) and group NO (studies that did not exclude LNR = 0 patients). In the group YES, patients with high LNR had shorter OS (RR = 1.68, 95% CI: 1.47–1.91), DFS (RR = 1.68, 95% CI: 1.42–1.99), DSS (RR = 1.94, 95% CI: 1.56–2.42), DMFS (RR = 1.83, 95% CI: 1.13–2.96), LRDFS (RR = 1.55, 95% CI: 1.10–2.20), and LRFS (RR = 1.73, 95% CI: 1.41–2.13) compared to patients with low LNR. In the group NO, patients with high LNR in comparison had shorter OS (RR = 2.38, 95% CI: 1.99–2.85), DFS (RR = 2.04, 95% CI: 1.48–2.81), and DSS (RR = 2.90, 95% CI: 2.35–3.57) compared to patients with low LNR. Based on those findings, LNR might be an independent prognostic factor for OS in patients with OSCC and could be incorporated into future classification systems for better risk stratification.

Adding Concomitant Chemotherapy to Postoperative Radiotherapy in Oral Cavity Carcinoma with Minor Risk Factors: Systematic Review of the Literature and Meta-Analysis

When presenting with major pathological risk factors, adjuvant radio-chemotherapy for oral cavity cancers (OCC) is recommended, but the addition of chemotherapy to radiotherapy (POCRT) when only minor pathological risk factors are present is controversial. A systematic review following the PICO-PRISMA methodology (PROSPERO registration ID: CRD42021267498) was conducted using the PubMed, Embase, and Cochrane libraries. Studies assessing outcomes of POCRT in patients with solely minor risk factors (perineural invasion or lymph vascular invasion; pN1 single; DOI ≥ 5 mm; close margin < 2−5 mm; node-positive level IV or V; pT3 or pT4; multiple lymph nodes without ENE) were evaluated. A meta-analysis technique with a single-arm study was performed. Radiotherapy was combined with chemotherapy in all studies. One study only included patients treated with POCRT. In the other 12 studies, patients were treated with only PORT (12,883 patients) and with POCRT (10,663 patients). Among the patients treated with POCRT, the pooled 3 year OS rate was 72.9% (95%CI: 65.5−79.2%); the pooled 3 year DFS was 70.9% (95%CI: 48.8−86.2%); and the pooled LRFS was 69.8% (95%CI: 46.1−86.1%). Results are in favor of POCRT in terms of OS but not significant for DFS and LRFS, probably due to the heterogeneity of the included studies and a combination of different prognostic factors.

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.

Limits and potential implementation of the present pN classification for oral squamous cell carcinoma

PURPOSE OF REVIEW

The purpose of this review is to highlight the most important changes in the eighth TNM classification system for oral squamous cell carcinomas compared with the seventh edition with focus on lymph node staging (pN). Nodal involvement is crucial when addressing prediction of survival, and staging must mirror the disease extension. pN classification will be evaluated with respect to lymph node yield (LNY), lymph node density (LND), and a recently proposed classification: pN-N+ reflecting positive regional lymph nodes (metastatic burden) and extra nodal extension.

RECENT FINDINGS

TNM8 was introduced in 2018, and the most noteworthy changes were depth of invasion (DOI) and extranodal extension (ENE). Recent studies indicate, that TNM8-related pN is not superior to TNM7 with respect to predicting survival. LNY and LND are biased with ecological interference fallacy, and currently not recommended in future iterations of TNM. In contrast, the pN-N+ classification has demonstrated improved survival prediction compared with TNM8.

SUMMARY

The recent findings support the inclusion of pN-N+, that is, metastatic burden and extranodal extension in future iterations of TNM.

Indication to postoperative radiotherapy for oral cavity squamous cell carcinoma: what’s new in the Depth of Infiltration (DOI) era?

Objectives:

The last edition of the American Joint Committee on Cancer (AJCC eighth) has introduced the depth of infiltration (DOI) as a new prognostic parameter in oral cavity squamous cell carcinomas (OCSCCs). Aim of this study is to analyze the impact of stage migration on the indication to postoperative radiotherapy (PORT).

Methods:

OCSCCs treated at two Institutions between 2014 and 2019 were retrieved. Per the AJCC eighth, only pT3 primarily OCSCCs were considered; availability of the pathologic specimen was a further inclusion criterion. Risk factors considered for PORT were: pT3-pT4, nodal involvement, positive/close surgical margins, perineural and lymph vascular invasion.

Results:

One-hundred forty-nine patients staged as pT3 AJCC eighth were included. A four-fold increase in the number of patients staged as pT3 from the seventh to the eighth AJCC was found. Stage migration to pT3 was equally due to the downstaging from former pT4 (38%) and upstaging of former pT1-pT2 (35%). Considering the former pT1-pT2 53 patients, 13 (25%) had no risk factors for PORT other than DOI. Among 25 cases with former pT1-pT2 and negative lymph nodes no additional risk factors were found in 11 (44%).

Conclusion:

Ninety percent of patients had at least one risk factor besides DOI and would have received PORT also according to the AJCC seventh; notably, of former pT1-pT2N0, half of them have been upstaged to pT3 in the current TNM classification. The role of PORT in this cohort of patients has not been clarified yet.

Advances in knowledge:

Other-than-DOI risk factors leading to PORT indication are highly prevalent in OCSSC patients classified as pT3 per the latest AJCC TNM staging system and should therefore be considered for a comprehensive oncological assessment.

The Impact of Post-Operative Radiotherapy in Early Stage (pT1-pT2N0M0) Oral Tongue Squamous Cell Carcinoma in Era of DOI

Simple Summary

The aim of the present study was to clarify the role of depth of infiltration (DOI) as an independent prognosticator in early stage (T1-T2N0M0) oral cavity tumors. Moreover, whether patients upstaged to pT3 for DOI > 10 mm need postoperative radiotherapy (PORT) in the absence of other risk factors has not been established yet. The DOI alone was not sufficient to impact the prognosis and therefore other risk factors should be considered to indicate PORT indications in upstaged patients due to DOI > 10 mm.

Abstract

Background: This study investigated the role of depth of infiltration (DOI) as an independent prognosticator in early stage (T1-T2N0M0) oral cavity tumors and to evaluate the need of postoperative radiotherapy in the case of patients upstaged to pT3 for DOI > 10 mm in the absence of other risk factors. Methods: We performed a retrospective analysis on patients treated with surgery and re-staged according to the 8th edition of malignant tumors classification (TNM). The role of DOI as well as other clinical/pathological features was investigated at both univariable and multivariable analyses on overall survival (OS), disease free survival (DFS), relapse free survival (RFS), and local RFS. Results: Among the 94 included patients, 23 would have been upstaged to pT3 based on DOI. Multivariable analysis showed that DOI was not an independent prognostic factor for any of the considered outcomes. The presence of perineural invasion was associated with a significant worse RFS (p = 0.02) and LRFS (p = 0.04). PORT was found to be significantly associated with DFS (p = 0.04) and RFS (p = 0.06). Conclusions: The increasing DOI alone was not sufficient to impact the prognosis, and therefore, should not be sufficient to dictate PORT indications in early-stage patients upstaged on the sole basis of DOI.

Prognostic stratification of patients with AJCC 2018 pStage IVB oral cavity cancer: Should pT4b and pN3 disease be reclassified?

OBJECTIVES

pStage IVB oral cavity squamous cell carcinoma (OCSCC) is defined as either pT4b or pN3 disease. We sought to devise an improved prognostic stratification of this patient group.

METHODS

Between December 2003 and January 2018, we retrospectively reviewed the clinical records of 1331 consecutive patients with OCSCC who received tumor excision and neck dissection. The number of patients with pT4a/pT4b, pT1N3b/pT2N3b/pT3N3b/pT4N3b, and pStage IVA/IVB was 370/83, 3/49/42/142, and 332/295, respectively.

RESULTS

The 5-year rates of disease-free survival (DFS) and disease-specific survival (DSS) for patients with pT4a/pT4b disease were 64%/63% (p = 0.973) and 72%/69% (p = 0.672), respectively. The 5-year DFS and DSS rates for patients with pT1N3b/pT2N3b/pT3N3b/pT4N3b disease were 67%/65%/40%/42% (p < 0.001; pT1-2N3b versus pT3-4N3b, p = 0.002) and 100%/68%/45%/49% (p < 0.001; pT1-2N3b versus pT3-4N3b, p = 0.002), respectively. We devised a new definition for pStage IV by considering patients with pT4bN0-2 and pT1-2N3b diseases as pStage-IVA. The number of patients with pStage IVA/IVB (pT3-4N3b) was 443/184. The 5-year rates of AJCC pStage IVA/IVB and the newly proposed pStage IVA/IVB (pT3-4N3b) were as follows: DFS, 74%/52% and 72%/42%; DSS, 83%/58% and 81%/47%; respectively, all p value < 0.001.

CONCLUSIONS

The clinical outcomes of pT4b and pT4a OCSCC are similar. However, patients with pT3-4N3b disease have a less favorable 5-year prognosis compared with cases with pT1-2N3b. In light of the unfavorable outcomes, pT3-4N3b disease should continue to be classified as pStage IVB. Conversely, pT4bN0-2 and pT1-2N3b diseases portend a less adverse prognosis and should therefore be downstaged to pStage IVA.

Derivation and Validation of a Prognostic Scoring Model Based on Clinical and Pathological Features for Risk Stratification in Oral Squamous Cell Carcinoma Patients: A Retrospective Multicenter Study

Objective

To develop and validate a simple-to-use prognostic scoring model based on clinical and pathological features which can predict overall survival (OS) of patients with oral squamous cell carcinoma (OSCC) and facilitate personalized treatment planning.

Materials and Methods

OSCC patients (n = 404) from a public hospital were divided into a training cohort (n = 282) and an internal validation cohort (n = 122). A total of 12 clinical and pathological features were included in Kaplan-Meier analysis to identify the factors associated with OS. Multivariable Cox proportional hazards regression analysis was performed to further identify important variables and establish prognostic models. Nomogram was generated to predict the individual's 1-, 3- and 5-year OS rates. The performance of the prognostic scoring model was compared with that of the pathological one and the AJCC TNM staging system by the receiver operating characteristic curve (ROC), concordance index (C-index), calibration curve, and decision curve analysis (DCA). Patients were classified into high- and low-risk groups according to the risk scores of the nomogram. The nomogram-illustrated model was independently tested in an external validation cohort of 95 patients.

Results

Four significant variables (physical examination-tumor size, imaging examination-tumor size, pathological nodal involvement stage, and histologic grade) were included into the nomogram-illustrated model (clinical-pathological model). The area under the ROC curve (AUC) of the clinical-pathological model was 0.687, 0.719, and 0.722 for 1-, 3- and 5-year survival, respectively, which was superior to that of the pathological model (AUC = 0.649, 0.707, 0.717, respectively) and AJCC TNM staging system (AUC = 0.628, 0.668, 0.677, respectively). The clinical-pathological model exhibited improved discriminative power compared with pathological model and AJCC TNM staging system (C-index = 0.755, 0.702, 0.642, respectively) in the external validation cohort. The calibration curves and DCA also displayed excellent predictive performances.

Conclusion

This clinical and pathological feature based prognostic scoring model showed better predictive ability compared with the pathological one, which would be a useful tool of personalized accurate risk stratification and precision therapy planning for OSCC patients.

TNM 8 staging is a better prognosticator than TNM 7 for patients with locally advanced oral cavity squamous cell carcinoma treated with surgery and post-operative radiotherapy

PURPOSE

To assess TNM 8 staging in discriminating overall survival (OS) amongst patients with locally advanced oral cavity squamous cell carcinoma (OCSCC) treated with surgery and post-operative radiotherapy (PORT), compared to TNM 7.

MATERIAL AND METHODS

Data from OCSCC patients treated with surgery and PORT between January 2010 and December 2018 were reviewed. Demographics, tumour characteristics and treatment response data were collected, and patients staged according to both TNM 7 and TNM 8. OS and disease free survival (DFS) were estimated using the Kaplan Meier method. Univariate and multivariable analyses were conducted for factors affecting OS, DFS and early disease recurrence within 12 months.

RESULTS

Overall 172 patients were analyzed. Median follow up was 32 months for all patients and 48 months for surviving patients. TNM 8 staging demonstrated significant stratification of OS and DFS amongst the entire cohort, whereas TNM 7 staging did not. On multivariable analysis, TNM 8 stage, performance status (PS) and a positive surgical margin were prognostic for OS. Looking at disease recurrence within 12 months, TNM 8 stage IVB, presence of lymphovascular invasion (LVSI), younger age and lesser smoking history were predictive factors on multivariable analysis.

CONCLUSION

TNM 8 is a good development of its predecessor in terms of predicting survival for patients with locally advanced OCSCC. We have also identified younger age (<60 years) and a smoking history of <10 pack years as risk factors for early disease recurrence, potentially representing a separate biological cohort within OCSCC patients.

Predicting Adverse Histopathology and Need for Postsurgical Adjuvant Therapy for Human Papilloma Virus-Associated Oropharynx Carcinoma

OBJECTIVE

For human papillomavirus-associated oropharynx carcinoma treated with definitive surgery, we aimed to find predictors of adverse histopathology indicating the possible need for adjuvant therapy.

STUDY DESIGN

Retrospective review.

SETTING

National Cancer Database.

METHODS

We analyzed 2347 eligible patients from 2010 to 2015. We evaluated (1) the ability of clinical nodal staging and extranodal extension designation per the AJCC, seventh edition (American Joint Committee on Cancer), to predict histopathology and (2) the likelihoods for adverse postsurgery histopathology by common clinical stages.

RESULTS

Clinical nodal staging predicted pathologic nodal staging 65% of the time, with 24% (569/2347) being upstaged and 11% (251/2347) being downstaged. In patients with cN+ disease, clinical extranodal extension distinction had the following accuracy for pathologic extranodal extension: positive predictive value, 81% (88/109); negative predictive value, 73.1% (505/691); sensitivity, 32.1% (88/274); and specificity, 96.0% (505/526). Patients with cT1-2, N0-N2c, without clinical extranodal extension had the following proportions of pN2+ without pathologic extranodal extension (indicating consideration for adjuvant radiation): cN0, 11%; cN1, 31%; cN2a, 67% (8% downstaged); cN2b, 66% (6% downstaged); and cN2c, 35% (17% downstaged). From this group, patients had the following proportions of pathologic extranodal extension (indicating consideration for adjuvant chemoradiation): cN0, 6%; cN1, 20%; cN2a, 27%; cN2b, 28%; and cN2c, 48%.

CONCLUSION

For human papillomavirus-associated oropharynx carcinoma, nodal clinical staging per the American Joint Committee on Cancer, seventh edition, predicts pathologic stage about two-thirds of the time, leading to up- and downstaging. Clinical extranodal extension assessment has low sensitivity and moderate predictive capability. With careful selection, definitive surgery can allow patients to often avoid adjuvant chemotherapy and sometimes avoid adjuvant radiation.

Staging and grading of oral squamous cell carcinoma: An update

Oral squamous cell carcinoma (OSCC) is a common malignancy of the head and neck region. OSCC has a relatively low survival rate and the incidence of the disease is increasing in some geographic areas. Staging and grading of OSCC are established prerequisites for management, as they influence risk stratification and are the first step toward personalized treatment. The current AJCC/UICC TNM staging (8th edition, 2017) of OSCC has included significant modifications through the incorporation of depth of invasion in the T stage and extracapsular spread/extranodal extension in the N stage. Further modifications for AJCC 8 have been suggested. On the other hand, the World Health Organization (WHO) classification (4th edition, 2017) still endorses a simple, differentiation-based histopathologic grading system of OSCC (despite its low prognostic value) and ignores factors such as tumor growth pattern and dissociation, stromal reactions (desmoplasia, local immune response), and tumor-stroma ratio. The various controversies and possible developments of the current staging and grading criteria of OSCC are briefly discussed in this update together with possible applications of artificial intelligence in the context of screening and risk stratification.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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