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

Occult metastasis is no burden factor in oral squamous cell carcinoma patients when adhering to a standardized approach in neck dissection

OBJECTIVES

Management of the neck in patients with oral squamous cell carcinoma (OSCC) is pivotal to oncologic control and survival. However, there is controversy regarding necessity of neck dissection (ND) in patients with clinically node-negative neck. We aimed to assess risk factors for occult metastasis and to explore whether the presence of occult lymph node metastases (LNMs) has an impact on recurrence and survival.

MATERIAL AND METHODS

A retrospective cohort study was performed including patients with primary OSCC who underwent radical tumor resection and ND in a high-volume center adhering to the prevailing German guideline. The ND was performed according to a standardized approach.

RESULTS

Four hundred twenty-one patients with primary surgically treated OSCC were included. The incidence of occult metastasis was 14.49%. A pathological T stage > 1 (multivariate analysis, odds ratio (OR) 3.958, p = 0.042) and the presence of extranodal extension in LNMs (multivariate analysis, OR 0.287, p = 0.020) were identified as independent risk factors for occult metastasis. When comparing patients with and without occult metastasis, there were no significant differences in terms of progression-free survival (log-rank, p = 0.297) and overall survival (log-rank, p = 0.320). There were no cases of ipsilateral neck recurrence. One patient developed contralateral neck metastasis; however, he initially presented with a unilateral pT1 pN0 tumor.

CONCLUSIONS

Overall, our findings suggest that conducting a standardized approach in ND should be applied in terms of management of the neck in order to maintain survival rates and to prevent neck recurrence in OSCC patients.

CLINICAL RELEVANCE

None of the risk factors for occult metastasis can be reliably assessed preoperatively. Although elective ND does not guarantee the complete prevention of neck recurrence, it increases the likelihood of either timely removal of micrometastases or strengthens the justification for adjuvant therapy. Consequently, this approach leads to improvements in clinical outcomes.

An Oral Microbial Biomarker for Early Detection of Recurrence of Oral Squamous Cell Carcinoma

Changes in the oral microbiome are associated with oral squamous cell carcinoma (OSCC). Oral microbe-derived signatures have been utilized as markers of OSCC. However, the structure of the oral microbiome during OSCC recurrence and biomarkers for the prediction of OSCC recurrence remains unknown. To identify OSCC recurrence-associated microbial biomarkers for the prediction of OSCC recurrence, we performed 16S rRNA amplicon sequencing on 54 oral swab samples from OSCC patients. Differences in bacterial compositions were observed in patients with vs without recurrence. We found that Granulicatella, Peptostreptococcus, Campylobacter, Porphyromonas, Oribacterium, Actinomyces, Corynebacterium, Capnocytophaga, and Dialister were enriched in OSCC recurrence. Functional analysis of the oral microbiome showed altered functions associated with OSCC recurrence compared with nonrecurrence. A random forest prediction model was constructed with five microbial signatures including Leptotrichia trevisanii, Capnocytophaga sputigena, Capnocytophaga, Cardiobacterium, and Olsenella to discriminate OSCC recurrence from original OSCC (accuracy = 0.963). Moreover, we validated the prediction model in another independent cohort (46 OSCC patients), achieving an accuracy of 0.761. We compared the accuracy of the prediction of OSCC recurrence between the five microbial signatures and two clinicopathological parameters, including resection margin and lymph node counts. The results predicted by the model with five microbial signatures showed a higher accuracy than those based on the clinical outcomes from the two clinicopathological parameters. This study demonstrated the validity of using recurrence-related microbial biomarkers, a noninvasive and effective method for the prediction of OSCC recurrence. Our findings may contribute to the prognosis and treatment of OSCC recurrence.

A robust and interpretable gene signature for predicting the lymph node status of primary T1/T2 oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OSCC) affects more than 30 000 individuals in the United States annually, with smoking and alcohol consumption being the main risk factors. Management of early-stage tumors usually includes surgical resection followed by postoperative radiotherapy in certain cases. The cervical lymph nodes (LNs) are the most common site for local metastasis, and elective neck dissection is usually performed if the primary tumor thickness is greater than 3.5 mm. However, postoperative histological examination often reveals that many patients with early-stage disease are negative for neck nodal metastasis, posing a pressing need for improved risk stratification to either avoid overtreatment or prevent the disease progression. To this end, we aimed to identify a primary tumor gene signature that can accurately predict cervical LN metastasis in patients with early-stage OSCC. Using gene expression profiles from 189 samples, we trained K-top scoring pairs models and identified six gene pairs that can distinguish primary tumors with nodal metastasis from those without metastasis. The signature was further validated on an independent cohort of 35 patients using real-time polymerase chain reaction (PCR) in which it achieved an area under the receiver operating characteristic (ROC) curve and accuracy of 90% and 91%, respectively. These results indicate that such signature holds promise as a quick and cost effective method for detecting patients at high risk of developing cervical LN metastasis, and may be potentially used to guide the neck treatment regimen in early-stage OSCC.

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

OBJECTIVE

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

DESIGN/SETTING/PARTICIPANTS/OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Predictive Value of Occult Metastasis and Survival Significance of Metabolic Tumor Volume Determined by PET-CT in cT1-2N0 Squamous Cell Carcinoma of the Tongue

Objectives

Our goal was to analyze the possibility of using metabolic tumor volume (MTV) to predict occult cervical metastasis and survival in cT1-2N0 squamous cell carcinoma (SCC) of the tongue.

Methods

Data on the primary tumor MTV and cervical node status as determined by the maximum standardized uptake value were retrieved. The sensitivity and specificity in predicting occult metastasis were calculated with a fourfold table. Associations between occult metastasis and clinicopathological variables were evaluated by univariate and multivariate analyses. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS).

Results

A total of 24 (20.3%) of 118 patients had occult metastasis. An MTV cutoff value of 4.3 cm³ showed a sensitivity of 50.0% and a specificity of 76.6% in predicting occult metastasis. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT1 tumors were 66.6 and 89.8%, respectively, with values of 83.3 and 67.3%, respectively, when combined with the MTV. The sensitivity and specificity of PET-CT in predicting occult metastasis in cT2 tumors were 72.2 and 82.2%, respectively, with values of 88.9 and 57.8%, respectively, when combined with the MTV. Patients with MTV ≥4.3 cm³ had a higher occult metastasis rate than patients with MTV <4.3 cm³. The 5-year LRC and DSS rates were 86 and 94%, respectively, in patients with MTV <4.3 cm³ and 54 and 72%, respectively, in patients with MTV ≥4.3 cm³. Both differences were found to be significant in univariate and multivariate analyses.

Conclusions

MTV ≥4.3 cm³ was associated with an increased probability of occult metastasis and lower LRC and DSS rates in early-stage SCC of the tongue.

Impact of histological Oral Tongue Cancer margins on locoregional recurrence: A multi-centre retrospective analysis

OBJECTIVES

To assess the effect of the histological margins (HM) upon locoregional failure (LRF) and overall survival (OS) for oral tongue squamous cell carcinoma (OTSCC).

MATERIALS AND METHODS

We undertook a retrospective review of 258 patients, across two institutions, treated for OTSCC between 2007 and 2016. A Cox-proportional hazards model was used to compare the relative hazard ratio of HM to the accepted standard of 5 mm margins for LRF and OS.

RESULTS

The median follow up period was 4.8 years. The 5 year OS and freedom from LRF were 69% and 75% respectively. The Cox-proportional hazards model adjusted for age, DOI and LVI showed increasing risk of mortality and LRF with decreasing HM widths of <5 mm.

CONCLUSION

HM >5 mm were associated with a risk reduction of both LRF and mortality in OTSCC. This study supports >5 mm HM being the oncologic goal of surgery.

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

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

Comparison Between PET-CT-Guided Neck Dissection and Elective Neck Dissection in cT1-2N0 Tongue Squamous Cell Carcinoma

Objective: Neck management in cT1-2N0 tongue squamous cell carcinoma (SCC) remains controversial. Our goal was to compare the survival difference between PET-CT–guided neck dissection and elective neck dissection (END) for the treatment of cT1-2 tongue SCC.

Methods: Patients with surgically treated cT1-2N0 tongue SCC were retrospectively enrolled. These patients were divided into two groups. Group A: The decision of whether to perform neck dissection was mainly based on the results of preoperative PET-CT examinations. Group B: Patients received END treatment without preoperative PET-CT examinations. The study endpoints were regional control (RC) and disease-specific survival (DSS). The Kaplan–Meier method was used to calculate the survival rates.

Results: Group A consisted of 66 patients, and 16 patients underwent neck dissection owing to positive PET-CT results. Group B consisted of 169 patients. The 5-year RC rates in group A and group B were 86 and 87%, respectively, and the difference was not significant (p = 0.731). The 5-year DSS rates in group A and group B were 93 and 90%, respectively, and the difference was not significant (p = 0.583).

Conclusions: Neck dissection can be safely avoided when the PET-CT scan reveals no neck lymph node involvement.

Significance of SUV Max for Predicting Occult Lymph Node Metastasis and Prognosis in Early-Stage Tongue Squamous Cell Carcinoma

Objective

Our goal was to clarify the significance of SUV max for predicting occult lymph node metastasis and prognosis in early-stage tongue squamous cell carcinoma (SCC).

Methods

cT1-2N0 tongue SCC patients who underwent a preoperative PET-CT examination were prospectively enrolled. The association between SUV max and occult lymph node metastasis was analyzed. The main study endpoint was locoregional control (LRC). The Cox model was used to determine the independent factors.

Results

A total of 120 patients were included for analysis, and the median SUV max was 9.7. In 60 patients with an SUV max ≤9.7, 5 patients had occult metastasis; in 60 patients with an SUV max >9.7, 13 patients had occult metastasis, and the difference was significant (p=0.041). In patients with an SUV max ≤9.7, the 5-year LRC rate was 93%; in patients with an SUV max >9.7, the 5-year LRC rate was 81%, and the difference was significant (p=0.045).

Conclusion

An SUV max >9.7 was a marker for occult lymph node metastasis and could decrease LRC in patients with cT1-2N0 tongue SCC.