The impact of pathologic close margin on the survival of patients with early stage oral squamous cell carcinoma

Initial negative resection margin versus revised negative resection margin in patients who underwent surgery without adjuvant therapy for early-stage oral tongue squamous cell carcinoma

BACKGROUND

In cases of positive resection margin (RM), re-resection is generally recommended. There has been controversy about the oncologic impact of revised negative RMs after re-resection. The aim of this study was to investigate the oncologic impact of revised negative RM in patients who underwent surgery without adjuvant therapy for early-stage (pT1-2/N0) oral tongue squamous cell carcinoma (OSCC).

METHODS

We retrospectively analyzed patients with pT1-2 N0 OSCC who did not receive adjuvant therapy (N=441). These patients were classified into an initial negative RM (R0, n = 380) group and a revised negative RM (R1-R0, n = 61) group. Demographic and clinical data (T stage, tumor length, depth of invasion [DOI], lymphovascular invasion [LVI], perineural invasion [PNI], and recurrence) were compared between the R0 and R1-R0 groups.

RESULTS

Age, sex, T stage, DOI, LVI, PNI, and SUVmax were not significantly different between the two groups. Local recurrence was more frequent (P=0.045) in the R1-R0 group (13.1 %) than in the R0 group (5.5 %). Local recurrence-free survival was better in the R0 group than in the R1-R0 group (P=0.046). There was no significant difference in overall recurrence or overall survival. On multivariate analysis, initial positive RM was the independent significant risk factor (hazard ratio, 2.249; 95 % confidence interval, 1.025-4.935; P=0.043) for local recurrence.

CONCLUSION

A revised clear RM after initial cut-through margin is a risk factor for local recurrence in early-stage OSCC. Cautious should be considered in early-stage OSCC patients with revised clear RM.

Evaluation of a 3D Printed Silicone Oral Cavity Cancer Model for Surgical Simulations

Adequate surgical margins are essential in oral cancer treatment, this is, however, difficult to appreciate during training. With advances in training aids, we propose a silicone-based surgical simulator to improve training proficiency for the ablation of oral cavity cancers. A silicone-based tongue cancer model constructed via a 3D mold was compared to a porcine tongue model used as a training model. Participants of varying surgical experience were then asked to resect the tumors with clear margins, and thereafter asked to fill out a questionnaire to evaluate the face and content validity of the models as a training tool. Eleven participants from the Otolaryngology-Head and Neck Surgery unit were included in this pilot study. In comparison to the porcine model, the silicone model attained a higher face (4 vs. 3.6) and content validity (4.4 vs. 4.1). Tumor consistency was far superior in the silicone model compared to the porcine model (4.1 vs. 2.8, p = 0.0042). Fellows and staff demonstrated a better margin clearance compared to residents (median 3.5 mm vs. 1.0 mm), and unlike the resident group, there was no incidence of positive margins. The surgical simulation was overall useful for trainees to appreciate the nature of margin clearance in oral cavity cancer ablation.

Margin to depth of invasion ratio as an indicator for stratifying close margins in early-stage oral squamous cell carcinoma

OBJECTIVES

In early-stage oral squamous cell carcinoma (OSCC) patients, whether the margin-to-depth-of-invasion ratio (MDR) can assist in stratifying the prognosis remains unclear.

METHODS

Patients diagnosed with early stage OSCC at National Taiwan University Hospital between January 2007 and December 2021 were reviewed. Patients with margin > 1 mm were classified into two groups: MDR < 0.5 and MDR ≥ 0.5.

RESULTS

We analyzed 911 pT1-2N0M0 OSCC patients, 723 (79.36 %) with MDR ≥ 0.5 and 188 (20.64 %) with MDR < 0.5. Patients in the MDR < 0.5 group displayed a significantly higher local recurrence rate (odds ratio 2.81, p = 0.002) compared with MDR ≥ 0.5 group. The 5-year disease-free survival were 80.8 % for clear margin, 76.3 % for close margin (MDR ≥ 0.5), and 65.2 % for close margin (MDR < 0.5). The overall survival displayed a similar pattern, with 5-year rates of 88.3 % for clear margin, 86.8 % for close margin (MDR ≥ 0.5), and 75.0 % for close margin (MDR < 0.5). There were no significant overall survival differences between the two MDR ≥ 0.5 groups, but both were significantly superior to patients with MDR < 0.5 (p = 0.001; p = 0.01). After multivariant cox analysis, MDR < 0.5 was a significant risk factor for disease-free survival (p < 0.001).

CONCLUSION

For early stage OSCC patients without positive margin (≦1mm), the survival outcome between MDR ≥ 0.5 group and MDR < 0.5 group was significantly different. The MDR < 0.5 group had significantly higher risk of local recurrence that may warrant adjuvant treatment.

Impact of dysplasia at resection margin on oncologic outcome after curative resection of oral tongue squamous cell carcinoma: significance of high-grade dysplastic resection margin

BACKGROUND

This study aimed to compare the oncologic outcomes among negative, close, positive, and dysplasia resection margins (RMs) with oral tongue squamous cell carcinoma (OSCC) and to investigate the impact of dysplastic RMs.

METHODS

The 565 patients were retrospectively analyzed and divided into four groups according to RM. Dysplasia was classified into mild, moderate, and severe subgroups.

RESULTS

RMs consisted of negative (62.1%), close (27.1%), positive (2.1%), and dysplastic (8.7%). In multivariate analysis, advanced T/N stages and positive RM were significant risk factors for overall survival, while dysplasia at the RM was not a significant risk factor for locoregional recurrence or overall survival. In subgroup analysis of patients with dysplastic margin, RM with severe dysplasia showed higher recurrence than mild and moderate dysplasia.

CONCLUSIONS

Dysplastic RM was not a risk factor for recurrence and survival. Severe dysplasia RM should be carefully observed due to higher recurrence compared to other dysplasia RMs.

Clinical Experience with Autofluorescence Guided Oral Squamous Cell Carcinoma Surgery

In our study, the effect of the use of autofluorescence (Visually Enhanced Lesion Scope-VELscope) on increasing the success rate of surgical treatment in oral squamous carcinoma (OSCC) was investigated. Our hypothesis was tested on a group of 122 patients suffering from OSCC, randomized into a study and a control group enrolled in our study after meeting the inclusion criteria. The preoperative checkup via VELscope, accompanied by the marking of the range of a loss of fluorescence in the study group, was performed before the surgery. We developed a unique mucosal tattoo marking technique for this purpose. The histopathological results after surgical treatment, i.e., the margin status, were then compared. In the study group, we achieved pathological free margin (pFM) in 55 patients, pathological close margin (pCM) in 6 cases, and we encountered no cases of pathological positive margin (pPM) in the mucosal layer. In comparison, the control group results revealed pPM in 7 cases, pCM in 14 cases, and pFM in 40 of all cases in the mucosal layer. This study demonstrated that preoperative autofluorescence assessment of the mucosal surroundings of OSCC increased the ability to achieve pFM resection 4.8 times in terms of lateral margins.

Tumor volume definitions in head and neck squamous cell carcinoma - Comparing PET/MRI and histopathology

BACKGROUND AND PURPOSE

In cancer treatment precise definition of the tumor volume is essential, but despite development in imaging modalities, this remains a challenge. Here, pathological tumor volumes from the surgical specimens were obtained and compared to tumor volumes defined from modern PET/MRI hybrid imaging. The purpose is to evaluate mismatch between the volumes defined from imaging and pathology was estimated and potential clinical impact.

METHODS AND MATERIALS

Twenty-five patients with head and neck squamous cell carcinoma were scanned on an integrated PET/MRI system prior to surgery. Three gross tumor volumes (GTVs) from the primary tumor site were delineated defined from MRI (GTV_MRI), PET (GTV_PET) and one by utilizing both anatomical images and clinical information (GTV_ONCO). Twenty-five primary tumor specimens were extracted en bloc, scanned with PET/MRI and co-registered to the patient images. Each specimen was sectioned in blocks, sliced and stained with haematoxylin and eosin. All slices were digitalized and tumor delineated by a head and neck pathologist. The pathological tumor areas in all slices were interpolated yielding a pathological 3D tumor volume (GTV_PATO). GTV_PATOwas compared with the imaging GTV's and potential mismatch was estimated.

RESULTS

Thirteen patients were included. The mean volume of GTV_ONCOwas larger than the GTV's defined from PET or MRI. The mean mismatch of the GTV_PATOcompared to the GTV_PET, GTV_MRIand GTV_ONCOwas 31.9 %, 54.5 % and 27.9 % respectively, and the entire GTV_PATO was only fully encompassed in GTV_ONCO in 1 of 13 patients. However, after the addition of a clinical 5 mm margin the GTV_PATO was fully encompassed in GTV_ONCO in 11 out of 13 patients.

CONCLUSIONS

Despite modern hybrid imaging modalities, a mismatch between imaging and pathological defined tumor volumes was observed in all patients.A 5 mm clinical margin was sufficient to ensure inclusion of the entire pathological volume in 11 out of 13 patients.

Surgical Extent for Oral Cancer: Emphasis on a Cut-Off Value for the Resection Margin Status: A Narrative Literature Review

The optimal cut-off point of the resection margin was recently debated in oral cancer. To evaluate the current evidence of the dynamic criteria of the resection margin, a review of the available literature was performed. Studies were sourced from PubMed and EMBASE by searching for the keywords "mouth neoplasm", "oral cancer", "oral cavity cancer", "oral squamous cell carcinoma", "tongue cancer", "margins of excision", "surgical margin" and "resection margin". We found approximately 998 articles on PubMed and 2227 articles on EMBASE. A total of 3225 articles was identified, and 2763 of those were left after removing the duplicates. By applying advanced filters about the relevance of the subjects, these were narrowed down to 111 articles. After the final exclusion, 42 full-text articles were reviewed. The universal cut-off criteria of 5 mm used for determining the resection margin status has been debated due to recent studies evaluating the impact of different margin criteria on patient prognosis. Of note, the degree of the microscopic extension from the gross tumor border correlates with tumor dimensions. Therefore, a relatively narrow safety margin can be justified in early-stage oral cancer without the additional risk of recurrence, while a wide safety margin might be required for advanced-stage oral cancer. This review suggests a surgical strategy to adjust the criteria for risk grouping and adjuvant treatments, according to individual tumor dimensions or characteristics. In the future, it might be possible to establish individual tumor-specific surgical margins and risk stratification during or after surgery. However, the results should be interpreted with caution because there is no strong evidence (e.g., prospective randomized controlled studies) yet to support the conclusions. Our study is meaningful in suggesting future research directions and discussions.

Risk Factors of Microscopically Tumor-Free Surgical Margins for Recurrence and Survival of Oral Squamous Cell Carcinoma Patients

Objectives

The concept of adequate surgical margins remains controversial in oral squamous cell carcinoma (OSCC) surgery. This study aimed to identify surgical margin-related indicators that might impact recurrence and survival of OSCC patients.

Materials and Methods

Histopathological examination was performed using hematoxylin-eosin-stained surgical margin tissue sections in 235 OSCC patients. Axin2 and Snail expression at the surgical margin was detected by immunohistochemistry. The impact of the Axin2-Snail cascade on tumorigenesis of the immortalized human oral keratinocyte (IHOK) line was investigated in vivo.

Results

The width and dysplasia of surgical margins were not significantly associated with the outcome of OSCC patients. In a multivariate analysis using variable clinicopathologic factors and with Axin2 and Snail expression as cofactors, higher age (hazard ratio [HR]:1.050; P=0.047), Axin2 (HR:6.883; P=0.014), and Snail abundance (HR:5.663; P=0.009) had independent impacts on worsened overall survival. Similarly, lesion site in retromolar trigone (HR:4.077; P=0.010), upper (HR:4.332; P=0.005) and lower gingiva (HR:3.545; P=0.012), presence of extranodal extension (HR:9.967; P<0.001), perineural invasion (HR:3.627; P=0.024), and Snail abundance (HR:3.587; P<0.001) had independent impacts on worsened recurrence-free survival. Furthermore, Axin2 knockdown induced decreased Snail expression and attenuated tumorigenesis in the IHOK line.

Conclusion

Histopathological examination of surgical margins may not be reliable to predict OSCC patient outcome. Molecular analysis may provide a more accurate risk assessment of surgical margins in OSCC. In particular, Axin2 and Snail are potential predictive biomarkers for the risk assessment of surgical margins in OSCC.

The effect of reconstruction on positive margin rates in oral cancer: Using length of stay as a proxy measure for flap reconstruction in a national database

PURPOSE

Planned flap reconstruction, allowing aggressive resections of oral cavity squamous cell carcinoma (OCSCC), may decrease positive surgical margins. The purpose of this study was to determine if length of stay (LOS), as a proxy measure for flap reconstruction, is associated with positive margin rates in OCSCC.

MATERIALS AND METHODS

Data from the National Cancer Database was retrospectively collected for patients undergoing surgery for previously untreated clinical T1-3 OCSCC. Post-operative LOS was dichotomized between ≤4 and >4 days as a proxy measure for whether patients may have received flap reconstruction. Patients with LOS >4 days represent a diverse group, but those with a LOS ≤4 days are less likely to have undergone an oral cavity flap reconstruction.

RESULTS

10,107 patients were included, of which 5290 (52%) were clinical T1 and 4852 (48%) were clinical T2-3. 771 (8%) patients had a positive surgical margin. On multivariable logistic regression analysis, LOS ≤4 days was significantly associated with a positive margin resection in patients with clinical T2-3 tumors (OR 1.68, 95%CI 1.37-2.06) compared to patients with LOS >4 days. LOS was not associated with surgical margin status in patients with clinical T1 disease (OR 0.76, 95%CI 0.55-1.06). Patients with positive margin resections demonstrated worse overall survival (cT1: OR 1.35, 95%CI 1.06-1.72; cT2-3: OR 1.52, 95%CI 1.33-1.74).

CONCLUSIONS

LOS >4 days after oral cavity cancer resection was significantly associated with negative surgical margins in clinical T2-3 oral cavity cancer, suggesting the possibility that patients undergoing flap reconstruction after resection have fewer positive surgical margins.

A systematic review of therapeutic outcomes following treatment of squamous cell carcinoma of the retromolar trigone

Squamous cell carcinoma (SCC) of the retromolar trigone (RMT) is a rare but potentially fatal disease that carries a poor prognosis due to its unique anatomic position. RMT SCCs tend to spread to vital nearby structures, including the tonsillar pillar, masticatory muscles, and underlying mandibular bone, even in their early stages, and aggressive treatment is often warranted. This systematic review appraises and qualitatively analyzes all available literature regarding the survival outcomes and prognosis of RMT SCC. Four databases were searched to identify all eligible articles published since January 1980. Of the 1,248 studies, a total of 15 studies representing 4,838 cases met the inclusion criteria. The evaluated patients had a high rate of advanced tumor stage (T3 or T4: 61.4%), lymph node metastasis (38.8%), and mandibular bone invasion (24%) at the time of diagnosis. Aggressive surgical treatments such as lip-splitting (92%), segmental mandibulectomy (61.1%), radical neck dissection (44.1%), and reconstruction using free flaps (49.5%) was undertaken for 92% of the pooled patient population. The mean rates for local, regional, and systemic recurrence were 23.40%, 8.40%, and 8.50%, respectively. The mean 5-year overall survival rate was 38.90%. Osteonecrosis was noted in 11.6% of the 328 patients who received radiotherapy. In conclusion, RMT SCC is generally associated with high recurrence, low survival, and high postoperative complication rates. Early diagnosis and aggressive treatment are thus warranted. However, significant methodological problems hamper current knowledge. Future studies of this topic that use randomized or cohort designs are thus needed.

Impact of Close Margins in Head and Neck Mucosal Squamous Cell Carcinoma: A Systematic Review

OBJECTIVES/HYPOTHESIS

The aim of the study is to investigate whether close surgical margins impact oncologic outcomes compared to clear or involved surgical margins. We hypothesize that close surgical margins portend worse outcomes compared with clear margins, but improved outcomes compared with involved margins.

STUDY DESIGN

Systematic review.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement standards, a systematic search was conducted for studies that reported oncologic outcomes following excision of primary mucosal head and neck squamous cell carcinoma (HNSCC). A meta-analysis was then performed, comparing local recurrence (LR), locoregional recurrence (LRR), and overall survival (OS) in patients with clear, close, and involved margins.

RESULTS

Twenty-six studies met the inclusion criteria, totaling 8,435 patients. About 96% of our included cases involved the oral cavity, 2% involved the oropharynx, and 2% other. Also, 68% of cases were T1/T2 and 32% were T3/T4. On meta-analysis, clear margins were associated with lower incidence of 5-year LR relative risk (RR) 0.50, 95% confidence interval [CI] 0.38-0.65) and higher 5-year OS (RR 1.22, 1.11-1.35), when compared with close margins. Involved margins had higher incidence of 5-year LR (RR 1.75, 1.16-2.64), higher incidence of LRR at last follow-up (RR 1.66, 1.37-2.00), and no difference in 5-year OS (RR 0.82, 0.60-1.11), when compared with close margins.

CONCLUSIONS

There is a stepwise improvement in oncologic outcomes as surgical margin categorically improves from involved to close to clear. Patients with close margins therefore may benefit from adjuvant therapy. Further research is required to investigate whether these findings are seen in non-oral cavity cases because they were underrepresented in this analysis. Laryngoscope, 2021.

MRE11 promotes oral cancer progression through RUNX2/CXCR4/AKT/FOXA2 signaling in a nuclease-independent manner

MRE11, the nuclease component of RAD50/MRE11/NBS1 DNA repair complex which is essential for repair of DNA double-strand-breaks in normal cells, has recently garnered attention as a critical factor in solid tumor development. Herein we report the crucial role of MRE11 in oral cancer progression in a nuclease-independent manner and delineate its key downstream effectors including CXCR4. MRE11 expression in oral cancer samples was positively associated with tumor size, cancer stage and lymph node metastasis, and was predictive of poorer patient survival and radiotherapy resistance. MRE11 promoted cell proliferation/migration/invasion in a nuclease-independent manner but enhanced radioresistance via a nuclease-dependent pathway. The nuclease independent promotion of EMT and metastasis was mediated by RUNX2, CXCR4, AKT, and FOXA2, while CXCR4 neutralizing antibody mitigated these effects in vitro and in vivo. Collectively, MRE11 may serve as a crucial prognostic factor and therapeutic target in oral cancer, displaying dual nuclease dependent and independent roles that permit separate targeting of tumor vulnerabilities in oral cancer treatment.

The impact of close surgical margins on recurrence in oral squamous cell carcinoma

BACKGROUND

Close margins influence treatment and outcome in patients with oral squamous cell carcinoma (OSCC). This study evaluates 187 cases of surgically treated OSCC regarding the impact of close margins on recurrence-free survival (RFS) and disease-specific survival (DSS).

METHODS

Predictors of worsened outcome were identified using Kaplan-Meier analysis and multivariate Cox regression analysis.

RESULTS

Tumour size [HR:1.70(0.95-3.08)], nodal status [HR:2.15(1.00-4.64)], presence of extracapsular spread (ECS) [HR:6.36(2.41-16.74)] and smoking history [HR:2.87(1.19-6.86)] were associated with worsened RFS. Similar factors were associated with worsened DSS. Close margins did not influence RFS or DSS.

CONCLUSIONS

While most conventional risk factors for OSCC conferred a worsened outcome, close margins did not. One explanation for this would be that close margins (< 5 mm) are equivalent to clear margins and the cutoff definition for a close margin should be re-evaluated. Lack of standardized pathology could also reduce accuracy of reporting of close surgical margins.

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.

Impact of surgical resection margins less than 5 mm in oral cavity squamous cell carcinoma: a systematic review

Background: The width of the surgical resection margin impacts recurrence and survival in oral cavity squamous cell carcinoma (OSCC). The most commonly used definition of a clear margin is one larger than 5 mm, although due to anatomical restrictions to e.g. bone or vessels, this size is not always feasible. Margins less than 5 mm affect postsurgical strategies and prognoses, and further knowledge of margins smaller than 5 mm is needed.Aims/objectives: We aimed to systematically review the literature on the impact of surgical resection margins less than 5 mm addressing recurrence and survival in OSCC.Methods/materials: A systematic literature search was performed in the PubMed and EMBASE databases identifying studies regardless of publication date that examined margin less than 5 mm, with or without a comparison to size of 5 mm or greater, in patients with OSCC. We assessed the impact on recurrence and survival.Results: We identified six studies (n = 1514 patients); all studies, investigated recurrence, and three (n = 768 patients) evaluated survival. The studies had noteworthy variability in, e.g. follow-up times, anatomical sublocations, T- and N-stage classifications, and outcome measures. Five studies (n = 1387 patients) reported that margins smaller than 5 mm would be safe and would not affect survival or recurrence negatively compared to their own data on larger margins. One study reported that a clear resection margin greater than five mm was necessary to ensure optimal outcomes.Conclusion/significance: The literature showed significant bias and risk issues. In five of the included studies with 1387 patients, we found in selected cases, where margins larger than 5 mm are not possible, a tendency regarding resection margins less than 5 mm to be sufficient for the surgical treatment of patients with primary OSCC. However, the data is insufficient to enable altered recommendations of resection margins in patients with primary OSCC.

Assessment of surgical tumor-free resection margins in fresh squamous-cell carcinoma resection specimens of the tongue using a clinical MRI system

BACKGROUND

Current intraoperative methods of visual inspection and tissue palpation by the surgeon, and frozen section analysis cannot reliably prevent inadequate surgical margins in patients treated for oral squamous-cell carcinoma (OSCC). This study assessed feasibility of MRI for the assessment of surgical resection margins in fresh OSCC specimens.

METHODS

Ten consecutive tongue specimens containing OSCC were scanned using 3 T clinical whole-body MRI. Two radiologists independently annotated OSCC location and minimal tumor-free margins. Whole-mount histology was the reference standard.

RESULTS

The positive predictive values (PPV) and negative predictive values (NPV) for OSCC localization were 96% and 75%, and 87% and 79% for reader 1 and 2, respectively. The PPV and NPV for identification of margins <5 mm were 38% and 91%, and 5% and 87% for reader 1 and 2, respectively.

CONCLUSIONS

MRI accurately localized OSCC with high inter-reader agreement in fresh OSCC specimens, but it seemed not yet feasible to accurately assess the surgical margin status.

What is the real prognostic value of close margins in oral oncology?

AIM

The surgical margin is usually considered an important prognostic factor in oral oncology. However, the real value of a close surgical margin and its relationship with survival is still unclear. Thus, the present report sought to identify the relationship between close surgical margins and overall 3-year survival, whilst also analyzing the association between such margins and recurrence.

MATERIALS AND METHODS

The medical records of 200 patients affected by oral squamous cell carcinoma were retrospectively reviewed. The patients were divided into three groups: positive margin (0-2 mm), close margin (2-5 mm), and negative margin (>5 mm). The relationship between surgical margins and overall survival and recurrence rate was analyzed.

RESULTS

Surgical margins and reoperation were found to have no significant association with overall survival (P > 0.05). Overall survival was 63% in our sample. Specifically, this was 50%, 64.7% and 66.2% in patients with positive, close and free margins, respectively. Perineural invasion, pN, and locoregional or cervical recurrences were the factors most directly related to overall survival.

DISCUSSION

The results of this study indicate that surgical margins are not directly related to overall survival and other factors might significantly influence patient outcomes. Advanced T stage, node involvement, perineural invasion, and ECS are strongly linked with patient survival (P < 0.05). These findings should be carefully evaluated in patients with close surgical margins. Our results indicate that an aggressive adjuvant treatment of patients with close surgical margins could help in obtaining a similar pattern of overall survival with patients with negative margins.

Impact of dysplastic surgical margins for patients with oral squamous cell carcinoma

OBJECTIVES

Dysplastic changes at the surgical margin of oral squamous cell carcinoma (OSCC) could be encountered frequently. However, the impact of a dysplastic surgical margin on patients with OSCC remains unclear.

MATERIALS AND METHODS

Retrospectively, we reviewed patients with OSCC who were diagnosed and treated at the National Taiwan University Hospital between January 2010 and December 2015. Patients were divided into four groups: clear (≥5 mm), close (<5 mm), positive, and dysplastic margins.

RESULTS

Of 1642 patients, 596 had clear margin, 169 had positive margin, 707 had close margin, and 170 had dysplastic margin. The mean age at diagnosis was 55 ± 11 years (range, 16-97 years). Dysplastic margins were frequently present in patients with primary T1/T2 OSCC (odds ratio [OR] = 1.7, p = 0.009), tumor without perineural invasion (OR = 1.48, p = 0.04), and tumor thickness ≤10 mm (OR = 1.94, p = 0.001). In patients with clear, close, positive, and dysplastic margins, the 5-year disease-free survival rates were 63.1%, 51%, 37.2%, and 54.7%, respectively; overall survival (OS) rates were 71.1%, 61.9%, 49%, and 72%, respectively. Disease-free and overall survival were not significantly different in patients with dysplastic and clear margins (p = 0.37 and p = 0.38, respectively). Adjuvant radiotherapy had no significant benefit for patients with dysplastic margins. Finally, a multivariate analysis showed that the presence of a dysplastic margin was not an independent risk factor for disease-free (p = 0.43) and overall survival (p = 0.71).

CONCLUSIONS

The survival rates of the patients with OSCC who had dysplastic margin were significantly better than those with positive margin.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

The impact of surgical margin status on the outcomes of locally advanced hypopharyngeal squamous cell carcinoma treated by primary surgery

BACKGROUND

The extent of surgical safety margin remained unclear in hypopharyngeal carcinoma surgery.

AIM

The purpose of this study was to evaluate the influence of surgical margin status on the outcomes of patients with advanced hypopharyngeal carcinoma.

MATERIAL AND METHODS

A retrospective analysis of clinical data was performed in 205 patients with stage III/IV hypopharyngeal carcinoma treated by primary surgery between January 2005 and December 2014. There were 129 patients with clear surgical margins (≥5 mm) and 76 with close surgical margins (<5 mm). The clinical characteristics and treatment outcomes were compared between the two groups.

RESULTS

Close surgical margin (cSM) was found to be a significant risk factor for local recurrence, overall survival (OS) and disease-specific survival (DSS). Analysis by stratification according to pT classification showed that the OS and DSS rates of T1/T2 tumors with clear surgical margins (nSM) were significantly higher than those with cSM (p < .05), while there was no significant difference in the OS and DSS rates between T3/T4 tumors with cSM and nSM (p > .05).

CONCLUSIONS AND SIGNIFICANCE

The tailored extent of surgical resection margin was recommended for locally advanced hypopharyngeal carcinomas according to primary tumor stage.

Depth of invasion on pathological outcomes in clinical low-stage oral tongue cancer patients

OBJECTIVES

Depth of invasion was added to the eighth edition American Joint Committee on Cancer guidelines for T staging of HPV-negative oral cavity squamous cell carcinoma. Our aim was to determine the impact of depth of invasion on pathological variables and outcomes in low-stage tongue cancer patients. We also examine the impact of tumor thickness and tumor clinical staging for comparison.

SUBJECTS AND METHODS

All clinical T1/T2 N0 HPV-negative tongue squamous cell carcinoma patients who received elective neck dissections at our institution between 2000 and 2015 were included. Logistic regression models and Cox proportional hazard models were used to examine pathological variables, recurrence, and 3-year disease-free survival.

RESULTS

Sixty-seven patients met criteria; the mean age was 52.0 (SD: 17.7). Depth of invasion was a significant predictor of occult metastasis (OR: 2.0, p = 0.05) and lymphovascular invasion (OR: 4.1, p = 0.02), and tumor thickness was a significant predictor of lymphovascular invasion (OR: 3.3, p = 0.04). None of the variables were predictive of recurrence or disease-free survival.

CONCLUSION

Depth of invasion at biopsy may be a potential useful metric to inform on regional management selection in this radiographic node-negative population.

Coherent Raman Scattering Microscopy for Evaluation of Head and Neck Carcinoma

Objective We aim to describe a novel, label-free, real-time imaging technique, coherent Raman scattering (CRS) microscopy, for histopathological evaluation of head and neck cancer. We evaluated the ability of CRS microscopy to delineate between tumor and nonneoplastic tissue in tissue samples from patients with head and neck cancer. Study Design Prospective case series. Setting Tertiary care medical center. Subjects and Methods Patients eligible were surgical candidates with biopsy-proven, previously untreated head and neck carcinoma and were consented preoperatively for participation in this study. Tissue was collected from 50 patients, and after confirmation of tumor and normal specimens by hematoxylin and eosin (H&E), there were 42 tumor samples and 42 normal adjacent controls. Results There were 42 confirmed carcinoma specimens on H&E, and CRS microscopy identified 37 as carcinoma. Of the 42 normal specimens, CRS microscopy identified 40 as normal. This resulted in a sensitivity of 88.1% and specificity of 95.2% in distinguishing between neoplastic and nonneoplastic images. Conclusion CRS microscopy is a unique label-free imaging technique that can provide rapid, high-resolution images and can accurately determine the presence of head and neck carcinoma. This holds potential for implementation into standard practice, allowing frozen margin evaluation even at institutions without a histopathology laboratory.

The importance of margins in head and neck cancer

An estimated 200,000 deaths each year worldwide are due to cancer of the head and neck, mostly mucosal squamous cell carcinoma and nonmelanoma skin cancer. The status of surgical margins is important for prognosis and need for adjuvant therapy. We will discuss how margin status impacts outcomes and therapy, and the conundrum of determining margin status.

DNA methylome analysis identifies epigenetic silencing of FHIT as a determining factor for radiosensitivity in oral cancer: an outcome-predicting and treatment-implicating study

Radioresistance is still an emerging problem for radiotherapy of oral cancer. Aberrant epigenetic alterations play an important role in cancer development, yet the role of such alterations in radioresistance of oral cancer is not fully explored. Using a methylation microarray, we identified promoter hypermethylation of FHIT (fragile histidine triad) in radioresistant OML1-R cells, established from hypo-fractionated irradiation of parental OML1 radiosensitive oral cancer cells. Further analysis confirmed that transcriptional repression of FHIT was due to promoter hypermethylation, H3K27me3 and overexpression of methyltransferase EZH2 in OML1-R cells. Epigenetic interventions or depletion of EZH2 restored FHIT expression. Ectopic expression of FHIT inhibited tumor growth in both in vitro and in vivo models, while also resensitizing radioresistant cancer cells to irradiation, by restoring Chk2 phosphorylation and G2/M arrest. Clinically, promoter hypermethylation of FHIT inversely correlated with its expression and independently predicted both locoregional control and overall survival in 40 match-paired oral cancer patient samples. Further in vivo therapeutic experiments confirmed that inhibition of DNA methylation significantly resensitized radioresistant oral cancer cell xenograft tumors. These results show that epigenetic silencing of FHIT contributes partially to radioresistance and predicts clinical outcomes in irradiated oral cancer. The radiosensitizing effect of epigenetic interventions warrants further clinical investigation.

Poor Correlation of Histologic Parameters Between Biopsy and Resection Specimen in Early Stage Oral Squamous Cell Carcinoma

OBJECTIVES

Infiltration depth, perineural growth (PG), vascular invasive growth (VG), and infiltrative growth (IG) are associated with regional metastases in oral squamous cell carcinomas (OSCCs). Preoperative knowledge of these parameters could facilitate the treatment planning of the neck. The aim of this study was to evaluate if the biopsy specimen correlates with the resection specimen.

METHODS

In total, 149 patients with a pT1-2cN0 OSCC were included. Biopsy thickness and tumor thickness were analyzed. Occurrence of PG, VG, and IG was determined on biopsy and resection specimens and correlated with the N status and survival. Sensitivity, specificity, positive and negative predictive value, and diagnostic gain of the biopsy specimen were calculated.

RESULTS

N+ patients showed PG, VG, and IG significantly more often in the resection specimen compared with N- patients (P = .02, P = .001, and P = .001, respectively). Histologic parameters in the biopsy specimens did not correlate with N status or survival. The positive diagnostic gain for biopsy specimens with PG, VG, and IG was 57%, 40%, and 19%, respectively. The negative diagnostic gain was 2%, 0%, and 22%, respectively.

CONCLUSIONS

Histologic parameters in biopsy specimens do not represent the resection specimen. Determination of histologic parameters in routinely taken biopsy specimens of OSCC is not helpful in deciding whether to treat the neck.

Molecular characterization of oral squamous cell carcinoma using targeted next-generation sequencing

OBJECTIVES

Many genetic factors play an important role in the development of oral squamous cell carcinoma. The aim of this study was to assess the mutational profile in oral squamous cell carcinoma using formalin-fixed, paraffin-embedded tumors from a Taiwanese population by performing targeted sequencing of 26 cancer-associated genes that are frequently mutated in solid tumors.

METHODS

Next-generation sequencing was performed in 50 formalin-fixed, paraffin-embedded tumor specimens obtained from patients with oral squamous cell carcinoma. Genetic alterations in the 26 cancer-associated genes were detected using a deep sequencing (>1000X) approach.

RESULTS

TP53, PIK3CA, MET, APC, CDH1, and FBXW7 were most frequently mutated genes. Most remarkably, TP53 mutations and PIK3CA mutations, which accounted for 68% and 18% of tumors, respectively, were more prevalent in a Taiwanese population. Other genes including MET (4%), APC (4%), CDH1 (2%), and FBXW7 (2%) were identified in our population.

CONCLUSIONS

In summary, our study shows the feasibility of performing targeted sequencing using formalin-fixed, paraffin-embedded samples. Additionally, this study also reports the mutational landscape of oral squamous cell carcinoma in the Taiwanese population. We believe that this study will shed new light on fundamental aspects in understanding the molecular pathogenesis of oral squamous cell carcinoma and may aid in the development of new targeted therapies.

Life expectancy and expected years of life lost to oral cancer in Taiwan: a nation-wide analysis of 22,024 cases followed for 10 years

OBJECTIVES

This analysis examined the life expectancies (LE) and expected years of life lost (EYLL) in relation to oral cancer in Taiwan.

MATERIALS AND METHODS

A semi-parametric extrapolation method was applied to estimate gender, age, histology, subsite, and stage stratified LE, EYLL of 22,024 pathologically verified oral cancer patients retrospectively recruited from the National Cancer Registry of Taiwan during 2002-2009, who were followed up to 2011.

RESULTS

The patients were predominantly male 20,101, (91.3%), and over 80% were less than 65years old. The mean age at diagnosis of males was younger than that of females (52.73years vs. 60.76years). The LE after diagnosis was longer among females than males (15.26years vs. 12.73years), with a smaller loss of the corresponding EYLL (8.88years vs. 14.05years), which prevails after stratification by age and stage. More than half of the oral cancer cases were diagnosed at a later stage, with 2921 cases (13.3%) of stage III and 8488 (38.5%) of stage IV. The five-year overall survival rate of oral cancer for stages I, II, III, and IV were 78.98%, 69.38%, 54.62%, and 36.17%, respectively. The earlier the diagnosis, the longer the life expectancy and the smaller the EYLL.

CONCLUSIONS

We concluded that early detection and early intervention of oral cancer can prolong life expectancy and reduce the years of life lost, indicating the importance of proactive screening and oral hygiene.

Positive Surgical Margins in Early Stage Oral Cavity Cancer

Objective

To report the incidence of positive surgical margins in early oral cavity cancer and identify patient, tumor, and system factors associated with their occurrence.

Study Design and Setting

Retrospective analysis of the National Cancer Database.

Subjects and Methods

Patients diagnosed with stage I or II oral cavity squamous cell cancer between 1998 and 2011 were identified. Univariate and multivariate analyses of factors associated with positive margins were conducted.

Results

In total, 20,602 patients with early oral cancer were identified. Margin status was reported in 94.8% of cases, and positive margins occurred in 7.5% of those cases. Incidence of positive margins by institution varied from 0% to 43.8%, with median incidence of 7.1%. Positive margins were associated with clinical factors including stage II disease (odds ratio [OR], 1.75; 95% confidence interval [CI], 1.55-1.98), intermediate grade (OR, 1.20; 95% CI, 1.04-1.37), high grade (OR, 1.68; 95% CI, 1.39-2.03), and floor of mouth (OR, 1.78; 95% CI, 1.52-2.08), buccal mucosa (OR, 2.06; 95% CI, 1.59-2.68), and retromolar locations (OR, 2.40; 95% CI, 1.85-3.11). Positive margins were also associated with treatment at nonacademic cancer centers (OR, 1.23; 95% CI, 1.04-1.44) and institutions with a low oral cancer case volume (OR, 1.45; 95% CI, 1.23-1.69).

Conclusion

Positive margins are associated with tumor factors, including stage, grade, and site, reflecting disease aggressiveness and difficulty of resection. Positive margins also are associated with factors such as treatment facility type, hospital case volume, and geographic region, suggesting potential variation in quality of care. Margin status may be a useful quality measure for early oral cavity cancer.

Unexpected close surgical margin in resected buccal cancer: very close margin and DAPK promoter hypermethylation predict poor clinical outcomes

OBJECTIVES

In resected buccal cancer patients, an unexpected close surgical margin has been observed to correlate with poor clinical outcomes. However, close surgical margin alone does not independently guide post-operative therapies, revealing a clinical debate. Hence, the present study intended to explore epigenetic-based bio-predictors for further stratifying this debating patient population.

MATERIALS AND METHODS

Between 2000 and 2008, we retrospectively recruited 44 resected buccal cancer patients with a close surgical margin of ≤5 mm. All patients had post-operative radiotherapy. Genomic DNA was extracted from tumor-enrich areas that contained cancer cells of >70%. Methylation-specific PCR was performed to detect promoter methylation of four tumor suppressor genes, including RASSF1A, DAPK, IRF8, and SFRP1. Post-irradiation locoregional control was defined as the primary end point.

RESULTS

There were 40 males and 4 females, with a median age of 53.5 years (range, 32-82 years). Multivariate analysis identified two independent predictors for locoregional recurrence: very close margin of ≤1 mm (HR: 4.96; 95% CI, 1.63-15.09; P=0.018) and promoter hypermethylation of DAPK (HR: 2.83; 95% CI, 1.05-7.63; P=0.042). The highest risk of locoregional recurrence was observed in patients with both of the two factors (HR, 8.05; 95% CI, 2.56-25.82; P=0.002) when compared with patients with none. Shorter disease-free survival, but not overall survival, was also observed.

CONCLUSION

More aggressive managements should be considered in resected buccal cancer patients with both very close margin and DAPK promoter hypermethylation rather than post-operative observation or radiotherapy alone.

The clinical predictive factors for subsequent distant metastasis in patients with locoregionally advanced oral squamous cell carcinoma

OBJECTIVES

Only a small portion of the patients with locoregionally advanced oral squamous cell carcinoma (OSCC) experience subsequent distant metastasis. This study is to evaluate the occurrence of distant metastasis after curative treatment and to explore the predictive factors for subsequent distant metastasis in patients with locoregionally advanced OSCC.

MATERIALS AND METHODS

The medical records of all patients with locoregionally advanced OSCC without distant metastasis at the time of diagnosis (AJCC stage III, IV but not IVC) who underwent curative surgery with or without adjuvant radiation between 2004 and 2009 were retrospectively reviewed.

RESULTS

A total of 628 patients were enrolled, including 562 male and 66 female patients. The 5-year distant metastasis rate was 13.2%. The 5-year disease-free and overall survival rates were 57.0% and 60.3%, respectively. Multivariate analyses revealed that poorly differentiated tumors (HR=2.3 (1.16-4.53), p=0.02) and contralateral neck metastasis (HR=7.55 (3.20-17.83), p<0.001) were independent adverse factors for distant metastasis-free survival. The 5-year distant metastasis rates of 447 patients with well-differentiated tumors, 140 patients with moderately differentiated tumors and 41 patients with poorly differentiated tumors were 12.1%, 18.2%, and 34.1%, respectively. The 5-year distant metastasis rates of 227 patients without neck metastasis, 350 patients with ipsilateral neck metastasis and 51 patients with contralateral neck metastasis were 6.7%, 15.1%, and 55.3%, respectively.

CONCLUSIONS

Poorly differentiated tumors and contralateral neck metastasis were independent factors for subsequent distant metastasis in patients with locoregionally advanced OSCC.