Treatment failure and margin status in head and neck cancer. A critical view on the potential value of molecular pathology

[On the relevance of histopathology results in oropharyngeal cancer with mandibular involvement and the necessary imaging]

BACKGROUND

Planning of surgical procedures in patients suffering from oropharyngeal cancer requires appropriate imaging, particularly in consideration of the spatial relationship to the mandible. Resection of portions of the mandible (box, marginal, or segmental resection) is often necessary, while simultaneously avoiding overtreatment. Typically, a computed tomography (CT) scan is initially performed. However, the question arises of whether CT alone is adequate for reliable assessment of mandibular involvement.

MATERIALS AND METHODS

A patient cohort of 25 individuals aged 44-79 years (mean 62 years) undergoing partial oropharyngeal resection with segmental mandibular resection was examined. The indication for segmental resection was based on the close relationship of the tumor to the mandible observed in imaging. Reconstruction was consistently carried out with a reconstruction plate and free or pedicled flaps. Preoperative radiological findings were compared with histopathology results after decalcification of the mandibular bone.

RESULTS

Cortical tumor infiltration was observed in the mandible in 9 patients (36%). Preoperatively, clear bone infiltration had been identified in CT in only 2 of these 9 patients; in the remaining 7, only direct tumor contact with the mandible was evident. Magnetic resonance imaging (MRI) revealed bone infiltration in 1 of these 7 patients.

DISCUSSION

Adhering to safety margins requires a radical surgical approach and reliable intraoperative frozen section analysis. However, at the bone level, intraoperative frozen section analysis is technically impractical due to the required decalcification. Only after decalcification can the entire specimen be assessed for tumor infiltration. In our cohort, a significant discrepancy in terms of bone infiltration was noted between preoperative imaging assessments and postoperative histopathology. CT preoperatively identified bone infiltration in only 8% of our patients. In two thirds of the specimens, no bone infiltration was evident after decalcification and histopathological processing, retrospectively indicating overtreatment by segmental resection; box or marginal resections may have been sufficient in these cases. Therefore, when tumors are adjacent to the bone in CT, MRI should also be performed preoperatively to more reliably detect bone infiltration.

Rethinking Surgical Margins: A New Approach to Predict Outcomes in Oral Squamous Cell Carcinoma

OBJECTIVE

The traditional categorical division of surgical margins using a 5 mm cutoff in oral cavity squamous cell carcinoma (OCSCC) is controversial. The primary aim of this study was to investigate the presence of an optimal cutoff point or, alternatively, assess the potential improvement in predictive value by considering the surgical margins as a continuum.

METHODS

Retrospective analysis of OCSCC patients at a tertiary medical center in 1995-2020. Clinical, pathological, and surgical data were evaluated for effect on survivability by regression analyses.

RESULTS

The cohort included 266 patients (48.1% male, mean age 65.4 ± 17.7). Patient stratification by categorical margin status yielded no significant between-group differences in survival (p = 0.54). Significance was achieved when margin distance was reevaluated as a continuous variable (p = 0.0018). Similar results were shown in local control (categorical p = 0.59 vs. continuous p = 0.06). Multivariate model excluded possible confounders. A predictive model was created to provide a more accurate prediction of survival.

CONCLUSIONS

The continuum spectrum of margin distance better predicts survival outcomes and locoregional control in OCSCC.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Comparison of histopathological margins after resection of oral squamous cell carcinoma using sharp dissection versus mono-polar electrocautery in T1 and T2 tumors

The study aims to compare histopathological margins after resection of oral squamous cell carcinoma (OSCC) with different surgical techniques: conventional sharp resection (SR) with scalpel versus monopolar electrocautery (ME). Hence, the question arises whether thermal damage by performing monopolar electrocautery surgery will lead to close margins more frequently than by using scalpels. 152 patients were included in this study. All patients received a primary tumor resection either performed with SR or with ME. Surgical margins were distributed into two groups: ≥5 mm (clear margins) and < 5 mm (close or involved margins). For comparing homogeneous groups, we considered tumor localizations, diameter and depth of invasion. The results were statistically analyzed by applying the Wilcoxon-Mann-Whitney-U-Test. The distribution of tumor diameter and depth of invasion was equal in both groups. There was no statistically significant difference between the amount of free surgical margins using SR or ME (p = 0.884). According to this study, the use of the monopolar electrocautery for tumor resection in the oral cavity does not increase the rate of compromised resection margins compared to the conventional scalpel.

Surgical margin status and role of adjuvant therapy in human papillomavirus-positive oropharyngeal cancer

BACKGROUND

We analyzed the difference in treatment results according to safety margin range and studied the role of adjuvant therapy in patients with human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC).

MATERIALS AND METHODS

A total of 279 patients with HPV+ OPSCC were included in this study.

RESULTS

Surgical margin and T classification were significant prognostic factors related to death. The difference in locoregional recurrence was analyzed by dividing the safety margin into groups of <1, 1-5, and >5 mm. There was no significant difference in local-regional recurrence for T1-T2 lesions between the three groups. Adjuvant therapy can significantly reduce disease recurrence in HPV+ OPSCC patients with risk factors.

CONCLUSIONS

In T1-T2 lesions without other risk factors, even with a safety margin ≥1 mm, adjuvant therapy can potentially be omitted. Adjuvant therapy can significantly reduce disease recurrence in HPV+ OPSCC patients with risk factors.

Significance of Worst Pattern of Invasion-5 in Early-Stage Oral Cavity Squamous Cell Carcinoma

BACKGROUND

There is an ongoing need to identify pathologic prognosticators in early-stage oral cavity squamous cell carcinoma (OCSCC) to aid selection of patients who may benefit from adjuvant treatment. The objective of this study was to evaluate the prognostic ability of worst pattern of invasion-5 (WPOI-5) defined by the presence of satellite nodules, extratumoural perineural invasion (PNI) and/or extratumoural lymphovascular space invasion (LVI) in low-stage, node negative OCSCC.

METHODS

This was a retrospective study of 160 patients with T1/T2N0 tumours staged using TNM7 treated surgically. Histology of the primary tumour was re-reviewed as appropriate to assess for the presence of WPOI-5 parameters. Univariate and multivariate analysis assessing impact of pathological features on survival outcomes was performed.

RESULTS

On univariate analysis, WPOI-5 and its 3 constituent components of satellite nodules, extratumoural PNI and extratumoural LVI were all significantly associated with disease-specific survival (DSS) and overall survival (OS). On multivariate analysis, satellite nodules (odds ratio 6.61, 95% CI 2.83-15.44, p < 0.0001) and extratumoural LVI (odds ratio 9.97, 95% CI 2.19-45.35, p = 0.003) were independently associated with OS. Postoperative radiotherapy (odds ratio 0.40, 95% CI 0.19-0.87, p = 0.02) and non-tongue subsite (odds ratio 3.03, 95% CI 1.70-5.39, p = 0.0002) were also significantly associated with OS on multivariate analysis.

CONCLUSION

Satellite nodules and extratumoural LVI correlated significantly with survival outcomes in our early-stage OSCC cohort. Further study is required to investigate the benefit of adjuvant treatment in these cases and to ascertain if WPOI-5 parameters including satellite nodules should be mandatory reporting data elements.

Cellular states are coupled to genomic and viral heterogeneity in HPV-related oropharyngeal carcinoma

Head and neck squamous cell carcinoma (HNSCC) includes a subset of cancers driven by human papillomavirus (HPV). Here we use single-cell RNA-seq to profile both HPV-positive and HPV-negative oropharyngeal tumors, uncovering a high level of cellular diversity within and between tumors. First, we detect diverse chromosomal aberrations within individual tumors, suggesting genomic instability and enabling the identification of malignant cells even at pathologically negative margins. Second, we uncover diversity with respect to HNSCC subtypes and other cellular states such as the cell cycle, senescence and epithelial-mesenchymal transitions. Third, we find heterogeneity in viral gene expression within HPV-positive tumors. HPV expression is lost or repressed in a subset of cells, which are associated with a decrease in HPV-associated cell cycle phenotypes, decreased response to treatment, increased invasion and poor prognosis. These findings suggest that HPV expression diversity must be considered during diagnosis and treatment of HPV-positive tumors, with important prognostic ramifications.

Predictors of survival in advanced oral cancers after salvage surgery with free tissue flap reconstruction

OBJECTIVE

To identify prognostic factors for patients with advanced persistent, recurrent, or 2nd primary oral cavity squamous cell carcinoma (OCSCC) potentially unsuitable for salvage surgery with free tissue flap (FTF) reconstruction.

MATERIALS AND METHODS

A population-based cohort of 83 consecutive patients with advanced OCSCC who underwent salvage surgery with FTF reconstruction at a tertiary referral centre between 1990 and 2017. Retrospective uni- and multivariable analyses were performed to identify factors affecting all-cause mortality (ACM), i.e., overall survival (OS), as well as disease-specific mortality (DSM), i.e., disease-specific survival (DSS) after salvage surgery.

RESULTS

Median disease-free interval until recurrence was 15 months with recurrent stage I/II in 31% and III/IV in 69%. Median age at salvage surgery was 67 years (range 31-87) and the median follow-up (alive patients) 126 months. At 2, 5, and 10 years after salvage surgery, respectively, DSS rates were 61%, 44%, and 37% and OS rates 52%, 30%, and 22%. Median DSS was 26 and OS 43 months. Multivariable analysis identified recurrent clinical regional (cN-plus) disease [HR 3.57; p < .001] and elevated gamma-glutamyl transferase (GGT) [HR 3.30; p = .003] as independent pre-salvage predictors for poor OS after salvage, whereas initial cN-plus [HR 2.07; p = .039] and recurrent cN-plus disease [HR 5.14; p < .001] predicted poor DSS. Among post-salvage factors, extranodal extension according to histopathology [HR ACM 6.11; HR DSM 9.99; p < .001] as well as positive [HR ACM 4.98; DSM 7.51; p < 0.001] and narrow surgical margins [HR ACM 2.12; DSM HR 2.80; p < 0.01] emerged as independent factors for poor survival.

CONCLUSION

While salvage surgery with FTF reconstruction is the primary curative option for patients with advanced recurrent OCSCC, the present findings may help guide discussions with patients who have advanced recurrent regional disease and high GGT preoperatively, especially if there is a small chance of reaching surgical radicality.

Intraoperative Use of Wide-Field Optical Coherence Tomography to Evaluate Tissue Microstructure in the Oral Cavity and Oropharynx

Importance

Involvement of deep margins represents a significant challenge in the treatment of oropharyngeal cancer, and given practical limitations of frozen-section analysis, a need exists for real-time, nondestructive intraoperative margin analysis. Wide-field optical coherence tomography (WF-OCT) has been evaluated as a tool for high-resolution adjunct specimen imaging in breast surgery, but its clinical application in head and neck surgery has not been explored.

Objective

To evaluate the utility of WF-OCT for visualizing microstructures at margins of excised oral and oropharyngeal tissue.

Design, Setting, and Participants

This nonrandomized, investigator-initiated qualitative study evaluated the feasibility of the Perimeter Medical Imaging AI Otis WF-OCT device at a single academic center. Included participants were adults undergoing primary ablative surgery of the oral cavity or oropharynx for squamous cell carcinoma in 2018 and 2019. Data were analyzed in October 2019.

Exposures

Patients were treated according to standard surgical care. Freshly resected specimens were imaged with high-resolution WF-OCT prior to routine pathology. Interdisciplinary interpretation was performed to interpret WF-OCT images and compare them with corresponding digitized pathology slides. No clinical decisions were made based on WF-OCT image data.

Main Outcomes and Measures

Visual comparisons were performed between WF-OCT images and hematoxylin and eosin slides.

Results

A total of 69 specimens were collected and scanned from 53 patients (mean [SD] age, 59.4 [15.2] years; 35 [72.9%] men among 48 patients with demographic data) undergoing oral cavity or oropharynx surgery for squamous cell carcinoma, including 42 tonsillar tissue, 17 base of the tongue, 4 buccal tissue, 3 mandibular, and 3 other specimens. There were 41 malignant specimens (59.4%) and 28 benign specimens (40.6%). In visual comparisons of WF-OCT images and hematoxylin and eosin slides, visual differentiation among mucosa, submucosa, muscle, dysplastic, and benign tissue was possible in real time using WF-OCT images. Microarchitectural features observed in WF-OCT images could be matched with corresponding features within the permanent histology with fidelity.

Conclusions and Relevance

This qualitative study found that WF-OCT imaging was feasible for visualizing tissue microarchitecture at the surface of resected tissues and was not associated with changes in specimen integrity or surgical and pathology workflow. These findings suggest that formal clinical studies investigating use of WF-OCT for intraoperative analysis of deep margins in head and neck surgery may be warranted.

Magnetic Resonance Imaging-Based Radiomics Features Associated with Depth of Invasion Predicted Lymph Node Metastasis and Prognosis in Tongue Cancer

Background

Adequate safe margin in tongue cancer radical surgery is one of the most important prognostic factors. However, the role of peritumoral tissues in predicting lymph node metastasis (LNM) and prognosis using radiomics analysis remains unclear.

Purpose

To investigate whether magnetic resonance imaging (MRI)‐based radiomics analysis with peritumoral extensions contributes toward the prediction of LNM and prognosis in tongue cancer.

Study type

Retrospective.

Population

Two hundred and thirty‐six patients (38.56% female) with tongue cancer (training set, N = 157; testing set, N = 79; 37.58% and 40.51% female for each).

Field Strength/Sequence

1.5 T; T2‐weighted turbo spin‐echo images.

Assessment

Radiomics models (R_prim, R_prim+3, R_prim+5, R_prim+10, R_prim+15) were developed with features extracted from the primary tumor without or with peritumoral extensions (3, 5, 10, and 15 mm, respectively). Clinicopathological characteristics selected from univariate analysis, including MRI‐reported LN status, radiological extrinsic lingual muscle invasion, and pathological depth of invasion (DOI) were further incorporated into radiomics models to develop combined radiomics models (CR_prim, CR_prim+3, CR_prim+5, CR_prim+10, CR_prim+15). Finally, the model performance was validated in the testing set. DOI was measured from the adjacent normal mucosa to the deepest point of tumor invasion.

Statistical Tests

Chi‐square test, regression analysis, receiver operating characteristic curve (ROC) analysis, decision analysis, spearman correlation analysis. The Delong test was used to compare area under the ROC (AUC). P < 0.05 was considered statistically significant.

Results

Of all the models, the CR_prim+10 reached the highest AUC of 0.995 in the training set and 0.872 in the testing set. Radiomics features were significantly correlated with pathological DOI (correlation coefficients, −0.157 to −0.336). The CR_prim+10 was an independent indicator for poor disease‐free survival (hazard ratio, 5.250) and overall survival (hazard ratio, 17.464) in the testing set.

Data Conclusion

Radiomics analysis with a 10‐mm peritumoral extension had excellent power to predict LNM and prognosis in tongue cancer.

Experimental study on needle insertion force to minimize tissue deformation in tongue tissue

This study reports on the effects of insertion velocity, needle tip geometry and needle diameter on tissue deformation and maximum insertion force. Moreover, the effect of multiple insertions with the same needle on the maximum insertion force is reported. The tissue deformation and maximum insertion force strongly depend on the insertion velocity and the tip geometry. No correlation was found between the outer diameter and the maximum insertion force for small needles (30G - 32G). The endurance experiments showed no remarkable difference in the maximum insertion force during 100 insertions.

Mammary analogue secretory carcinoma of a salivary gland of the hard palate with contralateral cervical lymph node metastases: A case report

Mammary analogue secretory carcinoma (MASC) is a rare malignant tumour of the salivary glands, with only few cases reported in the literature to date. Initial preoperative staging is crucial for all patients with an oral malignancy to visualize the tumour, detect lymph node or distant metastases and plan therapeutic interventions. In the case presented herein, radiological imaging revealed a tumour of the right hard palate with suspected positive contralateral lymph nodes. Therefore, local tumour resection comprising hemimaxillectomy and bilateral neck dissection was performed. The diagnosis of MASC was finally based on characteristic histopathological and immunohistochemical findings, such as S100 protein and mammaglobin positivity. The diagnosis of MASC may be challenging, as such findings lack specificity. To confirm the diagnosis, molecular genetic examinations may be performed to detect a highly specific ETV6-NTRK3 fusion gene. Depending on the results of these examinations, surgery, alone or combined with adjuvant radiation or chemoradiation, is the recommended approach. In summary, MASC should be treated similarly to other low-grade salivary gland tumours, such as acinic cell carcinoma, as they exhibit biological and histopathological similarities.

Impact of Planning Method (Conventional versus Virtual) on Time to Therapy Initiation and Resection Margins: A Retrospective Analysis of 104 Immediate Jaw Reconstructions

Simple Summary

Computer-aided design and manufacturing of osseous reconstructions are currently widely used in jaw reconstructive surgery, providing an improved surgical outcome and decreased procedural stumbling block. However, data on the influence of planning time on the time-to-surgery initiation and resection margin are missing in the literature. This retrospective, monocentric study compares process times from the first patient contact in hospital, time of in-house or out-of-house biopsy for tumor diagnosis and surgical therapy of tumor resection, and immediate reconstruction of the jaw with free fibula flaps (FFF). Two techniques for reconstruction are used: Virtual surgical planning (VSP) and non-VSP. A total of 104 patients who underwent FFF surgery for immediate jaw reconstruction from 2002 to 2020 are included. The study findings fill the gaps in the literature and obtain clear insights based on the investigated study subjects.

Abstract

Virtual surgical planning (VSP) and patient-specific implants are currently increasing for immediate jaw reconstruction after ablative oncologic surgery. This technique contributes to more accurate and efficient preoperative planning and shorter operation time. The present retrospective, single-center study analyzes the influence of time delay caused by VSP vs. conventional (non-VSP) reconstruction planning on the soft and hard tissue resection margins for necessary oncologic safety. A total number of 104 cases of immediate jaw reconstruction with free fibula flap are included in the present study. The selected method of reconstruction (conventionally, non-VSP: n = 63; digitally, VSP: n = 41) are analyzed in detail. The study reveals a statistically significant (p = 0.008) prolonged time to therapy initiation with a median of 42 days when the VSP method compared with non-VSP (31.0 days) is used. VSP did not significantly affect bony or soft tissue resection margin status. Apart from this observation, no significant differences concerning local tumor recurrence, lymph node, and distant metastases rates are found according to the reconstruction method, and affect soft or bone tissue resection margins. Thus, we conclude that VSP for immediate jaw reconstruction is safe for oncological purposes.

Assessment of the deep resection margin during oral cancer surgery: A systematic review

The main challenge for radical resection in oral cancer surgery is to obtain adequate resection margins. Especially the deep margin, which can only be estimated based on palpation during surgery, is often reported inadequate. To increase the percentage of radical resections, there is a need for a quick, easy, minimal invasive method, which assesses the deep resection margin without interrupting or prolonging surgery. This systematic review provides an overview of technologies that are currently being studied with the aim of fulfilling this demand. A literature search was conducted through the databases Medline, Embase and the Cochrane Library. A total of 62 studies were included. The results were categorized according to the type of technique: 'Frozen Section Analysis', 'Fluorescence', 'Optical Imaging', 'Conventional imaging techniques', and 'Cytological assessment'. This systematic review gives for each technique an overview of the reported performance (accuracy, sensitivity, specificity, positive predictive value, negative predictive value, or a different outcome measure), acquisition time, and sampling depth. At the moment, the most prevailing technique remains frozen section analysis. In the search for other assessment methods to evaluate the deep resection margin, some technologies are very promising for future use when effectiveness has been shown in larger trials, e.g., fluorescence (real-time, sampling depth up to 6 mm) or optical techniques such as hyperspectral imaging (real-time, sampling depth few mm) for microscopic margin assessment and ultrasound (less than 10 min, sampling depth several cm) for assessment on a macroscopic scale.

Additive Manufacturing of Resected Oral and Oropharyngeal Tissue: A Pilot Study

Better visualization of tumor structure and orientation are needed in the postoperative setting. We aimed to assess the feasibility of a system in which oral and oropharyngeal tumors are resected, photographed, 3D modeled, and printed using additive manufacturing techniques. Three patients diagnosed with oral/oropharyngeal cancer were included. All patients underwent preoperative magnetic resonance imaging followed by resection. In the operating room (OR), the resected tissue block was photographed using a smartphone. Digital photos were imported into Agisoft Photoscan to produce a digital 3D model of the resected tissue. Physical models were then printed using binder jetting techniques. The aforementioned process was applied in pilot cases including carcinomas of the tongue and larynx. The number of photographs taken for each case ranged from 63 to 195. The printing time for the physical models ranged from 2 to 9 h, costs ranging from 25 to 141 EUR (28 to 161 USD). Digital photography may be used to additively manufacture models of resected oral/oropharyngeal tumors in an easy, accessible and efficient fashion. The model may be used in interdisciplinary discussion regarding postoperative care to improve understanding and collaboration, but further investigation in prospective studies is required.

Survival analysis of segmental mandibulectomy with immediate vascularized fibula flap reconstruction in stage IV oral squamous cell carcinoma patients

PURPOSE

This study aims to assess the survival rate of oral squamous cell carcinoma (OSCC) patients following immediate mandibular reconstruction with vascularized fibula flap (VFF) and to identify risk factors influencing the overall survival rate and postoperative outcomes.

PATIENTS AND METHODS

Patients suitable for the inclusion criterion diagnosed and treated between January 1996 till June 2019 for OSCC were retrospectively reviewed (n = 74). Potential risk factors and postoperative outcomes were recorded and analyzed.

RESULTS

The overall cumulative survival rate of patients was 0.52 at the end of 5th year. Overall, advanced pN stage (p = 0.0422), poor tumor differentiation (p < 0.0001), positive/close surgical margins (p = 0.0209), vascular invasion (p = 0.0395), perineural invasion (p = 0.0022) and tumor recurrence (p = 0.0232) were significantly related to a decreased cumulative survival. Tumor recurrence was significantly correlated with involvement of positive/close surgical margins, moderate (p = 0.0488), poor-differentiated tumors (p = 0.202), extracapsular spread (p = 0.0465), computer-assisted surgery (p = 0.0014) and early complications (p = 0.0224). Pain was significantly associated with the extracapsular spread (p = 0.0353) and early complications (p = 0.0127).

CONCLUSION

The five-year survival rate of advanced OSCC patients after segmental mandibulectomy with fibula free-flap reconstruction was 52.4%. Clinical/pathological risk factors such as the pN stage, tumor differentiation, surgical margins, vascular invasion, perineural invasion, tumor recurrence significantly influenced the overall cumulative survival rate.

The usefulness of the narrow band imaging (NBI) in decision-making process regarding second look procedure (SL) in laryngeal cancer follow-up after transoral laser microsurgery

Background

The prognostic value of positive surgical margins after transoral laser microsurgery (TOLM) is still under debate. In case of positive superficial margins, some experts recommend a second-look surgery (SL) and some recommend wait and watch approach with close observation. Narrow band imaging (NBI) is an advanced imaging system used to enhance visualization of mucosal vascular pattern. In laryngology, NBI is used to improve the detection of premalignant, dysplastic and malignant lesions.

Aim

To assess the usefulness of NBI imaging in guiding clinical decision making regarding follow-up plan and SL after TOLM.

Materials and methods

A prospective cohort of 127 patients was divided into three groups based on the histology results and NBI vascular pattern of the mucosa. Group A (24/127, 18.90%) consisted of patients with suspicious vascular pattern in NBI or/and with positive deep margin. Group B (52/127, 40.94%) consisted of patients with positive or uncertain superficial margins and non-suspicious vascular pattern in NBI. Group C (51/127, 40.15%) had non-suspicious vascular NBI pattern and all negative margins.

Results

After the first TOLM procedure, 9/24 (37.5%) patients had positive deep margins, 1/24 (4.2%) had uncertain deep margin and 1/24 patient (4.2%) had both positive deep margin and suspicious vascular pattern in NBI. The remaining 13 cases in Group A had a suspicious NBI finding only during the first follow-up. All of the 24 patients (Group A) underwent a second look surgery. The final histology after SL showed squamous cell carcinoma in 10/24 (41.7%) patients. All 10 patients had suspicious vascular pattern in NBI and one patient had both a positive deep margins after the first TOLM and positive NBI finding. None of Group B and C subjects developed an early recurrence.

Conclusions

Our study provides evidence that NBI imaging will be a useful adjunct to margin status after TOLM and will facilitate clinical decision-making regarding performing the SL in patients with positive or uncertain superficial surgical margins in the first TOLM procedure. However, additional investigation with more subjects is required at this time to further validate this technique and change the standard of care.

Molecular margins in head and neck cancer: Current techniques and future directions

Complete tumor extirpation with clear surgical margins remains a central tenet of oncologic head and neck surgery. Rates of locoregional recurrence and survival are both significantly worse when clear margins are unable to be obtained. Current clinical practice relies on the use of frozen sections intra-operatively, followed by traditional histopathologic analysis post-operatively to assess the surgical margin. However, with improved understanding of tumor biology and advances in technology, new techniques have emerged to analyze margins at a molecular level. Such molecular margin analysis interrogates tissue for genetic, epigenetic, or proteomic changes that may belie tumor presence or aggressive features not captured by standard histopathologic techniques. Intra-operatively, this information may be used to guide resection, while post-operatively, it may help to stratify patients for adjuvant treatment. In this review, we summarize the current state of molecular margin analysis and describe directions for future research.

Prognostic impact of resection margin involvement in surgically managed HPV-positive tonsil cancer

OBJECTIVES

To find out the role of resection margin involvement in surgically managed HPV-positive tonsil cancer.

MATERIALS AND METHODS

The study included 94 subjects with HPV-positive tonsil cancer undergoing surgical treatment. We evaluated the relationships between the resection margin status, clinicopathological factors, and oncological outcome.

RESULTS

The rate of resection margin involvement was 22.3% (21/94) after ablative surgery. Margin involvement, lymphatic invasion, and extracapsular spread were associated with the 5-year disease-free survival (DFS) and disease-specific survival (DSS) rate in univariate analysis. Multivariate Cox regression analysis confirmed a significant association between the margin involvement and 5-year DFS rate (HR = 4.602; 95% CI = 1.202-17.620; p = 0.026) and 5-year DSS rate (HR = 12.826; 95% CI = 1.399-117.593; p = 0.024). The incidence of resection margin involvement was significantly higher in patients with larger tumors (35.19 ± 15.07 mm vs. 25.53 ± 10.32 mm, p = 0.011) and more invasive tumors (17.84 ± 7.90 mm vs. 13.46 ± 6.88 mm, p = 0.037). The cutoff value of tumor size and depth of invasion for resection margin involvement was 29.5 mm (74% sensitivity and 63% specificity) and 14.5 mm (74% sensitivity and 61% specificity), respectively.

CONCLUSION

Resection margin involvement was significantly correlated with tumor size and the depth of invasion in HPV-positive tonsil cancer. Furthermore, resection margin involvement was associated with adverse outcomes.

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.

Relocation of inadequate resection margins in the wound bed during oral cavity oncological surgery: A feasibility study

Background

Specimen‐driven intraoperative assessment of the resection margins provides immediate feedback if an additional excision is needed. However, relocation of an inadequate margin in the wound bed has shown to be difficult. The objective of this study is to assess a reliable method for accurate relocation of inadequate tumor resection margins in the wound bed after intraoperative assessment of the specimen.

Methods

During oral cavity cancer surgery, the surgeon placed numbered tags on both sides of the resection line in a pair‐wise manner. After resection, one tag of each pair remained on the specimen and the other tag in the wound bed. Upon detection of an inadequate margin in the specimen, the tags were used to relocate this margin in the wound bed.

Results

The method was applied during 80 resections for oral cavity cancer. In 31 resections an inadequate margin was detected, and based on the paired tagging an accurate additional resection was achieved.

Conclusion

Paired tagging facilitates a reliable relocation of inadequate margins, enabling an accurate additional resection during the initial surgery.

Raman spectroscopy for cancer detection and cancer surgery guidance: translation to the clinics

Oncological applications of Raman spectroscopy have been contemplated, pursued, and developed at academic level for at least 25 years. Published studies aim to detect pre-malignant lesions, detect cancer in less invasive stages, reduce the number of unnecessary biopsies and guide surgery towards the complete removal of the tumour with adequate tumour resection margins. This review summarizes actual clinical needs in oncology that can be addressed by spontaneous Raman spectroscopy and it provides an overview over the results that have been published between 2007 and 2017. An analysis is made of the current status of translation of these results into clinical practice. Despite many promising results, most of the applications addressed in scientific studies are still far from clinical adoption and commercialization. The main hurdles are identified, which need to be overcome to ensure that in the near future we will see the first Raman spectroscopy-based solutions being used in routine oncologic diagnostic and surgical procedures.

Methylation status of SFRP1, SFRP2, RASSF1A, RARβ and DAPK1 genes in patients with oral squamous cell carcinoma

Our study assessed the methylation status of the SFRP1, SFRP2, RASSF1A, RARβ and DAPK1 genes, which are associated with epigenetic silencing in cancers. In a group of 75 patients with oral squamous cell carcinoma, aberrant methylation was detected using methylation-specific PCR in tumours and matched margins. Our results showed significantly higher methylation frequency in tumours than in surgical margin of SFRP2 (26.6% vs 11.9%, p < 0.05) and DAPK1 (65.3% vs 41.3%, p < 0.01) genes. Moreover, methylation of the SFRP1 and DAPK1 genes was associated with older age. Advanced tumour stages were associated with lower rates of SFRP1 gene methylation. Decreased methylation levels of the SFRP2 and RASSF1A genes were associated with positive N stage. On the contrary, lymph node metastasis were associated with higher methylation rates of RARβ and DAPK1 genes. Patients with a familial history of cancer were associated with more frequently methylated SFRP1, SFRP2 and DAPK1 genes. Hypermethylation of DAPK1 was associated with decreased risk of death in patients. Our results are suggestive, although not conclusive, that some epigenetic changes, especially frequent hypermethylation of SFRP2 and DAPK1 genes, can be useful as potential diagnostic biomarkers of oral cavity cancer. Moreover, estimating the methylation status in surgical margins could become an additional strategy for more accurate treatment methods. Further efforts are needed to identify and validate this finding on a larger patient group and using new advanced methylation testing methods.

Data Set for the Reporting of Carcinomas of the Hypopharynx, Larynx, and Trachea: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

The International Collaboration on Cancer Reporting is a nonprofit organization whose mission is to develop evidence-based, universally available surgical pathology reporting data sets. Standardized pathologic reporting for cancers facilitates improved communication for patient care and prognosis and the comparison of data between countries to progressively improve clinical outcomes. Laryngeal cancers are often accompanied by significant morbidity, although surgical advances (such as transoral endoscopic laser microresection and transoral robotic surgery) provide new alternatives. The anatomy of the larynx is complex, with an understanding of the exact anatomic sites and subsites, along with recognizing anatomic landmarks, being crucial to classification and prognostication. This review outlines the data set developed for the histopathology reporting in Carcinomas of the Hypopharynx, Larynx and Trachea and discusses the main elements required and recommended for reporting.

Data Set for the Reporting of Carcinomas of the Nasal Cavity and Paranasal Sinuses: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

The International Collaboration on Cancer Reporting was established to internationally unify and standardize the pathologic reporting of cancers based on collected evidence, as well as to allow systematic multi-institutional intercountry data collection to guide cancer care in the future. This data set has been developed by the collaborative efforts of an international multidisciplinary panel of experts involved in the care of patients with carcinomas of the nasal cavity and paranasal sinuses (sinonasal tract). The nasal cavity and paranasal sinuses (including frontal, sphenoid, ethmoid, and maxillary sinuses) comprise a very complex anatomic area of the head and neck, affected by a sometimes bewildering array of neoplasms. Management of malignancies in this anatomic region involves complex surgery because of the anatomic confines and close proximity to many vital structures. Given a multidisciplinary approach, the standardized reporting of the carcinomas that develop in this anatomic region include both required (core) and recommended (noncore) elements in pathology reporting in order to be able to identify critical prognostic factors, often requiring clinical and radiologic correlation. A summary of the International Collaboration on Cancer Reporting guidelines and clinically relevant elements, along with additional explanatory notes, are provided, based on evidentiary support from the literature, set in the context of practical application.

Raman spectroscopy for assessment of bone resection margins in mandibulectomy for oral cavity squamous cell carcinoma

OBJECTIVES

The aim of this study was to investigate the potential of Raman spectroscopy for detection of oral cavity squamous cell carcinoma (OCSCC) in bone resection surfaces during mandibulectomy.

MATERIALS & METHODS

Raman mapping experiments were performed on fresh mandible resection specimens from patients treated with mandibulectomy for OCSCC. A tumour detection algorithm was created based on water concentration and the high-wavenumber range (2800 cm^-1-3050 cm^-1) of the Raman spectra.

RESULTS

Twenty-six ex vivo Raman mapping experiments were performed on 26 fresh mandible resection specimens obtained from 22 patients. The algorithm was applied on an independent test set and showed an accuracy of 95%, a sensitivity of 95%, and a specificity of 87%.

CONCLUSION

These results form the basis for further development of a Raman spectroscopy tool as an objective method for intraoperative assessment of bone resection margins.

Integrated miRNA-mRNA spatial signature for oral squamous cell carcinoma: a prospective profiling study of Narrow Band Imaging guided resection

Oral squamous cell carcinoma (OSCC) is a common malignancy for which there is poor prognosis and limited therapeutic options. The objective was to identify mRNA targets of dysregulated miRNAs in OSCC using integrated analysis and understand molecular abnormality in surgical margins. We used biopsies along the spatial axis from normal tissue defined by narrow band imaging (NBI) through conventional white light (WL) margins to tumour from 18 patients undergoing surgical resection for OSCC. Overall 119 miRNA and 4794 mRNA were differentially expressed along the adjacent normal tissue to tumour axis. Analysis of miRNA profiles demonstrated the NBI margins were molecularly distinct from both the tumour and WL margin. Integrated analysis identified 193 miRNA-mRNA interactions correlated to the spatial axis of NBI-WL-T. We used cross-validation analysis to derive a spatial interactome signature of OSCC comprising 100 putative miRNA-mRNA interactions between 40 miRNA and 96 mRNA. Bioinformatic analysis suggests that miRNA dysregulation in OSCC may contribute to activation of the oncostatin M, BDNF and TGF-β pathways. Our data demonstrates that surgical margins defined by NBI leave less potentially malignant residual tissue. The miRNA-mRNA interactome provides insight into dysregulated miRNA signalling in OSCC and supports molecular definition of tumour margins.

Close Resection Margins Do Not Influence Local Recurrence in Patients With Oral Squamous Cell Carcinoma: A Prospective Cohort Study

PURPOSE

This study investigated the clinical relevance of the distance between the resection margin and tumor cells of the primary sites for oral squamous cell carcinoma, with particular attention to local recurrence rate.

PATIENTS AND METHODS

All patients diagnosed with oral squamous cell carcinoma from 1995 to 2006 and treated primarily with surgery formed the initial cohort of the study. Patient with various degrees of dysplasia in the margin, patients who received radiotherapy, and patients who died of causes other than oral cancer were excluded. Margins 1 to 5 mm were considered close. A margin of at least 5 mm was considered free of disease (clear). Local recurrence was defined as tumor development at the site of the primary tumor during the follow-up period (≥5 yr). The Fisher exact test was used to determine the relevance of the differences between the studied groups (free vs close margins) in relation to local recurrence.

RESULTS

Histologic analysis of the specimens was performed. Of the 53 patients, 32 had free margins and 3 of the 32 had a local recurrence. In addition, 21 patients had close margins and 3 of the 21 had a local recurrence. The difference between the 2 groups was not statistically relevant.

CONCLUSIONS

The authors advocate that the strategy of using close resection margins as a generic indicator for local recurrence and adverse prognosis might have to be reassessed. The histopathologic evidence of tumor cells within a distance less than 0.5 cm from the surgical margins does not necessarily seem to offer a certain indication for additional treatment. Other prognostic factors, such as involvement of cervical lymph nodes and tumor depth, must be considered in the decision making for further treatment.

Therapeutic implications of tumor free margins in head and neck squamous cell carcinoma

OBJECTIVES

The resection status is one of the most important prognostic factors for patients with head and neck squamous cell carcinoma (HNSCC) concerning overall survival (OS) and recurrence free interval (RFI). To assess whether therapy concepts changed depending on different resection margins and extracapsular extension, OS and RFI data were set into clinical context.

METHODS

All HNSCC patients who underwent head and neck surgery with/without adjuvant therapy (n=534) were selected over a ten-year period (2001-2011). Clinical parameters and survival data were collected retrospectively and histopathological analysis of tumor free margins and extracapsular extension were done.

RESULTS

Patients with microscopic in-sano resection showed mean OS/RFI of 95/96 months. OS/RFI decreased in microscopic non-in-sano and macroscopic non-in-sano (56/58 and 35/39 months) as well as in unclear resection margins (63/60 months). Patients with extracapsular extension, microscopic non-in-sano resection as well as patients with in-sano resection after follow up resection demonstrated therapy escalation by adjuvant (chemo-) radiation.

CONCLUSIONS

Insufficient surgical margins and extracapsular extension are main risks for a reduced overall and recurrence free survival. Although there is no measure to prevent positive extracapsular extension, clear margins at first pass protect patients from adjuvant therapy escalation.

Shrinkage of Nasal Mucosa and Cartilage During Formalin Fixation

BACKGROUND

After resection, specimens are subjected to formalin fixation during histological processing. This procedure can result in tissue shrinkage, with the amount of shrinkage related to tissue composition and tissue type.

AIMS

To evaluate the shrinkage of nasal mucosa and cartilage tissue and compare differences in shrinkage after resection, after formalin fixation, and during microscopic examination to understand differences in the rate of shrinkage of different tissue types.

STUDY DESIGN

Animal experimentation.

METHODS

Fresh nasal septa were excised from sheep (10 mm diameter in 40 sheep and 20 mm diameter in 40 sheep). The mucosa was separated from one side of the cartilage, with the contralateral mucosa remaining attached to the cartilage. Specimen diameters were measured in situ, after resection, after fixation for 6 or 24 hours (10% formalin), and during microscopic examination.

RESULTS

There were no differences between the in situ and after resection diameters of any tissue components (free mucosa, mucosa attached to cartilage, and cartilage) of all nasal specimens (10- or 20-mm diameter and 6- or 24-hour fixation). However, significant shrinkage occurred between resection and after-fixation. Regarding tissue specimens that were fixed for different durations (6 or 24 hours), we observed a significantly smaller mean tissue diameter in specimens fixed for 24 hours versus those fixed for 6 hours for mucosa attached to cartilage (in the 10-mm diameter after-fixation samples), free mucosa (in the 20-mm diameter after-fixation samples), mucosa attached to cartilage (in the 20-mm diameter after-fixation and microscopic measurement samples), and cartilage (in the 20-mm diameter after-fixation samples). Tissue shrinkage was greatest in free mucosal tissue and least in cartilage.

CONCLUSION

These results should be considered when evaluating patients undergoing surgical procedures for nasal cavity and paranasal sinus malignancies. Surgical margins should be measured before fixation or evaluated if possible before fixation and shrinkage.

Clinical Significance and Prognostic Value of the Expression of LAMP3 in Oral Squamous Cell Carcinoma

Recent studies demonstrated high expression of lysosome-associated membrane protein 3 (LAMP3) in a variety of malignancies including esophageal squamous cell carcinoma, gastrointestinal cancer, breast cancer, and cervical cancer and its involvement in several biological activities of tumor cells. However, the expression of LAMP3 and its value in oral squamous cell carcinoma (OSCC) remain unclear. In this study, we examined the expression of LAMP3 in OSCC tissue samples and investigated the relationship between LAMP3 and clinical characteristics of patients with OSCC. We examined mRNA and protein levels of LAMP3 in OSCC tissues and neighboring normal tissues using quantitative real-time polymerase chain reaction and immunohistochemistry analyses, respectively. Both the mRNA and protein levels of LAMP3 were significantly higher in OSCC tissues than in adjacent normal tissues. Chi-square analysis showed that the high LAMP3 expression was notably linked to the degree of tumor differentiation and advanced TNM stage. Univariate and multivariate analyses showed that the high LAMP3 expression was an independent prognostic marker in OSCC. Our results suggest that LAMP3 might act as a potential anticancer target and a prognostic marker in patients with OSCC.

Adverse pathologic features in early oral squamous cell carcinoma and the role of postoperative radiotherapy-a review

The use of postoperative radiotherapy (PORT) in early stage oral cancer with adverse pathologic features (APFs) is controversial. Prognostically relevant APFs reviewed were perineural invasion, lymphovascular invasion, depth of invasion, worst pattern of invasion, and margin status. The current literature remains divided with regard to the benefit of treatment escalation in these patients; although these patients are at high risk for recurrence, the morbidity of PORT needs to be balanced against the likely benefit in disease control. A wide heterogeneity in the literature exists, likely as a result of differences in treatment protocols. We performed a literature review of the role of PORT in early-stage oral cancer with APFs. Based on the current evidence, the decision to administer adjuvant therapy needs to be made on an individual basis; patients with >1 APF are likely to benefit from PORT, and the use of risk-scoring systems may help in decision making.

Surgical margins in head and neck squamous cell carcinoma: Effect of heat artifact on immunohistochemistry as a future tool for assessment

BACKGROUND

Margins in head and neck squamous cell carcinoma (HNSCC) are determined by morphological changes assessed via hematoxylin-eosin staining. Physiological changes may not be detected by this technique. The purpose of this study was to determine if a protein biomarker, laminin-332γ2, overexpressed in cancer cells at the invasive front in HNSCC, remains unaffected by heat produced during resection, supporting a role for immunohistochemistry assessment of margins.

METHODS

Archived tissue blocks from glottic squamous cell carcinomas (SCCs) resected by CO2 laser likely to contain both cancer cells and artifact were identified; 129-paired slides were obtained. One slide of each pair was stained with hematoxylin-eosin; the second stained for laminin-332γ2. The presence of cancer cells, artifact, and positive laminin-332γ2 staining was recorded. Twenty-seven pairs met the inclusion criteria.

RESULTS

Immunohistochemistry staining of laminin-332γ is preserved in presence of heat artifact.

CONCLUSION

This study supports use of immunohistochemistry to assess margins. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1401-1406, 2016.

Water Concentration Analysis by Raman Spectroscopy to Determine the Location of the Tumor Border in Oral Cancer Surgery

Adequate resection of oral cavity squamous cell carcinoma (OCSCC) means complete tumor removal with a clear margin of more than 5 mm. For OCSCC, 85% of the surgical resections appear inadequate. Raman spectroscopy is an objective and fast tool that can provide real-time information about the molecular composition of tissue and has the potential to provide an objective and fast intraoperative assessment of the entire resection surface. A previous study demonstrated that OCSCC can be discriminated from healthy surrounding tissue based on the higher water concentration in tumor. In this study, we investigated how the water concentration changes across the tumor border toward the healthy surrounding tissue on freshly excised specimens from the oral cavity. Experiments were performed on tissue sections from 20 patients undergoing surgery for OCSCC. A transition from a high to a lower water concentration, from tumor (76% ± 8% of water) toward healthy surrounding tissue (54% ± 24% of water), takes place over a distance of about 4 to 6 mm across the tumor border. This was accompanied by an increase of the heterogeneity of the water concentration in the surrounding healthy tissue. The water concentration distributions between the regions were significantly different (P < 0.0001). This new finding highlights the potential of Raman spectroscopy for objective intraoperative assessment of the resection margins. Cancer Res; 76(20); 5945-53. ©2016 AACR.

Analysis of Survival Rates Following Primary Surgery of 178 Consecutive Patients with Oral Cancer in a Large District General Hospital

PURPOSE

The aim of this study is to present the survival rates in patients treated for oral cancer with primary surgery in a large district general hospital. We discuss the influence of the most significant prognostic factors on survival and compare our results with larger centres specializing in the management of oral cancer.

METHODS

All patients diagnosed with oral cancer from 1995 to 2006 and were treated in the Department had their details entered prospectively onto a computerized database. Demographic details of patients, type of treatment, pathological stage of tumor (TNM), local and regional recurrence rate, overall survival, disease specific survival and incidence of involved margins were recorded and calculated.

RESULTS

Of the 178 patients, 96 (54 %) were alive and free of oral cancer 5 years after surgery. Forty-four patients died of oral cancer (24.7 %) but 38 (21.3 %) died of other causes. The overall survival rate after primary surgery in relation to stage was: I 84 %, II 71 %, III 36 % and IV 28 %.

DISCUSSION

As almost half of our patients presented with advanced cancer and had discouraging survival rates, we emphasize the need for early recognition of the disease. Advanced disease signifies difficulty in obtaining clear margins which actually indicates a higher recurrence rate. 25 % of our patients died of oral cancer within 5 years of surgery which highlights the poor prognosis that recurrence carries after treatment. Effective educational campaign with purpose to raise oral cancer awareness and earlier referral may result in improvement of survival.

Clinicopathological study of surgical margins in squamous cell carcinoma of buccal mucosa

Objective

To evaluate the margins of resected specimen of oral squamous cell carcinoma (SCC) and to document the surgical margin (measured at the time of resection) and margins at the time of pathological examination (after immersion of the specimen in formalin).

Methods

Patients who were diagnosed and confirmed with squamous carcinoma of buccal mucosa were included in the study. Patients underwent resection of the tumor with a margin of 1 cm. Soon after resection, the distance between outermost visible margin of the tumor and the margin of the specimen was measured and documented. Specimens were fixed in 10% formalin and submitted for gross and histopathological examination. The closest histopathologic margin was compared with the in situ margin (10 mm) to determine and document any shrinkage of the margin and the percentage of discrepancy if any.

Results

A total of 52 specimens were collected from patients between January 2014 and December 2014. All specimens were obtained from the oral cavity (n = 52) of which 43 (82.7%) were squamous cell carcinoma and 9 (17.3%) were verrucous variant of squamous cell carcinoma. The average decrease in tumor margins measured after fixation in formalin was found to be statistically significant (P < 0.05) in 65% of cases.

Conclusion

Tumor margin shrinks significantly after formalin fixation by about 25%. The operating surgeon and pathologist should be well aware of such changes while planning for further management thereby ensuring adequate margin of resection and adjuvant treatment wherever required to prevent possible local recurrence of the disease.

Fluorescence imaging to localize head and neck squamous cell carcinoma for enhanced pathological assessment

Accurately identifying close or positive margins in real-time permits re-excision during surgical procedures. Intraoperative assessment of margins via gross examination and frozen section is a widely used tool to assist the surgeon in achieving complete resection. While this methodology permits diagnosis of freshly resected tissue, the process is fraught with misinterpretation and sampling errors. During fluorescence-guided surgery, an exogenous fluorescent agent specific for the target disease is imaged in order to navigate the surgical excision. As this technique quickly advances into the clinic, we hypothesize that the disease-specific fluorescence inherently contained within the resected tissues can be used to guide histopathological assessment. To evaluate the feasibility of fluorescence-guided pathology, we evaluated head and neck squamous cell carcinoma tumour specimens and margins resected from animals and patients after systemic injection of cetuximab-IRDye800CW. In a preclinical model of luciferase-positive tumour resection using bioluminescence as the gold standard, fluorescence assessment determined by closed-field fluorescence imaging of fresh resected margins accurately predicted the presence of disease in 33/39 positive margins yielding an overall sensitivity of 85%, specificity of 95%, positive predictive value (PPV) of 94%, and a negative predictive value (NPV) of 87%, which was superior to both surgical assessment (54%, 61%, 57%, and 58%) and pathological assessment (49%, 95%, 91%, and 66%), respectively. When the power of the technique was evaluated using human-derived tumour tissues, as little as 0.5mg (1mm(3)) of tumour tissue was identified (tumour-to-background-ratio:5.2). When the sensitivity/specificity of fluorescence-guided pathology was determined using traditional histological assessment as the gold standard in human tissues obtained during fluorescence-guided surgery, the technique was highly accurate with a sensitivity of 91%, specificity of 85%, PPV of 81%, and NPV of 93% for 90 human-derived samples. This approach can be used as a companion to the pathologist, eliminating confounding factors while impacting surgical intervention and patient management.

Surgical margins and primary site resection in achieving local control in oral cancer resections

OBJECTIVES/HYPOTHESIS

Evaluate effectiveness of resection of oral cavity cancer with a standardized approach for margin evaluation. Primary end points were local control and survival.

STUDY DESIGN

Retrospective, nonrandomized, single institution.

METHODS

One hundred eight patients who underwent surgery for oral cancer were evaluated using specific anatomical pathology criteria. Frozen section was performed with the surgeon and pathologist agreeing where on the specimen the frozen sections should be taken in most cases.

RESULTS

Ninety-one patients (84.3%) had frozen sections taken from the specimen, eight from the tumor bed, and nine had none taken at the time of surgery. Overall local recurrence rate was 18.5%, 25% in patients who had margins taken from the tumor bed and 17.6% when taken from the specimen. Twenty-nine patients had margins ≥5 mm, 53 <5 mm and clear, and 14 positive re-resected to negative with local recurrence rates of 3.4%, 26.4%, and 28.6%, respectively. The radial distance of the resection margin was shown to have an impact on overall survival (hazard ratio [HR] = 3.59, 95% confidence interval [CI] = 1.12-11.57), disease-free survival (HR = 7.00, 95% CI = 1.89-25.95), and local recurrence-free survival (HR = 28.80, 95% CI = 3.00-276.82).

CONCLUSIONS

Assessing margins from the resection specimen rather than the tumor bed consistently predicts local control. There is a statistical improvement in local control, disease-free, and overall survival with increasing radial margin distance from the tumor, and 5 mm should be agreed upon as the definition of a clear resection margin. Frozen sections can be used to revise positive or close resection margins intraoperatively with improved outcomes.

LEVEL OF EVIDENCE

4.

Discrimination between oral cancer and healthy tissue based on water content determined by Raman spectroscopy

Tumor-positive resection margins are a major problem in oral cancer surgery. High-wavenumber Raman spectroscopy is a reliable technique to determine the water content of tissues, which may contribute to differentiate between tumor and healthy tissue. The aim of this study was to examine the use of Raman spectroscopy to differentiate tumor from surrounding healthy tissue in oral squamous cell carcinoma. From 14 patients undergoing tongue resection for squamous cell carcinoma, the water content was determined at 170 locations on freshly excised tongue specimens using the Raman bands of the OH-stretching vibrations (3350-3550 cm(-1)) and of the CH-stretching vibrations (2910-2965 cm(-1)). The results were correlated with histopathological assessment of hematoxylin and eosin stained thin tissue sections obtained from the Raman measurement locations. The water content values from squamous cell carcinoma measurements were significantly higher than from surrounding healthy tissue (p-value < 0.0001). Tumor tissue could be detected with a sensitivity of 99% and a specificity of 92% using a cutoff water content value of 69%. Because the Raman measurements are fast and can be carried out on freshly excised tissue without any tissue preparation, this finding signifies an important step toward the development of an intraoperative tool for tumor resection guidance with the aim of enabling oncological radical surgery and improvement of patient outcome.

Significance of post-resection tissue shrinkage on surgical margins of oral squamous cell carcinoma

BACKGROUND

Resecting oral squamous cell carcinoma (SCC) with an appropriate margin of uninvolved tissue is critical in preventing local recurrence and in making decisions regarding postoperative radiation therapy. This task can be difficult due to the discrepancy between margins measured intraoperatively and those measured microscopically by the pathologist after specimen processing.

MATERIAL AND METHODS

A total of 61 patients underwent resective surgery with curative intent for primary oral SCC were included in this study. All patients underwent resection of the tumor with a measured 1-cm margin. Specimens were then submitted for processing and reviewing, and histopathologic margins were measured. The closest histopathologic margin was compared with the in situ margin (1 cm) to determine the percentage discrepancy.

RESULTS

The mean discrepancy between the in situ margins and the histopathological margins of all close and positive margins were 47.6% for the buccal mucosa (with a P value corresponding to 0.05 equaling 2.1), which is statistically significant, 4.8% for the floor of mouth, 9.5% for the mandibular alveolus, 4.8% for the retromolar trigon, and 33.3% for the tongue.

CONCLUSION

There is a significant difference among resection margins based on tumor anatomical location. Margins shrinkage after resection and processing should be considered at the time of the initial resection. Tumors located in the buccal mucosa show significantly greater discrepancies than tumors at other sites. These findings suggest that it is critical to consider the oral site when outlining margins to ensure adequacy of resection. Buccal SCC is an aggressive disease, and should be considered as an aggressive subsite within the oral cavity, requiring a radical and aggressive resective approach.