Accuracy of Frozen Section Examination in Oral Cavity Cancers

Latin American Consensus on the Treatment of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is well known as a serious health problem worldwide, especially in low-income countries or those with limited resources, such as most countries in Latin America. International guidelines cannot always be applied to a population from a large region with specific conditions. This study established a Latin American guideline for care of patients with head and neck cancer and presented evidence of HNSCC management considering availability and oncologic benefit. A panel composed of 41 head and neck cancer experts systematically worked according to a modified Delphi process on (1) document compilation of evidence-based answers to different questions contextualized by resource availability and oncologic benefit regarding Latin America (region of limited resources and/or without access to all necessary health care system infrastructure), (2) revision of the answers and the classification of levels of evidence and degrees of recommendations of all recommendations, (3) validation of the consensus through two rounds of online surveys, and (4) manuscript composition. The consensus consists of 12 sections: Head and neck cancer staging, Histopathologic evaluation of head and neck cancer, Head and neck surgery-oral cavity, Clinical oncology-oral cavity, Head and neck surgery-oropharynx, Clinical oncology-oropharynx, Head and neck surgery-larynx, Head and neck surgery-larynx/hypopharynx, Clinical oncology-larynx/hypopharynx, Clinical oncology-recurrent and metastatic head and neck cancer, Head and neck surgery-reconstruction and rehabilitation, and Radiation therapy. The present consensus established 48 recommendations on HNSCC patient care considering the availability of resources and focusing on oncologic benefit. These recommendations could also be used to formulate strategies in other regions like Latin America countries.

Image-Guided Intraoperative Assessment of Surgical Margins in Oral Cavity Squamous Cell Cancer: A Diagnostic Test Accuracy Review

(1) Background: The assessment of resection margins during surgery of oral cavity squamous cell cancer (OCSCC) dramatically impacts the prognosis of the patient as well as the need for adjuvant treatment in the future. Currently there is an unmet need to improve OCSCC surgical margins which appear to be involved in around 45% cases. Intraoperative imaging techniques, magnetic resonance imaging (MRI) and intraoral ultrasound (ioUS), have emerged as promising tools in guiding surgical resection, although the number of studies available on this subject is still low. The aim of this diagnostic test accuracy (DTA) review is to investigate the accuracy of intraoperative imaging in the assessment of OCSCC margins. (2) Methods: By using the Cochrane-supported platform Review Manager version 5.4, a systematic search was performed on the online databases MEDLINE-EMBASE-CENTRAL using the keywords "oral cavity cancer, squamous cell carcinoma, tongue cancer, surgical margins, magnetic resonance imaging, intraoperative, intra-oral ultrasound". (3) Results: Ten papers were identified for full-text analysis. The negative predictive value (cutoff < 5 mm) for ioUS ranged from 0.55 to 0.91, that of MRI ranged from 0.5 to 0.91; accuracy analysis performed on four selected studies showed a sensitivity ranging from 0.07 to 0.75 and specificity ranging from 0.81 to 1. Image guidance allowed for a mean improvement in free margin resection of 35%. (4) Conclusions: IoUS shows comparable accuracy to that of ex vivo MRI for the assessment of close and involved surgical margins, and should be preferred as the more affordable and reproducible technique. Both techniques showed higher diagnostic yield if applied to early OCSCC (T1-T2 stages), and when histology is favorable.

Intraoperative Assessment of Margin Accuracy in Early Oral Squamous Cell Carcinoma (cT1, T2, N0): Clinical Versus Frozen Section Analysis

Background The incidence of oral cavity cancer is increasing. During oral carcinoma surgery, to achieve a tumor-free margin, intraoperative margin assessment includes two primary methods, namely, clinical examination and frozen section analysis. With extensive preoperative imaging investigations and intraoperative clinical margin assessment, the need for further cost and resource-intensive frozen section analysis has recently come under question. This study aimed to assess whether frozen section analysis can be safely omitted in most cases of early oral squamous cell carcinoma surgeries for cost-effectiveness. Methodology A hospital-based, observational study including 30 admitted cases of early oral squamous cell carcinoma was conducted at the Department of General Surgery, Pradyumna Bal Memorial Hospital, Bhubaneswar. All consecutive confirmed cases of early oral squamous cell carcinoma of all age groups and both genders after considering the inclusion and exclusion criteria were involved in the study. A comparative assessment of the free margins after tumor excision was done by the surgeon followed by frozen section analysis. Results The mean age was 53.03 ± 13.72 years, with a male-to-female ratio of 6.5:1. Carcinoma of the lower alveolus with gingivobuccal sulcus was the most common presentation of the study (33.33%). In our study, clinically assessed margins had a sensitivity of 75.39%, a specificity of 94.43%, and an accuracy of 92.77%. Frozen section assessed margins had a sensitivity of 66.5%, a specificity of 96.94%, and an accuracy of 92.77%. Conclusions Based on the accuracy of clinically assessed and frozen section assessed margins, this study concluded that surgically resected/excised specimen by the surgeon plays a vital role in assessing the adequacy of resected/excised margins in early oral squamous cell carcinoma (cT1, T2, N0) cases, which can possibly replace the costly frozen section analysis.

In Vitro Antibody Quantification with Hyperspectral Imaging in a Large Field of View for Clinical Applications

Hyperspectral imaging (HSI) is a non-invasive, contrast-free optical-based tool that has recently been applied in medical and basic research fields. The opportunity to use HSI to identify exogenous tumor markers in a large field of view (LFOV) could increase precision in oncological diagnosis and surgical treatment. In this study, the anti-high mobility group B1 (HMGB1) labeled with Alexa fluorophore (647 nm) was used as the target molecule. This is the proof-of-concept of HSI’s ability to quantify antibodies via an in vitro setting. A first test was performed to understand whether the relative absorbance provided by the HSI camera was dependent on volume at a 1:1 concentration. A serial dilution of 1:1, 10, 100, 1000, and 10,000 with phosphatase-buffered saline (PBS) was then used to test the sensitivity of the camera at the minimum and maximum volumes. For the analysis, images at 640 nm were extracted from the hypercubes according to peak signals matching the specificities of the antibody manufacturer. The results showed a positive correlation between relative absorbance and volume (r = 0.9709, p = 0.0013). The correlation between concentration and relative absorbance at min (1 µL) and max (20 µL) volume showed r = 0.9925, p < 0.0001, and r = 0.9992, p < 0.0001, respectively. These results demonstrate the HSI potential in quantifying HMGB1, hence deserving further studies in ex vivo and in vivo settings.

Association of Intraoperative Frozen Section Controls With Improved Margin Assessment During Transoral Robotic Surgery for Human Papillomavirus-Positive Oropharyngeal Squamous Cell Carcinoma

Importance

Intraoperative margin assessment is an important technique for ensuring complete tumor resection in malignant cancers. However, in patients undergoing transoral robotic surgery (TORS) for oropharyngeal carcinomas, tissue artifact may provide pathologic uncertainty.

Objective

To assess the benefit of providing frozen section control samples ("positive tumor biopsies") for use during intraoperative margin assessment for patients undergoing TORS for human papillomavirus (HPV)-16-positive oropharyngeal squamous cell carcinoma (OPSCC).

Design, Setting, and Participants

In this cohort study, patients receiving curative-intent TORS for biopsy-proven HPV-16-positive OPSCC performed by a single attending surgeon (A.H.M.) at Ronald Reagan UCLA Medical Center from 2017 to 2021 were included in a retrospective data analysis. Exclusion criteria included HPV-negative status, participation in clinical trials, and tumors of unknown primary origin.

Main Outcomes and Measures

Survival outcomes investigated included overall and disease-free survival. Adverse pathologic outcomes measured included occurrence of nondiagnostic margins and margin reversal from frozen to fixed pathology.

Results

Of the 170 patients included (mean [SD] age, 61.8 [9.9] years; 140 [82%] male), 50% of patients (n = 85) received a frozen section control. Use of a frozen section control was associated with statistically significantly improved sensitivity of intraoperative margin assessment, from 82.8% to 88.9% (difference, 6.1%; 95% CI, 3.9%-8.3%). Eleven percent (n = 18) of all tumors evaluated exhibited at least 1 nondiagnostic intraoperative margin, and 11% (n = 18) experienced margin reversal from frozen to fixed pathology. In patients with nondiagnostic margins, use of frozen section controls was associated with statistically significantly reduced time spent in the operating room (Cohen d, 1.14; 95% CI, 0.12-2.14).

Conclusions and Relevance

In this cohort study, frozen intraoperative margins assessed during TORS resections of HPV-16-positive OPSCC were diagnostically challenging. Adverse pathologic outcomes, such as margin status reversal from positive on frozen pathology to negative on formal analysis, were common. Providing intraoperative frozen section control biopsies may offer clarity in cases with nondiagnostic margins, reducing the need for additional sampling and time spent in the operating room.