Evaluation of frozen section margins in high-risk cutaneous squamous cell carcinomas of the head and neck

Implications of Malignancy, Radiation, and Timing of Major Nasal Reconstruction

Owing to the complex, multilayered anatomy of the nose in the central face, major nasal reconstruction can pose a significant challenge for reconstructive surgeons. It is the responsibility of reconstructive surgeons to have an understanding of the most common cutaneous malignancies and excisional techniques that may lead to complex nasal defects. The purpose of this article is to discuss these malignancies, excisional techniques, and impacts of radiation on tissue that has implications for reconstructive surgeons.

Resection of Skin Cancer Resulting in Free Vascularized Tissue Reconstruction: Always a Therapeutic Failure?

The globally increasing incidence of cutaneous malignancies leads, in parallel, to increasing numbers of locally advanced skin cancer resulting in reconstructive surgery. Reasons for locally advanced skin cancer may be a patient's neglect or aggressive tumor growth, such as desmoplastic growth or perineural invasion. This study investigates characteristics of cutaneous malignancies requiring microsurgical reconstruction with the aim of identifying possible pitfalls and improving diagnostic and therapeutic processes. A retrospective data analysis from 2015 to 2020 was conducted. Seventeen patients (n = 17) were included. The mean age at reconstructive surgery was 68.5 (±13) years. The majority of patients (14/17, 82%) presented with recurrent skin cancer. The most common histological entity was squamous cell carcinoma (10/17, 59%). All neoplasms showed at least one of the following histopathological characteristics: desmoplastic growth (12/17, 71%), perineural invasion (6/17, 35%), or tumor thickness of at least 6 mm (9/17, 53%). The mean number of surgical resections until cancer-free resection margins (R0) were achieved was 2.4 (±0.7). The local recurrence rate and the rate of distant metastases were 36%. Identified high-risk neoplastic characteristics, such as desmoplastic growth, perineural invasion, and a tumor depth of at least 6 mm, require a more extensive surgical treatment without concerns about defect size.

Intraoperative imaging in pathology-assisted surgery

The pathological assessment of surgical specimens during surgery can reduce the incidence of positive resection margins, which otherwise can result in additional surgeries or aggressive therapeutic regimens. To improve patient outcomes, intraoperative spectroscopic, fluorescence-based, structural, optoacoustic and radiological imaging techniques are being tested on freshly excised tissue. The specific clinical setting and tumour type largely determine whether endogenous or exogenous contrast is to be detected and whether the tumour specificity of the detected biomarker, image resolution, image-acquisition times or penetration depth are to be prioritized. In this Perspective, we describe current clinical standards for intraoperative tissue analysis and discuss how intraoperative imaging is being implemented. We also discuss potential implementations of intraoperative pathology-assisted surgery for clinical decision-making.

Current Surgical Therapy of Locally Advanced cSCC: From Patient Selection to Microsurgical Tissue Transplant. Review

Among the non-melanoma skin cancers (NMSC) the squamous cell carcinoma (SCC) is one of the most challenging for the surgeon. Local aggressiveness and a tendency to metastasize to regional lymph nodes characterize the biologic behavior. The variants locally advanced and metastatic require wide excision and node dissection. Such procedures can be extremely detrimental for patients. The limit of the surgery can be safely pushed forward with a multidisciplinary approach. The concept of skin oncoplastic surgery, the ablative procedures and the reconstructive options (skin graft, pedicled flap, microsurgical free flap) are discussed together with a literature review.

Use of Intraoperative Frozen Section in the Surgical Management of Patients with Nonmelanoma Skin Cancer

Background

Intraoperative frozen section (IFS) is often utilised in the surgical treatment of nonmelanocytic skin cancer (NMSC) in sensitive facial regions when Mohs micrographic surgery (MMS) is not available.

Objective

To compare the outcome of NMSC patients with excision performed with and without IFS.

Materials and Methods

A retrospective, single-centre study was performed on all patients who had undergone resection of NMSC with and without IFS control at the National University Hospital (NUH) from 2010 to 2015.

Results

116 patients were recruited, of which 86 had IFS and 30 did not. The complete excision rate of patients with IFS was higher at 87.2% (p=0.0194), need for secondary operation was lower at 1.2% (p=0.005), and need for postsurgery radiotherapy or chemotherapy was lower at 1.2% (p=0.001). The average duration of surgery in patients who underwent IFS was 95.4 minutes compared to 70.1 minutes in cases which did not undergo IFS.

Conclusion

Our study showed an increased complete excision rate and reduced need for secondary surgeries and adjuvant therapy in patients with IFS. However, a longer operative duration was required. Use of IFS may be useful in patients with NMSC lesions in sensitive regions requiring complex reconstruction after tumour excision.

Specimen oriented intraoperative margin assessment in oral cavity and oropharyngeal squamous cell carcinoma

OBJECTIVE

Evaluate the oncologic outcomes and cost analysis of transitioning to a specimen oriented intraoperative margin assessment protocol from a tumour bed sampling protocol in oral cavity (OCSCC) and oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

Retrospective case series and subsequent prospective cohort study SETTING: Tertiary care academic teaching hospital SUBJECTS AND METHODS: Retrospective case series of all institutional T1-T2 OCSCC or OPSCC treated with primary surgery between January 1st 2009 - December 31st 2014. Kaplan-Meier survival estimates with log rank tests were used to compare patients based on final margin status. Cost analysis was performed for escalation of therapy due to positive final margins. Following introduction of a specimen derived margin protocol, successive prospective cohort study of T1-T4 OCSCC or OPSCC treated with primary surgery from January 1st 2017 - December 31st 2018. Analysis and comparison of both protocols included review of intraoperative margins, final pathology and treatment cost.

RESULTS

Analysis of our intra-operative tumour bed frozen section protocol revealed 15 of 116 (12.9%) patients had positive final pathology margins, resulting in post-operative escalation of therapy for 14/15 patients in the form of re-resection (7/14), radiation therapy (6/14) and chemoradiotherapy (1/14). One other patient with positive final margins received escalated therapy for additional negative prognostic factors. Recurrence free survival at 3 years was 88.4 and 50.7% for negative and positive final margins respectively (p = 0.048). Implementation of a specimen oriented frozen section protocol resulted in 1 of 111 patients (0.9%) having positive final pathology margins, a statistically significant decrease (p < 0.001). Utilizing our specimen oriented protocol, there was an absolute risk reduction for having a final positive margin of 12.0% and relative risk reduction of 93.0%. Estimated cost avoidance applying the specimen oriented protocol to our previous cohort was $412,052.812017 CAD.

CONCLUSION

Implementation of a specimen oriented intraoperative margin protocol provides a statistically significant decrease in final positive margins. This change in protocol leads to decreased patient morbidity by avoiding therapy escalation attributable only to positive margins, and avoids the economic costs of these treatments.

High-resolution spatiotemporal pHe and pO2 imaging in head and neck and oesophageal carcinoma cells

Background

pO₂ and pH are physiological parameters relevant for different processes in health and disease, including wound healing and cancer progression. Head and neck squamous cell carcinomas (HNSCC) and oesophageal squamous cell carcinomas (ESCC) have a high rate of local recurrence that is partly related to treatment-resistant residual tumour cells. Hence, novel diagnostic tools are required to visualise potential residual tumour cells and thereby improve treatment outcome for HNSCC and ESCC patients. We developed a device to spatiotemporally measure oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) to distinguish HNSCC and ESCC cells from healthy cells in vitro, exploiting general metabolic differences between cancer cells and healthy cells.

Methods

OCR and ECAR were measured via a newly developed device named STO₂p-Q (SpatioTemporal O₂ and pH Quantification) using the VisiSens technology based on ratiometric fluorescence imaging, facilitating spatiotemporal resolution. Results were confirmed using extracellular flux analyses (Seahorse technology).

Results

STO₂p-Q is described and used to measure OCR and ECAR in HNSCC and ESCC cell lines and normal fibroblast and epithelial cells as components of the tumour microenvironment. OCR measurements showed differences amongst HNSCC and ESCC cell lines and between HNSCC/ESCC and normal cells, which on average had lower OCR than HNSCC/ESCC cells. Both OCR and ECAR measurements were independently verified using the Seahorse technology. Additionally, using STO₂p-Q, HNSCC/ESCC, and normal cells could be spatially resolved with a resolution in the low millimetre range.

Conclusions

We developed a method to spatiotemporally measure OCR and ECAR of cells, which has many potential in vitro applications and lays the foundation for the development of novel diagnostic tools for the detection of cancerous tissue in HNSCC and ESCC patients in vivo.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-021-00257-6.

Intraoperative Frozen Section Analysis for the Excision of Nonmelanoma Skin Cancer: A Single-Center Experience

Surgical resection of nonmelanoma skin cancer (NMSC) may be performed via Mohs micrographic surgery (MMS) or standard surgical excision with complete margin analysis. Whereas MMS may necessitate delayed reconstruction surgery, intraoperative frozen section analysis (IFSA) may be used to ensure clear surgical margins before proceeding with reconstruction. To achieve curative resection while optimizing aesthetic outcomes, surgeons may use surgical excision guided by IFSA to forego extensive or delayed reconstruction. Patients undergoing wide local excision for NMSC using IFSA from October 2008 to November 2016 were evaluated. Analysis included IFSA versus permanent section outcomes, the number of required excisions, and the recurrence rate. Our analysis contained 145 patients involving 162 lesions. IFSA demonstrated that 73.4 per cent of margins were negative after one excision and 26.5 per cent were re-excised until achieving negative margins. Analysis revealed one false-positive case (0.62%) and four false-negative cases (2.47%). Nine patients had local recurrence (5.56%). Frozen section sensitivity was 88.99 per cent and specificity 99.20 per cent. The positive predictive value was 96.97 per cent, and negative predictive value was 96.90 per cent. Mean follow-up time was 39 months. Both resection and recurrence data of excised NMSC lesions at our institution suggest that surgical excision using IFSA is a safe and effective alternative to MMS.

Cutaneous squamous cell carcinoma in the organ transplant recipient

One in twenty solid organ transplant recipients (SOTRs) will develop a highly morbid or fatal cutaneous carcinoma after transplantation. The majority of these cases develop on the head and neck and may require intervention on the part of dermatology, dermatologic surgery, otolaryngology, transplant medicine, radiation oncology, and medical oncology. In this review, we discuss the problem of cutaneous squamous cell carcinoma (cSCC) in SOTRs as well as the prognostic factors and management strategies to care for this population.

Intraoperative Surgical Margin Clearance - Correlation of Touch Imprint Cytology, Frozen Section Diagnosis, and Histopathological Diagnosis

Introduction:

Touch imprint cytology (TIC) and frozen section diagnosis are valuable intraoperative guides for the management of malignancies as they make a prompt therapeutic decision that may prevent surgical re-intervention. The present study emphasizes on the correlation of TIC and frozen section for the evaluation of surgical margins considering histopathological diagnosis as the gold standard.

Aim:

The aim of the study was to assess the accuracy of frozen section diagnosis and TIC in the evaluation of surgical margin clearance.

Materials and Methods:

It is a prospective analytical study of 103 patients carried in the histopathology section of department of pathology for 1 year from July 2017 to July 2018. Specimens were received in the frozen section room, grossed by the standard protocol. Touch imprints of margins were taken, and frozen sections were stained by rapid hematoxylin and eosin stain. The same margins were sent for permanent histopathology sections.

Results:

Of 103 patients, 51 (49.51%) were oral squamous cell carcinoma, 35 (33.98%) carcinoma breast, 9 (8.74%) carcinoma colon, 4 (3.88%) squamous cell carcinoma of skin, 3 (2.91%) basal cell carcinoma, and 1 (0.97%) malignant peripheral nerve sheath tumor. Frozen section diagnosis for margin clearance of the above organs showed that the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were found to be 100%, 98.71%, 100%, 100%, and 99.02%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of TIC for surgical margin clearance were 46.15%, 100%, 100%, 84.62%, and 86.40%, respectively.

Conclusion:

Frozen section diagnosis is an accurate method for the assessment of surgical margin clearance as compared to TIC. This study evaluated predominantly epithelial malignancies than mesenchymal malignancies, thus emphasizing its utility in it. More research needs to be done for the assessment of the utility of these lesions.

Angiotropism in recurrent cutaneous squamous cell carcinoma: Implications for regional tumor recurrence and extravascular migratory spread

Extravascular migratory metastasis is a form of cancer metastasis in which tumor cells spread by tracking along the abluminal aspect of vessel walls without breaking the vascular endothelial lining or intraluminal invasion. This phenomenon has been extensively described in melanoma and is being increasingly recognized in other neoplasms. Various modalities of treatment, including radiation-, chemo-, targeted-, and immune- therapies may potentially induce angiotropic behavior in neoplastic cells. Although there is a risk for tumor recurrence and metastasis, angiotropism may be under-recognized and is rarely reported. Here, we report a case of recurrent poorly-differentiated acantholytic squamous cell carcinoma of the scalp with extensive perineural invasion, previously treated with multiple therapies. There was multifocal extravascular cuffing of neoplastic cells around and focally involving the walls of small to medium-caliber blood vessels within and surrounding the tumor, without obvious tumor intravasation. In addition, small subtle nests of neoplastic keratinocytes were noted along the abluminal aspect of a large-caliber deep dermal blood vessel in an en-face margin, away from the main tumor mass. Such involvement can be difficult to identify; and thus, may be missed particularly during intra-operative frozen section evaluation, leading to false-negative margins and is therefore, a diagnostic pitfall.

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.

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.

Successful Translation of Fluorescence Navigation During Oncologic Surgery: A Consensus Report

Navigation with fluorescence guidance has emerged in the last decade as a promising strategy to improve the efficacy of oncologic surgery. To achieve routine clinical use, the onus is on the surgical community to objectively assess the value of this technique. This assessment may facilitate both Food and Drug Administration approval of new optical imaging agents and reimbursement for the imaging procedures. It is critical to characterize fluorescence-guided procedural benefits over existing practices and to elucidate both the costs and the safety risks. This report is the result of a meeting of the International Society of Image Guided Surgery (www.isigs.org) on February 6, 2015, in Miami, Florida, and reflects a consensus of the participants' opinions. Our objective was to critically evaluate the imaging platform technology and optical imaging agents and to make recommendations for successful clinical trial development of this highly promising approach in oncologic surgery.