An assessment of histological margins and recurrence of completely excised cutaneous SCC

Histological deep margins in cutaneous squamous cell carcinoma of the scalp and risk of recurrence

BACKGROUND

Consensus is lacking on adequate deep histological margins in cutaneous squamous cell carcinoma (cSCC). Deep clearance for tumours located on the scalp is limited by anatomic constraints.

OBJECTIVE

To determine whether clear but close deep histological margins (<1 mm) confer a higher risk of recurrence in cSCCs of the scalp treated by wide local excision, compared to deep histological margins ≥1 mm.

METHODS

Multicentre retrospective observational cohort study and multivariate competing risk analysis to evaluate risk factors for recurrence.

RESULTS

In total, 295 patients with 338 cSCCs were included. Close deep histological margins were not associated with an increased cumulative incidence of recurrence (subhazard ratio [SHR] 1.96 [95% CI 0.87-4.41]). However, an increased risk of recurrence was observed for those tumours that presented concurrent invasion of the galea aponeurotica and close deep margins, as opposed to patients without these factors (SHR 3.52 [1.24-10.01]). Tumours with clear but close peripheral margins (<1 mm) also had higher risk of recurrence (SHR 5.01 [1.68-14.97]).

LIMITATIONS

Retrospective observational study based on pathology reports.

CONCLUSION

Deep histological margins <1 mm do not confer a greater risk of recurrence as long as the tumour is completely excised and the galea aponeurotica is not involved. Surgical excision of cSCC on the scalp should include the galea to ensure proper assessment of deep margins.

Management of Cutaneous Squamous Cell Carcinoma of the Scalp: The Role of Imaging and Therapeutic Approaches

Cutaneous squamous cell carcinoma (cSCC) is the second most common subtype of skin cancer. The scalp is one of the most frequently affected locations and is associated with a higher rate of complications, compared to other locations. In addition, it has a characteristic thickness and anatomical structure that may influence both growth pattern and treatment of primary cSCC; while clinical peripheral margins may be easily achieved during the surgery, vertical excision of the tumor is limited by the skull. Despite having a unique anatomy, current guidelines do not contemplate specific recommendations for scalp cSCC, which leads to inconsistent decision-making in multidisciplinary committees when discussing tumors with high risk factors or with close margins. This article provides specific recommendations for the management of patients with scalp cSCC, based on current evidence, as well as those aspects in which evidence is lacking, pointing out possible future lines of research. Topics addressed include epidemiology, clinical presentation and diagnosis, imaging techniques, surgical and radiation treatments, systemic therapy for advanced cases, and follow-up. The primary focus of this review is on management of primary cSCC of the scalp with localized disease, although where relevant, some points about recurrent cSCCs or advanced disease cases are also discussed.

Association of Patient Risk Factors, Tumor Characteristics, and Treatment Modality With Poor Outcomes in Primary Cutaneous Squamous Cell Carcinoma: A Systematic Review and Meta-analysis

Importance

Primary cutaneous squamous cell carcinoma is usually curable; however, a subset of patients develops poor outcomes, including local recurrence, nodal metastasis, distant metastasis, and disease-specific death.

Objectives

To evaluate all evidence-based reports of patient risk factors and tumor characteristics associated with poor outcomes in primary cutaneous squamous cell carcinoma and to identify treatment modalities that minimize poor outcomes.

Data Sources

PubMed, Embase, and SCOPUS databases were searched for studies of the topic in humans, published in the English language, from database inception through February 8, 2022.

Study Selection

Two authors independently screened the identified articles and included those that were original research with a sample size of 10 patients or more and that assessed risk factors and/or treatment modalities associated with poor outcomes among patients with primary cutaneous squamous cell carcinoma.

Data Extraction and Synthesis

Data extraction was performed by a single author, per international guidelines. The search terms, study objectives, and protocol methods were defined before study initiation. A total of 310 studies were included for full-text assessment. Owing to heterogeneity of the included studies, a random-effects model was used. Data analyses were performed from May 25 to September 15, 2022.

Main Outcomes and Measures

For studies of risk factors, risk ratios and incidence proportions; and for treatment studies, incidence proportions.

Results

In all, 129 studies and a total of 137 449 patients with primary cutaneous squamous cell carcinoma and 126 553 tumors were included in the meta-analysis. Several patient risk factors and tumor characteristics were associated with local recurrence, nodal metastasis, distant metastasis, disease-specific death, and all-cause death were identified. Among all factors reported by more than 1 study, the highest risks for local recurrence and disease-specific death were associated with tumor invasion beyond subcutaneous fat (risk ratio, 9.1 [95% CI, 2.8-29.2] and 10.4 [95% CI, 3.0- 36.3], respectively), and the highest risk of any metastasis was associated with perineural invasion (risk ratio, 5.0; 95% CI, 2.3-11.1). Patients who received Mohs micrographic surgery had the lowest incidence of nearly all poor outcomes; however, in some results, the 95% CIs overlapped with those of other treatment modalities.

Conclusions and Relevance

This meta-analysis identified the prognostic value of several risk factors and the effectiveness of the available treatment modalities. These findings carry important implications for the prognostication, workup, treatment, and follow-up of patients with primary cutaneous squamous cell carcinoma.

Trial Registration

PROSPERO Identifier: CRD42022311250.

3D-printed Model and guide plate for accurate resection of advanced cutaneous squamous cell carcinomas

Purpose

Advanced cutaneous squamous cell carcinomas (cSCC) can have unclear borders, and simple expanded resection may not only destroy surrounding normal tissues unnecessarily, but can also leave residual tumor cells behind. In this article, we describe a new method for resection and evaluate its accuracy.

Methods

The magnetic resonance imaging (MRI) data of 12 patients with advanced cSCC were reconstructed to obtain three-dimensional (3D) tumor models and guide plates for surgeries. Thirty-eight patients with the same cSCC stage, who underwent expanded resection, were included. The distances between the upper, lower, left and right horizontal margins and tumor pathological boundaries were classified as "positive", "close" (0-6 mm), "adequate" (6-12 mm) or "excessive" (>12 mm). The positive margin rate and margin distance were compared between the groups.

Results

The 3D tumor models of 12 patients were all successfully reconstructed. The positive rate of 48 surgical margins in the guide plate group was 2.1%, and the proportion of "adequate" margins was 70.8%. A total of 152 margins of 38 patients were included in the extended resection group, for which the positive rate was 13.8%; this was higher than that of the guide plate group (P = 0.045). The proportion of "adequate" margins was 27.6%, with group differences seen in the distance distribution (P < 0.01).

Conclusions

In surgical resection of advanced cSCC, compared with simple expanded resection, surgical planning using a 3D tumor model and guide plate can reduce the rate of horizontal surgical margins, and the probability of under- or over-resection.Clinical Trial Registration: http://www.chictr.org.cn, Identifier [No. ChiCTR2100050174].