Incidence of residual nonmelanoma skin cancer in excisions after shave biopsy

Clinical Observation or Further Excision: A Retrospective Review of Margin-positive Squamous and Basal Cell Carcinomas

Background

Patients determined to have margin-positive nonmelanoma skin cancer (NMSC) after initial shave or punch biopsy performed by a primary care physician or dermatologist are commonly referred to extirpative surgeons for definitive removal. Not infrequently, the residual tumor is not appreciable, and the exact location of the lesion is indiscernible. The consulting surgeon must decide to excise the presumed lesion or clinically monitor for recurrence.

Methods

This single-center, retrospective review examined patients with squamous and basal cell carcinomas referred over a 5-year period to two senior authors.

Results

In total, 233 patients had a total of 312 lesions excised. Thirty-nine (12.5%) of these lesions (in 33 patients) demonstrated no residual tumor on pathologic examination. Twelve patients were managed nonoperatively (5.15%) and observed to have had no tumor recurrence with a mean observation period of 14.66 months (range 1-54 months). Thus, approximately 19.3% of all patients referred had no residual tumor.

Conclusion

Based on our observations and low proclivity for metastases, nonoperative monitoring of NMSC may be a reasonable option for certain lesions less than 1 cm that are undiscernible at the time of referral.

Deep Shave Removal of Suspected Basal Cell Carcinoma: A Prospective Study

BACKGROUND

Diagnosis and treatment of basal cell carcinoma (BCC) in the same visit by shave removal may decrease health care spending and promote patient satisfaction.

OBJECTIVE

To prospectively evaluate deep shave removal of lesions clinically suspicious for low-risk BCC on the trunk or extremities in immunocompetent patients.

MATERIALS AND METHODS

Deep shave removal with the intent to remove the entire tumor was performed from January 2015 to June 2016, and patients were followed prospectively for clinical evidence of tumor recurrence.

RESULTS

Seventy-seven lesions were removed from 51 patients, including 29 (37%) superficial and nodular BCCs, 27 (35%) superficial BCCs, 16 (21%) nodular BCCs, and 5 (6%) non-BCCs. Fifteen BCCs (21%) had positive residual margins after deep shave removal, which was significantly more likely to occur in nodular compared with superficial BCCs (odds ratio = 7.8, 95% confidence interval = 1.4-43), and underwent re-excision. Fourteen specimens initially reported to have negative margins after deep shave underwent resectioning, which revealed positive margins in 4 specimens (28.6%). No BCCs have recurred clinically after an average follow-up of 50 months (SE 3.2).

CONCLUSION

Consider deep shave removal for low-risk BCCs on the trunk or extremities in immunocompetent patients hoping to avoid a second treatment visit.

Surgical delays of less than 1 year in Mohs surgery associated with tumor growth in moderately- and poorly-differentiated squamous cell carcinomas but not lower-grade squamous cell carcinomas or basal cell carcinomas: A retrospective analysis

BACKGROUND

Evidence is controversial and limited concerning whether surgical delays are associated with tumor growth for cutaneous squamous cell carcinomas (SCCs) and basal cell carcinomas.

OBJECTIVE

Identify tumor subpopulations that may demonstrate an association between tumor growth and surgical delay.

METHODS

We retrospectively analyzed 299 SCCs and 802 basal cell carcinomas treated with Mohs surgery at a single institution. Time interval from biopsy to surgery represented surgical delay. Change in major diameter (ΔMD) from size at biopsy to postoperative defect represented tumor growth. Independent predictors of ΔMD were identified by multivariate analysis. Linear regression was then utilized to assess for whether the ΔMD from these independent predictors trended with surgical delay.

RESULTS

Surgical delays ranged from 0 to 331 days. Among SCCs, histologic subtype and prior treatment were identified as independent predictors of ΔMD. Significant associations between ΔMD and surgical delay were found for poorly- and moderately-differentiated SCCs, demonstrating growth rates of 0.28 cm and 0.24 cm per month of delay, respectively. The ΔMD for SCCs with prior treatment and basal cell carcinoma subgroups did not vary with surgical delay.

LIMITATIONS

Retrospective design, single center.

CONCLUSION

Surgical delays of less than a year were associated with tumor growth for higher-grade SCCs, with effect sizes bearing potential for clinical significance.

A Protease-Activated Fluorescent Probe Allows Rapid Visualization of Keratinocyte Carcinoma during Excision

Keratinocyte carcinomas, including basal and squamous cell carcinomas, are the most common human cancers worldwide. While 75% of all keratinocyte carcinoma (4 million annual cases in the United States) are treated with conventional excision, this surgical modality has much lower cure rates than Mohs micrographic surgery, likely due to the bread-loaf histopathologic assessment that visualizes <1% of the tissue margins. A quenched protease-activated fluorescent probe 6qcNIR, which produces a signal only in the protease-rich tumor microenvironment, was topically applied to 90 specimens ex vivo immediately following excision. "Puzzle-fit" analysis was used to correlate the fluorescent images with histology. Probe-dependent fluorescent images correlated with cancer determined by conventional histology. Point-of-care fluorescent detection of skin cancer had a clinically relevant sensitivity of 0.73 and corresponding specificity of 0.88. Importantly, clinicians were effectively trained to read fluorescent images within 15 minutes with reliability and confidence, resulting in sensitivities of 62%-78% and specificities of 92%-97%. Fluorescent imaging using 6qcNIR allows 100% tumor margin assessment by generating en face images that correlate with histology and may be used to overcome the limitations of conventional bread-loaf histology. The utility of 6qcNIR was validated in a busy real-world clinical setting, and clinicians were trained to effectively read fluorescent margins with a short guided instruction, highlighting clinical adaptability. When used in conventional excision, this approach may result in higher cure rates at a lower cost by allowing same-day reexcision when needed, reducing patient anxiety and improving compliance by expediting postsurgical specimen assessment. SIGNIFICANCE: A fluorescent-probe-tumor-visualization platform was developed and validated in human keratinocyte carcinoma excision specimens that may provide simple, rapid, and global assessment of margins during skin cancer excision, allowing same-day reexcision when needed.

Multispectral autofluorescence dermoscope for skin lesion assessment

Basal cell carcinoma (BCC) is the most common type of skin cancer. Diagnosis and edge assessment of BCC lesions are based on clinical and dermoscopy evaluation, which are strongly dependent on the expertise and training of the physician. There is a high rate of underdiagnosis because BCC is frequently confused with certain common benign lesions and is often indistinguishable from the surrounding healthy tissue. In the present study, a multispectral fluorescence lifetime imaging (FLIm) dermoscopy system, designed for imaging and analyzing the autofluorescence emission of skin tissue, was used to image thirty-eight patients with diagnosed nodular BCC (nBCC) lesions, using clinically acceptable levels of excitation light exposure. With this system, skin autofluorescence was imaged simultaneously using three emission bands: 390 ± 20 nm, 452 ± 22 nm, and >496 nm, preferentially targeting collagen, NADH, and FAD autofluorescence, respectively. Statistical classifiers based on FLIm features developed to discriminate BCC from healthy tissue showed promising performance (ROC area-under-the-curve of 0.82). This study demonstrates the feasibility of clinically performing multispectral endogenous FLIm dermoscopy providing baseline results indicating the potential of this technology as an image-guided tool to improve the delineation of nBCC during surgical lesion resection.

Economic Analysis of a Noninvasive Molecular Pathologic Assay for Pigmented Skin Lesions

Importance

A recently described noninvasive gene expression test (the pigmented lesion assay [PLA]) with adhesive patch-based sampling has the potential to rule out melanoma and the need for surgical biopsy of pigmented lesions suggestive of melanoma with a negative predictive value of 99% compared with 83% for the histopathologic standard of care. The cost implications of using this molecular test vs visual assessment followed by biopsy and histopathologic assessment (VAH) have not been evaluated.

Objective

To determine potential cost savings of PLA use vs the VAH pathway.

Design, Setting, and Participants

This health economic analysis performed from a US payer perspective was based on consensus treatment guidelines and fee schedules from the Centers for Medicare & Medicaid Services. Data for model input were derived from routine use of the test in US dermatology practices and literature. Participants included patients with primary cutaneous pigmented lesions suggestive of melanoma. Data were analyzed from February 8 to December 1, 2017.

Main Outcomes and Measures

The primary analysis consisted of the relative reduction in costs of diagnostic surgical procedures for PLA vs VAH management. Additional analyses included stage-related treatment costs associated with delays in diagnosis.

Results

In the cost analysis for this economic model, the relative reduction in surgical procedure costs (biopsy and subsequent excision), assuming $0 for the PLA to facilitate multiple comparison scenarios, was -$395 compared with VAH. The relative reduction in stage-related treatment costs associated with the PLA was -$433 compared with VAH, primarily associated with avoidance of delays due to false-negative diagnoses. Surveillance costs were reduced by -$119 with the PLA. The total cost of fully adjudicating a lesion suggestive of melanoma by VAH was $947. At a mean selling price reference point for PLA of $500, cost savings of $447 (47%) per lesion tested could be realized.

Conclusions and Relevance

The results of this analysis suggest that the PLA reduces cost and may improve the care of patients with primary pigmented skin lesions suggestive of melanoma.

Predictive value of basal cell carcinoma biopsies with negative margins: A retrospective cohort study

BACKGROUND

Pathology reports of basal cell carcinoma (BCC) biopsies often contain comments of positive or negative margins, with only 1%-2% of the margin evaluated. The negative predictive value (NPV) of biopsy margin status on residual BCC is unknown.

OBJECTIVE

The purpose of this study was to determine the NPV of BCC biopsy margin status on the absence of residual BCC in the corresponding excision.

METHODS

From our institution's archives, we collected BCC biopsies with negative margin readings that had subsequent excisions. For excisions read as negative for residual BCC, the excision blocks were sectioned at 150-μm intervals until exhausted.

RESULTS

We collected 143 cases that met criteria; 34 (24%) were found to contain residual BCC in the corresponding excision leading to a NPV of 76%; in 31 of 34 (91%) of these cases, the residual histologic subtype was superficial.

LIMITATIONS

Our sectioning technique did not evaluate 100% of the excision specimens.

CONCLUSION

Negative margins in a BCC biopsy are a poor predictor of residual disease in the patient. We recommend that clinicians treat these lesions, and that pathologists who comment on margin status of BCC biopsies consider adding a caveat to reflect these findings.

Updates on the Management of Non-Melanoma Skin Cancer (NMSC)

Non-melanoma skin cancers (NMSCs) are the most common malignancy worldwide, of which 99% are basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of skin. NMSCs are generally considered a curable diseases, yet they currently pose an increasing global healthcare problem due to rising incidence. This has led to a shift in emphasis on prevention of NMSCs with development of various skin cancer prevention programs worldwide. This article aims to summarize the most recent changes and advances made in NMSC management with a focus on prevention, screening, diagnosis, and staging.

Intraoperative imaging during Mohs surgery with reflectance confocal microscopy: initial clinical experience

Mohs surgery for the removal of nonmelanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is time consuming and labor intensive. Real-time intraoperative reflectance confocal microscopy(RCM), combined with video mosaicking, may enable rapid detection of residual tumor directly in the surgical wounds on patients. We report our initial experience on 25 patients, using aluminum chloride for nuclear contrast. Imaging was performed in quadrants in the wound to simulate the Mohs surgeon’s examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin and detectable in residual NMSC tumors. The presence of residual tumor and normal skin features could be detected in the peripheral and deep dermal margins. Intraoperative RCM imaging may enable detection of residual tumor directly on patients during Mohs surgery, and may serve as an adjunct for frozen pathology. Ultimately, for routine clinical utility, a stronger tumor-to-dermis contrast may be necessary, and also a smaller microscope with an automated approach for imaging in the entire wound in a rapid and controlled manner.