Accuracy of diagnostic biopsy for cutaneous melanoma: implications for surgical oncologists

Photoacoustic imaging for cutaneous melanoma assessment: a comprehensive review

Significance

Cutaneous melanoma (CM) has a high morbidity and mortality rate, but it can be cured if the primary lesion is detected and treated at an early stage. Imaging techniques such as photoacoustic (PA) imaging (PAI) have been studied and implemented to aid in the detection and diagnosis of CM.

Aim

Provide an overview of different PAI systems and applications for the study of CM, including the determination of tumor depth/thickness, cancer-related angiogenesis, metastases to lymph nodes, circulating tumor cells (CTCs), virtual histology, and studies using exogenous contrast agents.

Approach

A systematic review and classification of different PAI configurations was conducted based on their specific applications for melanoma detection. This review encompasses animal and preclinical studies, offering insights into the future potential of PAI in melanoma diagnosis in the clinic.

Results

PAI holds great clinical potential as a noninvasive technique for melanoma detection and disease management. PA microscopy has predominantly been used to image and study angiogenesis surrounding tumors and provide information on tumor characteristics. Additionally, PA tomography, with its increased penetration depth, has demonstrated its ability to assess melanoma thickness. Both modalities have shown promise in detecting metastases to lymph nodes and CTCs, and an all-optical implementation has been developed to perform virtual histology analyses. Animal and human studies have successfully shown the capability of PAI to detect, visualize, classify, and stage CM.

Conclusions

PAI is a promising technique for assessing the status of the skin without a surgical procedure. The capability of the modality to image microvasculature, visualize tumor boundaries, detect metastases in lymph nodes, perform fast and label-free histology, and identify CTCs could aid in the early diagnosis and classification of CM, including determination of metastatic status. In addition, it could be useful for monitoring treatment efficacy noninvasively.

Diagnostic biopsy of cutaneous melanoma, sentinel lymph node biopsy and indications for lymphadenectomy

The incidence of cutaneous melanoma appears to be increasing worldwide and this is attributed to solar radiation exposure. Early diagnosis is a challenging task. Any clinically suspected lesion must be assessed by complete diagnostic excision biopsy (margins 1-2 mm); however, there are other biopsy techniques that are less commonly used. Melanomas are characterized by Breslow thickness as thin (< 1 mm), intermediate (1-4 mm) and thick (> 4 mm). This thickness determines their biological behavior, therapy, prognosis and survival. If the biopsy is positive, a wide local excision (margins 1-2 cm) is finally performed. However, metastasis to regional lymph nodes is the most accurate prognostic determinant. Therefore, sentinel lymph node biopsy (SLNB) for diagnosed melanoma plays a pivotal role in the management strategy. Complete lymph node clearance has undoubted advantages and is recommended in all cases of positive SLN biopsy. A PET-CT (positron emission tomography-computed tomography) scan is necessary for staging and follow-up after treatment. Novel targeted therapies and immunotherapies have shown improved outcomes in advanced cases.

Effect of changes in Breslow thickness between the initial punch biopsy results and final pathology reports in acral lentiginous melanoma patients

Acral lentiginous melanoma (ALM) is the most common subtype of cutaneous melanoma among Asians; punch biopsy is widely performed for its diagnosis. However, the pathologic parameters evaluated via punch biopsy may not be sufficient for predicting disease prognosis compared to the parameters evaluated via excisional biopsy. We investigated whether changes in Breslow thickness (BT) between initial punch biopsy results and final pathology reports can affect the prognosis of ALM. Pathologic parameters were recorded from specimens acquired through the initial punch biopsy and wide excision. Patients were classified into two groups based on a change in Breslow depth: the BT increased or decreased on comparing the samples from the initial punch biopsy and final wide excision. We compared clinical characteristics, and a Cox regression model was used to identify independent prognostic factors influencing melanoma-specific death (MSD). Changes in BT did not affect MSD (hazard ratio [HR]: 0.55, P = 0.447). In multivariate analysis, a higher BT (> 2 mm) (HR: 9.93, P = 0.046) and nodal metastasis (HR: 5.66, P = 0.041) were significantly associated with an increased MSD risk. The use of punch biopsy did not affect MSD despite the inaccuracy of BT measurement as long as ALM was accurately diagnosed.

Seeing through the Skin: Photoacoustic Tomography of Skin Vasculature and Beyond

Skin diseases are the most common human diseases and manifest in distinct structural and functional changes to skin tissue components such as basal cells, vasculature, and pigmentation. Although biopsy is the standard practice for skin disease diagnosis, it is not sufficient to provide in vivo status of the skin and highly depends on the timing of diagnosis. Noninvasive imaging technologies that can provide structural and functional tissue information in real time would be invaluable for skin disease diagnosis and treatment evaluation. Among the modern medical imaging technologies, photoacoustic (PA) tomography (PAT) shows great promise as an emerging optical imaging modality with high spatial resolution, high imaging speed, deep penetration depth, rich contrast, and inherent sensitivity to functional and molecular information. Over the last decade, PAT has undergone an explosion in technical development and biomedical applications. Particularly, PAT has attracted increasing attention in skin disease diagnosis, providing structural, functional, metabolic, molecular, and histological information. In this concise review, we introduce the principles and imaging capability of various PA skin imaging technologies. We highlight the representative applications in the past decade with a focus on imaging skin vasculature and melanoma. We also envision the critical technical developments necessary to further accelerate the translation of PAT technologies to fundamental skin research and clinical impacts.

In-vivo imaging of melanoma with simultaneous dual-wavelength acoustic-resolution-based photoacoustic/ultrasound microscopy

Melanoma is a common, highly fatal skin cancer. Photoacoustic imaging can achieve highly sensitive and high-contrast detection of melanin molecules in tissues, also inheriting the high penetration depth and high spatial resolution characteristics of ultrasound imaging, thus it is a very promising non-invasive diagnostic tool for early melanoma. In this work, we built an acoustic-resolution-based photoacoustic microscopy system, using 1064 nm/532 nm pulsed light to observe melanoma in the back of a mouse with simultaneous photoacoustic/ultrasound imaging. Through the fusion of multi-modal images, accurate positioning of melanoma and its surrounding normal tissues were realized. This work will further promote the application of photoacoustic imaging in the clinical diagnosis of early melanoma.

Impact of Shave Biopsy on Diagnosis and Management of Cutaneous Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Melanoma is the most lethal skin cancer. Excision biopsy is generally recommended for clinically suspicious pigmented lesions; however, a proportion of cutaneous melanomas are diagnosed by shave biopsy. A systematic review was undertaken to investigate the impact of shave biopsy on tumor staging, treatment recommendations, and prognosis.

METHODOLOGY

The MEDLINE, Embase, and Cochrane Library databases were searched for relevant articles. Data on deep margin status on shave biopsy, tumor upstaging, and additional treatments on wide local excision (WLE), disease recurrence, and survival effect were analyzed across studies.

RESULTS

Fourteen articles from 2010 to 2020 were included. In total, 3713 patients had melanoma diagnosed on shave biopsy. Meta-analysis revealed a positive deep margin in 42.9% of shave biopsies. Following WLE, change in tumor stage was reported in 7.7% of patients. Additional treatment was recommended for 2.3% of patients in the form of either further WLE and/or sentinel lymph node biopsy. There was high heterogeneity across studies in all outcomes. Four studies reported survival, while no studies found any significant difference in disease-free or overall survival between shave biopsy and other biopsy modalities.

CONCLUSIONS

Just over 40% of melanomas diagnosed on shave biopsy report a positive deep margin; however, this translated into a change in tumor stage or treatment recommendations in relatively few patients (7.7% and 2.3%, respectively), with no impact on local recurrence or survival among the studies analyzed.

Cutaneous Malignant Melanoma: A Review of Early Diagnosis and Management

Cutaneous melanoma (CM) is a malignant tumor formed from pigment-producing cells called melanocytes. It is one of the most aggressive and fatal forms of skin malignancy. In the last decades, CM's incidence has gradually risen, with 351,880 new cases in 2015. Since the 1960s, its incidence has increased steadily, in 2019, with approximately 96,000 new cases. A greater understanding of early diagnosis and management of CM is urgently needed because of the high mortality rates due to metastatic melanoma. Timely detection of melanoma is crucial for successful treatment, but diagnosis with histopathology may also pose a significant challenge to this objective. Early diagnosis and management are essential and contribute to better survival rates of the patient. To better control this malignancy, such information is expected to be particularly useful in the early detection of possible metastatic lesions and the development of new therapeutic approaches. This article reviews the available information on the early diagnosis and management of CM and discusses such information's potential in facilitating the future prospective.

Impact of Biopsy Technique on Clinically Important Outcomes for Cutaneous Melanoma: A Systematic Review and Meta-analysis

We performed a systematic review and meta-analysis to examine the relationship between the type of biopsy technique employed in the diagnosis of cutaneous melanoma and 4 clinically important outcomes: melanoma-specific mortality, all-cause mortality, Breslow tumor depth, or melanoma recurrence. Our database was obtained by searching PubMed, Ovid MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and the Cochrane Library from inception until December 6, 2019. Studies were identified that compared biopsy techniques used to diagnose cutaneous melanoma with any of our study outcomes. We included 7 observational studies for our meta-analysis after screening 3231 titles and abstracts. Pooled data identified a significantly higher all-cause mortality in the punch biopsy group (risk ratio [RR], 1.520; P=.02). A higher, but nonsignificant, rate of melanoma-specific mortality (RR, 1.96; P=.22) and melanoma recurrence (RR, 1.20; P=.186) was also found for the punch biopsy group. Breslow tumor thickness was not significantly lower for punch incision (standardized mean difference, −0.42; P=.27). We found limited evidence for differences in clinically important outcomes across the spectrum of the most common methods employed in clinical practice for the initial diagnosis of cutaneous melanoma. A small, but significant, increase (P=.02) in all-cause mortality with punch biopsies was not seen for the other outcomes and was most likely due to small sample sizes and demographic differences in the included studies and unlikely represents a clinically important outcome. Our findings support the use of existing clinical practice guidelines for evaluating pigmented lesions suspicious for cutaneous melanoma.

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.

Photoacoustic/Ultrasound/Optical Coherence Tomography Evaluation of Melanoma Lesion and Healthy Skin in a Swine Model

The marked increase in the incidence of melanoma coupled with the rapid drop in the survival rate after metastasis has promoted the investigation into improved diagnostic methods for melanoma. High-frequency ultrasound (US), optical coherence tomography (OCT), and photoacoustic imaging (PAI) are three potential modalities that can assist a dermatologist by providing extra information beyond dermoscopic features. In this study, we imaged a swine model with spontaneous melanoma using these modalities and compared the images with images of nearby healthy skin. Histology images were used for validation.

Re-biopsy of partially sampled thin melanoma impacts sentinel lymph node sampling as well as surgical margins

AIM

To assess the impact of re-biopsy on partially sampled melanoma in situ (MIS), atypical melanocytic proliferation (AMP) and thin invasive melanoma.

MATERIALS & METHODS

We retrospectively identified cases of re-biopsied partially sampled neoplasms initially diagnosed as melanoma in situ, AMP or thin melanoma (Breslow depth ≤0.75 mm).

RESULTS & CONCLUSION

Re-biopsy led to sentinel lymph node biopsy (SLNB) in 18.3% of cases. No patients upstaged from AMP or MIS had a positive SLNB. One out of nine (11.1%) initially diagnosed as a thin melanoma ≤0.75 mm, upstaged with a re-biopsy, had a positive SLNB. After re-biopsy 8.5% underwent an increased surgical margin. Selective re-biopsy of partially sampled melanoma with gross residual disease can increase the accuracy of microstaging and optimize treatment regarding surgical margins and SLNB.

Differences in cutaneous melanoma treatment and patient satisfaction

Although clinical guidelines exist, the management of patients with cutaneous melanoma (CM) is a complex process that may vary between different care providers with potential dysfunctions ultimately mirrored in the overall patient satisfaction. The aim of the present study was to investigate the CM management as related to lead times, surgical quality and diagnosis communication with the hypothesis that the care may differ between providers and disparities may impact patient satisfaction. Medical records of 181 patients were retrospectively analyzed with parallel patient satisfaction evaluation by telephone interviews. Overall mean lead times from initial diagnosis until completion of all surgery and histopathology reports were 80-100 days and delays occurred at every step of the process. General practitioners performed excision biopsies faster however this was mitigated by slower histopathology processing. University level CM care showed less lag time between excision biopsy, wide local excision for thick melanomas and histopathology confirmation. University level care operated with twice the surgical margin as compared to general practitioners and non-university level specialists. Male patients had larger excision biopsy margins and significantly shorter lead times than female patients. Patient satisfaction rates were generally higher in the academic hospitals as compared to general practitioners and non-university dermatology clinics. Surprisingly, there was no correlation between lead times and patient satisfaction. Taken together, CM show substantial variation and caution should be practiced when using patient satisfaction as a quality indicator.

Preoperative measurement of cutaneous melanoma and nevi thickness with photoacoustic imaging

Photoacoustic imaging (PAI) is an emerging biomedical imaging technology, which can potentially be used in the clinic to preoperatively measure melanoma thickness and guide biopsy depth and sample location. We recruited 27 patients with pigmented cutaneous lesions suspicious for melanoma to test the feasibility of a handheld linear-array photoacoustic probe in imaging lesion architecture and measuring tumor depth. The probe was assessed in terms of measurement accuracy, image quality, and ease of application. Photoacoustic scans included single wavelength, spectral unmixing, and three-dimensional (3-D) scans. The photoacoustically measured lesion thickness gave a high correlation with the histological thickness measured from resected surgical samples (r=0.99, P<0.001 for melanomas, r=0.98, P<0.001 for nevi). Thickness measurements were possible for 23 of 26 cases for nevi and all (6) cases for melanoma. Our results show that handheld, linear-array PAI is highly reliable in measuring cutaneous lesion thickness in vivo, and can potentially be used to inform biopsy procedure and improve patient management.

Guidelines of the Brazilian Dermatology Society for diagnosis, treatment and follow up of primary cutaneous melanoma--Part I

The last Brazilian guidelines on melanoma were published in 2002. Development in diagnosis and treatment made updating necessary. The coordinators elaborated ten clinical questions, based on PICO system. A Medline search, according to specific MeSH terms for each of the 10 questions was performed and articles selected were classified from A to D according to level of scientific evidence. Based on the results, recommendations were defined and classified according to scientific strength. The present Guidelines were divided in two parts for editorial and publication reasons. In the first part, the following clinical questions were answered: 1) The use of dermoscopy for diagnosis of primary cutaneous melanoma brings benefits for patients when compared with clinical examination? 2) Does dermoscopy favor diagnosis of nail apparatus melanoma? 3) Is there a prognostic difference when incisional or excisional biopsies are used? 4) Does revision by a pathologist trained in melanoma contribute to diagnosis and treatment of primary cutaneous melanoma? What margins should be used to treat lentigo maligna melanoma and melanoma in situ?