Global incidence of incomplete surgical excision in adult patients with non-melanoma skin cancer: study protocol for a systematic review and meta-analysis of observational studies

High-Frequency Ultrasound in Diagnosis and Treatment of Non-Melanoma Skin Cancer in the Head and Neck Region

Non-melanoma skin cancer is one of the most frequently diagnosed cancers in the human body and unfortunately the incidence continues to increase. NMSC is represented by the basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), which are the most prevalent forms, and basosquamous cell carcinomas (BSC) together with Merkel cell carcinoma (MCC), which are rare types but with a very aggressive pattern and poor prognosis. The pathological diagnosis is hard to assess without a biopsy, even by the dermoscopy. Moreover, the staging can be problematic because there is no access clinically to the thickness of the tumor and the depth of the invasion. The aim of this study was to evaluate the role of ultrasonography (US), which is a very efficient imaging method, non-irradiating and cheap, in diagnosis and treatment of non-melanoma skin cancer in the head and neck region. Thirty-one patients with highly suspicious malignant lesions of the head and neck skin were evaluated in the Oral and Maxillo-facial Surgery Department and Imaging Department in Cluj Napoca, Romania. All tumors were measured with three transducers: 13 MHz, 20 MHz and 40 MHz. Doppler examination and elastography were also used. The length, width, diameter, thickness, the presence of necrosis, status of regional lymph nodes, the presence of hyperechoic spots, strain ratio and vascularization were all recorded. After that, all patients were treated by surgical resection of the tumor and reconstruction of the defect. Immediately after surgical resection, all tumors were measured again after the same protocol. The resection margins were evaluated by all three types of transducers in order to detect malignant involvement and the results were compared with the histopathological report. We found that the 13 MHz transducers offered a big picture of the tumor but the level of details, in the form of the presence of the hyperechoic spots, is reduced. We recommend this transducer for evaluation of surgical margins or for the large skin tumors. The 20 and 40 MHz transducers are better for viewing the particularities of malignant lesions and for an accurate measurement; however, in the case of large size lesions, assessing all three dimensions of the tumor can be difficult. The intralesional hyperechoic spots are present in case of BCC and they can be used for differential diagnosis of BCC.

National audit of non-melanoma skin cancer excisions performed by plastic surgery in the UK

A national, multi-centre audit of non-melanoma skin cancer excisions by plastic surgery.

Does experience affect surgical margins in head and neck basal cell carcinoma?

Purpose: The aim of our study was to evaluate the impact of surgical experience in a high volume head and neck surgery department on basal cell carcinoma margin status. Methods: A retrospective analysis of 546 patients surgically treated for primary basal cell carcinoma of the head and neck region was done. Resections were performed by 4 specialists with equal experience in head and neck surgery and 4 ENT residents at the same level of surgical training. A margin of 3-5mm was chosen, according to guidelines. Results: The study consisted of 304 males and 242 females, mean age of 69 (range 26 – 100). Most of the tumors were located on the nose (165 pts; 30,2%) and auricle (119; 21,7%). The most common histological subtype was nodular (119; 21,7%). Tumor size was up to 20mm in 394 cases (72%). Positive surgical margins were found in 112 cases (20,5%). There was no difference in terms of positive surgical margins between residents (19/119 cases; 15,9%) and specialists (93/426; 21,8%; p=0.161). Conclusions: The results of our study have shown that adequate surgical training in dedicated head and neck surgery department is an efficient factor in obtaining free surgical margins in head and neck basal cell carcinoma.

Exploring the cause of the dual allosteric targeted inhibition attaching to allosteric sites enhancing SHP2 inhibition

SHP2 is a protein tyrosine phosphatase (PTP) that can regulate the tyrosine phosphorylation level. Overexpression of SHP2 will promote the development of cancer diseases, so SHP2 has become one of the popular targets for the treatment of cancer. Studies have reported that both SHP099 and SHP844 are inhibitors of SHP2 and bind to different allosteric sites 1 and 2, respectively. Studies have shown that combining SHP099 with SHP844 will enhance pharmacological pathway inhibition in cells. This study uses molecular dynamic simulations to explore the dual allosteric targeted inhibition mechanism. The result shows that the residues THR108-TRP112 (allosteric site 1) move to LEU236-GLN245 (αB-αC link loop in PTP domain) , the residues of GLN79-GLN87 (allosteric site 2) get close to LEU262-GLN269 (αA-αB link loop in PTP domain) and HIS458-ARG465 (P-loop) come near to ARG501-THR507 (Q-loop) in SHP2-SHP099-SHP844 system, which makes the "inactive conformation" more stable and prevents the substrate from entering the catalytic site. Meanwhile, residue GLU110 (allosteric site 1), ARG265 (allosteric site 2), and ARG501 (Q-loop) are speculated to be the key residues that causing the SHP2 protein in auto-inhibition conformation. It is hoped that this study will provide clues for the development of the dual allosteric targeted inhibition of SHP2.

Incomplete surgical excision of keratinocyte skin cancers: a systematic review and meta‐analysis*

BACKGROUND

Keratinocyte or nonmelanoma skin cancer (NMSC) is the commonest malignancy worldwide. The usual treatment is surgical excision. Current guidelines underestimate incomplete excision rates.

OBJECTIVES

We aimed to determine the risk of incomplete excision of NMSCs through a systematic review and meta-analysis of primary clinical studies.

METHODS

A PRISMA-compliant systematic review and meta-analysis was performed using methodology proposed by Cochrane (PROSPERO CRD42019157936). A comprehensive search strategy was applied to MEDLINE, Embase, Scopus, CINAHL, EMCare, Cochrane Library and the grey literature (January 2000-27 November 2019). All studies were included except those on Mohs micrographic surgery, frozen section or biopsies. Abstract screening and data extraction were performed in duplicate. Risk of bias was assessed using a tool for prevalence/incidence studies. The primary outcome was the proportion of incomplete surgical excisions. A random-effects model for pooling of binomial data was used. Differences between proportions were assessed by subgroup meta-analysis and meta-regression, which were presented as risk ratios (RRs).

RESULTS

Searching identified 3477 records, with 110 studies included, comprising 53 796 patients with 106 832 basal cell carcinomas (BCCs) and 21 569 squamous cell carcinomas (SCCs). The proportion of incomplete excisions for BCC was 11·0% [95% confidence interval (CI) 9·7-12·4] and for SCC 9·4% (95% CI 7·6-11·4). Proportions of incomplete excisions by specialty were: dermatology, BCCs 6·2% and SCCs 4·7%; plastic surgery, BCCs 9·4% and SCCs 8·2%; general practitioners, BCCs 20·4% and SCCs 18·9%. The risk of incomplete excision for general practitioners was four times that of dermatologists for both BCCs (RR 3·9, 95% CI 2·0-7·3) and SCCs (RR 4·8, 95% CI 1·0-22·8). Studies were heterogeneous (I²  = 98%) and at high risk of bias.

CONCLUSIONS

The proportion of incomplete excisions is higher than previously reported. Excisions performed by specialists may lower the risk of incomplete excision.