Attributes and risk factors of positive margins on 864 excisions of basal cell carcinomas: a single-center retrospective study

Assessment of Standard Surgical Excision Efficacy and Analysis of Recurrence-Associated Factors in 343 Cases of Nasal Basal Cell Carcinoma: A Single-Center Retrospective Study

In Caucasians, basal cell carcinoma, the predominant non-melanoma skin cancer type, poses challenges for surgeons due to anatomical and aesthetic concerns, particularly when located on the nose. The study aimed to evaluate tumor distribution, size, morphological subtypes, surgical outcomes, radicality levels, and their correlation with recurrence rates. A retrospective analysis encompassed 343 cases of nasal skin cancer over a four-year period from 1 January 2019 to 31 December 2022. The research cohort comprised 252 female and 91 male participants, averaging 75.2 years old. Tumors were most found on the left sidewall of the nose (25.4%) and the dorsum (24.8%). The infiltrative morphological subtype was predominant (70.8%). Standard surgical excision with fasciocutaneous plastic was the preferred surgical procedure. Radical excision, defined by the absence of tumor cells in a resection margin, was accomplished in 79.0% of lesions, whereas 16.9% demonstrated incomplete excision, signifying the presence of tumor cells in the resection margin. Non-radically excised tumors exhibited a significantly higher recurrence rate (24.1%) compared to those with radical excision (6.3%). In nasal reconstruction, diverse surgical techniques are essential for precise adaptation based on factors like tumor characteristics and patient needs. Despite surgeons' careful adherence to excision margin guidelines, the possibility of non-radical outcome cannot be eliminated.

Adequacy of surgical margins, re-excision, and evaluation of factors associated with recurrence: a retrospective study of 769 basal cell carcinomas

BACKGROUND

Achieving adequate surgical margins and preventing recurrence are important in the treatment of basal cell carcinoma (BCC).

OBJECTIVES

The objectives of this study were to evaluate the adequacy of surgical margins and the re-excision rates in patients with primary BCC who underwent standard surgical treatment using our proposed algorithm and to define the risk factors in patients with recurrent BCC.

METHODS

The medical records of patients who were histopathologically diagnosed with BCC were reviewed. An algorithm created based on previous literature was used to determine the distribution of optimal surgical margins adequacy and re-excision rates.

RESULTS

Statistically significant differences were observed between the cases with and without recurrence in age at diagnosis (p=0.004), tumor size (p=0.023), tumor location in the H zone of the face (p=0.005), and aggressive histopathological subtype (p=0.000). When the tumors were evaluated for adequacy of deep and lateral surgical margins and re-excision rates, higher rates of adequate excision (457 cases, 68.0%) and re-excision (43 cases, 33.9%) were noted for tumors in the H or M zone.

STUDY LIMITATIONS

Inadequate follow-up of newly diagnosed patients in terms of recurrence and metastasis and the retrospective application of our proposed algorithm are the limitations of the present study.

CONCLUSIONS

Our results showed that if BCC was detected at an early age and at an early stage, recurrence was lower. The H and M zones were the regions with the highest rates of optimal surgical outcomes.

Uncertainty estimation for margin detection in cancer surgery using mass spectrometry

PURPOSE

Rapid evaporative ionization mass spectrometry (REIMS) is an emerging technology for clinical margin detection. Deployment of REIMS depends on construction of reliable deep learning models that can categorize tissue according to its metabolomic signature. Challenges associated with developing these models include the presence of noise during data acquisition and the variance in tissue signatures between patients. In this study, we propose integration of uncertainty estimation in deep models to factor predictive confidence into margin detection in cancer surgery.

METHODS

iKnife is used to collect 693 spectra of cancer and healthy samples acquired from 91 patients during basal cell carcinoma resection. A Bayesian neural network and two baseline models are trained on these data to perform classification as well as uncertainty estimation. The samples with high estimated uncertainty are then removed, and new models are trained using the clean data. The performance of proposed and baseline models, with different ratios of filtered data, is then compared.

RESULTS

The data filtering does not improve the performance of the baseline models as they cannot provide reliable estimations of uncertainty. In comparison, the proposed model demonstrates a statistically significant improvement in average balanced accuracy (75.2%), sensitivity (74.1%) and AUC (82.1%) after removing uncertain training samples. We also demonstrate that if highly uncertain samples are predicted and removed from the test data, sensitivity further improves to 88.2%.

CONCLUSIONS

This is the first study that applies uncertainty estimation to inform model training and deployment for tissue recognition in cancer surgery. Uncertainty estimation is leveraged in two ways: by factoring a measure of input noise in training the models and by including predictive confidence in reporting the outputs. We empirically show that considering uncertainty for model development can help improve the overall accuracy of a margin detection system using REIMS.

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.

HLA-G, cytokines, and cytokine receptors in the non-aggressive basal cell carcinoma microenvironment

Non-aggressive basal cell carcinoma (BCC) growth is slow and might be mediated by the immune system. This study analysed the human leukocyte antigen (HLA)-G expression and cytokine profile in non-aggressive BCC subtypes from distinct locations. HLA-G was evaluated via immunohistochemistry and cytokine expression was analysed by a quantitative real-time polymerase chain reaction in 26 primary BCC samples, including nodular BCC (nBCC, n = 16) and superficial BCC (n = 10) from cephalic (ceBCC, n = 12) and non-cephalic (n = 14) locations, and by bioinformatics analysis of public GEO databases. Inflammatory infiltrate was concentrated around the tumour nests. HLA-G-positive inflammatory cells (53.85%) were more abundant than HLA-G-positive tumour cells (21.54%, p < 0.001). HLA-G immunoreactivity was predominantly cytoplasmic in BCC cells and was primarily associated with lymphocytes and macrophages surrounding the tumour. nBCC showed a higher percentage of HLA-G-positive tumour cells (p = 0.04), and ceBCC showed stronger intensity (p = 0.04). IFN-gamma and IL-10 expression were 1.95 and 1.22-fold higher, respectively, relative to that in normal skin, with a positive correlation between them (r = 0.61; p = 0.002). IL-23 expression was higher in nBCC (p = 0.04) and positively correlated (r = 0.47; p = 0.05) with slight intensity of HLA-G-positive tumour cells. The up-regulation of IL23A and IL10RB and down-regulation of IFNGR1 and IL4R gene expression in BCC compared to levels in adjacent tissues were demonstrated in the GSE125285 dataset. The exhibited cytokine profile was consistent with the induction of HLA-G expression in non-aggressive BCC subtypes. HLA-G expression in tumour cells and inflammatory cells surrounding BCCs supports the generation of inhibitory signals on various immune cells that exert anti-tumour responses.

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.