Acta Dermato-Venereologica 98-10CompleteContent | Page 22

991 SHORT COMMUNICATION Eccrine Porocarcinoma of the Skin is Rising in Incidence in the East of England Peter K. C. GOON 1 , Puran GURUNG 1 , Nick J. LEVELL 1 , Priya SUBRAMANIAN 1 , Adrian S. W. YONG 4 , Kevin Y. C. LEE 1 , Laszlo IGALI 2 , David GREENBERG 3 , Syed N. SHAH 1 and Eunice K. H. TAN 1 Departments of 1 Dermatology and 2 Cellular Pathology, Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, 3 Public Health England National Cancer Registration and Analysis Service, Fulbourn, Cambridge, UK, and 4 Department of Medicine, University of Malaya, Faculty of Medicine, Unit of Dermatology, Kuala Lumpur, West Malaysia. E-mail: [email protected] Accepted Jun 26, 2018 Epub ahead of print Jun 29, 2018 Eccrine porocarcinoma (EPC) was first described by Pinkus & Mehregan in 1963 (1) as “epidermotropic eccrine carcinoma” and is the malignant counterpart of eccrine poroma. It is a rare tumour (0.005–0.01% (2, 3) of cutaneous tumours), thought to arise from the acrosyringium of the sweat gland of the skin. The term “porocarcinoma” was first used by Mishima & Morioka in 1969 (4). Although initial case series suggested that this was a highly aggressive tumour, with approximately 60% of cases reported to have local recurrence, metas- tases or death, later larger case series of 18, 24 and 27 patients, respectively, did not support such an aggressive natural history (3, 5, 6) The largest case series to date (69 cases) in 2001 (7), reported EPC as a less aggressive tumour, with 17% local recurrence, 19% lymph node metastasis and 11% distant metastases or death. This study analysed the age-standardised incidence rates for the population of the East of England (East Nor- folk and Waveney), and estimated the numbers of cases likely to be found here and in the UK for 2020, 2025 and 2030. This cohort (n = 152) is the largest reported so far and there are long-term follow-up data for recurrences, metastases and survival/death, thus helping to clarify the natural history of this tumour. excluded from analyses. Only patients with verified survival and recurrence data were included in the study. Statistical analyses were performed using statistics package GraphPad™ Prism 7 (2016). RESULTS Over the 10-year study period stated above, the popula- tion of ENW increased by approximately 10.4% at a steady rate (8–11). Our recorded data for the numbers of EPC from the study period are shown in Fig. 1. Based on these data, linear regression analyses estimate numbers of cases for the years 2,020 (n = 54), 2,025 (n = 71) and 2,030 (n = 88). The East of England has a higher number of the el- derly (> 65 years of age), Caucasians (White) and more sunshine per annum by comparison with the UK mean. The technique of approximation to the means (8–10) controlled for these risk factors and extrapolated regional ENW data to UK levels, this allowed estimation of the national incidence in future years. The predicted total number of cases of EPC for the whole of the UK was 2,979 in 2020, 3,873 in 2025 and 4,746 in 2030. [These figures are calculated estimates only, and the risk of error increases the further away the estimate is made (see Fig. 1)]. METHODS Electronic databases from the pathology department at the Norfolk and Norwich University Hospital (NNUH) from East Norfolk and Waveney (ENW): (Breckland, Broadland, Great Yarmouth, North Norfolk, Norwich, South Norfolk and Waveney community districts) in the Eastern Region of the UK (population: 794,043 in 2004 increasing to 870,100 in 2013) (8–11), were analysed and collected from the 1 st of January, 2004 to 31 st December 2013 for this retrospective cohort analyses. Skin cancer histology results from each hospital in the region are coded and recorded monthly by the International Classification of Diseases categories ICD10/ICDO-2. There have been no changes in catchment area for the pathology laboratory or change in practice protocols or routines for the pa­ thologists and laboratory involved for the period of study. There have been no changes in physician patterns of referral of lesions over the study period. Standard immunohistochemical stains for markers known to be helpful in diagnosis of EPC such as epithelial membrane antigen (EMA), carcino-embryonic antigen (CEA), CD117 (KIT), etc, have been used as required or as available. Specialist dermatopathologists in the NNUH led the routine ana- lyses of skin specimens. All porocarcinoma in situ samples were Fig. 1. Number of cases of eccrine porocarcinoma diagnosed in East Norfolk and Waveney, with predicted cases in 2020, 2025 and 2030. Total no. of cases per year were 1, 5, 5, 11, 14, 13, 14, 31, 28, 30 for the data points shown below from 2004–2013. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica. doi: 10.2340/00015555-3000 Acta Derm Venereol 2018; 98: 991–992