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Incidence Differences Between First Primary Cancers and Second Primary Cancers Following Skin Squamous Cell Carcinoma as Etiological Clues

Authors Zheng G, Sundquist K, Sundquist J, Försti A, Hemminki A, Hemminki K

Received 2 April 2020

Accepted for publication 23 June 2020

Published 6 August 2020 Volume 2020:12 Pages 857—864


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 3

Editor who approved publication: Professor Henrik Toft Sørensen

Guoqiao Zheng,1– 3 Kristina Sundquist,4– 6 Jan Sundquist,4– 6 Asta Försti,1,4,7,8 Akseli Hemminki,9,10 Kari Hemminki1,2,4,11

1Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg D-69120, Germany; 2Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg D-69120, Germany; 3Faculty of Medicine, University of Heidelberg, Heidelberg, Germany; 4Center for Primary Health Care Research, Lund University, Malmö 205 02, Sweden; 5Department of Family Medicine and Community Health, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 6Center for Community-Based Healthcare Research and Education (CoHRE), Department of Functional Pathology, School of Medicine, Shimane University, Izumo, Japan; 7Hopp Children’s Cancer Center (KiTZ), Heidelberg, Germany; 8Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany; 9Cancer Gene Therapy Group, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; 10Comprehensive Cancer Center, Helsinki University Hospital, Helsinki, Finland; 11Faculty of Medicine and Biomedical Center in Pilsen, Charles University in Prague, Pilsen 30605, Czech Republic

Correspondence: Kari Hemminki
Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, Heidelberg 69120, Germany
Tel +49 6221421800
Fax +49 6221421810

Background: Most literature on second primary cancers (SPCs) focuses on possible factors, which may increase the risk of these cancers, and little attention has been paid for the overall incidence differences between first primary cancers (FPCs) and same SPCs. We wanted to compare the incidence rates for all common cancers when these were diagnosed as FPCs and SPCs after invasive and in situ squamous cell carcinoma (SCC) of the skin, which are usually treated by surgery only.
Methods: Cancers were identified from the Swedish Cancer Registry from the years 1990 through to 2015, and they included, in addition to skin cancers, 20 male cancers totaling 484,850 patients and 22 female cancers totaling 452,909 patients. Standardized incidence rates and relative risks (RRs) were calculated for sex-specific common cancers as FPC and as SPC after skin SCC. Spearman rank correlations were used in the analysis of incidence ranking of FPC and SPC.
Results: Of total, 29,061 men and 23,533 women developed invasive SCC and 27,842 men and 36,383 women in situ SCC. The total number of 20 other male cancers was 484,850 and of 22 female cancers it was 452,909. Rank correlations ranged from 0.90 to 0.96 (P∼ 5× 10− 6), indicating that overall skin SCC did not interfere with SPC formation. The exceptions were increased SPC risks for melanoma, sharing risk factors with skin SCC, and non-Hodgkin and Hodgkin lymphoma, and cancers of the upper aerodigestive tract, connective tissue, and male and female genitals suggesting contribution by skin cancer initiated immune dysfunction.
Conclusion: The incidence ranking of SPCs after skin cancers largely follows the incidence ranking of FPCs indicating that overall skin SCC does not greatly interfere with the intrinsic carcinogenic process. The main deviations in incidence between FPC and SPC appeared to be due to shared risk factors or immunological processes promoting immune responsive cancer types.

Keywords: skin cancer, second cancer, first primary cancer, immune disturbance

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