Olav Dahl1,2, Mette Pernille Myklebust1, Jon Espen Dale1, Otilia Leon3, Eva Serup-Hansen4, Anders Jakobsen5, Per Pfeiffer6, Inger Marie Løes1, Frank Pfeffer7,8, Karen-Lise Garm Spindler9,10, Marianne Grønlie Guren11, Bengt Glimelius12, Anders Johnsson3. 1. Department of Oncology, Haukeland University Hospital, Bergen, Norway. 2. Department of Clinical Science, Medical Faculty, University of Bergen, Bergen, Norway. 3. Department of Oncology, Skåne University Hospital, Lund, Sweden. 4. Department of Oncology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark. 5. Department of Oncology, Vejle Hospital, University of Southern Denmark, Vejle, Denmark. 6. Department of Oncology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark. 7. Department of Gastroenterological Surgery, Haukeland University Hospital, Bergen, Norway. 8. Department of Clinical Medicine, University of Bergen, Bergen, Norway. 9. Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark. 10. Department of Oncology, Aarhus University Hospital, Aarhus, Denmark. 11. Department of Oncology and K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway. 12. Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
Abstract
Background: The UICC TNM 7th edition introduced stage groups for anal cancer which in 2019 has not yet come into general use. The new TNM 8th edition from 2016 defines 7 sub-stages. Background data for these changes are lacking. We aimed to investigate whether the new classification for anal cancer reliably predict the prognosis in the different stages.Patients and methods: The Nordic Anal Cancer Group (NOAC) conducted a large retrospective study of all anal cancers in Norway, Sweden and most of Denmark in 2000-2007. From the Nordic cohort 1151 anal cancer patients with follow-up data were classified by the TNM 4th edition which has identical T, N and M definitions as the TNM 7th edition, and therefore also can be classified by the TNM 7th stage groups. We used the Nordic cohort to translate the T, N and M stages into the TNM 8th stages and sub-stages. Overall survival for each stage was assessed. Results: Although the summary stage groups for TNM 8th edition discriminates patients with different prognosis reasonably well, the analyses of the seven sub-stages show overlapping overall survival: HR for stage IIA 1.30 (95%CI 0.80-2.12) is not significantly different from stage I (p = .30) and HR for stage IIB 2.35 (95%CI 1.40-3.95) and IIIA 2.48 (95%CI 1.43-4.31) are also similar as were HRs for stage IIIB 3.41 (95%CI 1.99-5.85) and IIIC 3.22 (95%CI 1.99-5.20). Similar overlapping was shown for local recurrence and distant spread. Conclusion: The results for the sub-stages calls for a revision of the staging system. We propose a modification of the TNM 8th edition for staging of anal cancer into four stages based on the T, N and M definitions of the TNM 8th classification.
Background: The UICC TNM 7th edition introduced stage groups for anal cancer which in 2019 has not yet come into general use. The new TNM 8th edition from 2016 defines 7 sub-stages. Background data for these changes are lacking. We aimed to investigate whether the new classification for anal cancer reliably predict the prognosis in the different stages.Patients and methods: The Nordic Anal Cancer Group (NOAC) conducted a large retrospective study of all anal cancers in Norway, Sweden and most of Denmark in 2000-2007. From the Nordic cohort 1151 anal cancerpatients with follow-up data were classified by the TNM 4th edition which has identical T, N and M definitions as the TNM 7th edition, and therefore also can be classified by the TNM 7th stage groups. We used the Nordic cohort to translate the T, N and M stages into the TNM 8th stages and sub-stages. Overall survival for each stage was assessed. Results: Although the summary stage groups for TNM 8th edition discriminates patients with different prognosis reasonably well, the analyses of the seven sub-stages show overlapping overall survival: HR for stage IIA 1.30 (95%CI 0.80-2.12) is not significantly different from stage I (p = .30) and HR for stage IIB 2.35 (95%CI 1.40-3.95) and IIIA 2.48 (95%CI 1.43-4.31) are also similar as were HRs for stage IIIB 3.41 (95%CI 1.99-5.85) and IIIC 3.22 (95%CI 1.99-5.20). Similar overlapping was shown for local recurrence and distant spread. Conclusion: The results for the sub-stages calls for a revision of the staging system. We propose a modification of the TNM 8th edition for staging of anal cancer into four stages based on the T, N and M definitions of the TNM 8th classification.