Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results

Verena A Katzke; Volker Arndt; Karin Halina Greiser; Florian Karpa; Dorothee Zoller; Renée Fortner; Karen Steindorf; Michael Hoffmeister; Hermann Brenner; Peter Schirmacher; Michael Leitzmann; Katharina Nimptsch; Ulrike Haug; Katharina Hofmann; Christoph Stallmann; Ulrich Mueller; Andrea Werdecker; Iris Pigeot; Enno Swart; Wolfang Ahrens; Martin Meyer; Sabine Luttmann; Alice Nennecke; Anne von Rüsten; Joachim Kieschke; Tobias Hartz; Andreas Stang; Wolfgang Hoffmann; Bernd Holleczek; Hans Gert Fabian; Annette Peters; Stefan N Willich; Lilian Krist; Matthias B Schulze; Kathrin Guenther; Hajo Zeeb; Nina Ebert; Börge Schmidt; Anna Köttgen; Alexander Kluttig; Rafael Mikolajczyk; Volker Harth; Nadia Obi; Carolina Klett-Tammen; Manuela Harries; Wolfgang Lieb; Heiko Becher; Heike Minnerup; André Karch; Claudia Meinke-Franze; Hansjörg Baurecht; Ute Mons; Lena Koch-Gallenkamp; Klaus Berger; Henry Völzke; Tobias Pischon; Alexander Katalinic; Rudolf Kaaks

doi:10.3238/arztebl.m2026.0061

Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results

Verena A Katzke, Volker Arndt, Karin Halina Greiser, Florian Karpa, Dorothee Zoller, Renée Fortner, Karen Steindorf, Michael Hoffmeister, Hermann Brenner, Peter Schirmacher, Michael Leitzmann, Katharina Nimptsch, Ulrike Haug, Katharina Hofmann, Christoph Stallmann, Ulrich Mueller, Andrea Werdecker, Iris Pigeot, Enno Swart, Wolfang AhrensMartin Meyer, Sabine Luttmann, Alice Nennecke, Anne von Rüsten, Joachim Kieschke, Tobias Hartz, Andreas Stang, Wolfgang Hoffmann, Bernd Holleczek, Hans Gert Fabian, Annette Peters, Stefan N Willich, Lilian Krist, Matthias B Schulze, Kathrin Guenther, Hajo Zeeb, Nina Ebert, Börge Schmidt, Anna Köttgen, Alexander Kluttig, Rafael Mikolajczyk, Volker Harth, Nadia Obi, Carolina Klett-Tammen, Manuela Harries, Wolfgang Lieb, Heiko Becher, Heike Minnerup, André Karch, Claudia Meinke-Franze, Hansjörg Baurecht, Ute Mons, Lena Koch-Gallenkamp, Klaus Berger, Henry Völzke, Tobias Pischon, Alexander Katalinic, Rudolf Kaaks

Abstract

BACKGROUND: The German National Cohort (NAKO Gesundheitsstudie) is a prospective cohort study with 205 053 participants. Its goal is to identify risk factors for chronic diseases, including cancer.

METHODS: We describe the methods of ascertaining cancer cases in NAKO (i.e., linkage with cancer registries and self-reporting), the incidence and prevalence figures obtained so far, and the ratios of observed to expected (O/E) case numbers.

RESULTS: Case ascertainment identified 2774 existing cancer cases diagnosed within the five years prior to study enrollment and 4295 new cancer cases diagnosed up to five years after enrollment. Cancers of the breast, prostate, lung, and colorectum made up 55% of the incident cases. Fewer incident cases were found than would have been expected on the basis of incidences in the general population (O/E ratio 0.80, 95% confidence interval [0.76;0.83] for the first two-years of prospective follow-up); the O/E ratio varied across tumor sites (breast 1.02, prostate 1.12, lung 0.38, colorectum 0.62). Possible explanations include healthy volunteer bias, delayed reporting, as well as incomplete data collection from registries and self-reporting.

CONCLUSION: Rising case numbers for the most common types of cancer are expected in the next few years and will enable comprehensive epidemiological analysis of the risk factors of cancer.

Original language	English
Journal	Deutsches Arzteblatt International
Volume	123
Issue number	14
ISSN	1866-0452
DOIs	https://doi.org/10.3238/arztebl.m2026.0061
Publication status	E-pub ahead of print - 10.07.2026

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

Research Areas and Centers

Research Area: Center for Population Medicine and Public Health (ZBV)

Access to Document

10.3238/arztebl.m2026.0061

Cite this

Katzke, V. A., Arndt, V., Greiser, K. H., Karpa, F., Zoller, D., Fortner, R., Steindorf, K., Hoffmeister, M., Brenner, H., Schirmacher, P., Leitzmann, M., Nimptsch, K., Haug, U., Hofmann, K., Stallmann, C., Mueller, U., Werdecker, A., Pigeot, I., Swart, E., ... Kaaks, R. (2026). Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results. Deutsches Arzteblatt International, 123(14). Advance online publication. https://doi.org/10.3238/arztebl.m2026.0061

@article{7fcdffd202c34824bba83071bd1e4798,

title = "Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results",

abstract = "BACKGROUND: The German National Cohort (NAKO Gesundheitsstudie) is a prospective cohort study with 205 053 participants. Its goal is to identify risk factors for chronic diseases, including cancer.METHODS: We describe the methods of ascertaining cancer cases in NAKO (i.e., linkage with cancer registries and self-reporting), the incidence and prevalence figures obtained so far, and the ratios of observed to expected (O/E) case numbers.RESULTS: Case ascertainment identified 2774 existing cancer cases diagnosed within the five years prior to study enrollment and 4295 new cancer cases diagnosed up to five years after enrollment. Cancers of the breast, prostate, lung, and colorectum made up 55\% of the incident cases. Fewer incident cases were found than would have been expected on the basis of incidences in the general population (O/E ratio 0.80, 95\% confidence interval [0.76;0.83] for the first two-years of prospective follow-up); the O/E ratio varied across tumor sites (breast 1.02, prostate 1.12, lung 0.38, colorectum 0.62). Possible explanations include healthy volunteer bias, delayed reporting, as well as incomplete data collection from registries and self-reporting.CONCLUSION: Rising case numbers for the most common types of cancer are expected in the next few years and will enable comprehensive epidemiological analysis of the risk factors of cancer.",

author = "Katzke, \{Verena A\} and Volker Arndt and Greiser, \{Karin Halina\} and Florian Karpa and Dorothee Zoller and Ren{\'e}e Fortner and Karen Steindorf and Michael Hoffmeister and Hermann Brenner and Peter Schirmacher and Michael Leitzmann and Katharina Nimptsch and Ulrike Haug and Katharina Hofmann and Christoph Stallmann and Ulrich Mueller and Andrea Werdecker and Iris Pigeot and Enno Swart and Wolfang Ahrens and Martin Meyer and Sabine Luttmann and Alice Nennecke and \{von R{\"u}sten\}, Anne and Joachim Kieschke and Tobias Hartz and Andreas Stang and Wolfgang Hoffmann and Bernd Holleczek and Fabian, \{Hans Gert\} and Annette Peters and Willich, \{Stefan N\} and Lilian Krist and Schulze, \{Matthias B\} and Kathrin Guenther and Hajo Zeeb and Nina Ebert and B{\"o}rge Schmidt and Anna K{\"o}ttgen and Alexander Kluttig and Rafael Mikolajczyk and Volker Harth and Nadia Obi and Carolina Klett-Tammen and Manuela Harries and Wolfgang Lieb and Heiko Becher and Heike Minnerup and Andr{\'e} Karch and Claudia Meinke-Franze and Hansj{\"o}rg Baurecht and Ute Mons and Lena Koch-Gallenkamp and Klaus Berger and Henry V{\"o}lzke and Tobias Pischon and Alexander Katalinic and Rudolf Kaaks",

year = "2026",

month = jul,

day = "10",

doi = "10.3238/arztebl.m2026.0061",

language = "English",

volume = "123",

journal = "Deutsches Arzteblatt International",

issn = "1866-0452",

publisher = "Deutscher Arzte-Verlag GmbH",

number = "14",

}

Katzke, VA, Arndt, V, Greiser, KH, Karpa, F, Zoller, D, Fortner, R, Steindorf, K, Hoffmeister, M, Brenner, H, Schirmacher, P, Leitzmann, M, Nimptsch, K, Haug, U, Hofmann, K, Stallmann, C, Mueller, U, Werdecker, A, Pigeot, I, Swart, E, Ahrens, W, Meyer, M, Luttmann, S, Nennecke, A, von Rüsten, A, Kieschke, J, Hartz, T, Stang, A, Hoffmann, W, Holleczek, B, Fabian, HG, Peters, A, Willich, SN, Krist, L, Schulze, MB, Guenther, K, Zeeb, H, Ebert, N, Schmidt, B, Köttgen, A, Kluttig, A, Mikolajczyk, R, Harth, V, Obi, N, Klett-Tammen, C, Harries, M, Lieb, W, Becher, H, Minnerup, H, Karch, A, Meinke-Franze, C, Baurecht, H, Mons, U, Koch-Gallenkamp, L, Berger, K, Völzke, H, Pischon, T, Katalinic, A & Kaaks, R 2026, 'Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results', Deutsches Arzteblatt International, vol. 123, no. 14. https://doi.org/10.3238/arztebl.m2026.0061

TY - JOUR

T1 - Ascertainment of Cancer Cases in the German National Cohort (NAKO)

T2 - Methods and Initial Results

AU - Katzke, Verena A

AU - Arndt, Volker

AU - Greiser, Karin Halina

AU - Karpa, Florian

AU - Zoller, Dorothee

AU - Fortner, Renée

AU - Steindorf, Karen

AU - Hoffmeister, Michael

AU - Brenner, Hermann

AU - Schirmacher, Peter

AU - Leitzmann, Michael

AU - Nimptsch, Katharina

AU - Haug, Ulrike

AU - Hofmann, Katharina

AU - Stallmann, Christoph

AU - Mueller, Ulrich

AU - Werdecker, Andrea

AU - Pigeot, Iris

AU - Swart, Enno

AU - Ahrens, Wolfang

AU - Meyer, Martin

AU - Luttmann, Sabine

AU - Nennecke, Alice

AU - von Rüsten, Anne

AU - Kieschke, Joachim

AU - Hartz, Tobias

AU - Stang, Andreas

AU - Hoffmann, Wolfgang

AU - Holleczek, Bernd

AU - Fabian, Hans Gert

AU - Peters, Annette

AU - Willich, Stefan N

AU - Krist, Lilian

AU - Schulze, Matthias B

AU - Guenther, Kathrin

AU - Zeeb, Hajo

AU - Ebert, Nina

AU - Schmidt, Börge

AU - Köttgen, Anna

AU - Kluttig, Alexander

AU - Mikolajczyk, Rafael

AU - Harth, Volker

AU - Obi, Nadia

AU - Klett-Tammen, Carolina

AU - Harries, Manuela

AU - Lieb, Wolfgang

AU - Becher, Heiko

AU - Minnerup, Heike

AU - Karch, André

AU - Meinke-Franze, Claudia

AU - Baurecht, Hansjörg

AU - Mons, Ute

AU - Koch-Gallenkamp, Lena

AU - Berger, Klaus

AU - Völzke, Henry

AU - Pischon, Tobias

AU - Katalinic, Alexander

AU - Kaaks, Rudolf

PY - 2026/7/10

Y1 - 2026/7/10

N2 - BACKGROUND: The German National Cohort (NAKO Gesundheitsstudie) is a prospective cohort study with 205 053 participants. Its goal is to identify risk factors for chronic diseases, including cancer.METHODS: We describe the methods of ascertaining cancer cases in NAKO (i.e., linkage with cancer registries and self-reporting), the incidence and prevalence figures obtained so far, and the ratios of observed to expected (O/E) case numbers.RESULTS: Case ascertainment identified 2774 existing cancer cases diagnosed within the five years prior to study enrollment and 4295 new cancer cases diagnosed up to five years after enrollment. Cancers of the breast, prostate, lung, and colorectum made up 55% of the incident cases. Fewer incident cases were found than would have been expected on the basis of incidences in the general population (O/E ratio 0.80, 95% confidence interval [0.76;0.83] for the first two-years of prospective follow-up); the O/E ratio varied across tumor sites (breast 1.02, prostate 1.12, lung 0.38, colorectum 0.62). Possible explanations include healthy volunteer bias, delayed reporting, as well as incomplete data collection from registries and self-reporting.CONCLUSION: Rising case numbers for the most common types of cancer are expected in the next few years and will enable comprehensive epidemiological analysis of the risk factors of cancer.

AB - BACKGROUND: The German National Cohort (NAKO Gesundheitsstudie) is a prospective cohort study with 205 053 participants. Its goal is to identify risk factors for chronic diseases, including cancer.METHODS: We describe the methods of ascertaining cancer cases in NAKO (i.e., linkage with cancer registries and self-reporting), the incidence and prevalence figures obtained so far, and the ratios of observed to expected (O/E) case numbers.RESULTS: Case ascertainment identified 2774 existing cancer cases diagnosed within the five years prior to study enrollment and 4295 new cancer cases diagnosed up to five years after enrollment. Cancers of the breast, prostate, lung, and colorectum made up 55% of the incident cases. Fewer incident cases were found than would have been expected on the basis of incidences in the general population (O/E ratio 0.80, 95% confidence interval [0.76;0.83] for the first two-years of prospective follow-up); the O/E ratio varied across tumor sites (breast 1.02, prostate 1.12, lung 0.38, colorectum 0.62). Possible explanations include healthy volunteer bias, delayed reporting, as well as incomplete data collection from registries and self-reporting.CONCLUSION: Rising case numbers for the most common types of cancer are expected in the next few years and will enable comprehensive epidemiological analysis of the risk factors of cancer.

U2 - 10.3238/arztebl.m2026.0061

DO - 10.3238/arztebl.m2026.0061

M3 - Journal articles

C2 - 42240299

SN - 1866-0452

VL - 123

JO - Deutsches Arzteblatt International

JF - Deutsches Arzteblatt International

IS - 14

ER -

Ascertainment of Cancer Cases in the German National Cohort (NAKO): Methods and Initial Results

Abstract

UN SDGs

Research Areas and Centers

Access to Document

Fingerprint

Cite this