Cassia Trewin-Nybråten

Cassia Trewin-Nybråten is a statistician in the Analysis and Research Section of the Registry Department.

Her main task is to prepare analyses for the annual reports from the National Quality Registry for Breast Cancer.


Cassia has a background as an epidemiologist, graduated from the London School of Hygiene & Tropical Medicine in 2010, and as a sports physiologist, graduating from the University of Wollongong in Australia in 1998.

She is also pursuing a PhD in socioeconomic differences in breast cancer incidence, mortality and survival in Norway.

She has previously worked with statistics at Statistics Norway and the Norwegian Institute of Public Health, and as a sports physiologist at the Australian Institute of Sport.


Selected publications

Hjerkind KV, Johansson ALV, Trewin CB, Russnes HG, Ursin G (2022) Incidence of breast cancer subtypes in immigrant and non-immigrant women in Norway. Breast Cancer Res, 24(1):4 doi 10.1186 /s13058-021-01498-5, PubMed 35012613

Johansson ALV, Trewin CB, Fredriksson I, Reinertsen KV, Russnes H, Ursin G (2021)                                In modern times, how important are breast cancer stage, grade and receptor subtype for survival: a population-based cohort study. Breast Cancer Res, 23(1):17 doi 10.1186/s13058-021-01393-z, PubMed 33526044

Trewin CB, Johansson ALV, Hjerkind KV, Strand BH, Kiserud CE, Ursin G (2020)                                      Stage-specific survival has improved for young breast cancer patients since 2000: but not equally. Breast Cancer Res Treat, 182(2) 477-89 DOI 10.1007/s10549-020-05698-z, PubMed 32495000

Trewin CB, Hjerkind KV, Johansson ALV, Strand BH, Kiserud CE, Ursin G (2020)                                      Socioeconomic inequalities in stage-specific breast cancer incidence: a nationwide registry study of 1.1 million young women in Norway, 2000-2015.                                                              Acta Oncol, 59(11), 1284-90 DOI 10.1080 /0284186X.2020.1753888, PubMed 32319848

Hudson S, Vik Hjerkind K, Vinnicombe S, Allen S, Trewin C, Ursin G, Dos-Santos-Silva I, De Stavola BL (2018) Adjusting for BMI in analyses of volumetric mammographic density and breast cancer risk Breast Cancer Res, 20 (1), 156 DOI 10.1186/s13058-018-1078-8, PubMed 30594212

Johansson ALV, Trewin CB, Hjerkind KV, Ellingjord-Dale M, Johannesen TB, Ursin G (2018)
Breast cancer-specific survival by clinical subtype after 7 years follow-up of young and elderly women in a nationwide cohort Int J Cancer, 144(6), 1251-1261 DOI 10.1002 /ijc.31950, PubMed 30367449

Gadeyne S, Menvielle G, Kulhanova I, Bopp M, Deboosere P, Eikemo TA, Hoffmann R, Kovács K, Leinsalu M, Martikainen P, Regidor E, Rychtarikova J, Spadea T, Strand BH, Trewin C, Wojtyniak B, Mackenbach JP (2017) The turn of the gradient? Educational differences in breast cancer mortality in 18 European populations during the 2000s Int J Cancer, 141 (1), 33-44 DOI 10.1002/ijc.30685, PubMed 28268249

Trewin CB, Strand BH, Weedon-Fekjær H, Ursin G (2017) Changing patterns of breast cancer incidence and mortality by education level over four decades in Norway, 1971-2009
Eur J Public Health, 27(1), 160-166 DOI 10.1093/eurpub/ckw148, PubMed 28177482