Christina Bording Rasmussen1, Susanne K Kjær2, Bent Ejlertsen1, Michael Andersson1, Maj-Britt Jensen1, Jane Christensen1, Rikke Langballe1, Lene Mellemkjær3. 1. Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 2. Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 3. Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark, Department of Gynecology, Department of Oncology and Danish Breast Cancer Cooperative Group, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark lene@cancer.dk.
Abstract
BACKGROUND: Incidence of contralateral breast cancer (CBC) is much less studied than primary breast cancer. We aimed to assess incidence rates of CBC in relation to age, calendar period and time since first breast cancer. METHODS: Using the nationwide Danish Cancer Registry, we identified 85 863 women with a first primary invasive breast cancer without distant metastases in Denmark during 1978-2009. Among these, 3120 women developed metachronous CBC. Crude incidence rates for CBC were calculated by age and calendar period at first breast cancer as well as time since first breast cancer. Mutual adjustments were made by use of Poisson regression models. RESULTS: The incidence of CBC decreased with increasing age at first breast cancer. Before 1998, incidence rates of CBC showed little variation. The rates decreased by period of first primary from 546 per 10(5) person-years in 1993-97 to 328 per 10(5) person-years in 2003-09. After adjustment for age and calendar period, no clear trend was observed in the overall incidence according to time since first breast cancer. CONCLUSIONS: Occurrence of cancer in the contralateral breast seems to be rather independent of time passed since the first primary. The finding of a decreasing incidence of CBC after 1997 is likely to be due to more women receiving systemic adjuvant therapy such as tamoxifen and longer duration of this treatment as well as the introduction of aromatase inhibitors.
BACKGROUND: Incidence of contralateral breast cancer (CBC) is much less studied than primary breast cancer. We aimed to assess incidence rates of CBC in relation to age, calendar period and time since first breast cancer. METHODS: Using the nationwide Danish Cancer Registry, we identified 85 863 women with a first primary invasive breast cancer without distant metastases in Denmark during 1978-2009. Among these, 3120 women developed metachronous CBC. Crude incidence rates for CBC were calculated by age and calendar period at first breast cancer as well as time since first breast cancer. Mutual adjustments were made by use of Poisson regression models. RESULTS: The incidence of CBC decreased with increasing age at first breast cancer. Before 1998, incidence rates of CBC showed little variation. The rates decreased by period of first primary from 546 per 10(5) person-years in 1993-97 to 328 per 10(5) person-years in 2003-09. After adjustment for age and calendar period, no clear trend was observed in the overall incidence according to time since first breast cancer. CONCLUSIONS: Occurrence of cancer in the contralateral breast seems to be rather independent of time passed since the first primary. The finding of a decreasing incidence of CBC after 1997 is likely to be due to more women receiving systemic adjuvant therapy such as tamoxifen and longer duration of this treatment as well as the introduction of aromatase inhibitors.
Authors: Rachel A Freedman; Nancy L Keating; Lydia E Pace; Joyce Lii; Ellen P McCarthy; Mara A Schonberg Journal: J Clin Oncol Date: 2017-07-27 Impact factor: 44.544
Authors: Rachel A Freedman; Nancy L Keating; Ann H Partridge; Hyman B Muss; Arti Hurria; Eric P Winer Journal: JAMA Oncol Date: 2017-03-01 Impact factor: 31.777
Authors: Rachel A Freedman; Christina A Minami; Eric P Winer; Monica Morrow; Alexander K Smith; Louise C Walter; Mina S Sedrak; Haley Gagnon; Adriana Perilla-Glen; Hans Wildiers; Tanya M Wildes; Stuart M Lichtman; Kah Poh Loh; Etienne G C Brain; Pamela S Ganschow; Kelly K Hunt; Deborah K Mayer; Kathryn J Ruddy; Reshma Jagsi; Nancy U Lin; Beverly Canin; Barbara K LeStage; Anna C Revette; Mara A Schonberg; Nancy L Keating Journal: JAMA Oncol Date: 2021-04-01 Impact factor: 33.006