alexa Natural history of breast cancers detected in the Swedish mammography screening programme: a cohort study.
Oncology

Oncology

Journal of Cancer Science & Therapy

Author(s): Zahl PH, Gtzsche PC, Mhlen J, Zahl PH, Gtzsche PC, Mhlen J

Abstract Share this page

Abstract BACKGROUND: The natural history of screen-detected breast cancers is not well understood. A previous analysis of the incidence change during the introduction of the Norwegian screening programme in the late 1990s suggested that the natural history of many screen-detected invasive breast cancers is to regress spontaneously but the study was possibly confounded by use of hormone replacement therapy in the population. We did a similar analysis of data collected during an earlier period when few women were exposed to hormone replacement therapy. METHODS: We compared cumulative breast cancer incidence in age-matched cohorts of women living in seven Swedish counties before and after the initiation of public mammography screening between 1986 and 1990. Women aged 40-49 years were invited to screening every year and women aged 50-74 years were invited every 2 years. A screened group including all women aged 40-69 years (n=328,927) was followed-up for 6 years after the first invitation to the programme. A control group including all women in the same age range (n=317,404) was also followed-up for 6 years--4 years without screening and 2 years when they entered the screening programme. Screening attendance was much the same in both groups (close to 80\%). Counts of incident invasive breast cancers were obtained from the Swedish Cancer Registry (in-situ cancers were excluded). FINDINGS: Before the age-matched controls were invited to be screened at the end of their follow-up period, the 4-year cumulative incidence of invasive breast cancer was significantly higher in the screened group (982 per 100,000) than it was in the control group (658 per 100,000) (relative risk [RR] 1·49, 95\% CI 1·41-1·58). Even after prevalence screening in the control group, the screened group had higher 6-year cumulative incidence of invasive breast cancer (1443 per 100,000 vs 1269 per 100,000; RR 1·14, 1·10-1·18). INTERPRETATION: Because the cumulative incidence among controls did not reach that of the screened group, we believe that many invasive breast cancers detected by repeated mammography screening do not persist to be detected by screening at the end of 6 years, suggesting that the natural course of many of the screen-detected invasive breast cancers is to spontaneously regress. FUNDING: None. Copyright © 2011 Elsevier Ltd. All rights reserved. This article was published in Lancet Oncol and referenced in Journal of Cancer Science & Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

eng[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords