Under- and Overdiagnosis in BreastScreen Norway

Breast Cancer Clinical Trial

Official title:

Under- and Overdiagnosis in BreastScreen Norway

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03852953
• Other study ID #: 17/222
• Secondary ID: 2018/FO201362
• Status: Completed
• Start date: July 1, 2018
• Est. completion date: June 8, 2020

Study information

• Verified date: January 2021
• Source: Cancer Registry of Norway
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

This PhD project will describe tumour characteristics and survival associated with of under- and overdiagnosed breast cancers, the rate of overdiagnosis in BreastScreen Norway, and whether women and family doctors are aware of, and knowledgeable about, under- and overdiagnosis in breast cancer screening.

Description:

Mammographic screening among women aged 50-69 reduces breast cancer mortality but also carries some risk. This PhD project will study under- and overdiagnosis, two risks associated with mammographic screening, in BreastScreen Norway. Underdiagnosis can occur when a tumour is present but not detected as a result of screening, while overdiagnosis can occur when a woman is diagnosed with a slow growing cancer that would not become symptomatic during her lifetime. This project will address the following topics and research questions using observational study methods. Study 1: To determine whether tumour histopathology and survival differentially associated with potentially under- or overdiagnosed interval and screen-detected breast cancers. - Do women with potentially underdiagnosed interval cancers have different tumour histopathology and survival than those whose interval cancers showed no signs at the prior screen? - Do women with potentially overdiagnosed screen-detected cancer have different tumour histopathology and survival than those whose screen-detected cancer showed no signs at the prior screen? Study 2: To estimate overdiagnosis in the screening program using individual-level data: - What was the rate of overdiagnosis for women screened in the program during 1996-2003? - How does adjusting for sociodemographic factors affect estimates of overdiagnosis? Study 3: To describe awareness and knowledge about under- and overdiagnosis and breast screening in general: - Are women aware of and knowledgeable about under- and overdiagnosis in breast screening? - Are family doctors aware of and knowledgeable about breast screening, and under- and overdiagnosis? Are they confident in their ability to relay this information to their patients? Study 1 is a quality improvement study and has approval from Personvernombudet (PVO 2016-4696). Study 2 has research ethics board (REK) approval (REK 2013/795), while REK approval will be sought for Study 3.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 3915
• Est. completion date: June 8, 2020
• Est. primary completion date: June 8, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 25 Years to 75 Years

Eligibility

Study 1

Inclusion Criteria:

• Breast cancer diagnosed within BreastScreen Norway using digital mammography
• Prior screening images available for review Study 2

Inclusion Criteria:

• Women born between 1927 and 1934 (inclusive)
• Legal resident in Norway at any time between 1996 and 2003 (inclusive) Study 3

Inclusion Criteria:

• Women residing in Norway, aged 50-69 (inclusive)
• Practising family doctors in Norway, aged 25-75 (inclusive)
• Provide informed consent

Related Conditions & MeSH terms

• Breast Cancer

Intervention

Other:
• Under- or overdiagnosed cancer
Diagnosed with a cancer that was visible on prior mammograms
• Screening
Invited or attended BreastScreen Norway

Locations

Country	Name	City	State
Norway	Cancer Registry of Norway	Oslo

Sponsors (2)

Lead Sponsor	Collaborator
Cancer Registry of Norway	Extrastiftelsen

Country where clinical trial is conducted

Norway, 

References & Publications (3)

Hovda T, Tsuruda K, Hoff SR, Sahlberg KK, Hofvind S. Radiological review of prior screening mammograms of screen-detected breast cancer. Eur Radiol. 2021 Apr;31(4):2568-2579. doi: 10.1007/s00330-020-07130-y. Epub 2020 Oct 1. — View Citation

Tsuruda KM, Hovda T, Bhargava S, Veierød MB, Hofvind S. Survival among women diagnosed with screen-detected or interval breast cancer classified as true, minimal signs, or missed through an informed radiological review. Eur Radiol. 2021 May;31(5):2677-268 — View Citation

Tsuruda KM. Overdiagnosis and 'underdiagnosis' in BreastScreen Norway [dissertation]. [Oslo, Norway]: University of Oslo; 2021. 108 p. Available at: http://urn.nb.no/URN:NBN:no-91337

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Study 3: Factors associated with awareness and knowledge of overdiagnosis	Using a self-administered web-based questionnaire designed for this study, the investigators will analyse survey responses to determine whether self-reported age (categorised into 5-year age groups) is associated with awareness and knowledge of overdiagnosis. This will be done separately for women and family doctors.	One day (Measurements taken once at time of survey completion)
Other	Study 3: Factors associated with awareness and knowledge of overdiagnosis	Using a self-administered web-based questionnaire designed for this study, the investigators will analyse survey responses to determine whether self-reported formal education (none; primary school; high school; up to 4 years postsecondary; more than 4 years of postsecondary education) is associated with awareness and knowledge of overdiagnosis among women.	One day (Measurements taken once at time of survey completion)
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Histopathological type (Ductal carcinoma in situ, invasive carcinoma of no special type, invasive lobular carcinoma)	At time of diagnosis
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Maximum tumour diameter (mm)	At time of diagnosis
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Tumour grade (1, 2, 3)	At time of diagnosis
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Lymph node involvement (Yes/No)	At time of diagnosis
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Receptor status (Positive/Negative)	At time of diagnosis
Primary	Study 1: Prognostic and predictive histopathologic characteristics	- Ki67 expression (0-100%)	At time of diagnosis
Primary	Study 2: Crude and adjusted rate of overdiagnosis	- Crude and adjusted measures of overdiagnosis will be presented to show the amount and direction of confounding resulting from sociodemographic factors.	1996 to 2016
Primary	Study 3: Agreement between awareness and knowledge of overdiagnosis	Agreement between awareness (yes versus no/incomplete) and knowledge (yes versus no/incomplete) of overdiagnosis	One day (Measurements taken once at time of survey completion)
Secondary	Study 1: Survival	- Overall survival	Date of diagnosis until 31 December 2017
Secondary	Study 1: Survival	- Breast cancer specific survival	Date of diagnosis until 31 December 2017

External Links

•   Article about study with interview (Norwegian; pages 23-24)
•   Project description on Extrastiftelsen's website (Norwegian)