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Breast CancerNCT03852953

Under- and Overdiagnosis in BreastScreen Norway

An observational study of Breast Cancer, run by Norwegian Institute of Public Health at 1 site in Norway.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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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. Read more about this study

Who is it for?
Ages 25 to 75 yearsHealthy volunteers can take part
Conditions the study is for
Breast Cancer
What is being tested?
Under- or overdiagnosed cancer and Screening
How many people
3,915 participants
Where
1 siteNorway
Study dates
1 Jul 2018to 8 Jun 2020
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 25 to 75 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Women aged 50-69, and practising female and male family doctors aged 25-75, residing in Norway.

Who may be able to join

  • Breast cancer diagnosed within BreastScreen Norway using digital mammography
  • Prior screening images available for review
  • Study 2
  • Women born between 1927 and 1934 (inclusive)
  • Legal resident in Norway at any time between 1996 and 2003 (inclusive)
  • Study 3
Show all 9Show fewer
  • Women residing in Norway, aged 50-69 (inclusive)
  • Practising family doctors in Norway, aged 25-75 (inclusive)
  • Provide informed consent

Who cannot join

None listed.

Trial locations and contacts

1 site in 1 country.

Norway1 site

  • Cancer Registry of Norway

    Oslo, 0379

Other trials in Norway

About this study

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.

Read the detailed 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.

Conditions
Breast Cancer
Being tested
Under- or overdiagnosed cancer, Screening
Keywords
Screening, Mammography, Overdiagnosis, Womens' perspectives, Harms and benefits, False negative, Quantitative methods, Survival
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Under- or overdiagnosed cancerOther

    Diagnosed with a cancer that was visible on prior mammograms

  • ScreeningOther

    Invited or attended BreastScreen Norway

Study groups in NCT03852953
Study groupRoleWhat they receive
Study 1: Under- and overdiagnosed groupNon-proportional stratified sample of women diagnosed with interval or screen-detected breast cancers after participation in BreastScreen Norway. This sample will include under- or overdiagnosed cancers, as well as cancers that were not under- or overdiagnosed.
Receives: Other: Under- or overdiagnosed cancer
Study 2: Rate of overdiagnosis groupWomen residing in Norway, born between 1927 and 1934 (inclusive). This cohort will include women who have attended screening and who have not attended screening.
Receives: Other: Screening
Study 3: Awareness and knowledge groupWomen aged 50-69, and practising family doctors aged 25-75, currently living in Norway.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Study 1: Prognostic and predictive histopathologic characteristics

    • Histopathological type (Ductal carcinoma in situ, invasive carcinoma of no special type, invasive lobular carcinoma)

    Measured: At time of diagnosis

  2. Study 1: Prognostic and predictive histopathologic characteristics

    • Maximum tumour diameter (mm)

    Measured: At time of diagnosis

  3. Study 1: Prognostic and predictive histopathologic characteristics

    • Tumour grade (1, 2, 3)

    Measured: At time of diagnosis

  4. Study 1: Prognostic and predictive histopathologic characteristics

    • Lymph node involvement (Yes/No)

    Measured: At time of diagnosis

  5. Study 1: Prognostic and predictive histopathologic characteristics

    • Receptor status (Positive/Negative)

    Measured: At time of diagnosis

  6. Study 1: Prognostic and predictive histopathologic characteristics

    • Ki67 expression (0-100%)

    Measured: At time of diagnosis

  7. 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.

    Measured: 1996 to 2016

  8. Study 3: Agreement between awareness and knowledge of overdiagnosis

    Agreement between awareness (yes versus no/incomplete) and knowledge (yes versus no/incomplete) of overdiagnosis

    Measured: One day (Measurements taken once at time of survey completion)

Secondary outcomes (2)

  1. Study 1: Survival

    • Overall survival

    Measured: Date of diagnosis until 31 December 2017

  2. Study 1: Survival

    • Breast cancer specific survival

    Measured: Date of diagnosis until 31 December 2017

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Feb 2019
  2. Study start1 Jul 2018
  3. Primary completion8 Jun 2020
  4. Study completion8 Jun 2020

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Other
Time perspective
Retrospective
Enrolment
3,915 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03852953
Sponsor's protocol ID
17/222
Other IDs
2018/FO201362
Status last verified
Jan 2021
First submitted
12 Nov 2018
Last updated
28 Aug 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • 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.

    PubMed 33001307

  • Tsuruda KM, Hovda T, Bhargava S, Veierod 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):2677-2686. doi: 10.1007/s00330-020-07340-4. Epub 2020 Nov 12.

    PubMed 33180162

  • 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

Questions about this trial

What is this clinical trial studying?

An observational study of Breast Cancer, run by Norwegian Institute of Public Health at 1 site in Norway.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 28 Aug 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Study 1: Prognostic and predictive histopathologic characteristics (time frame: At time of diagnosis). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03852953, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Aug 2024.

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