Solveig Hofvind - Academia.edu (original) (raw)

Papers by Solveig Hofvind

International Journal of Cancer, 2002

Interval cancers in breast cancer screening : mistakes by the radiolgists or a special group of c... more Interval cancers in breast cancer screening : mistakes by the radiolgists or a special group of cancers?

While studies have shown that the use of post-menopausal hormone therapy increases mammographic d... more While studies have shown that the use of post-menopausal hormone therapy increases mammographic density, certain aspects of this association remain unclear. We examined whether mammographic density differs according to the type of hormone therapy used, dose, duration of use, time since last use, as well as whether the effects are modified by age and body mass index (BMI). We used a cross-sectional design and recruited 2265 post-menopausal women, aged 50-69 who participated in the Norwegian Breast Cancer Screening Program in 2004. Mammographic density was assessed with the computer-assisted method (Madena), and we estimated mean percent mammographic density, controlling for possible confounding factors. Statistical analyzes were performed for all women combined and by age and BMI. Mammographic density was higher among current hormone therapy users (percent density: 20.8%; 95% CI: 19.6-21.9%), than among former (18.7%; 18.1-19.3%) or never HT users (16.7%; 15.8-17.6%). Ever users of combined estrogen-progestogen therapy (EPT) had higher percent density (20.0%; 19.1-20.9%) than estrogen-only (ET) users (18.3%, 17.7-18.9%) and never users (16.7%, 15.8-17.6%), and the highest density was seen in current EPT users (21.4%; 20.1-22.6%). Time since last use was significantly associated with density, with women who quit more than 3 years ago having density similar to never users. Mammographic density declined with increasing age and BMI. In analyses stratified by BMI, we found higher densities with EPT use in all categories, with somewhat smaller differences between ever and never EPT users in women with BMI of 26 and higher. When stratifying analyses by age, mammographic density was similar in EPT users and never users in women aged 55 and below. However, this was not true in leaner women (BMI of 23 or less). Among these young women (55 or less) with low BMI (23 or less), EPT users had higher percent density than never users. The percent density was 26.8% (23.7-29.8%) in never users, and 31.7% (28.0-35.4%) in ever users. No statistically significant difference in density was found in women older than 62 years old with a BMI of 26 and above, with percent density of 6.8% (5.3-8.3%), and 9.3% (6.9-11.6%) in never and ever users, respectively. Higher mammographic density was seen in ever users of estradiol and norethisterone acetate regimens (Activelle and Kliogest) compared to other EPT. Mammographic density was higher in women using high rather than low doses of estradiol and progestogen. In conclusion, the highest mammographic density was found in EPT users compared to ET and never users, particularly in users of the norethisterone acetate regimens. This increase was bigger in women taking high rather than low EPT doses. The association between EPT use and mammographic density was modified by age and BMI. These results have important implications and should be considered when, for example, deciding on which type and dose of hormones to prescribe. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3726. doi:10.1158/1538-7445.AM2011-3726

European Radiology, Apr 4, 2013

Objectives To compare double readings when interpreting full field digital mammography (2D) and t... more Objectives To compare double readings when interpreting full field digital mammography (2D) and tomosynthesis (3D) during mammographic screening. Methods A prospective, Ethical Committee approved screening study is underway. During the first year 12,621 consenting women underwent both 2D and 3D imaging. Each examination was independently interpreted by four radiologists under four reading modes: Arm A-2D; Arm B-2D + CAD; Arm C-2D + 3D; Arm D-synthesised 2D+3D. Examinations with a positive score by at least one reader were discussed at an arbitration meeting before a final management decision. Paired double reading of 2D (Arm A+B) and 2D+3D (Arm C+D) were analysed. Performance measures were compared using generalised linear mixed models, accounting for inter-reader performance heterogeneity (P<0.05). Results Pre-arbitration false-positive scores were 10.3 % (1,286/12,501) and 8.5 % (1,057/12,501) for 2D and 2D+ 3D, respectively (P < 0.001). Recall rates were 2.9 % (365/12,621) and 3.7 % (463/12,621), respectively (P=0. 005). Cancer detection was 7.1 (90/12,621) and 9.4 (119/12,621) per 1,000 examinations, respectively (30 % increase, P<0.001); positive predictive values (detected cancer patients per 100 recalls) were 24.7 % and 25.5 %, respectively (P=0.97). Using 2D+3D, double-reading radiologists detected 27 additional invasive cancers (P<0.001). Conclusion Double reading of 2D+3D significantly improves the cancer detection rate in mammography screening. Key Points • Tomosynthesis-based screening was successfully implemented in a large prospective screening trial. • Double reading of tomosynthesis-based examinations significantly reduced false-positive interpretations. • Double reading of tomosynthesis significantly increased the detection of invasive cancers.

Radiology, Apr 1, 2019

Background Several studies in Europe and the US have shown promising results favouring digital br... more Background Several studies in Europe and the US have shown promising results favouring digital breast tomosynthesis compared to standard digital mammography (DM). However, the costs of implementing the technology in screening programmes are not yet known. Methods A randomised controlled trial comparing the results from digital breast tomosynthesis including synthetic mammograms (DBT) vs. DM was performed in Bergen during 2016 and 2017 as a part of BreastScreen Norway. The trial included 29,453 women and allowed for a detailed comparison of procedure use and screening, recall and treatment costs estimated at the individual level. Results The increased cost of equipment, examination and reading time with DBT vs. DM was €8.5 per screened woman (95% CI 8.4−8.6). Costs of DBT remained significantly higher after adding recall assessment costs, €6.2 (95% CI 4.6−7.9). Substantial reductions in either examination and reading times, price of DBT equipment or price of IT storage and connectivity did not change the conclusion. Adding treatment costs resulted in too wide confidence intervals to draw definitive conclusions (additional costs of tomosynthesis €9.8, 95% CI-56 to 74). Performing biopsy at recall, radiation therapy and chemotherapy was significantly more frequent among women screened with DBT. Conclusion The results showed lower incremental costs of DBT vs. DM, compared to what is found in previous cost analyses of DBT and DM. However, the incremental costs were still higher for DBT compared with DM after including recall costs. Further studies with long-term treatment data are needed to understand the complete costs of implementing DBT in screening.

Radiology, Apr 1, 2013

To assess cancer detection rates, false-positive rates before arbitration, positive predictive va... more To assess cancer detection rates, false-positive rates before arbitration, positive predictive values for women recalled after arbitration, and the type of cancers detected with use of digital mammography alone and combined with tomosynthesis in a large prospective screening trial. Materials and Methods: A prospective, reader-and modality-balanced screening study of participants undergoing combined mammography plus tomosynthesis, the results of which were read independently by four different radiologists, is under way. The study was approved by a regional ethics committee, and all participants provided written informed consent. The authors performed a preplanned interim analysis of results from 12 631 examinations interpreted by using mammography alone and mammography plus tomosynthesis from November 22, 2010, to December 31, 2011. Analyses were based on marginal loglinear models for binary data, accounting for correlated interpretations and adjusting for reader-specific performance levels by using a two-sided significance level of .0294. Results: Detection rates, including those for invasive and in situ cancers, were 6.1 per 1000 examinations for mammography alone and 8.0 per 1000 examinations for mammography plus tomosynthesis (27% increase, adjusted for reader; P = .001). False-positive rates before arbitration were 61.1 per 1000 examinations with mammography alone and 53.1 per 1000 examinations with mammography plus tomosynthesis (15% decrease, adjusted for reader; P , .001). After arbitration, positive predictive values for recalled patients with cancers verified later were comparable (29.1% and 28.5%, respectively, with mammography alone and mammography plus tomosynthesis; P = .72). Twenty-five additional invasive cancers were detected with mammography plus tomosynthesis (40% increase, adjusted for reader; P , .001). The mean interpretation time was 45 seconds for mammography alone and 91 seconds for mammography plus tomosynthesis (P , .001). Conclusion: The use of mammography plus tomosynthesis in a screening environment resulted in a significantly higher cancer detection rate and enabled the detection of more invasive cancers.

Annals of Internal Medicine, Aug 7, 2012

European Radiology, Oct 1, 2020

Objective To perform a radiological review of mammograms from prior screening and diagnosis of sc... more Objective To perform a radiological review of mammograms from prior screening and diagnosis of screen-detected breast cancer in BreastScreen Norway, a population-based screening program. Methods We performed a consensus-based informed review of mammograms from prior screening and diagnosis for screendetected breast cancers. Mammographic density and findings on screening and diagnostic mammograms were classified according to the Breast Imaging-Reporting and Data System®. Cases were classified based on visible findings on prior screening mammograms as true (no findings), missed (obvious findings), minimal signs (minor/non-specific findings), or occult (no findings at diagnosis). Histopathologic tumor characteristics were extracted from the Cancer Registry of Norway. The Bonferroni correction was used to adjust for multiple testing; p < 0.001 was considered statistically significant. Results The study included mammograms for 1225 women with screen-detected breast cancer. Mean age was 62 years ± 5 (SD); 46% (567/1225) were classified as true, 22% (266/1225) as missed, and 32% (392/1225) as minimal signs. No difference in mammographic density was observed between the classification categories. At diagnosis, 59% (336/567) of true and 70% (185/ 266) of missed cancers were classified as masses (p = 0.004). The percentage of histological grade 3 cancers was higher for true (30% (138/469)) than for missed (14% (33/234)) cancers (p < 0.001). Estrogen receptor positivity was observed in 86% (387/ 469) of true and 95% (215/234) of missed (p < 0.001) cancers. Conclusions We classified 22% of the screen-detected cancers as missed based on a review of prior screening mammograms with diagnostic images available. One main goal of the study was quality improvement of radiologists' performance and the program. Visible findings on prior screening mammograms were not necessarily indicative of screening failure. Key Points • After a consensus-based informed review, 46% of screen-detected breast cancers were classified as true, 22% as missed, and 32% as minimal signs. • Less favorable prognostic and predictive tumor characteristics were observed in true screen-detected breast cancer compared with missed. • The most frequent mammographic finding for all classification categories at the time of diagnosis was mass, while the most frequent mammographic finding on prior screening mammograms was a mass for missed cancers and asymmetry for minimal signs.

European Radiology, Apr 2, 2022

Objectives To analyze rates, odds ratios (OR), and characteristics of screen-detected and interva... more Objectives To analyze rates, odds ratios (OR), and characteristics of screen-detected and interval cancers after concordant and discordant initial interpretations and consensus in a population-based screening program. Methods Data were extracted from the Cancer Registry of Norway for 487,118 women who participated in BreastScreen Norway, 2006-2017, with 2 years of follow-up. All mammograms were independently interpreted by two radiologists, using a score from 1 (negative) to 5 (high suspicion of cancer). A score of 2+ by one of the two radiologists was defined as discordant and 2+ by both radiologists as concordant positive. Consensus was performed on all discordant and concordant positive, with decisions of recall for further assessment or dismiss. OR was estimated with logistic regression with 95% confidence interval (CI), and histopathological tumor characteristics were analyzed for screen-detected and interval cancer. Results Among screen-detected cancers, 23.0% (697/3024) had discordant scores, while 12.8% (117/911) of the interval cancers were dismissed at index screening. Adjusted OR was 2.4 (95% CI: 1.9-2.9) for interval cancer and 2.8 (95% CI: 2.5-3.2) for subsequent screen-detected cancer for women dismissed at consensus compared to women with concordant negative scores. We found 3.4% (4/117) of the interval cancers diagnosed after being dismissed to be DCIS, compared to 20.3% (12/59) of those with false-positive result after index screening. Conclusion Twenty-three percent of the screen-detected cancers was scored negative by one of the two radiologists. A higher odds of interval and subsequent screen-detected cancer was observed among women dismissed at consensus compared to concordant negative scores. Our findings indicate a benefit of personalized follow-up. Key Points • In this study of 487,118 women participating in a screening program using independent double reading with consensus, 23% screen-detected cancers were detected by only one of the two radiologists. • The adjusted odds ratio for interval cancer was 2.4 (95% confidence interval: 1.9, 2.9) for cases dismissed at consensus using concordant negative interpretations as the reference. • Interval cancers diagnosed after being dismissed at consensus or after concordant negative scores had clinically less favorable prognostic tumor characteristics compared to those diagnosed after false-positive results.

PharmacoEconomics - Open

Background Although several studies from Europe and the US have shown promising screening results... more Background Although several studies from Europe and the US have shown promising screening results favoring digital breast tomosynthesis compared with standard digital mammography (DM), both costs and effects of implementing tomosynthesis in routine screening programs remain uncertain. The cost effectiveness of using tomosynthesis in routine screening is debated in the literature, and model inputs from randomized trials are lacking. Using parameters mainly from a randomized controlled trial (the To-Be trial), we simulated costs and effects of implementing tomosynthesis in the national screening program BreastScreen Norway. Methods The To-Be trial was performed in Bergen from 2016 to 2017 within BreastScreen Norway, where females were randomized to either digital breast tomosynthesis including synthetic mammograms (DBT) or DM. The trial was followed by a cohort study offering all females DBT in 2018-2019. The trial included over 37,000 females, and allowed for estimation of short-term costs and effects related to screening, recall examinations and cancer detection. Using these and recent Norwegian estimates for 10-year stage-specific survival and treatment costs, the cost effectiveness of replacing DM with DBT in BreastScreen Norway was simulated in a decision tree model with probabilistic sensitivity analyses. Outcomes included false-positive screening results, screen-detected and interval cancers, stage at diagnosis, all-cause deaths, life-years gained, costs at recall and treatment and incremental cost-effectiveness ratio. Results The estimated additional cost of DBT was €8.10. Simulating ten rounds of screening from 2018 and 10-year survival and costs, 500 deaths were averted and 2300 life-years gained at an additional screening cost of €29 million for females screened with DBT versus DM. Taking over-diagnosis, recall and treatment costs into account, DBT was dominant in the deterministic analysis. The incremental cost-effectiveness ratio indicated cost savings of €1400 per life-year gained. Probabilistic sensitivity analyses showed that DBT was cost effective in over 50% of the simulations at all willingness-to-pay levels per life-year gained, and in 80% of the simulations at levels above €22,000. If willingness-to-pay levels up to €35,000 were assumed, DBT would be cost effective in over 50% of the simulations for additional costs of DBT of up to €32, almost four times the estimated additional cost of €8.10. Conclusion DBT may be cost effective if implemented in BreastScreen Norway. However, generalizability of results could depend on factors varying between countries, such as recall rates, program sensitivity and specificity, treatment cost and willingness-to-pay levels.

Academic Radiology, 2022

Background Breast compression is used in mammography to improve image quality and reduce radiatio... more Background Breast compression is used in mammography to improve image quality and reduce radiation dose. However, the compression may lead to discomfort or pain for the women. Breast compression time is longer with digital breast tomosynthesis (DBT) than with digital mammography (DM). We aimed to explore breast compression parameters with DM and DBT. Material and Methods We used information from 16,832 women participating in the Tomosynthesis Trial in Bergen between January 2016 and April 2017. We compared mean values of applied compression force (N), compression pressure (kPa) and compressed breast thickness (mm) for DM and DBT, by view (craniocaudal, CC, and mediolateral-oblique, MLO). Two-sample ttests were used to test statistical significance. Results Number of women screened with DM or DBT were similar (DM: n= 8354 and DBT: n= 8478). Mean compression force was statistically significantly higher for DM compared to DBT (CC: 108.6 N versus 102.7 N; MLO: 122.4 N versus 120.8 N, p ...

European Radiology, 2020

The European Journal of Health Economics, 2019

The Lancet Oncology, 2019

Two-view digital breast tomosynthesis versus digital mammography in a population-based breast can... more Two-view digital breast tomosynthesis versus digital mammography in a population-based breast cancer screening program (To-Be): a randomized, controlled trial Tomosynthesis breast in screeninga randomized controlled trial

European Radiology, 2018

Objectives To describe a randomized controlled trial (RCT) of digital breast tomosynthesis includ... more Objectives To describe a randomized controlled trial (RCT) of digital breast tomosynthesis including synthesized twodimensional mammograms (DBT) versus digital mammography (DM) in a population-based screening program for breast cancer and to compare selected secondary screening outcomes for the two techniques. Methods This RCT, performed in Bergen as part of BreastScreen Norway, was approved by the Regional Committees for Medical Health Research Ethics. All screening attendees in Bergen were invited to participate, of which 89% (14,274/15,976) concented during the first year, and were randomized to DBT (n = 7155) or DM (n = 7119). Secondary screening outcomes were stratified by mammographic density and compared using two-sample t-tests, chi-square tests, ANOVA, negative binomial regression and tests of proportions (z tests). Results Mean reading time was 1 min 11 s for DBT and 41 s for DM (p < 0.01). Mean time spent at consensus was 3 min 12 s for DBT and 2 min 12 s for DM (p < 0.01), while the rate of cases discussed at consensus was 6.4% and 7.4%, respectively for DBT and DM (p = 0.03). The recall rate was 3.0% for DBT and 3.6% for DM (p = 0.03). For women with non-dense breasts, recall rate was 2.2% for DBT versus 3.4% for DM (p = 0.04). The rate did not differ for women with dense breasts (3.6% for both). Mean glandular dose per examination was 2.96 mGy for DBT and 2.95 mGy for DM (p = 0.433). Conclusions Interim analysis of a screening RCT showed that DBT took longer to read than DM, but had significantly lower recall rate than DM. We found no differences in radiation dose between the two techniques. Key Points • In this RCT, DBT was associated with longer interpretation time than DM • Recall rates were lower for DBT than for DM • Mean glandular radiation dose did not differ between DBT and DM Keywords Mammography. Breast cancer. Mass screening. Digital breast tomosynthesis. Randomized controlled trial Abbreviations CC Craniocaudal DBT Digital breast thomosynthesis DM Digital mammography MGD Mean glandular dose MLO Mediolateral oblique RCT Randomized controlled trial SD Standard deviation SM Synthetic two-dimensional mammogram VBD Volumetric breast density VDG Volpara density grade

Radiology, 2018

To compare the performance of digital breast tomosynthesis (DBT) and two-dimensional synthetic ma... more To compare the performance of digital breast tomosynthesis (DBT) and two-dimensional synthetic mammography (SM) with that of digital mammography (DM) in a population-based mammographic screening program.

Acta Radiologica, 2017

Background Breast radiologists of the Norwegian Breast Cancer Screening Program subjectively clas... more Background Breast radiologists of the Norwegian Breast Cancer Screening Program subjectively classified mammographic density using a three-point scale between 1996 and 2012 and changed into the fourth edition of the BI-RADS classification since 2013. In 2015, an automated volumetric breast density assessment software was installed at two screening units. Purpose To compare volumetric breast density measurements from the automated method with two subjective methods: the three-point scale and the BI-RADS density classification. Material and Methods Information on subjective and automated density assessment was obtained from screening examinations of 3635 women recalled for further assessment due to positive screening mammography between 2007 and 2015. The score of the three-point scale (I = fatty; II = medium dense; III = dense) was available for 2310 women. The BI-RADS density score was provided for 1325 women. Mean volumetric breast density was estimated for each category of the sub...

European Journal of Radiology, 2016

Acta radiologica open, 2015

High mammographic density might mask breast tumors, resulting in delayed diagnosis or missed canc... more High mammographic density might mask breast tumors, resulting in delayed diagnosis or missed cancers. To investigate the association between mammographic density and histopathologic tumor characteristics (histologic type, size, grade, and lymph node status) among women screened in the Norwegian Breast Cancer Screening Program. Information about 1760 screen-detected ductal carcinoma in situ (DCIS) and 7366 invasive breast cancers diagnosed among women aged 50-69 years, 1996-2010, was analyzed. The screening mammograms were classified subjectively according to the amount of fibroglandular tissue into fatty, medium dense, and dense by breast radiologists. Chi-square test was used to compare the distribution of tumor characteristics by mammographic density. Odds ratio (OR) of tumor characteristics by density was estimated by means of logistic regression, adjusting for screening mode (screen-film and full-field digital mammography), and age. Mean and median tumor size of invasive breast ...