Solveig Hofvind

Publications (38)146.63 Total impact

• Article: Response to comments.

  Ragnhild Sørum Falk, Solveig Hofvind, Per Skaane, Tor Haldorsen
  International Journal of Cancer 05/2013; · 5.44 Impact Factor
• Article: Overdiagnosis among women attending a population-based mammography screening program.

  Ragnhild Sørum Falk, Solveig Hofvind, Per Skaane, Tor Haldorsen
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  ABSTRACT: Increased incidence of ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC) after introduction of organized screening has prompted debate about overdiagnosis. The aim was to examine the excess in incidence of DCIS and IBC during the screening period and the deficit after women left the program, and thereby to estimate the proportion of overdiagnosis. Women invited to the Norwegian Breast Cancer Screening Program were analyzed for DCIS or IBC during the period 1995-2009. Incidence rate ratios (IRRs) were calculated for attended versus never attended women. The IRRs were adjusted by Mantel-Haenszel (MH) method and applied to a set of reference rates and a reference population to estimate the proportion of overdiagnosis during the women's lifespan after the age of 50 years. A total of 702 131 women were invited to the program. An excess of DCIS and IBC was observed among women who attended screening during the screening period; prevalently invited women aged 50-51 years had an MH IRR of 1.86 (95% CI 1.65-2.09) and subsequently invited women aged 52-69 had an MH IRR of 1.56 (95% CI 1.45-1.68). In women aged 70-79, a deficit of 30% (MH IRR 0.70, 95% CI 0.62-0.80) was observed 1 to 10 years after they left the screening program. The estimated proportion of overdiagnosis varied from 10% to 20% depending on outcome and whether the women were invited or actually screened. The results highlight the need for individual data with longitudinal screening history and long-term follow-up as a basis for estimating overdiagnosis.
  International Journal of Cancer 01/2013; · 5.44 Impact Factor
• Article: Physical activity and mammographic density in a cohort of postmenopausal Norwegian women; a cross-sectional study.

  Samera Azeem Qureshi, Merete Ellingjord-Dale, Solveig Hofvind, Anna H Wu, Giske Ursin
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  ABSTRACT: Mammographic density (MD) is a strong risk factor for breast cancer and may represent a useful intermediate marker for breast cancer risk. Physical activity (PA) is known to be associated with a reduced risk of breast cancer. If PA is associated with MD then this would be useful for breast cancer prevention studies. MD was assessed on digitized mammograms using a computer assisted method (Madena) in 2218 postmenopausal women. A questionnaire assessed PA, by asking about the duration and intensity of light, moderate, strenuous PA/week. We used multivariate linear regression models to estimate least square means of percent MD by total and intensity of PA with adjustment for confounders. The mean age (± s.d) was 58.4 (±5.3) and mean BMI was 24.6 (±4.6). We observed a statistically significant inverse association between total PA and MD in the over-weight (BMI = 25.0-29.9) women, where mean MD among women with highest activity (>360 mins/week) was 12.6% (95%CI; 11.2%-14.0%), while among women with no activity it was 15.9% (95 CI; 13.6%-18.2%, p for trend = 0.04). There was no association in the other BMI strata. MD was 12.1% (11.2%-13.0%) in the highest group (> 180 mins/week) of moderate/strenuous activity and in the no activity group 14.8% (14.2%-15.5%, p for trend = 0.001) in the over-weight women. There was no association between light PA and MD in all women combined or in any other BMI strata. We found some evidence of an inverse association between PA and MD among overweight women.
  SpringerPlus. 12/2012; 1(1):75.
• Article: Polymorphisms in hormone metabolism and growth factor genes and mammographic density in Norwegian postmenopausal hormone therapy users and non-users.

  Merete Ellingjord-Dale, Eunjung Lee, Elisabeth Couto, Ali Ozhand, Samera A Qureshi, Solveig Hofvind, David J Van Den Berg, Lars A Akslen, Tom Grotmol, Giske Ursin
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  ABSTRACT: INTRODUCTION: Mammographic density (MD) is one of the strongest known breast cancer risk factors. Estrogen and progestin therapy (EPT) has been associated with increases in MD. Dense breast tissue is characterized by increased stromal tissue and (to a lesser degree) increased numbers of breast epithelial cells. It is possible that genetic factors modify the association between EPT and MD, and that certain genetic variants are particularly important in determining MD in hormone users. We evaluated the association between MD and 340 tagging singular nucleotide polymorphisms (SNPs) from about 30 candidate genes in hormone metabolism / growth factor pathways among women who participated in the Norwegian Breast Cancer Screening Program (NBCSP) in 2004. METHODS: We assessed MD on 2036 postmenopausal women aged 50 to 69 years using a computer assisted method (Madena, University of Southern California) in a cross-sectional study. We used linear regression to determine the association between each SNP and MD, adjusting for potential confounders. The postmenopausal women were stratified into HT users (EPT and estrogen only) and non-users (never HT). RESULTS: For current EPT users, there was an association between a variant in the prolactin gene (PRL; rs10946545) and MD (dominant model, Bonferroni adjusted p (pb) = 0.0144). This association remained statistically significant among current users of norethisterone acetate (NETA) based EPT, a regimen common in Nordic countries. Among current estrogen only users (ET), there was an association between rs4670813 in the cytochrome P450 gene (CYP1B1) and MD (dominant model pb= 0.0396). In never HT users, rs769177 in the tumor necrosis factor (TNF) gene and rs1968752 in the region of the sulfotransferase gene (SULT1A1/ SULT1A2), were significantly associated with MD (pb= 0.0202; pb= 0.0349). CONCLUSIONS: We found some evidence that variants in the PRL gene were associated with MD in current EPT and NETA users. In never HT users, variants in the TNF and SULT1A1/ SULT1A2 genes were significantly associated with MD. These findings may suggest that several genes in the hormone metabolism and growth factor pathways are implicated in determining MD.
  Breast cancer research: BCR 10/2012; 14(5):R135. · 5.24 Impact Factor
• Article: Overdiagnosis of Invasive Breast Cancer due to Mammography Screening.

  Ragnhild Sørum Falk, Solveig Hofvind, Per Skaane
  Annals of internal medicine 08/2012; 157(3):219; author reply 221-2. · 16.73 Impact Factor
• Article: Stage-specific breast cancer incidence rates among participants and non-participants of a population-based mammographic screening program.

  Solveig Hofvind, Christoph I Lee, Joann G Elmore
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  ABSTRACT: The Norwegian Breast Cancer Screening Program was rolled out county by county over the course of a decade, from 1996 to 2005, and now encompasses all Norwegian women aged 50-69 years. We aim to compare DCIS and stage-specific invasive breast cancer incidence rates among participants, non-participants, and women not yet invited to the screening program over this entire implementation period. We estimate stage-specific breast tumor incidence rates for 640,347 women 50-69 years of age invited to the screening program between 1996 and 2007. We compare incidence rates and stage distribution among women diagnosed with breast cancer who were invited and participated, invited but not participated, and women not yet invited to the screening program using two-sided Chi-squared tests to determine statistical significance between groups. The incidence of ductal carcinoma in situ (DCIS) was 3.0 times higher and invasive breast cancer was 1.5 times higher for invited participants compared to invited non-participants (p < 0.001). While the incidence of Stage I cancer was two times higher among participants compared to non-participants (p < 0.001), the incidences of Stages III and IV cancer were two and three times lower, respectively, among participants compared to non-participants (p < 0.001 for both). No significant differences in stage-specific incidence or treatment utilization rates were observed between invited non-participants and not yet invited women, except for stage IV cancers, which were detected at a higher rate among women who were not yet invited (7.5 vs. 4.6 %, p = 0.001). Compared with women invited who did not participate, participants in the screening program are more likely to be diagnosed with DCIS and early stage invasive breast cancer and are less likely to be diagnosed with advanced stage breast cancer. More research is required to determine whether these differences in stage-specific incidences among invited participants and non-participants are associated with differences in mortality rates.
  Breast Cancer Research and Treatment 07/2012; 135(1):291-9. · 4.43 Impact Factor
• Article: Breast cancer: missed interval and screening-detected cancer at full-field digital mammography and screen-film mammography-- results from a retrospective review.

  Solveig R Hoff, Anne-Line Abrahamsen, Jon Helge Samset, Einar Vigeland, Olbjørn Klepp, Solveig Hofvind
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  ABSTRACT: To compare the percentages and mammographic features of cancers missed at full-field digital mammography (FFDM) and screen-film mammography (SFM) in women who participated in the Norwegian Breast Cancer Screening Program in 2002-2008. Social Science Data Services approval was obtained; the requirement for informed consent was waived. Cases were all the interval and screening-detected cancers from 35&emsp14;127 FFDM and 52&emsp14;444 SFM examinations in two Norwegian counties. Prior and diagnostic FFDM examinations of 49 interval and 86 screening-detected breast cancers were reviewed by four breast radiologists and compared with a review of SFM examinations of 81 interval and 123 screening-detected cancers. Cancers were classified as missed or true, mammographic features were described, percentages were compared by using the χ(2) or Fisher exact test, and 95% confidence intervals (CIs) were calculated. The percentages of interval and screening-detected cancers missed at FFDM and SFM did not differ significantly. (interval cancers missed: 33% [16 of 49] at FFDM vs 30% [24 of 81] at SFM [P = .868]; screening-detected cancers missed: 20% [17 of 86] at FFDM vs 21% [26 of 123] at SFM [P = .946]). Asymmetry was present in 27% (95% CI: 13.3%, 45.5%) of prior mammograms of cancers missed at FFDM and 10% (95% CI: 3.3%, 21.8%) of those missed at SFM (P = .070). Calcifications were observed in 18% (95% CI: 7.0%, 35.5%) of the cancers missed at FFDM and 34% (95% CI: 21.2%, 48.8%) of those missed at SFM (P = .185). Average mammographic tumor size of missed cancers manifesting as masses was 10.4 mm at FFDM and 13.6 mm at SFM (P = .036). The use of FFDM has not reduced the challenge of missed cancers. Cancers missed at FFDM tend to have different mammographic features than those missed at SFM.
  Radiology 06/2012; 264(2):378-86. · 5.73 Impact Factor
• Article: Alcohol intake and mammographic density in postmenopausal Norwegian women.

  Samera Azeem Qureshi, Elisabeth Couto, Solveig Hofvind, Anna H Wu, Giske Ursin
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  ABSTRACT: Mammographic density is a strong risk factor for breast cancer. While alcohol intake has been associated with increased breast cancer risk, the association between alcohol consumption and mammographic density is not clear. We assessed the association between alcohol consumption and mammographic density among women who participated in the Norwegian Breast Cancer Screening Program in 2004. Mammographic density was assessed on digitized mammograms from 2,251 postmenopausal women aged 50-69 years, using a computer assisted method. Current intake of beer, wine (red and white), and liquor was assessed using a validated food frequency questionnaire. Non-drinkers were defined as complete abstainers (i.e., those who reported no intake of any type of alcohol). We used multivariate linear regression models to estimate least square means of percent mammographic density by categories of alcohol intake with adjustment for potential confounders. We also checked for possible effect modification by stratifying the analyses by age, body mass index, and hormone therapy. The mean percent mammographic density was almost similar for drinkers 18.3% (95% CI: 17.6-18.9%) and non-drinkers 17.8% (95% CI: 16.1-19.4%) (P = 0.59). There was no indication that amount of alcohol consumed was associated with percent mammographic density, with a mean percent density among women with the highest intake (>90 g of alcohol per week) of 18.2% (95% CI: 16.9-19.0%), only slightly different from that of non-drinkers 18.3% (17.3-19.6%) (P for trend = 0.99). There was no association between any type of alcohol consumed and mammographic density.There was no effect modification by body mass index, age, or hormone therapy use. We found no evidence of an association between alcohol intake and percent mammographic density.
  Breast Cancer Research and Treatment 02/2012; 131(3):993-1002. · 4.43 Impact Factor
• Article: Mammography screening using independent double reading with consensus: is there a potential benefit for computer-aided detection?

  Per Skaane, Ashwini Kshirsagar, Solveig Hofvind, Gunnar Jahr, Ronald A Castellino
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  ABSTRACT: Double reading improves the cancer detection rate in mammography screening. Single reading with computer-aided detection (CAD) has been considered to be an alternative to double reading. Little is known about the potential benefit of CAD in breast cancer screening with double reading. To compare prospective independent double reading of screen-film (SFM) and full-field digital (FFDM) mammography in population-based screening with retrospective standalone CAD performance on the baseline mammograms of the screen-detected cancers and subsequent cancers diagnosed during the follow-up period. The study had ethics committee approval. A 5-point rating scale for probability of cancer was used for 23,923 (SFM = 16,983; FFDM = 6940) screening mammograms. Of 208 evaluable cancers, 104 were screen-detected and 104 were subsequent (44 interval and 60 next screening round) cancers. Baseline mammograms of subsequent cancers were retrospectively classified in consensus without information about cancer location, histology, or CAD prompting as normal, non-specific minimal signs, significant minimal signs, and false-negatives. The baseline mammograms of the screen-detected cancers and subsequent cancers were evaluated by CAD. Significant minimal signs and false-negatives were considered 'actionable' and potentially diagnosable if correctly prompted by CAD. CAD correctly marked 94% (98/104) of the baseline mammograms of the screen-detected cancers (SFM = 95% [61/64]; FFDM = 93% [37/40]), including 96% (23/24) of those with discordant interpretations. Considering only those baseline examinations of subsequent cancers prospectively interpreted as normal and retrospectively categorized as 'actionable', CAD input at baseline screening had the potential to increase the cancer detection rate from 0.43% to 0.51% (P = 0.13); and to increase cancer detection by 16% ([104 + 17]/104) and decrease interval cancers by 20% (from 44 to 35). CAD may have the potential to increase cancer detection by up to 16%, and to reduce the number of interval cancers by up to 20% in SFM and FFDM screening programs using independent double reading with consensus review. The influence of true- and false-positive CAD marks on decision-making can, however, only be evaluated in a prospective clinical study.
  Acta Radiologica 01/2012; 53(3):241-8. · 1.37 Impact Factor
• Article: Asymptomatic breast cancer in non-participants of the national screening programme in Norway: a confounding factor in evaluation?

  Solveig R Hoff, Olbjørn Klepp, Solveig Hofvind
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  ABSTRACT: To evaluate the extent and histopathological characteristics of asymptomatic breast cancer detected outside the Norwegian Breast Cancer Screening Program (NBCSP) in women targeted by the programme. Our study included 568 primary breast cancers (523 invasive and 45 ductal carcinoma in situ) diagnosed in 553 women aged 50-70, residing in Møre og Romsdal County, 2002-2008. The cancers were divided into screening-detected cancers in the NBCSP, interval cancers (ICs) and cancers detected in women not participating in the NBCSP (never participated and lapsed attendees), and further into asymptomatic and symptomatic cancers. Nottingham Prognostic Index (NPI) was used for comparisons across the groups and the distributions were compared using chi-square tests for statistical significance. Twenty percent (19/97) of the ICs and 32% (69/213) of the breast cancers in non-participants were asymptomatic, with opportunistic screening as the most frequent detection method (42%, 8/19 for ICs and 54%, 37/69 for non-participants). There were no differences in distribution of NPI prognostic categories across subgroups of asymptomatic invasive cancers (screening-detected cancers in the NBCSP, asymptomatic ICs and asymptomatic cancers in non-participants) or between subgroups of symptomatic invasive cancers (symptomatic ICs and symptomatic cancers in non-participants). Asymptomatic cancers had a significantly more favourable distribution of NPI prognostic categories compared with symptomatic cancers (P < 0.001). The proportion of invasive cancers with excellent/good NPI was 53% (164/310) for all asymptomatic and 25% (52/211) for all symptomatic invasive cancers. A considerable percentage of breast cancers detected outside the organized screening programme were asymptomatic, with a prognostic profile comparable with screening-detected breast cancers in the NBCSP. Individual data regarding the detection method for all breast cancers are needed for a complete evaluation of the organized screening programme in Norway.
  Journal of Medical Screening 01/2012; 19(4):177-83. · 1.69 Impact Factor
• Article: Hormone therapy use and mammographic density in postmenopausal Norwegian women.

  Elisabeth Couto, Samera Azeem Qureshi, Solveig Hofvind, Marit Hilsen, Hildegunn Aase, Per Skaane, Lars Vatten, Giske Ursin
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  ABSTRACT: While studies have shown that use of postmenopausal hormone therapy with estrogen and progestogen (EPT) increases mammographic density, aspects of this association remain unclear. We examined whether mammographic density differed by type of hormone therapy (HT) used, dose, duration of use, time since last use, and whether the effects are modified by age and body mass index (BMI). Using a cross-sectional design, we recruited 2,424 postmenopausal women aged 50-69 years participating in the Norwegian Breast Cancer Screening Program. Mammographic density was assessed with a computer-assisted method, and we estimated mean absolute and percent mammographic density through multiple linear regression, and adjusting for possible confounders. Mammographic density was higher among current HT users (percent density: 22.6%; 95% CI: 22.1-23.2%) than among former (17.7%; 17.2-18.2%) or never users (16.3%; 15.7-16.8%). The highest density was seen in current EPT users of high-dose norethisterone acetate (NETA) regimens who had a percent density of 26.2% (24.3-28.1%). Results differed when considering the combined effect of age and BMI. The effect of EPT on mammographic density was modified by age and BMI, with no apparent association among the youngest women (aged 50-55) with the highest BMI (BMI ≥ 26). A higher mammographic density was found in EPT users compared to never HT users, particularly in women using high-dose NETA regimens. Age and BMI modified the association between EPT use and mammographic density.
  Breast Cancer Research and Treatment 11/2011; 132(1):297-305. · 4.43 Impact Factor
• Article: Mammographic density and intake of selected nutrients and vitamins in Norwegian women.

  Samera Azeem Qureshi, Elisabeth Couto, Marit Hilsen, Solveig Hofvind, Anna H Wu, Giske Ursin
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  ABSTRACT: Investigating the association between dietary factors and mammographic density (MD) could shed light on the relationship between diet and breast cancer risk. We took advantage of a national mammographic screening program to study the association between intake of nutrients and MD. In this study, we analyzed data of 2,252 postmenopausal women aged 50-69 yr who participated in the Norwegian Breast Cancer Screening Program in 2004. MD was assessed on digitized mammograms using a computer-assisted method. We used multivariate linear regression models to determine least square means of percent and absolute MD. Overall, we observed no associations between MD and intake of total calories, protein, carbohydrates, cholesterol, and dietary fiber. There was a positive borderline statistically significant association between absolute MD and total fat intake (P = 0.10) and between percent MD and intake of saturated fat (P = 0.06). There was no association between MD and intake of calcium, retinol, vitamins A, B12, C, or D, or combined intake of vitamin D and calcium. This study provides some evidence of an association between MD and dietary intake. Our study highlights the importance of adequate adjustments for BMI in studies of diet and MD.
  Nutrition and Cancer 09/2011; 63(7):1011-20. · 2.78 Impact Factor
• Article: Breast cancer incidence trends in Norway--explained by hormone therapy or mammographic screening?

  Solveig Hofvind, Solveig Sakshaug, Giske Ursin, Sidsel Graff-Iversen
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  ABSTRACT: A decline in breast cancer incidence has been observed in several countries after 2002. Reduced use of menopausal hormonal therapy (HT), as a consequence of the publication of results from the Women's Health Initiative, has been argued to be the main reason. In Norway, the governmentally funded Norwegian Breast Cancer Screening Program (NBCSP) was implemented during the same time period as the increased use of HT. This study investigated trends in breast cancer incidence by use of HT and introduction of the screening program. We obtained rates of breast cancer from the Cancer Registry of Norway and sales data of HT preparations from the Norwegian Institute of Public Health. Mammography rates were estimated from published reports. Breast cancer incidence rates increased steadily from 1956 to the end of the 20th century, particularly in women aged 55-69 during 1996-2002 residing in the counties where the NBCSP was first introduced. The rates declined after 2002-2003. HT use increased in 1987-2001, peaking around year 2000. In particular, sales of combined estrogen and progestogen preparations declined after 2002. Among women aged 55-59, rates of hormone receptor positive breast cancers peaked in 2000-2003. No such trend was seen in other age groups. In conclusion, the interpretation of breast cancer incidence trends in Norway from 1987 to 2009 is complicated because the NBCSP was introduced during a period with increasing HT use. Both factors likely contributed to the observed trends, and the role of each may vary across age groups.
  International Journal of Cancer 07/2011; 130(12):2930-8. · 5.44 Impact Factor
• Article: Mammographic morphology and distribution of calcifications in ductal carcinoma in situ diagnosed in organized screening.

  Solveig Hofvind, Barbro F Iversen, Liv Eriksen, Bodil M Styr, Kjell Kjellevold, Kathinka D Kurz
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  ABSTRACT: Ductal carcinoma in situ of the breast (DCIS) represents a challenge in mammographic screening due to its unknown progression into invasive cancer. The majority of the DCIS is detected due to signs of calcifications on the mammograms. To analyze the combinations of mammographic morphology and distribution of calcifications by Van Nuys nuclear grade (grade). A total of 217 DCIS diagnosed in women aged 50-69 years old who participated in the Norwegian Breast Cancer Screening Program in the period November 1995 to December 2007 were reviewed by four breast imaging specialists. The mammograms were classified according to the morphology and distribution of the calcifications, using BI-RADS nomenclature. Chi square test was used to compare the groups of morphology and distribution by grade. Calcifications were identified in 93% (202/217) of the cases, 15% (30/202) as grade 1 and 74% (149/202) as grade 3. Fine pleomorphic calcifications were seen in 38% (77/202) of the lesions and fine linear and fine linear branching in 31% (62/202). Sixty-nine percent (53/77) of the fine pleomorphic and 84% (52/62) of the fine linear and fine linear branching calcifications were high grade lesions. Grouped distribution was seen in about half of all the cases (104/202). Among the high grade lesions with fine pleomorphic or fine linear and fine linear branching calcifications, 75% (40/53) and 69% (36/52), respectively, had grouped or segmental distribution. DCIS presented overlapping groups of morphology and distribution of calcification by grade, but fine pleomorphic and fine linear and fine linear branching calcifications with grouped and segmental distributions were associated with high grade DCIS. Seeking for further knowledge that allows separation of non-high grade from high grade DCIS has to continue to improve the quality of mammographic screening.
  Acta Radiologica 06/2011; 52(5):481-7. · 1.37 Impact Factor
• Article: Second events following ductal carcinoma in situ of the breast: a register-based cohort study.

  Ragnhild Sørum Falk, Solveig Hofvind, Per Skaane, Tor Haldorsen
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  ABSTRACT: The incidence of ductal carcinoma in situ (DCIS) of the breast has increased in recent decades, particularly, in counties offering mammography screening. The aims of the present study are to examine factors that may predict subsequent breast malignancy amongst patients with DCIS, and to compare the incidence of the subsequent malignancy and mortality with that of the general population. This population-based study includes all primary cases of pure DCIS diagnosed in Norway in the period 1993 to 2007 (N = 3167). The patients were followed to subsequent malignancy (DCIS or invasive cancer) or death. Risk estimates within 10 years of follow-up were calculated using Kaplan-Meier methods adjusting for competing risks, Cox regression models and Standard Incidence and Mortality Ratios. Patients with DCIS had a 11.2% risk of being diagnosed with a subsequent breast malignancy within 10 years (9.4% for invasive cancer), implying that they were five times as likely to be diagnosed with breast malignancy as the general female population in Norway. The risk was dependent on the treatment of the DCIS; patients treated with mastectomy and breast-conserving treatment had a 3.8 and 9.8% risk of ipsilateral invasive cancer within 10 years, respectively. Breast cancer mortality was 2.5% within 10 years of follow-up, a fourfold risk compared with the general population. Patients with DCIS have an increased risk of both subsequent breast malignancy and breast cancer death compared with women in the general population. Our results support previous knowledge of DCIS as a heterogeneous disease.
  Breast Cancer Research and Treatment 05/2011; 129(3):929-38. · 4.43 Impact Factor
• Article: Missed and true interval and screen-detected breast cancers in a population based screening program.

  Solveig Roth Hoff, Jon Helge Samset, Anne-Line Abrahamsen, Einar Vigeland, Olbjørn Klepp, Solveig Hofvind
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  ABSTRACT: To increase radiologic knowledge, the distribution of mammographic features on prior screening mammograms of missed interval and screen-detected cancers was compared to the distribution on diagnostic mammograms of screen-detected cancers. The same variables were compared on mammograms of discordant and concordant screen-detected cancers. The study was performed in Møre og Romsdal County, Norway, as a part of the quality assurance of the Norwegian Breast Cancer Screening Program. Women were screened using analog techniques and diagnosed from 2002 to 2008. Prior and diagnostic mammograms of 81 interval and 123 screen-detected breast cancers in women aged 50 to 71 years were retrospectively reviewed and classified as either missed or true by four experienced breast radiologists. Mammographic features were classified according to a modified Breast Imaging Reporting and Data System. Thirty percent (24 of 81) of the interval cancers and 21% (26 of 123) of the screen-detected cancers were classified as missed. Calcifications, alone or in association with mass or asymmetry, tended to be more common on prior mammograms of missed cancers compared to diagnostic mammograms of screen-detected cancers (34% [17 of 50] vs 21% [26 of 123], P = .114), whereas an opposite trend was seen for mass (54% [27 of 50] vs 68% [84 of 123], P = .109). Similar results were seen when comparing discordant and concordant cancers. Calcifications represent a challenge in the interpretation of screening mammograms. For educational purposes, the importance of reviewing both interval and screen-detected cancers is obvious. Knowledge gained from systematic reviews might reduce the number of missed cancers on mammographic screening. Performing reviews according to established guidelines would make it possible to compare results across screening programs.
  Academic radiology 01/2011; 18(4):454-60. · 2.09 Impact Factor
• Article: Screen-film mammography versus full-field digital mammography in a population-based screening program: The Sogn and Fjordane study.

  Inger-Marie Juel, Per Skaane, Solveig Roth Hoff, Gunnar Johannessen, Solveig Hofvind
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  ABSTRACT: Studies comparing analog and digital mammography in breast cancer screening have shown conflicting results. Little is known about the use of digital photon-counting detectors. To retrospectively compare performance indicators in screen-film (SFM) and full-field digital mammography (FFDM) using a photon-counting detector in a population-based screening program. The Norwegian Social Science Data Services approved the study, which was part of the Norwegian Breast Cancer Screening Program. The program invites women aged 50–69 years to two-view mammography biannually. The study period was January 2005 to June 2006 for SFM and August 2006 to December 2007 for FFDM. Independent double reading was performed using a five-point rating scale for probability of cancer. Recalls due to abnormal mammography were retrospectively reviewed by an expert panel. Performance indicators for the two techniques were compared. Attendance rate was 83.6% (7442/8901) for SFM and 82.0% (6932/8451) for FFDM. The recall rate due to abnormal mammography, cancer detection rate and positive predictive value did not differ significantly between SFM and FFDM: recall 2.3% (174/7442) versus 2.4% (168/6932), cancer detection 0.39% (29/7442) versus 0.48% (33/6932), positive predictive value 16.7% (29/174) versus 19.6% (33/168), respectively (P>0.05 for all). The recall rate due to technically inadequate mammograms was 0.3% (19/7442) for SFM and 0.01% (1/6932) for FFDM. In the retrospective review, a significantly higher proportion of calcifications and asymmetric density were categorized as normal or definitively benign in FFDM compared with SFM. The average glandular dose was 2.17 mGy for SFM and 1.25 mGy for FFDM. Performance indicators show that FFDM using photon-counting detector is suitable for breast cancer screening. The lower radiation dose and lower recalls due to technically inadequate mammograms are of importance in mammography screening.
  Acta Radiologica 11/2010; 51(9):962-8. · 1.37 Impact Factor
• Article: Trends in incidence of ductal carcinoma in situ: the effect of a population-based screening programme.

  Ragnhild Sørum, Solveig Hofvind, Per Skaane, Tor Haldorsen
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  ABSTRACT: The incidence of ductal carcinoma in situ (DCIS) has increased substantially in the western world in recent decades. The aim of this study was to investigate the incidence according to grade distribution, age, and implementation of a population-based screening programme. Cases of primary pure DCIS (n = 3167) were obtained from the Cancer Registry of Norway. Poisson regression was used to estimate trends in incidence. Age-adjusted incidence of DCIS increased from 4 to 11 per 100, 000 women-years from 1993 to 2007, in parallel with the implementation of screening. Higher incidence was observed among prevalent (IRR 3.3) and subsequent (IRR 2.8) invited women compared with those not invited. The proportion of DCIS among breast malignancies increased throughout the period, most markedly in the age range of screening. The increased proportion of DCIS during the study period is probably due to improved diagnostics resulting from the implementation of population-based screening.
  Breast (Edinburgh, Scotland) 06/2010; 19(6):499-505. · 2.09 Impact Factor
• Article: A pooled analysis of interval cancer rates in six European countries.

  Sven Törnberg, Levent Kemetli, Nieves Ascunce, Solveig Hofvind, Ahti Anttila, Brigitte Sèradour, Eugenio Paci, Cathrine Guldenfels, Edward Azavedo, Alfonso Frigerio, Vitor Rodrigues, Antonio Ponti
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  ABSTRACT: The objective of this study was to assess detection rates and interval breast cancer (IC) rates from eight programmes in the European Breast Cancer Screening Network. A common data collection protocol was used to explore differences in IC rates among programmes and discuss their potential determinants. Pooled analysis was used to describe IC rates by age, compliance in screening, recall rate, screening detection (SD) rate and expected breast cancer incidence. Participation in screening averaged 77.9% (range 42.6-88.7%), recall rate 5.4% (range 3.3-17.7%) in the initial and 3.4% (range 1.8-8.9%) in the subsequent screening rounds, and SD rate was 60.4 (range 41.6-91) per 10 000 women in initial and 38.5 (range 31.3-62.6) in subsequent screens. IC rate during first 12 months after screening was 5.9 (range 2.1-7.3) per 10 000 women screened negative and 12.6 (range 6.3-15) in the second year of the interval. IC comprised 28% of the IC and SD cancers. The ratio between IC rate and expected incidence was 0.29 for the first 12 months and 0.63 for the 13-24 months period. Sensitivity was higher for the ages 60-69 years and for initial tests than subsequent tests. There were distinct differences in the IC rates between programmes. The results of this study reveal large variations in screening sensitivity and performance. Pooled evaluation of some process indicators within the European breast cancer screening programmes proved to be feasible and is likely to be useful for the future, particularly if it is performed regularly and extensively.
  European journal of cancer prevention: the official journal of the European Cancer Prevention Organisation (ECP) 12/2009; 19(2):87-93. · 2.21 Impact Factor
• Article: Screening-detected breast cancers: discordant independent double reading in a population-based screening program.

  Solveig Hofvind, Berta M Geller, Robert D Rosenberg, Per Skaane
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  ABSTRACT: To analyze discordant and concordant screening-detected breast cancers in a nationwide population-based screening program by using independent double reading with consensus. The study is a part of the evaluation of the Norwegian Breast Cancer Screening Program and is covered by the Cancer Registry regulation. Analyses were based on prospective initial interpretation scores of 1 033 870 screenings that included 5611 breast cancers. A five-point scale for probability of cancer was used in the initial interpretation. Screening mammograms with a score of 2 or higher by either radiologist were discussed at consensus meetings where the decision whether to recall was made. A score of 1 by one reader and 2 or higher by the other was defined as a discordant interpretation and discordant cancer, whereas a score of 2 or higher by both readers was defined as a concordant recall and cancer. Discordant interpretation was present in 5.3% (54 447 of 1 033 870) of the screenings, whereas 2.1% (21 928 of 1 033 870) were concordant positive interpretations. Of the screening-detected cancers, 23.6% (1326 of 5611) were diagnosed in women who were recalled because of screenings with discordant interpretation. One hundred seventeen interval breast cancers were diagnosed among the 40 312 screenings that were dismissed at consensus; these were 6.5% of all interval cancers. A significantly higher proportion of microcalcifications alone was present in discordant cancers (24.9% [304 of 1219]) compared with concordant cancers (17.7% [704 of 3972]) (P < .001). Independent double reading with consensus at mammography screening has the potential to increase the cancer detection rate compared with single reading. Mammograms with microcalcifications alone are significantly more common among discordant cancers.
  Radiology 09/2009; 253(3):652-60. · 5.73 Impact Factor