Mammographic screening after the age of 65 years: Evidence for a reduction in breast cancer mortality

We evaluated whether regular mammographic screening of women aged 65 years or older affected breast cancer mortality. In Nijmegen, a population-based screening program for breast cancer was started in 1975, with biennial mammography for women aged 35–64 years. Since 1977, elderly women have also been participating. For the present case-control study, women were selected who were over 64 years of age at the most recent invitation. Eighty-two of them had died from breast cancer. For these cases, 410 age-matched population controls were selected. The ratio of breast cancer mortality rates of the women who had participated regularly (i.e., in the 2 most recent screening rounds prior to diagnosis) vs. the women who had not participated in the screening was 0.56 (95% Cl = 0.28−1.13). The rate ratio was 0.45 in the women aged 65–74 years at the most recent invitation (95% Cl = 0.20−1.02), whereas it was 1.05 in the women aged 75 years and older (95% Cl = 0.27−4.14). While the breast cancer survival rate of the non-participant patients was fairly equal to that of patients from a control population, the underlying incidence rate of breast cancer was higher in the participants than in the no-participants. Therefore, we conclude that bias was present, but that it had decreased our effect estimate. The real reduction in breast cancer mortality due to regular screening will be even larger. Regular mammographic screening of women over age 65 (at least up to 75 years) can reduce breast cancer mortality by approximately 45%. © 1996 Wiley-Liss, Inc.     

Patterns of treatment for older women with newly diagnosed breast carcinoma

The patterns of treatment for newly diagnosed breast carcinomas in older women aged 65 years or more have not been well studied, particularly in relation to screening mammography performed for the early detection of breast cancer. Therefore, the present study was performed to determine the patterns of treatment for newly diagnosed breast carcinomas in older women aged 65 years or more and to determine the impact of screening mammography on these patterns of treatment. The study population consisted of 130 women aged 65 years or more with newly diagnosed breast carcinoma from 1993 through 1994 enrolled in a large health maintenance organization. The medical records of these 130 patients were reviewed. The breast cancers detected in women who had undergone mammographic screening were more often eligible for breast-conservation treatment than the breast cancers detected in women who had not undergone mammographic screening (79% vs. 48%, respectively; p = 0.0044). For the breast cancers that were eligible for breast-conservation treatment, breast-conservation treatment was used more often for the women who had undergone mammographic screening than for the women who had not undergone mammographic screening (70% vs. 27%, respectively; p = 0.0077). Definitive radiation therapy was delivered after breast-conservation surgery in 89% (55/62) of the patients. Medical oncology consultation was obtained more commonly for more advanced staged breast cancers. Clinical management was altered in 9% (12/130) of the patients because of older patient age, comorbid medical conditions, or both. These findings have documented the patterns of treatment for older women aged 65 years or more with newly diagnosed breast cancer. Screening mammography had a significant impact on the patterns of breast cancer management, as demonstrated by the association of screening mammography with an increased eligibility for breast-conservation treatment and an increased use of breast-conservation treatment for eligible patients.     

Screening for breast cancer in Nijmegen. Report of 6 screening rounds, 1975-1986

A population-based screening programme for breast cancer was initiated in Nijmegen in 1975 with mammography as the only screening procedure. Up to January 1987, 6 screening rounds were carried out with a 2-year screening interval. Rates of attendance, referral, biopsy and detection were calculated and numbers of interval cancers are presented in order to give a clear view of what repeated screening can accomplish in a population. At the first screening round the attendance rate was 87% for women under age 50 and 83% for women aged 50-64. For women aged 65 or over the initial attendance rate was 40%. Rates of attendance declined in subsequent years. Detection rates were highest for elderly women at their first examination: 9.5 per 1,000 screened women. Corresponding rates were 5.6 and 2.3 per 1,000 for women aged 50-64 and below 50 respectively. The positive predictive value for referral was, on average, 20% for women under age 50 and 50% for elderly women, although a sharp increase was seen in the last 2 screening examinations for all age-groups. Predictive values for biopsy were higher: 30% on average for women aged under 50 and 60%-70% for elderly women, again with a sharp increase in the last 2 screening rounds. Interval cancer rates, calculated as the number of cancers occurring within 2 years among negatively screened women at risk, showed no particular trend and varied between 0.9-1.3 per 1,000 woman-years after each screening round. Compared to screen-detected cancers, interval cancers occurred more frequently in younger women. In women under age 50, the ratio between screen-detected and interval cancer was about 1:1, while it was about 2:1 for elderly women.     

Influence of mammographic screening on trends in breast-conserving surgery in Ireland.

Debate exists about the influence of screening on breast cancer surgery. We compared rates and odds of mastectomy and breast-conserving surgery (BCS) during 1994-1999 between Northern Ireland, which has had organized mammographic screening (age group 50-64) since 1993, and the Republic of Ireland, where large-scale screening did not begin until 2000. Trends in BCS were similar in both populations: significant increases in BCS rates for age groups 20-49 and, especially, 50-64, and significant increases in mastectomy rates for age group 65+ only. Use of BCS among surgical patients was significantly higher in Northern Ireland (46%) than the Republic of Ireland (35%) and, in Northern Ireland, was significantly higher in age group 50-64 than other age groups. Geographic and age-related variations were substantially, but not wholly, explained by tumour characteristics and screen-detection status. Among Northern Ireland women aged 50-64, BCS use among screen-detected cases, even after adjustment for tumour characteristics, was 40-50% higher and increased more rapidly during 1994-1999 than among other cases. However, trends in BCS in Northern Ireland were not explained by changes in screen-detection status or tumour characteristics. Our findings are consistent with expectations that mammographic screening, together with modern treatment guidelines, should lead to reduced use of mastectomy and increased (proportional) use of BCS. But similar trends occurred in the absence of large-scale screening (in the Republic of Ireland), and surgical treatment of screen-detected cases did not reflect tumour characteristics alone.     

Detection of ductal carcinoma in situ in women undergoing screening mammography

BACKGROUND: With the large number of women having mammography-an estimated 28.4 million U.S. women aged 40 years and older in 1998-the percentage of cancers detected as ductal carcinoma in situ (DCIS), which has an uncertain prognosis, has increased. We pooled data from seven regional mammography registries to determine the percentage of mammographically detected cancers that are DCIS and the rate of DCIS per 1000 mammograms. METHODS: We analyzed data on 653 833 mammograms from 540 738 women between 40 and 84 years of age who underwent screening mammography at facilities participating in the National Cancer Institute's Breast Cancer Surveillance Consortium (BCSC) throughout 1996 and 1997. Mammography results were linked to population-based cancer and pathology registries. We calculated the percentage of screen-detected breast cancers that were DCIS, the rate of screen-detected DCIS per 1000 mammograms by age and by previous mammography status, and the sensitivity of screening mammography. Statistical tests were two-sided. RESULTS: A total of 3266 cases of breast cancer were identified, 591 DCIS and 2675 invasive breast cancer. The percentage of screen-detected breast cancers that were DCIS decreased with age (from 28.2% [95% confidence interval (CI) = 23.9% to 32.5%] for women aged 40-49 years to 16.0% [95% CI = 13.3% to 18.7%] for women aged 70-84 years). However, the rate of screen-detected DCIS cases per 1000 mammograms increased with age (from 0.56 [95% CI = 0.41 to 0.70] for women aged 40-49 years to 1.07 [95% CI = 0.87 to 1.27] for women aged 70-84 years). Sensitivity of screening mammography in all age groups combined was higher for detecting DCIS (86.0% [95% CI = 83.2% to 88.8%]) than it was for detecting invasive breast cancer (75.1% [95% CI = 73.5% to 76.8%]). CONCLUSIONS: Overall, approximately 1 in every 1300 screening mammography examinations leads to a diagnosis of DCIS. Given uncertainty about the natural history of DCIS, the clinical significance of screen-detected DCIS needs further investigation.     

Impressive time-related influence of the Dutch screening programme on breast cancer incidence and mortality, 1975-2006

The aim of this study was to assess changes in the trends in breast cancer mortality and incidence from 1975 to 2006 among Dutch women, in relation to the implementation of the national breast cancer screening programme. Screening started in 1989 for women aged 50-69 and was extended to women aged 70-75 years in 1998 (attendance rate approximately >80%). A joinpoint Poisson regression analysis was used to identify significant changes in rates over time. Breast cancer mortality rates increased until 1994 (age group 35-84), but thereafter showed a marked decline of 2.3-2.8% per annum for the age groups 55-64 and 65-74 years, respectively. For the age group of 75-84 years, a decrease started in the year 2001. In women aged 45-54, an early decline in breast cancer mortality rates was noted (1971-1980), which is ongoing from 1992. For all ages, breast cancer incidence rates showed an increase between 1989 and 1993, mainly caused by the age group 50-69, and thereafter, a moderate increase caused by age group 70-74 years. This increase can partly be explained by the introduction of screening. The results indicate an impressive decrease in breast cancer mortality in the age group invited for breast cancer screening, starting to show quite soon after implementation.     

Followup after 11 years – update of mortality results in the Stockholm mammographic screening trial

Results from several randomised mammography screening trials haveshown that it is possible to reduce mortalityin breast cancer by mammographic screening at leastfor women above 50 years of age. Thepurpose of this article is to present dataon mortality in breast cancer in study andcontrol groups of the Stockholm trial after 11years of followup, to analyse which age groupbenefits most from screening. In March 1981, 40,318women in Stockholm, aged 40 through 64 years,entered a randomized trial of breast cancer screeningby single view mammography alone, versus no interventionin a control group of 20 000 women.Two screening rounds were performed and the attendancerate was over 80% in the two rounds.During 1986 the control group was invited onceto screening. Totally 428 and 217 cases ofbreast cancer were diagnosed in the study andcontrol groups respectively. After a mean follow-up of11.4 years a nonsignificant mortality reduction of 26%was observed for the whole study group, witha relative risk (RR) of death in breastcancer of 0.74 (CI(confidence interval)=0.5–1.1). Forwomen aged 50–64 years a significant 38% mortalityreduction was observed with a RR of 0.62(CI=0.38–1.0). For women aged 40–49 yearsno effect on mortality was found, with aRR of death in breast cancer of 1.08(CI=0.54–2.17). The breakpoint for benefit inthis study seemed to be at 50 yearsof age when 5-year age groups were analysed,but this tendency is uncertain because of thelow statistical power in the analysis of theyounger age groups. Long screening intervals, the useof single-view mammography, and the fact that morethan 50% of the women in age group40–49 years were still below 50 years ofage when the study was closed, were allfacts that could have influenced the results inage group 40–49 years. Larger studies are neededto answer the question whether mammographic screening canbe successful in younger age groups.     

Modelling the overdiagnosis of breast cancer due to mammography screening in women aged 40 to 49 in the United Kingdom

Introduction

Overdiagnosis of breast cancer due to mammography screening, defined as the diagnosis of screen-detected cancers that would not have presented clinically in a women''s lifetime in the absence of screening, has emerged as a highly contentious issue, as harm caused may question the benefit of mammographic screening. Most studies included women over 50 years old and little information is available for younger women.

Methods

We estimated the overdiagnosis of breast cancer due to screening in women aged 40 to 49 years using data from a randomised trial of annual mammographic screening starting at age 40 conducted in the UK. A six-state Markov model was constructed to estimate the sensitivity of mammography for invasive and in situ breast cancer and the screen-detectable mean sojourn time for non-progressive in situ, progressive in situ, and invasive breast cancer. Then, a 10-state simulation model of cancer progression, screening, and death, was developed to estimate overdiagnosis attributable to screening.

Results

The sensitivity of mammography for invasive and in situ breast cancers was 90% (95% CI, 72 to 99) and 82% (43 to 99), respectively. The screen-detectable mean sojourn time of preclinical non-progressive and progressive in situ cancers was 1.3 (0.4 to 3.4) and 0.11 (0.05 to 0.19) years, respectively, and 0.8 years (0.6 to 1.2) for preclinical invasive breast cancer. The proportion of screen-detected in situ cancers that were non-progressive was 55% (25 to 77) for the first and 40% (22 to 60) for subsequent screens. In our main analysis, overdiagnosis was estimated as 0.7% of screen-detected cancers. A sensitivity analysis, covering a wide range of alternative scenarios, yielded a range of 0.5% to 2.9%.

Conclusion

Although a high proportion of screen-detected in situ cancers were non-progressive, a majority of these would have presented clinically in the absence of screening. The extent of overdiagnosis due to screening in women aged 40 to 49 was small. Results also suggest annual screening is most suitable for women aged 40 to 49 in the United Kingdom due to short cancer sojourn times.     

Screening younger women with a family history of breast cancer – does early detection improve outcome?

Women with a family history are often offered mammographic surveillance at an earlier age and with greater frequency than those in the National Breast Screening Programme. In this study, we compared the survival of 62 breast cancer patients diagnosed in the context of a family history clinic offering 12-18 monthly mammographic screening with that of 1108 patients of the same age range but having no exposure to screening. We subtracted the expected additional observation time due to lead time from the survival of the screen-detected cases. Survival was significantly better in the family history group with relative hazards of 0.19 (95% CI 0.07-0.52, P<0.001) for breast cancer death and 0.19 (95% CI 0.08-0.43, P<0.001) for disease-free survival. After correcting for lead-time, the relative hazards were 0.24 (95% CI 0.09-0.66, P=0.005) for breast cancer death and 0.25 (95% CI 0.11-0.57, P<0.001) for disease-free survival. These results strongly suggest that screening younger women with a family history of breast cancer leads to improved survival. More precise estimates of the benefit will accrue from further follow-up and other such studies.     

Screen-detected vs symptomatic breast cancer: is improved survival due to stage migration alone?

This paper examines whether screen-detected breast cancer confers additional prognostic benefit to the patient, over and above that expected by any shift in stage at presentation. In all, 5604 women (aged 50-70 years) diagnosed with invasive breast cancer between 1998 and 2003 were identified by the Eastern Cancer Registration and Information Centre (ECRIC) and mammographic screening status was determined. Using proportional hazards regression, we estimated the effect of screen detection compared with symptomatic diagnosis on 5-year survival unadjusted, then adjusted for age and Nottingham Prognostic Index (NPI). A total of 72% of the survival benefit associated with screen-detected breast cancer can be accounted for by age and shift in NPI. Survival analysis by continuous NPI showed a small but systematic survival benefit for screen-detected cancers at each NPI value. These data show that although most of the screen-detected survival advantage is due to a shift in NPI, the mode of detection does impact on survival in patients with equivalent NPI scores. This residual survival benefit is small but significant, and is likely to be due to differences in tumour biology. Current prognostication tools may, therefore, overestimate the benefit of systemic treatments in screen-detected cancers and lead to overtreatment of these patients.     

Risk Factors for Screen-Detected Breast cancer a case-control study

Risk factors for breast cancer (BC) detected in mammography screening were sought using a questionnaire among 31 927 women aged from 40 to 74 years who attended screening. Data from 204 women with screen-detected BC were compared with those of 612 controls who did not have EC in screening. Mothers of women with BC had more often BC than those of the controls (8% vs. 3%, odds ratio, OR, 3.18, 95% CI 1.59-6.35). Women with screen-detected BC were older at their first, childbirth (25.7 years vs. 24.7 years, OR 1.61, 1.14-2.33), and younger at menarche (13.6 years vs. 13.8 years, OR 1.38, 1.00-1.91), but there was no significant difference in the body mass index, number of pregnancies, breast size, smoking, or in the use of contraceptive pills between the cases and the controls. In multivariate logistic regression analyses, late age at the first childbirth, BC in the mother, and early age at menarche were independent risk factors for screen-detected BC but they appear to be of limited value in targeting screening in the female population aged from 40 to 74 in order to improve its cost-effectiveness.     

Using mammographic density to improve breast cancer screening outcomes

It is possible that the performance of mammographic screening would be improved if it is targeted at women at higher risk of breast cancer or who are more likely to have their cancer missed at screening, through more intensive screening or alternative screening modalities. We conducted a case-control study within a population-based Australian mammographic screening program (1,706 invasive breast cancers and 5,637 randomly selected controls). We used logistic regression to examine the effects of breast density, age, and hormone therapy use, all known to influence both breast cancer risk and the sensitivity of mammographic screening, on the risk of small (15 mm) screen-detected and interval breast cancers. The risk of small screen-detected cancers was not associated with density, but the risk of large screen-detected cancers was nearly 3-fold for the second quintile and approximately 4-fold for the four highest density categories (third and fourth quintiles and the two highest deciles) compared with the lowest quintile. The risk of interval cancers increased monotonically across the density categories [highest decile odds ratio (OR), 4.65; 95% confidence interval (95% CI), 2.96-7.31]. The risk of small and large screen-detected cancers, but not interval cancers, increased with age. After adjusting for age and density, hormone therapy use was associated with a moderately elevated risk of interval cancers (OR, 1.43; 95% CI, 1.12-1.81). The effectiveness of the screening program could be improved if density were to be used to identify women most likely to have poor screening outcomes. There would be little additional benefit in targeting screening based on age and hormone therapy use.     

Comparison of 1- and 2-year screening intervals for women undergoing screening mammography

We compared the long-term impact of 1- and 2-year screening mammography intervals using prognostic, screening, and outcome information for women aged 50-74 years obtained from the Screening Mammography Program of British Columbia in two time periods, prior to 1997 (policy of annual mammography) and after 1997 (biennial mammography). Survival was estimated for both periods using a prognostic model and the expected rate of interval and screen-detected cancers. The likelihood of a screen-detected cancer with annual screening was 2.32 per thousand screens and with biennial screening was 3.32 per thousand screens. The prognostic profile of screen-detected cancers was better than that of interval cancers. Among both screen-detected and interval cancers, the prognostic profiles with annual and biennial screening were similar. The estimated breast cancer-specific survival rates for women undergoing annual and biennial screening mammography were 95.2 and 94.6% at 5 years, and 90.4 and 89.2% at 10 years, respectively. Annual compared to biennial mammography was associated with a 1.2% increase in the estimated 10-year breast cancer-specific survival for women aged 50-74 years, diagnosed with invasive breast cancer after screening programme attendance.     

Routine breast screening for women aged 65-69: results from evaluation of the demonstration sites.

Routine programme data and specially designed surveys from 3 demonstration sites were analysed to determine the implications of extending the NHS Breast Screening Programme (NHSBSP), to include routine invitations for women up to 69 years. All women aged 65-69 and registered with GPs in these areas received routine invitations for breast screening along with those aged 50-64. Overall uptake was 71% in women aged 65-69 compared with 78% in younger women, but was > or = 90% in both groups who had previously attended within 5 years. Recall rates were lower for older women, but with a higher positive predictive value for cancer. The percentages of invasive cancer in different prognostic categories were similar in the 2 age groups. Older women took no longer to screen than younger women. The costs per woman invited or per woman screened were also similar to those for women aged 50-64, whilst the cost per cancer detected was some 34% lower in older women. Breast screening is as cost effective for women aged 65-69 as for those aged 50-64, with a higher cancer detection rate balancing shorter life expectancy. The proposed extension to the national programme will have considerable workforce implications for the NHSBSP and require additional resources.     

Breast cancer in New South Wales in 1972-1995: tumor size and the impact of mammographic screening.

To examine the use of mammographic screening in women in New South Wales (NSW), we measured uptake of initial mammograms and estimated the proportions of breast cancers that were screen detected. To see if mammographic screening has been associated with reductions in advanced breast cancers and mortality from breast cancer, we analyzed trends in age-specific and age-standardized breast cancer incidence and mortality from 1972 to 1995 and tumor size in 1986, 1989, 1992 and April to September 1995. Between 1984 and the end of 1995, an estimated 72% of NSW women in their 50s and 67% in their 60s had had at least 1 mammogram and, in 1995, an estimated 39% of invasive breast cancers in women in these age groups were detected by mammography. Before 1989, breast cancer incidence increased only slightly (+1.3% annually) but then, from 1990 to 1995, increased more rapidly (+3.1% annually). Between 1986 and 1995, rates of small cancers (< 1 cm) increased steeply by 2.7 times in women 40-49 years of age and 5.6 times in women 50-69 years of age. The incidence of large breast cancers (3+ cm), after little apparent change to 1992, fell by 17% in women 40-49 years of age and 20% in those 50-69 years of age to 1995. Breast cancer mortality increased slightly between 1972 and 1989 (+0.5% annually) but then fell (-2.3% annually) from 1990 to 1995. We concluded that breast cancer rates had been influenced in expected directions by the introduction of mammographic screening in women resident in NSW. We expect that recent falls in incidence of larger breast cancers and breast cancer mortality will become steeper as screening coverage increases in the second half of the 1990s.     

Mammography screening interval and the frequency of interval cancers in a population-based screening.

In a population-based mammography screening, 129,731 examinations were carried out among 36,000 women aged 40-74 in the city of Turku, Finland, in the period 1987-94. Women older than 50 were screened at 2-year intervals, and those younger than 50 at either 1-year or 3-year intervals, depending on their year of birth. Screen-detected breast cancers numbered 385 and, during the same time period, 154 women were diagnosed with breast cancer outside screening in the same age group in the same city, and 100 interval cancers were detected. Two hundred and fifty (67%) of the screen-detected cancers were of post-surgical stage I compared with 45 (45%) of the interval cancers and 52 (34%) of the cancers found outside screening (P<0.0001). However, among women aged 40-49 the frequency of stage I cancers did not differ significantly among screen-detected cancers, interval cancers and cancers found outside screening (50%, 42% and 44% respectively; P=0.73). Invasive interval cancers were more frequent among women aged 40-49 if screening was done at either 1-year (27%) or 3-year intervals (39%) than in older women screened at 2-year intervals (18%; P=0.08 and P=0.0009 respectively). Even if adjusted for the primary tumour size, screen-detected cancers had smaller S-phase fractions than interval cancers or control cancers (P=0.01), but no difference in the S-phase fraction size was found between cancers of women younger than 50 and those older than this (P=0.13). We conclude that more interval cancers were found among women younger than 50 than among those older than 50 and that this could not be explained by the rate of cancer cell proliferation.     

Extending Screening in “Elderly” Patients: Should We Consider a Selective Approach?

BackgroundBreast cancer screening has been shown to reduce breast cancer-associated mortality. However, screening is limited to the targeted age group of 45 to 69 years in New Zealand despite the recognized increased risk with age. This study aims to compare the outcomes of women aged over 70 years with screen-detected and clinically detected cancers.Patients and MethodsA retrospective review was performed of prospectively collected data from June 2000 to May 2013 by the Auckland Breast Cancer Register. Demographic and tumor characteristics of women with invasive cancer and ductal carcinoma in situ diagnosis aged 70 years and over were compared between those screened and clinically detected. Five-year disease-free and overall survival outcomes were reviewed.ResultsA total of 2128 women aged 70 years and over were diagnosed with breast cancer (median, 77 years; interquartile range [IQR], 74-84 years). Of these, 416 (19.5%) were diagnosed through mammography screening, with a median age of 74 years (IQR, 71-77 years) compared with 79 years (IQR, 74-85 years) for those with clinical detected cancer diagnosis. Screen-detected cancers accounted for a significantly higher proportion of diagnoses in those aged 70 to 74 years compared with older patients (P < .001). Screen-detected cancers were of lower T and N stages. Disease-specific survival was significantly longer in screen-detected cancers versus other cancers (5-year survival, 93.7% vs. 81.9%; P < .001), as was overall survival (5-year survival, 84.7% vs. 57.4%; P < .001).ConclusionScreening in those aged 70 years and over continues to identify breast cancer at early stages and with improved survival. Although aware of the potential for lead-time bias and the healthy volunteer effect, there should still be consideration to extend breast cancer screening to patients aged to up 74 years after appropriate assessment of comorbidities and functional status.     

Successful First Round Results of a Turkish Breast Cancer Screening Program with Mammography in Bahcesehir,Istanbul

Background: The Bahcesehir Breast Cancer Screening Project is the first organized population basedbreast cancer mammographic screening project in Turkey. The objective of this prospective observationalstudy was to demonstrate the feasibility of a screening program in a developing country and to determine theappropriate age (40 or 50 years old) to start with screening in Turkish women. Materials and Methods: BetweenJanuary 2009 to December 2010, a total of 3,758 women aged 40-69 years were recruited in this prospectivestudy. Screening was conducted biannually, and five rounds were planned. After clinical breast examination(CBE), two-view mammograms were obtained. True positivity, false positivity, positive predictive values (PPV)according to ACR, cancer detection rate, minimal cancer detection rate, axillary node positivity and recall ratewere calculated. Breast ultrasound and biopsy were performed in suspicious cases. Results: Breast biopsy wasperformed in 55 patients, and 18 cancers were detected in the first round. The overall cancer detection rate was4.8 per 1,000 women. Most of the screened women (54%) and detected cancers (56%) were in women aged 40-49. Ductal carcinoma in situ (DCIS) and stage I cancer and axillary node positivity rates were 22%, 61%, and16.6%, respectively. The positive predictivity for biopsy was 32.7%, whereas the overall recall rate was 18.4 %.Conclusions: Preliminary results of the study suggest that population based organized screening are feasibleand age of onset of mammographic screening should be 40 years in Turkey.     

The role of mammography in breast cancer prevention.

Screening mammography has been shown to reduce breast cancer mortality by detecting small, nonpalpable, early-stage breast cancers. In 1998, several studies were published, reinforcing the value of screening mammography in women aged 40 years and older. Some studies focused on when screening should begin (age 40 years), while others analyzed the process of screening mammography, with particular attention to recall rates and false-positive studies. Other reports emphasized the limitations of mammographic interpretation, the use of computers to aid in mammographic diagnosis, and screening with ultrasound.