Breast and cervical cancer screening for women between 50 and 69 years of age: what prompts women to screen?

The objective of this study was to examine mammography and cervical cancer screening rates among women aged 50 to 69 and to understand which prompts are effective for improving screening compliance. A self-administered survey was sent to 800 randomly selected participants in a health region in a relatively poor, rural province in Eastern Canada with a universal health care system. Since 1995, New Brunswick has instituted a biannual self-referral mammography screening program for women between 50 and 69 years of age. The response rate to the survey was 66%. Mammography screening compliance was 73% and was most significantly associated with annual clinical breast examinations, compliance with cervical cancer screening, and physician suggestion (p <.001). Cervical cancer screening compliance was 91% and was significantly associated with annual clinical breast examinations, compliance with mammography screening, and physician suggestion (p<.001). Contact with a physician is most effective for promoting screening compliance.

A cross-cultural consumer-based decision aid for screening mammography

BACKGROUND

"Women should have mammograms" is the usual perspective of educational interventions about screening. The perspective that "women should be informed" about potential risks and benefits so they can make value- and evidence-integrated personal decisions has recently been advocated. However, this perspective has not previously been operationalized. We developed an evidence-based cross-cultural mammography decision aid (MDA), for European American and Mexican American women who are 50-70 years old, at average risk of breast cancer, of varying educational levels, and English- or Spanish-speaking.

METHODS

MDA development included: (1) content development by a multidisciplinary team and lay women and (2) testing for validity and reliability. Four parts include: (1) introduction; (2) information about logistics (cost, time, discomfort) and risks (sequelae of false-positive or negative results; (3) probability of developing breast cancer; and (4) benefit of mammography regarding breast cancer outcomes (e.g., death and recurrence). We assessed reliability (stability of decisions with the same information) after 1-2 weeks. We assessed validity (comprehension of information) quantitatively (probabilities were changed to see whether preferences changed predictably) and qualitatively (focus groups, standardized probes for comprehension). Subjects were a convenience sample of 49 European American (50-81 years old) and 54 Mexican American (49-89 years old) women from administrative staff at a medical school, the waiting room of an indigent primary care clinic, and a community center.

RESULTS

Reliability was 100%. In quantitative validity testing, 22 of 28 women (89%) changed preference as predicted with changed probabilities. Comprehension was confirmed qualitatively in all phases of testing with both Spanish and English versions.

CONCLUSION

The decision aid is valid and reliable in English and Spanish for southwestern Mexican American and European American women at average risk of breast cancer, including those of low educational levels.

A comparison of the performance and impact of breast cancer screening programmes in East Anglia, U.K. and Bouches du Rhône, France

The purpose of this study was to compare results from the first screening round of two breast cancer screening programmes of similar design implemented in different health care settings. The East Anglian programme is part of the U.K. National Health Service Breast Screening Programme, which is a centralised programme with a limited number of dedicated screening units. The Bouches du Rhône programme is one of 13 French programmes based on a decentralised model using existing radiology clinics. Compliance and cancer detection rates were lower in the Bouches du Rhône programme. Detection rates for small invasive cancers (< or = 10 mm) were similar in the two programmes, although larger cancers (> or = 20 mm) were detected in the Bouches du Rhône programme. Significantly, the shift towards more favourable distribution of prognostic characteristics associated with screen-detected breast cancers compared with those arising outside the programme is less marked in the Bouches du Rhône programme. This is probably due to the more favourable underlying disease status in the district resulting from a long history of breast awareness and spontaneous mammography.

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 (ie., in the 2 most recent screening rounds prior to diagnosis) vs. the women who had not participated in the screening was 0.56 (95% CI = 0.28-1.13). The rate ratio was 0.45 in the women aged 65-74 years at the most recent invitation (95% CI = 0.20-1.02), whereas it was 1.05 in the women aged 75 years and older (95% CI = 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 non-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%.

Long term breast cancer screening in Nijmegen, The Netherlands: the nine rounds from 1975-92

STUDY OBJECTIVE

To assess the performance of breast cancer screening in different age categories over two decades.

DESIGN

Important determinants of reduced breast cancer mortality such as attendance, mammography performance, cancer detection, and disease stage were recorded.

SETTING

Nijmegen, The Netherlands, 1975-92.

SUBJECTS

Since 1975 more than 40,000 women aged 35 years and older have been invited biennially for breast screening in a population based project in Nijmegen.

MAIN RESULTS

Rates of attendance, referral, detection, and disease stage were calculated, as well as the specificity of screening mammography and the predictive value of referral and biopsy. From round 3 onwards, the attendance rate of women younger than 50 years stabilised at 70%, in women of 50-69 years it was 62%, and in women aged 70 and over it was 22%. In these three age categories, the referral rates of a positive screening mammography per 1000 screened women were 4.9, 6.2, and 11.8, respectively. Specificity rates were between 99% and 100%. Current predictive values of referral were high: in the specific age categories 39%, 59%, and 68% of the referred women had cancer. Detection rates remained fairly stable over the rounds 4-9, at 1.9, 3.6, and 8.0 cancers per 1000 screened women. In the two year period between screening the numbers of interval cancers per 1000 screened women were 2.2, 2.2, and 2.9, for the three age categories respectively. With regard to invasive cancers detected during screening, the percentage of small tumours (< or = 20 mm on the mammogram) was 84% in each age category. For women younger than 50 years, the proportion of intraductal carcinoma in all the cancers detected at screening was 40%, while it was 15% in the other age categories.

CONCLUSION

Throughout the nine rounds, the screening outcomes were found to be adequate, particularly considering the high specificity rate and the predictive value of referral without the interference of a low detection rate. Although the occurrence of interval cancers seemed high, it was similar to other screening programmes. Despite a relatively low referral rate, the ratios of screen detected versus interval cancer cases were favourable. Well organised screening programmes can achieve good mammography results without too many false positives. It is important that women continue to participate in a screening programme because cancer can still be detected even after several successive negative screening examinations.

Audit of mammography in a community setting

A Northwest community concentrated all mammography services in one location and instituted a program of annual review. The 32,118 mammograms prompted 466 biopsies of women who had no palpable abnormality. Over the 5-year study, there were 142 nonpalpable cancers found for a positive biopsy rate of 30%. In the first year, the positive biopsy rate was 17%, and, in the last year, it was 42%. The increase in apparent selectivity prompted a search for false negatives or missed breast cancers. One percent of women subjected to mammography underwent biopsy, but, interestingly, only 84% of women undergoing mammography received a normal report. Eighty-seven percent of the cancers were invasive, and 13% were considered to be noninvasive. A review of the literature suggests significant variation in the frequency of identifying nonpalpable breast cancer, and respected pathologists report variations in the pathologic evaluation of these nonpalpable cancers.