Breast cancer mortality in relation to receipt of screening mammography: a case-control study in Saskatchewan, Canada

The Benefits of Early Detection: Evidence From Modern International Mammography Service Screening Programs

Research from randomized controlled trials initiated up to 60 years ago consistently confirms that regular screening with mammography significantly reduces breast cancer mortality. Despite this success, there is ongoing debate regarding the efficacy of screening, which is confounded by technologic advances and concerns about cost, overdiagnosis, overtreatment, and equitable care of diverse patient populations. More recent screening research, designed to quell the debates, derives data from variable study designs, each with unique strengths and weaknesses. This article reviews observational population-based screening research that has followed the early initial long-term randomized controlled trials that are no longer practical or ethical to perform. The advantages and disadvantages of observational data and study design are outlined, including the three subtypes of population-based observational studies: cohort/case-control, trend, and incidence-based mortality/staging. The most recent research, typically performed in countries that administer screening mammography to women through centralized health service programs and directly track patient-specific outcomes and detection data, is summarized. These data are essential to understand and inform construction of effective new databases that facilitate continuous assessment of optimal screening techniques in the current era of rapidly developing medical technology, combined with a focus on health care that is both personal and equitable.

Breast Cancer Screening Recommendations Inclusive of All Women at Average Risk: Update from the ACR and Society of Breast Imaging

Breast cancer remains the most common nonskin cancer, the second leading cause of cancer deaths, and the leading cause of premature death in US women. Mammography screening has been proven effective in reducing breast cancer deaths in women age 40 years and older. A mortality reduction of 40% is possible with regular screening. Treatment advances cannot overcome the disadvantage of being diagnosed with an advanced-stage tumor. The ACR and Society of Breast Imaging recommend annual mammography screening beginning at age 40, which provides the greatest mortality reduction, diagnosis at earlier stage, better surgical options, and more effective chemotherapy. Annual screening results in more screening-detected tumors, tumors of smaller sizes, and fewer interval cancers than longer screening intervals. Screened women in their 40s are more likely to have early-stage disease, negative lymph nodes, and smaller tumors than unscreened women. Delaying screening until age 45 or 50 will result in an unnecessary loss of life to breast cancer and adversely affects minority women in particular. Screening should continue past age 74 years, without an upper age limit unless severe comorbidities limit life expectancy. Benefits of screening should be considered along with the possibilities of recall for additional imaging and benign biopsy and the less tangible risks of anxiety and overdiagnosis. Although recall and biopsy recommendations are higher with more frequent screening, so are life-years gained and breast cancer deaths averted. Women who wish to maximize benefit will choose annual screening starting at age 40 years and will not stop screening prematurely.

The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening

Background

Women and their health care providers need a reliable answer to this important question: If a woman chooses to participate in regular mammography screening, then how much will this choice improve her chances of avoiding a death from breast cancer compared with women who choose not to participate?

Methods

To answer this question, we used comprehensive registries for population, screening history, breast cancer incidence, and disease‐specific death data in a defined population in Dalarna County, Sweden. The annual incidence of breast cancer was calculated along with the annual incidence of breast cancers that were fatal within 10 and within 11 to 20 years of diagnosis among women aged 40 to 69 years who either did or did not participate in mammography screening during a 39‐year period (1977‐2015). For an additional comparison, corresponding data are presented from 19 years of the prescreening period (1958‐1976). All patients received stage‐specific therapy according to the latest national guidelines, irrespective of the mode of detection.

Results

The benefit for women who chose to participate in an organized breast cancer screening program was a 60% lower risk of dying from breast cancer within 10 years after diagnosis (relative risk, 0.40; 95% confidence interval, 0.34‐0.48) and a 47% lower risk of dying from breast cancer within 20 years after diagnosis (relative risk, 0.53; 95% confidence interval, 0.44‐0.63) compared with the corresponding risks for nonparticipants.

Conclusions

Although all patients with breast cancer stand to benefit from advances in breast cancer therapy, the current results demonstrate that women who have participated in mammography screening obtain a significantly greater benefit from the therapy available at the time of diagnosis than do those who have not participated.

After 20 years of follow‐up, women who participate in mammography screening have a 47% lower risk of dying from breast cancer. Although all patients with breast cancer potentially can benefit from advances in breast cancer therapy, women who participate in mammography screening obtain a significantly greater benefit from the therapy available at the time of diagnosis than those who do not participate.

Double-blind placebo-controlled randomized clinical trial on the use of paracetamol for performing mammography

BACKGROUND

This study was conducted within the Goias Mastology Research Network. To verify the possibility of diminishing pain, and discomfort during the mammography using analgesic administration.

METHODS

Randomized, double-blinded, placebo controlled trial, testing paracetamol to diminish the pain, and discomfort during mammography. Three hundred patients who came for screening mammography were randomized for this study. A questionnaire with 2 parts was used: the first had questions that concerned the patient identification, and factors related to the pain during mammography; and the second asked about the scale of discomfort (no discomfort; uncomfortable; very uncomfortable; intolerable), and the pain (analogical linear scale) during the mammography. Each patient received 1000 mg of paracetamol, or placebo. Afterwards each patient filled out the second part of the questionnaire. Six patients were excluded from the analysis; this resulted in 149 in the paracetamol group, and 145 in the placebo group.

RESULTS

The 2 groups were homogenous concerning the mean of the ages, weight, height, and breast size. The mean of the pain was 3.5 in the paracetamol, and 2.8 in the placebo group (P = .12). There were fewer women experiencing mild pain in the paracetamol group when compared with those in placebo group (relative risk [RR] 0.76, confidence interval [CI] 95% 0.52-0.98). There was no significant difference between the 2 groups, according to the degrees of discomfort (P =  .69).

CONCLUSION

The use of paracetamol can reduces the mild pain for women undergoing mammography.

Breast cancer screening effect across breast density strata: A case-control study

Breast cancer screening is known to reduce breast cancer mortality. A high breast density may affect this reduction. We assessed the effect of screening on breast cancer mortality in women with dense and fatty breasts separately. Analyses were performed within the Nijmegen (Dutch) screening programme (1975-2008), which invites women (aged 50-74 years) biennially. Performance measures were determined. Furthermore, a case-control study was performed for women having dense and women having fatty breasts. Breast density was assessed visually with a dichotomized Wolfe scale. Breast density data were available for cases. The prevalence of dense breasts among controls was estimated with age-specific rates from the general population. Sensitivity analyses were performed on these estimates. Screening performance was better in the fatty than in the dense group (sensitivity 75.7% vs 57.8%). The mortality reduction appeared to be smaller for women with dense breasts, with an odds ratio (OR) of 0.87 (95% CI 0.52-1.45) in the dense and 0.59 (95% CI 0.44-0.79) in the fatty group. We can conclude that high density results in lower screening performance and appears to be associated with a smaller mortality reduction. Breast density is thus a likely candidate for risk-stratified screening. More research is needed on the association between density and screening harms.

Evaluation of a Culturally Tailored Education to Promote Breast and Cervical Cancer Screening Among Chinese-Australian Women

This paper aims to evaluate the impact of the culturally sensitive and linguistically appropriate education program on the following: (i) awareness of screening practices (breast awareness, mammogram, and Pap smear test); (ii) screening intention within the next six months; and (iii) knowledge about breast and cervical cancer among Chinese-Australian women. Titled "Happy and Healthy Life in Sydney," this was a quasi-experimental study with both pre- and post-test design. A convenience sample of 288 Chinese women was recruited through Chinese organizations such as churches and community centers. Participants completed the questionnaires before and after the educational program. The results show that the program was effective in promoting awareness of breast and cervical cancer screening and resulted in increased participative intentions in both mammogram and Pap smear testing within the next 6 months. Results also indicate that knowledge and belief scores were significantly increased.

CONCLUSION

Our study supports that educational programs which use culturally sensitive and linguistically appropriate strategies are effective in improving both knowledge of breast and cervical cancer and awareness of their early detection practices among Chinese-Australian women.