Impact of Screening Mammography on Mortality from Breast Cancer

            Despite being clinical screenings, including annual screening mammography and other treatments, being named the most effective method for reducing mortality and detecting early cancers by the United States Preventative Services Task Force (Greco et al., 2009), there is great difficulty in determining the actual efficacy of the technique on mortality rates (Spencer et al., 2004). The difficulty lies in separating the effect of screening on the actual mortality rates of detected cancers versus its effect on the time of detection, what researchers refer to as the lead-time bias (Spencer et al., 2004). Also, any longitudinal study faces the issue that as medical science improves, long-term survival rates for cancer patients improves as well. The sample becomes contaminated as the researchers cannot separate survival due to better screening or due to better treatment (Marshall, 2005).

            This leads us to the research question: what is the effect of screening mammography on breast cancer mortality?

Theoretical Framework

            Many of the studies reviewed focusing on the level of patient knowledge about various screening techniques and patient expectations of their effectiveness. Since breast cancer primarily occurs in women, and screening mammography is generally done routinely only for women, a perception of its effectiveness should be examined under Madeleine Leininger’s theory of transcultural nursing. Women in and of themselves could be considered a cultural group, and they are also subject to high levels of pressures on their behavior due to their cultural environment.

            Cultural care requires making allowances for the age, ethnic background, and other personal background characteristics of a patient (Hammerschmidt, Zagonel, and Lenardt, 2007). Breast cancer screening effectiveness must be looked at through the eyes of the women in different cultures, generations, racial and ethnic backgrounds, and income brackets (Shyyan et al., 2006; Wujcik et al., 2009), as the usage of screening treatments by all of these women is integral to the success of any study.

Research Methodology

            The determination of effectiveness requires quantitative analysis of numerical data. The literature research method should therefore focus on finding such statistics, but also ensuring that such statistics are comparable. Data from different age groups, for example, should not be analyzed together without allowances for that variance.

            CINAHL was searched for articles that contained the phrases “breast cancer”, “screening mammography”, and “breast cancer mortality”. The search was limited to articles since 2001. Additionally, Google Scholar was used to locate articles and information about the Leininger theory of cultural care. All sources used are from peer-reviewed medical and nursing journals to ensure the quality of the research.

Review of Literature

            Two major types of studies exist about screening mammography: attempts to determine, empirically, the success of screening techniques, and the general perception of the treatments among the target population. Since the success of a treatment requires both the treatment to work and for patients to make use of it, these are both vital parts of determining the effect of screening mammography on breast cancer mortality.

Empirical Screening Effectiveness

            According to Behavioral Factor Surveillance System, 63% of women receive the recommended breast cancer screenings in the United States. And of those who receive the regular screenings but still end up dying of the disease, they are on average eight years older at death than those who do not receive routine screenings (Spencer et al., 2003). While this does not show that the screening reduced mortality, it does decrease the number of years of life lost to cancer.

            Additional support for the reduction of mortality by screening mammography is found by the same Spencer et al study. They found that “57% of fatal cancers occurred in women who had never had a screening mammogram” (2003) and that 73% of the patients in the study who died of the disease were not taking part in a recommended biannual screening program.

            However, 15% of the cancers in the study were found by palpation during a screening interval. Those women were following a defined screening program and still developed an eventually fatal breast cancer. In fact, median tumor size at diagnosis was largest for women with interval cancers. Only 12% of the cancers in the study that eventually resulted in the patient’s death were non-palpable and detectable only by mammogram (Spencer et al., 2003). If 1000 women over the age of 40 currently begin a mammography screening problem, 17 of them will still be diagnosed with and die from breast cancer before the age of 75. Also, screening has been determined to have no effect on mortality at all for the first five years (Marshall, 2005).

            The effectiveness of screening mammography is greatly reduced by delay in treatment after the detection of an abnormality. A delay as short as sixty days from the original finding could have major consequences if the abnormality is eventually determined to be cancer (Wujcik et al., 2009).

            Another reason for the effectiveness of breast screening mammography is that it provides an assessment indicating overall breast health in the patient. Abnormalities in just one breast indicate a need for further study of both breasts. In cases where regular screening is not feasible, as in low-income countries, mammography can at least allow study of the extent of diagnosed cancerous growths within the breast. This determination can allow safer and more effective surgeries, increasing rates of patient survival and breast tissue conservation (Shyyan et al., 2005).

Patient Perception Studies

            Even the most impressive treatments will be unsuccessful if patients do not seek them out. For this reason, an understand patient perception of treatments, especially routine ones such as screenings, is vital to understanding the success rate of a given treatment.

            Clearly, more work is necessary to ensure that women are informed about screening mammography. Ensuring the patients are informed, and that their treatment preferences are met based on this information is key to the cross-cultural theory of care; information is key to the relationship between the caretaker and patient. Even among college educated women, knowledge about various screening methods and risks for breast cancer is limited (Vahabi, 2005). Vahabi and Gastalado, in a separate study, note that the lack of information about screening treatments it has been credited as a cause of the low use of those treatments. Their study indicated that women are inordinately reliant on the opinions of experts as to whether they require screening mammography, but a single anecdotal experience from someone they can cause distrust of the treatment (2003). Many women do not begin screening programs until a close friend or relative is diagnosed, again indicating that women prefer personal anecdotes to clinical recommendations (Greco et al., 2009).

            Further evidence for women’s lack of information and trust of clinical examinations is showed in that women who do not have palpable lumps or other self-reported symptoms do not seek follow-up treatment as rapidly as those who have self-reported symptoms (Wujcik et al., 2009). Unless they can confirm it for themselves, they may not trust what their doctor’s clinical screening determines. This could indicate that self-examination, for example, may be a better technique on which to focus public service dollars for informing patients.

            A possibility for increasing trust, and potentially increasing the effectiveness of screening programs, is to increase openness about the possibility of failure of the process (Marshall, 2005). Providers who discuss screening mammography with their patients often, more than 93% of the time, do not mention that the procedure has risks, and less than 23% of the time even discuss the uncertainties (Nekhlyudov, Li, and Fletcher, 2008). Women who are presented with a more balanced view of mammography may react less extremely to negative anecdotes (Marshall, 2005). For example, only about 13% of women are aware of the possibility of false-negatives and false-positives in screening mammographies; if they knew that physicians expected such results, they might not refuse a screening because they “know someone” who had a positive screening but no cancer or a negative screening but a later diagnosed interval cancer (Nekhlyudov, Li, and Fletcher, 2008). Teaching unmitigated trust in the success of mammography leads to fear when a repeated screening is required, or even if the test results are merely delayed in being returned to the patient (Greco et al., 2009). It is possible an at-risk patient could avoid setting up regular screenings to avoid that fear, especially if she has been subject to several such false positives.

            Returning to the cross-culture theory of care, another area of perception of breast mammography in the Vahabi and Gastalado study was culturally related (2003). Cultural experiences can have a large effect on the intention of the patient to begin or continue a screening regime. For example, many women believe that prayer or religious belief will cure their cancer if it not time for them to die. Many women reported that the exposure of their breasts to a physician violates a personal or community belief about their modesty. Some from the other end of the continuumwomen avoid screening mammography because they feel it de-sexualizes their breasts simply to have the test done, or focuses their attention on the fact that part of their sexuality may need to be removed (Vahabi and Gastalado, 2003).

            Race and ethnicity, especially for African-American and Hispanic women, also consistently correlates with a delay in treatment, indicating a cultural resistance to seeking treatment. This is especially true since the Wujcik study was only on women below the poverty line and difference in access to treatment does not apply (2009).

Conclusion

            No screening process is perfect, and a screening treatment does not stop or reverse the growth of a cancer. Despite conflicting findings, no researcher suggests that screening mammography should not be recommended. There is little conclusive evidence if the screening process alone reduces mortality among breast cancer patients, but it definitely increases the number of cancers that are caught in their early stages and so may be treated with less invasive methods. Screening mammography is definitely improves quality of life, and reduces years of life lost to cancer.

            While perception of treatment may seem unrelated to the research question about mortality, no screening process can work unless it is first sought out, and then follow-up treatment is received. A patient must believe they need such screenings, be willing to undergo them, have access to them, trust their physician’s finding, and seek follow-up care. Research shows that on every level, women who should be continuing on a treatment program instead follow personal or cultural beliefs leading them not to seek care. These women then add to the mortality rate for breast cancer, as women who are not treated generally do not survive the cancer.

References;

• Greco, K. E., Nail, L. M., Kendall, J., Cartwright, J., & Messecar, D. C. (2010). Mammography decision making in older women with a breast cancer family history. Journal of Nursing Scholarship, 42(3), 348-356.
• Hammerschmidt, K.. S. de A., Zagonel, I. P. S., & Lenardt, M. H. (2007, July). A critical analysis of gerontological nursing practice guided by Leininger’s theory of culture care diversity and universaity. Acta Paulista de Enfermagen, 20(3), 362-367.
• Marshall, T. (2005). Informed consent for mammography screening: modelling the risks and benefits for American women. Health Expectations, 8, 295-305.
• Shyyan, R., Masood, S., Badwe, R. A., Errico, K. M., Liberman, L., Ozmen, V., & Stalsberg, H. (2006). Breast cancer in limited-resource countries: Diagnosis and pathology. The Breast Journal, 12(S1), S27-S37.
• Spencer, D. B., Potter, J. E., Chung, M. A., Fulton, J., Hebert, W., & Cady, B. (2004). Mammographic Screening and Disease Presentation of breast cancer patients who die of disease. The Breast Journal, 10(4), 298-303.
• Vahabi, M., & Gastaldo, D. (2003). Rational choice(s)? Rethinking decision-making on breast cancer risk and screening mammography. Nursing Inquiry, 10(4), 245-256.
• Vahabi, M. (2005). Knowledge of breast cancer and screening practices. Health Education  Journal, 64(218), 218-228.
• Wujcik, D., Shyr, Y., Li, M., Clayton, M. F., Ellington, L., Menon, U., & Mooni, K. (2009, November). Delay in diagnostic testing after abnormal mammography in low-income  women. Oncology Nursing Forum, 36(6), 709-718.