Clinical Review

Breast Cancer Screening in Older Women

Clinician Reviews. 2011 April;21(4):29, 34-39

References

1. US Preventive Services Task Force. Screening for breast cancer: US Preventive Services Task Force recommendation statement. Ann Intern Med. 2009;151(10):716-726, W-236.

2. American Cancer Society Guidelines for the Early Detection of Cancer. Breast cancer. www.cancer.org/Healthy/FindCancerEarly/Cancer ScreeningGuidelines/american-cancer-society-guidelines-for-the-early-detection-of-cancer. Accessed March 28, 2011.

3. American College of Obstetricians and Gynecologists. Response of The American College of Obstetricians and Gynecologists to New Breast Cancer Screening Recommendations from the US Preventive Services Task Force. www.acog .org/from_home/misc/uspstfresponse.cfm. Accessed March 28, 2011.

4. American Academy of Family Physicians. American Academy of Family Physicians updates breast cancer screening recommendations (2010). www.aafp.org/online/en/home/media/releases/2010b/breast-cancer-screening-recom mendations.html. Accessed March 28, 2011.

5. American Geriatrics Society Ethics Committee. Health screening decisions for older adults: AGS position paper. J Am Geriatr Soc. 2003; 51(2):270-271.

6. Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD001877.

7. Traa MJ, Meijs CM, de Jongh MA, et al. Elderly women with breast cancer often die due to other causes regardless of primary endocrine therapy or primary surgical therapy. Breast. 2011 Feb 14. [Epub ahead of print]

8. Schonberg MA, McCarthy EP. Mammography screening among women age 80 years and older: consider the risks. J Clin Oncol. 2009;27 (4):640-641.

9. Mandelblatt JS, Silliman R. Hanging in the balance: making decisions about the benefits and harms of breast cancer screening among the oldest old without a safety net of scientific evidence. J Clin Oncol. 2009;27(4):487-490.

10. National Cancer Institute. Surveillance Epidemiology and End Results, 1975-2007 (2010). Table 4.17. Cancer of the Female Breast (Ages 50+, Invasive). http://seer.cancer.gov/csr/1975_2007/browse_csr.php?section=4&page=sect_04_table.17.html. Accessed March 28, 2011.

11. National Cancer Institute. Breast Cancer Screening PDQ. Breast cancer diagnosis (2010). www.cancer.gov/cancertopics/pdq/screening/breast/HealthProfessional/page3. Accessed March 28, 2011.

12. Nyström L, Andersson I, Bjurstam N, et al. Long-term effects of mammography screening: updated overview of the Swedish randomised trials. Lancet. 2002;359(9310):909-919.

13. Walter LC, Covinsky KE. Cancer screening in elderly patients: A framework for individualized decision making. JAMA. 2001;285(21): 2750-2756.

14. Badgwell BD, Giordano SH, Duan ZZ, et al. Mammography before diagnosis among women age 80 years and older with breast cancer. J Clin Oncol. 2008;26(15):2482-2488.

15. Mathis KL, Hoskin TL, Boughey JC, et al. Palpable presentation of breast cancer persists in the era of screening mammography. J Am Coll Surg. 2010;210(3):314-318.

16. Kalager M, Zelen M, Langmark F, Adami H-O. Effect of screening mammography on breast-cancer mortality in Norway. N Engl J Med. 2010;363(13):1203-1210.

17. National Cancer Institute Breast Cancer Surveillance Consortium. Performance measures for 3,884,059 screening mammography examinations from 1996 to 2007 by age (2009). http://breastscreening.cancer.gov/data/performance/screening/perf_age.html. Accessed March 28, 2011.

18. Welch HG, Fisher ES. Diagnostic testing following screening mammography in the elderly. J Natl Cancer Inst. 1998;90(18):1389-1392.

19. Tan A, Freeman DH Jr, Goodwin JS, Freeman JL. Variation in false-positive rates of mammography reading among 1067 radiologists: a population-based assessment. Breast Cancer Res Treat. 2006;100(3):309-318.

20. Schonberg M. Breast cancer screening: at what age to stop? www.consultantlive.com/geriatrics/content/article/10162/1563530. Accessed March 28, 2011.

21. Thomas DB, Gao DL, Self SG, et al. Randomized trial of breast self-examination in Shanghai: methodology and preliminary results. J Natl Cancer Inst. 1997;89(5):355-65.

22. Semiglazov VF, Moiseyenko VM, Bavli JL, et al. The role of breast self-examination in early breast cancer detection (results of the 5-year USSR/WHO randomized study in Leningrad). Eur J Epidemiol. 1992;8(4):498-502.

23. de Koning HJ, Boer R, Warmerdam PG, et al. Quantitative interpretation of age-specific mortality reductions from the Swedish breast cancer–screening trials. J Natl Cancer Inst. 1995;87 (16):1217-1223.

24. Schonberg MA, Marcantonio ER, Li D, et al. Breast cancer among the oldest old: tumor characteristics, treatment choices, and survival. J Clin Onc. 2010;28(12):2038-2045.

25. McCarthy EP, Burns RB, Freund KM, et al. Mammography use, breast cancer stage at diagnosis, and survival among older women. J Am Ger Soc. 2000;48(10):1226-1233.

26. Smith BD, Gross CP, Smith GL, et al. Effectiveness of radiation therapy for older women with early breast cancer. J Natl Cancer Inst. 2006;98(10):681-690.

27. Walter LC, Eng C, Covinsky KE. Screening mammography for frail older women: what are the burdens? J Gen Int Med. 2001;16(11): 779-784.

28. Arias E. United States life tables, 2006. Natl Vital Stat Rep. 2010;58(21):1-40.

29. National Cancer Institute. Surveillance Epidemiology and End Results, 1975-2007 (2010). Table 4.12. Cancer of the Breast (Invasive). http://seer.cancer.gov/csr/1975_2007/browse_csr.php?section=4&page=sect_04_table.12 .html. Accessed March 21, 2011.

30. RAND Health Project. Assessing care of vulnerable elders: Vulnerable Elders Survey (VES-13, 2011). www.rand.org/health/projects/acove/survey.html. Accessed March 28, 2011.

31. Saliba S, Elliott M, Rubenstein LA, et al. The Vulnerable Elders Survey: a tool for identifying vulnerable older people in the community. J Am Geriatr Soc. 2001;49(12):1691-1699.

32. National Cancer Institute. Breast Cancer Risk Assessment Tool. www.cancer.gov/bcrisk tool. Accessed March 28, 2011.

33. Vogel VG. Breast cancer (2010). www.merck.com/mmpe/sec18/ch253/ch253e.html. Accessed March 28, 2011.

In the US, 57% of breast cancers are detected by mammography; in the remaining cases, patients present with a palpable mass or in response to other breast symptoms. Cancers detected by mammography are found at an earlier stage.¹⁵

When statisticians used several models to assess the role of screening mammography in reducing breast cancer mortality, they found that mammography has contributed to about 46% of the overall reduction in breast cancer deaths in the US during the past 20 years.¹⁶ Mammography is more effective in detecting breast cancers in older than younger women, and the number of false-positive results decreases among women of advancing age. The sensitivity and specificity of mammography for detection of breast cancer is 85% and 94%, respectively, for women ages 75 to 89.¹⁷

Although this strong specificity would seem to suggest that older women are at low risk for overdiagnosis, this is not the case. Many benign and clinically insignificant lesions are also detected through mammography, resulting in unnecessary breast biopsies. In one group of 23,000 women age 65 or older who underwent a one-time screening mammogram, 8% had an abnormal result that required additional evaluation. Among these women, only about 10% actually had cancer.¹⁸ Rates of false-positive mammographic findings vary by radiologist but are generally higher among women who are younger than 65.¹⁹

Schonberg²⁰ followed 2,011 community-dwelling women 80 and older who underwent mammography screening and found an 11% rate of false-positive results. Ductal carcinoma in situ (DCIS) is a common mammographic finding in older women. Since only one-third of these cases will convert to invasive breast cancer over 10 to 15 years, DCIS likely exemplifies overdiagnosis in older women.²⁰

Clinical Breast Exams and Self-Examination
There is insufficient evidence to determine whether clinical breast exams improve early detection and treatment outcomes in women with breast cancer. Additionally, results from two large randomized controlled trials of breast self-examination suggest that the practice is not of benefit in reducing breast cancer mortality and morbidity.^1,21,22

Age, Breast Cancer Types, and Outcomes
It has been suggested that older women may be subject to less aggressive cancers and thus be more vulnerable to overdiagnosis.²³ Schonberg et al²⁴ evaluated SEER data to determine the tumor characteristics, treatments, and outcomes in women 80 and older, compared with women ages 67 to 79. They found no difference in tumor grade or hormone receptivity between these groups. It is important to note that women older than 80 were significantly more likely than younger women to die of breast cancer, perhaps in part because the older patients were less likely to receive aggressive treatment (see “Breast Cancer Treatment in Older Women”^24-26).

Women between ages 74 and 85 who undergo regular mammographic screenings have been shown to have half the risk for breast cancer–related death, compared with those who are not screened.²⁵ However, risks have been shown to outweigh benefits when mammography is continued into old age without regard to life expectancy.

Walter et al²⁷ studied a group of 216 frail, nursing home–eligible older women who had had at least one mammogram. Seventeen percent had abnormal results, and most opted for further evaluation with breast biopsy. Of these biopsies, 23% yielded positive results, and of these, 75% revealed invasive breast cancer; the remaining 25% of women had DCIS.

All of the women with abnormal biopsy results underwent surgical treatment, but half died of other causes or experienced surgical complications. The investigators found that 1% of the women may have received some benefit from screening, but more women experienced harm as a result of the mammogram and subsequent procedures. The study authors, along with almost all clinicians who have written on this topic, agree that mammography is inappropriate for frail, elderly women with less than five years’ life expectancy.²⁷

Expert Guideline Recommendations
Provider recommendation has been found to be the most important factor in older women’s decisions to have or forego a mammogram.⁸ Unfortunately, there is little clear, decisive support for providers to help women make this decision. The summary of breast cancer screening recommendations for older women shown in the table reveals that no consensus exists among the expert panels regarding the best approach. In part, these discrepancies can be explained by the low numbers of women older than 75 who have been included in clinical trials evaluating the risks and benefits of mammography screening.

Helpful Criteria for Breast Cancer Screening Decisions
In 2003, the American Geriatrics Society Ethics Committee published a set of basic rules to guide decision making regarding screening tests.⁵ These include the following:

• In patients with a limited life expectancy, focus should be on treatments that are likely to offer immediate benefit