General Information About Breast Cancer

Incidence and Mortality
Genetic Characteristics and Risk Factors
Screening
Patient Evaluation
Prognostic and Predictive Factors
Contralateral Disease
Hormone Replacement Therapy
Breast Reconstruction
Follow-up
Related Summaries

This summary discusses only primary epithelial breast cancers. Rarely, the breast may be involved by other tumors such as lymphomas, sarcomas, or melanomas. (Refer to the PDQ summaries on Adult Hodgkin Lymphoma Treatment, Adult Soft Tissue Sarcoma Treatment, and Melanoma Treatment for more information.)

Estimated new cases and deaths from breast cancer (women only) in the United States in 2012:[1]

• New cases: 226,870.
• Deaths: 39,510.

Several well-established factors have been associated with an increased risk of breast cancer, including family history, nulliparity, early menarche, advanced age, and a personal history of breast cancer (in situ or invasive).

Age-specific risk estimates are available to help counsel and design screening strategies for women with a family history of breast cancer.[2,3] Of all women with breast cancer, 5% to 10% may have a germ-line mutation of the genes BRCA1 and BRCA2.[4] Specific mutations of BRCA1 and BRCA2 are more common in women of Jewish ancestry.[5] The estimated lifetime risk of developing breast cancer for women with BRCA1 and BRCA2 mutations is 40% to 85%. Carriers with a history of breast cancer have an increased risk of contralateral disease that may be as great as 5% per year.[6] Ma le carriers of BRCA2 mutations are also at increased risk for breast cancer.[7]

Mutations in either the BRCA1 or BRCA2 gene also confer an increased risk of ovarian cancer.[7-9] In addition, mutation carriers may be at increased risk of other primary cancers.[7,9] Genetic testing is available to detect mutations in members of high-risk families.[10-14] Such individuals should first be referred for counseling.[15] (Refer to the PDQ summaries on Genetics of Breast and Ovarian Cancer; Breast Cancer Prevention; and Breast Cancer Screening for more information.)

Clinical trials have established that screening with mammography, with or without clinical breast examination, may decrease breast cancer mortality. (Refer to the PDQ summary on Breast Cancer Screening for more information.)

Patient management following initial suspicion of breast cancer generally includes confirmation of the diagnosis, evaluation of stage of disease, and selection of therapy. At the time the tumor tissue is surgically removed, estrogen receptor (ER) and progesterone receptor (PR) status should be determined.

Breast cancer is commonly treated by various combinations of surgery, radiation therapy, chemotherapy, and hormone therapy. Prognosis and selection of therapy may be influenced by the following clinical and pathology features (based on conventional histology and immunohistochemistry):[16]

• The age and menopausal status of the patient.
• The stage of the disease.
• The histologic and nuclear grade of the primary tumor.
• The ER and PR status of the tumor.
• Human epidermal growth factor type 2 receptor (HER2/neu) overexpression.
• Proliferative capacity of the tumor (e.g., Ki67).

Molecular profiling has led to classification of breast cancer into the following five distinct subtypes:[17,18]

• Basal-like.
• HER2+.
• Normal.
• Luminal A.
• Luminal B.

The use of molecular profiling in breast cancer includes the following:[17,18]

• ER and PR status testing.
• HER2/neu receptor status testing.
• Gene profile testing by microarray assay or reverse transcription-polymerase chain reaction (e.g., MammaPrint, Oncotype DX).

Although certain rare inherited mutations, such as those of BRCA1 and BRCA2, predispose women to develop breast cancer, prognostic data on BRCA1/BRCA2 mutation carriers who have developed breast cancer are conflicting; these women are at greater risk of developing contralateral breast cancer. Since criteria for menopausal status vary widely, some studies have substituted age older than 50 years as a surrogate for the postmenopausal state. Breast cancer is classified into a variety of histologic types, some of which have prognostic importance. For example, favorable histologic types include mucinous, medullary, and tubular carcinoma.[19-21]

Pathologically, breast cancer can be a multicentric and bilateral disease. Bilateral disease is somewhat more common in patients with infiltrating lobular carcinoma. Patients who have breast cancer should have bilateral mammography at the time of diagnosis to rule out synchronous disease. The role of magnetic resonance imaging (MRI) in screening and follow-up continues to evolve. Having demonstrated an increased detection rate of mammographically occult disease, the selective use of MRI for additional screening is being used with increased frequency despite the absence of randomized, controlled data. Because only 25% of MRI-positive findings represent malignancy, pathologic confirmation prior to treatment action is recommended. Whether this increased detection rate will translate into improved treatment outcome is unknown.[22-24] When BRCA1/BRCA2 mutation carriers were diagnosed at a young age, the risk of a contralateral breast cancer reached nearly 50% in the ensuing 25 years.[25,26]

Patients should continue to have regular breast physical examinations and mammography to detect either recurrence in the ipsilateral breast in those patients treated with breast-conserving surgery or a second primary cancer in the contralateral breast.[27] The risk of a primary breast cancer in the contralateral breast is approximately 1% per year.[28,29] Patient age younger than 55 years at the time of diagnosis or lobular tumor histology appear to increase this risk to 1.5%.[30] The development of a contralateral breast cancer is associated with an increased risk of distant recurrence.[31,32]

The use of hormone replacement therapy (HRT) poses a dilemma for the rising numbers of breast cancer survivors, many of whom enter menopause prematurely as a result of therapy. HRT has generally not been used for women with a history of breast cancer because estrogen is a growth factor for most breast cancer cells in the laboratory; however, empiric data on the safety of HRT after breast cancer are limited.[33,34]

Two randomized trials (including Regional Oncologic Center-Hormonal Replacement Therapy After Breast Cancer--Is It Safe [ROC-HABITS]) comparing HRT with no hormonal supplementation have been reported.[35,36] The first trial included 345 evaluable breast cancer patients with menopausal symptoms and was terminated early because of an increased incidence of recurrences and new primaries in the HRT group (hazard ratio [HR], 3.5; 95% confidence interval [CI], 1.5–7.4).[35][Level of evidence: 1iiDii] In total, 26 women in the HRT group and 7 in the non-HRT group developed recurrences or new primaries. This study, however, was not double blinded, and it is possible that patients on HRT were monitored more closely. Because of the results of the first trial, the second trial, which was conducted under a joint steering committee with the first, closed prematurely after the enrollment of 378 patients.[36] With a median follow-up of 4.1 years, there were 11 recurrences in the hormone replacement group and 13 recurrences in the patients assigned to no hormone replacement (HR, 0.82; 95% CI, 0.35–1.9).[36][Level of evidence: 1iiDii] The trials differed in several ways;[37] however, until further data become available, decisions concerning the use of HRT in patients with breast cancer will have to be based on the results of these studies and on inferences from the impact of HRT use on breast cancer risk in other settings.[37] A comprehensive intervention, including education, counseling, and nonhormonal drug therapy, has been shown to reduce menopausal symptoms and to improve sexual functioning in breast cancer survivors.[38][Level of evidence: 1iiC] (Refer to the PDQ summaries on Fever, Sweats, and Hot Flashes and Sexuality and Reproductive Issues for more information.)

For patients who opt for a total mastectomy, reconstructive surgery may be used at the time of the mastectomy (immediate reconstruction) or at some subsequent time (delayed reconstruction).[39-42] Breast contour can be restored by the submuscular insertion of an artificial implant (saline-filled) or a rectus muscle or other flap. If a saline implant is used, a tissue expander can be inserted beneath the pectoral muscle. Saline is injected into the expander to stretch the tissues for a period of weeks or months until the desired volume is obtained. The tissue expander is replaced by a permanent implant. (Visit the FDA's Web site for more information on breast implants.) Rectus muscle flaps require a considerably more complicated and prolonged operative procedure, and blood transfusions may be required.

Following breast reconstruction, radiation therapy can be delivered to the chest wall and regional nodes either in the adjuvant setting or if local disease recurs. Radiation therapy following reconstruction with a breast prosthesis may affect cosmesis, and the incidence of capsular fibrosis, pain, or the need for implant removal may be increased.[43]

Evidence from randomized trials indicates that periodic follow-up with bone scans, liver sonography, chest x-rays, and blood tests of liver function does not improve survival or quality of life when compared to routine physical examinations.[44-46] Even when these tests permit earlier detection of recurrent disease, patient survival is unaffected.[45] Based on these data, some investigators recommend that acceptable follow-up be limited to physical examination and annual mammography for asymptomatic patients who complete treatment for stage I to stage III breast cancer. The frequency of follow-up and the appropriateness of screening tests after the completion of primary treatment for stage I to breast cancer remain controversial.

Other PDQ summaries containing information related to breast cancer include the following:

• Breast Cancer Prevention
• Breast Cancer Screening
• Breast Cancer Treatment and Pregnancy
• Genetics of Breast and Ovarian Cancer
• Male Breast Cancer Treatment
• Unusual Cancers of Childhood Treatment (breast cancer in children)

References

1. American Cancer Society.: Cancer Facts and Figures 2012. Atlanta, Ga: American Cancer Society, 2012. Available online. Last accessed September 24, 2012. 
   
   
2. Claus EB, Risch N, Thompson WD: Autosomal dominant inheritance of early-onset breast cancer. Implications for risk prediction. Cancer 73 (3): 643-51, 1994.  [PUBMED Abstract]
   
   
3. Gail MH, Brinton LA, Byar DP, et al.: Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst 81 (24): 1879-86, 1989.  [PUBMED Abstract]
   
   
4. Blackwood MA, Weber BL: BRCA1 and BRCA2: from molecular genetics to clinical medicine. J Clin Oncol 16 (5): 1969-77, 1998.  [PUBMED Abstract]
   
   
5. Offit K, Gilewski T, McGuire P, et al.: Germline BRCA1 185delAG mutations in Jewish women with breast cancer. Lancet 347 (9016): 1643-5, 1996.  [PUBMED Abstract]
   
   
6. Frank TS, Manley SA, Olopade OI, et al.: Sequence analysis of BRCA1 and BRCA2: correlation of mutations with family history and ovarian cancer risk. J Clin Oncol 16 (7): 2417-25, 1998.  [PUBMED Abstract]
   
   
7. Cancer risks in BRCA2 mutation carriers. The Breast Cancer Linkage Consortium. J Natl Cancer Inst 91 (15): 1310-6, 1999.  [PUBMED Abstract]
   
   
8. Miki Y, Swensen J, Shattuck-Eidens D, et al.: A strong candidate for the breast and ovarian cancer susceptibility gene BRCA1. Science 266 (5182): 66-71, 1994.  [PUBMED Abstract]
   
   
9. Ford D, Easton DF, Bishop DT, et al.: Risks of cancer in BRCA1-mutation carriers. Breast Cancer Linkage Consortium. Lancet 343 (8899): 692-5, 1994.  [PUBMED Abstract]
   
   
10. Biesecker BB, Boehnke M, Calzone K, et al.: Genetic counseling for families with inherited susceptibility to breast and ovarian cancer. JAMA 269 (15): 1970-4, 1993.  [PUBMED Abstract]
    
    
11. Hall JM, Lee MK, Newman B, et al.: Linkage of early-onset familial breast cancer to chromosome 17q21. Science 250 (4988): 1684-9, 1990.  [PUBMED Abstract]
    
    
12. Easton DF, Bishop DT, Ford D, et al.: Genetic linkage analysis in familial breast and ovarian cancer: results from 214 families. The Breast Cancer Linkage Consortium. Am J Hum Genet 52 (4): 678-701, 1993.  [PUBMED Abstract]
    
    
13. Berry DA, Parmigiani G, Sanchez J, et al.: Probability of carrying a mutation of breast-ovarian cancer gene BRCA1 based on family history. J Natl Cancer Inst 89 (3): 227-38, 1997.  [PUBMED Abstract]
    
    
14. Hoskins KF, Stopfer JE, Calzone KA, et al.: Assessment and counseling for women with a family history of breast cancer. A guide for clinicians. JAMA 273 (7): 577-85, 1995.  [PUBMED Abstract]
    
    
15. Statement of the American Society of Clinical Oncology: genetic testing for cancer susceptibility, Adopted on February 20, 1996. J Clin Oncol 14 (5): 1730-6; discussion 1737-40, 1996.  [PUBMED Abstract]
    
    
16. Simpson JF, Gray R, Dressler LG, et al.: Prognostic value of histologic grade and proliferative activity in axillary node-positive breast cancer: results from the Eastern Cooperative Oncology Group Companion Study, EST 4189. J Clin Oncol 18 (10): 2059-69, 2000.  [PUBMED Abstract]
    
    
17. Sørlie T, Perou CM, Tibshirani R, et al.: Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications. Proc Natl Acad Sci U S A 98 (19): 10869-74, 2001.  [PUBMED Abstract]
    
    
18. Perou CM, Sørlie T, Eisen MB, et al.: Molecular portraits of human breast tumours. Nature 406 (6797): 747-52, 2000.  [PUBMED Abstract]
    
    
19. Rosen PP, Groshen S, Kinne DW: Prognosis in T2N0M0 stage I breast carcinoma: a 20-year follow-up study. J Clin Oncol 9 (9): 1650-61, 1991.  [PUBMED Abstract]
    
    
20. Diab SG, Clark GM, Osborne CK, et al.: Tumor characteristics and clinical outcome of tubular and mucinous breast carcinomas. J Clin Oncol 17 (5): 1442-8, 1999.  [PUBMED Abstract]
    
    
21. Rakha EA, Lee AH, Evans AJ, et al.: Tubular carcinoma of the breast: further evidence to support its excellent prognosis. J Clin Oncol 28 (1): 99-104, 2010.  [PUBMED Abstract]
    
    
22. Lehman CD, Gatsonis C, Kuhl CK, et al.: MRI evaluation of the contralateral breast in women with recently diagnosed breast cancer. N Engl J Med 356 (13): 1295-303, 2007.  [PUBMED Abstract]
    
    
23. Solin LJ, Orel SG, Hwang WT, et al.: Relationship of breast magnetic resonance imaging to outcome after breast-conservation treatment with radiation for women with early-stage invasive breast carcinoma or ductal carcinoma in situ. J Clin Oncol 26 (3): 386-91, 2008.  [PUBMED Abstract]
    
    
24. Morrow M: Magnetic resonance imaging in the breast cancer patient: curb your enthusiasm. J Clin Oncol 26 (3): 352-3, 2008.  [PUBMED Abstract]
    
    
25. Graeser MK, Engel C, Rhiem K, et al.: Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers. J Clin Oncol 27 (35): 5887-92, 2009.  [PUBMED Abstract]
    
    
26. Garber JE, Golshan M: Contralateral breast cancer in BRCA1/BRCA2 mutation carriers: the story of the other side. J Clin Oncol 27 (35): 5862-4, 2009.  [PUBMED Abstract]
    
    
27. Orel SG, Troupin RH, Patterson EA, et al.: Breast cancer recurrence after lumpectomy and irradiation: role of mammography in detection. Radiology 183 (1): 201-6, 1992.  [PUBMED Abstract]
    
    
28. Rosen PP, Groshen S, Kinne DW, et al.: Factors influencing prognosis in node-negative breast carcinoma: analysis of 767 T1N0M0/T2N0M0 patients with long-term follow-up. J Clin Oncol 11 (11): 2090-100, 1993.  [PUBMED Abstract]
    
    
29. Gustafsson A, Tartter PI, Brower ST, et al.: Prognosis of patients with bilateral carcinoma of the breast. J Am Coll Surg 178 (2): 111-6, 1994.  [PUBMED Abstract]
    
    
30. Broët P, de la Rochefordière A, Scholl SM, et al.: Contralateral breast cancer: annual incidence and risk parameters. J Clin Oncol 13 (7): 1578-83, 1995.  [PUBMED Abstract]
    
    
31. Healey EA, Cook EF, Orav EJ, et al.: Contralateral breast cancer: clinical characteristics and impact on prognosis. J Clin Oncol 11 (8): 1545-52, 1993.  [PUBMED Abstract]
    
    
32. Heron DE, Komarnicky LT, Hyslop T, et al.: Bilateral breast carcinoma: risk factors and outcomes for patients with synchronous and metachronous disease. Cancer 88 (12): 2739-50, 2000.  [PUBMED Abstract]
    
    
33. Cobleigh MA, Berris RF, Bush T, et al.: Estrogen replacement therapy in breast cancer survivors. A time for change. Breast Cancer Committees of the Eastern Cooperative Oncology Group. JAMA 272 (7): 540-5, 1994.  [PUBMED Abstract]
    
    
34. Roy JA, Sawka CA, Pritchard KI: Hormone replacement therapy in women with breast cancer. Do the risks outweigh the benefits? J Clin Oncol 14 (3): 997-1006, 1996.  [PUBMED Abstract]
    
    
35. Holmberg L, Anderson H; HABITS steering and data monitoring committees.: HABITS (hormonal replacement therapy after breast cancer--is it safe?), a randomised comparison: trial stopped. Lancet 363 (9407): 453-5, 2004.  [PUBMED Abstract]
    
    
36. von Schoultz E, Rutqvist LE; Stockholm Breast Cancer Study Group.: Menopausal hormone therapy after breast cancer: the Stockholm randomized trial. J Natl Cancer Inst 97 (7): 533-5, 2005.  [PUBMED Abstract]
    
    
37. Chlebowski RT, Anderson GL: Progestins and recurrence in breast cancer survivors. J Natl Cancer Inst 97 (7): 471-2, 2005.  [PUBMED Abstract]
    
    
38. Ganz PA, Greendale GA, Petersen L, et al.: Managing menopausal symptoms in breast cancer survivors: results of a randomized controlled trial. J Natl Cancer Inst 92 (13): 1054-64, 2000.  [PUBMED Abstract]
    
    
39. Feller WF, Holt R, Spear S, et al.: Modified radical mastectomy with immediate breast reconstruction. Am Surg 52 (3): 129-33, 1986.  [PUBMED Abstract]
    
    
40. Cunningham BL: Breast reconstruction following mastectomy. In: Najarian JS, Delaney JP, eds.: Advances in Breast and Endocrine Surgery. Chicago, Ill: Year Book Medical Publishers, 1986, pp 213-226. 
    
    
41. Scanlon EF: The role of reconstruction in breast cancer. Cancer 68 (5 Suppl): 1144-7, 1991.  [PUBMED Abstract]
    
    
42. Hang-Fu L, Snyderman RK: State-of-the-art breast reconstruction. Cancer 68 (5 Suppl): 1148-56, 1991.  [PUBMED Abstract]
    
    
43. Kuske RR, Schuster R, Klein E, et al.: Radiotherapy and breast reconstruction: clinical results and dosimetry. Int J Radiat Oncol Biol Phys 21 (2): 339-46, 1991.  [PUBMED Abstract]
    
    
44. Impact of follow-up testing on survival and health-related quality of life in breast cancer patients. A multicenter randomized controlled trial. The GIVIO Investigators. JAMA 271 (20): 1587-92, 1994.  [PUBMED Abstract]
    
    
45. Rosselli Del Turco M, Palli D, Cariddi A, et al.: Intensive diagnostic follow-up after treatment of primary breast cancer. A randomized trial. National Research Council Project on Breast Cancer follow-up. JAMA 271 (20): 1593-7, 1994.  [PUBMED Abstract]
    
    
46. Khatcheressian JL, Wolff AC, Smith TJ, et al.: American Society of Clinical Oncology 2006 update of the breast cancer follow-up and management guidelines in the adjuvant setting. J Clin Oncol 24 (31): 5091-7, 2006.  [PUBMED Abstract]