Breast Cancer Treatment (PDQ®)–Health Professional Version

General Information About Breast Cancer

This summary discusses primary epithelial breast cancers in women. The breast is rarely affected by other tumors such as lymphomas, sarcomas, or melanomas. Refer to the following PDQ summaries for more information on these cancer types:

  • Adult Hodgkin Lymphoma Treatment
  • Adult Soft Tissue Sarcoma Treatment
  • Melanoma Treatment

Breast cancer also affects men and children and may occur during pregnancy, although it is rare in these populations. Refer to the following PDQ summaries for more information:

  • Male Breast Cancer Treatment
  • Breast Cancer Treatment During Pregnancy
  • Unusual Cancers of Childhood Treatment

Incidence and Mortality

Estimated new cases and deaths from breast cancer (women only) in the United States in 2018:[1]

  • New cases: 268,670.
  • Deaths: 41,400.

Breast cancer is the most common noncutaneous cancer in U.S. women, with an estimated 63,960 cases of in situ disease and 266,120 cases of invasive disease in 2018.[1] Thus, fewer than one of six women diagnosed with breast cancer die of the disease. By comparison, it is estimated that about 70,500 American women will die of lung cancer in 2018.[1] Men account for 1% of breast cancer cases and breast cancer deaths (refer to the Special Populations section in the PDQ summary on Breast Cancer Screening for more information).

Widespread adoption of screening increases breast cancer incidence in a given population and changes the characteristics of cancers detected, with increased incidence of lower-risk cancers, premalignant lesions, and ductal carcinoma in situ (DCIS). (Refer to the Ductal carcinoma in situ (DCIS) section in the Pathologic Evaluation of Breast Tissue section in the PDQ summary on Breast Cancer Screening for more information.) Population studies from the United States [2] and the United Kingdom [3] demonstrate an increase in DCIS and invasive breast cancer incidence since the 1970s, attributable to the widespread adoption of both postmenopausal hormone therapy and screening mammography. In the last decade, women have refrained from using postmenopausal hormones, and breast cancer incidence has declined, but not to the levels seen before the widespread use of screening mammography.[4]

Anatomy

ENLARGEDrawing of female breast anatomy showing  the lymph nodes, nipple, areola, chest wall, ribs, muscle, fatty tissue, lobe, ducts, and lobules.
Anatomy of the female breast. The nipple and areola are shown on the outside of the breast. The lymph nodes, lobes, lobules, ducts, and other parts of the inside of the breast are also shown.

Risk Factors

Increasing age is the most important risk factor for most cancers. Other risk factors for breast cancer include the following:

  • Family health history.[5]
  • Major inheritance susceptibility.[6,7]
    • Germline mutation of the BRCA1 and BRCA2 genes and other breast cancer susceptibility genes.[8,9]
  • Alcohol intake.
  • Breast tissue density (mammographic).[10]
  • Estrogen (endogenous).[11-13]
    • Menstrual history (early menarche/late menopause).[14,15]
    • Nulliparity.
    • Older age at first birth.
  • Hormone therapy history.
    • Combination estrogen plus progestin hormone replacement therapy.
  • Obesity (postmenopausal).[16]
  • Personal history of breast cancer.[17]
  • Personal history of benign breast disease (BBD) (proliferative forms of BBD).[18-20]
  • Radiation exposure to breast/chest.[21]

Age-specific risk estimates are available to help counsel and design screening strategies for women with a family history of breast cancer.[22,23]

Of all women with breast cancer, 5% to 10% may have a germline mutation of the genes BRCA1 and BRCA2.[24] Specific mutations of BRCA1 and BRCA2 are more common in women of Jewish ancestry.[25] 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 high as 5% per year.[26] Male BRCA2 mutation carriers also have an increased risk of breast cancer.[27]

Mutations in either the BRCA1 or the BRCA2 gene also confer an increased risk of ovarian cancer [27,28] or other primary cancers.[27,28] Once a BRCA1 or BRCA2 mutation has been identified, other family members can be referred for genetic counseling and testing.[29-32] (Refer to the PDQ summaries on Genetics of Breast and Gynecologic Cancers; Breast Cancer Prevention; and Breast Cancer Screening for more information.)

(Refer to the PDQ summary on Breast Cancer Prevention for more information about factors that increase the risk of breast cancer.)

Protective Factors

Protective factors and interventions to reduce the risk of female breast cancer include the following:

  • Estrogen use (after hysterectomy).[33-35]
  • Exercise.[36-38]
  • Early pregnancy.[39-41]
  • Breast feeding.[42]
  • Selective estrogen receptor modulators (SERMs).[43]
  • Aromatase inhibitors or inactivators.[44,45]
  • Risk-reducing mastectomy.[46]
  • Risk-reducing oophorectomy or ovarian ablation.[47-50]

(Refer to the PDQ summary on Breast Cancer Prevention for more information about factors that decrease the risk of breast cancer.)

Screening

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

Diagnosis

Patient evaluation

When breast cancer is suspected, patient management generally includes the following:

  • Confirmation of the diagnosis.
  • Evaluation of the stage of disease.
  • Selection of therapy.

The following tests and procedures are used to diagnose breast cancer:

  • Mammography.
  • Ultrasound.
  • Breast magnetic resonance imaging (MRI), if clinically indicated.
  • Biopsy.

Contralateral disease

Pathologically, breast cancer can be a multicentric and bilateral disease. Bilateral disease is somewhat more common in patients with infiltrating lobular carcinoma. At 10 years after diagnosis, the risk of a primary breast cancer in the contralateral breast ranges from 3% to 10%, although endocrine therapy decreases that risk.[51-53] The development of a contralateral breast cancer is associated with an increased risk of distant recurrence.[54] When BRCA1/BRCA2 mutation carriers were diagnosed before age 40 years, the risk of a contralateral breast cancer reached nearly 50% in the ensuing 25 years.[55,56]

Patients who have breast cancer will undergo bilateral mammography at the time of diagnosis to rule out synchronous disease. To detect either recurrence in the ipsilateral breast in patients treated with breast-conserving surgery or a second primary cancer in the contralateral breast, patients will continue to have regular breast physical examinations and mammograms.

The role of MRI in screening the contralateral breast and monitoring women treated with breast-conserving therapy continues to evolve. Because an increased detection rate of mammographically occult disease has been demonstrated, the selective use of MRI for additional screening is occurring more frequently despite the absence of randomized, controlled data. Because only 25% of MRI-positive findings represent malignancy, pathologic confirmation before treatment is recommended. Whether this increased detection rate will translate into improved treatment outcome is unknown.[57-59]

Prognostic and Predictive Factors

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):[60]

  • Menopausal status of the patient.
  • Stage of the disease.
  • Grade of the primary tumor.
  • Estrogen receptor (ER) and progesterone receptor (PR) status of the tumor.
  • Human epidermal growth factor type 2 receptor (HER2/neu) overexpression and/or amplification.
  • Histologic type. Breast cancer is classified into a variety of histologic types, some of which have prognostic importance. Favorable histologic types include mucinous, medullary, and tubular carcinomas.[61-63]

The use of molecular profiling in breast cancer includes the following:[64]

  • 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).

On the basis of ER, PR, and HER2/neu results, breast cancer is classified as one of the following types:

  • Hormone receptor positive.
  • HER2/neu positive.
  • Triple negative (ER, PR, and HER2/neu negative).

ER, PR, and HER2 status are important in determining prognosis and in predicting response to endocrine and HER2-directed therapy. The American Society of Clinical Oncology/College of American Pathologists consensus panel has published guidelines to help standardize the performance, interpretation, and reporting of assays used to assess the ER/PR status by immunohistochemistry and HER2 status by immunohistochemistry and in situ hybridization.[65,66]

Gene profile tests include the following:

  • MammaPrint: The first gene profile test to be approved by the U.S. Food and Drug Administration was the MammaPrint gene signature. Its prognostic utility primarily targets adjuvant therapy−decision making in women aged 61 years and younger with stage I/II lymph node–negative breast cancer 5 cm or smaller.[67-71] The MINDACTtrial (NCT00433589) will help determine if the assay should be used to decide whether adjuvant chemotherapy may benefit a patient.
  • Oncotype DX: The Oncotype DX 21 gene assay is the gene profile test with the most extensive clinical validation thus far, albeit in a prospective–retrospective fashion. A 21-gene recurrence score (RS) is generated based on the level of expression of each of the 21 genes:
    • RS <18: low risk.
    • RS ≥18 and <31: intermediate-risk.
    • RS ≥31: high risk.

The following trials describe the prognostic and predictive value of multigene assays:

  1. The prognostic ability of the Oncotype DX 21-gene assay was assessed in two randomized trials.
    • The National Surgical Adjuvant Breast and Bowel Project (NSABP B-14) trial randomly assigned patients to receive tamoxifen or placebo; the results favoring tamoxifen changed clinical practice in the late 1980s.[72] Formalin-fixed, paraffin-embedded tissue was available for 668 patients. The 10-year distant recurrence risk for patients treated with tamoxifen was 7% for those with a low RS, 14% for those with an intermediate RS, and 31% for those with high RS (P < .001).[73]
    • A community-based, case-control study examined the prognostic ability of the RS to predict breast cancer deaths after 10 years in a group of tamoxifen-treated patients and observed a similar prognostic pattern to that seen in patients from NSABP B-14.[74]
  2. Prediction of benefit from chemotherapy in patients with node-negative, ER-positive breast cancer was assessed by the tamoxifen alone (n = 227) and the combination arms (n = 424) of the NSABP B-20 trial.[72] Patients in the NSABP B-20 trial were randomly assigned to receive tamoxifen alone or tamoxifen concurrently with methotrexate and 5-fluorouracil (MF) or cyclophosphamide with MF (CMF).[75]
    • The 10-year distant disease-free survival (DFS) improved from 60% to 88% by adding chemotherapy to tamoxifen in the high-risk group, while no benefit was observed in the low RS group.[76]
  3. Similar findings were reported in the prospective-retrospective evaluation of Southwestern Oncology Group (SWOG-8814) trial in lymph node-positive patients treated with tamoxifen with or without cyclophosphamide, doxorubicin, and fluorouracil (CAF).[77] However, the sample size in this analysis was small, follow-up was only 5 years, and the prognostic impact of having positive nodes needs to be taken into consideration.
    • Of note, both analyses (NSABP B-20 and S8814) were underpowered for any conclusive predictive analysis among patients identified as having an intermediate RS.
  4. Results from the TAILORx (NCT00310180) trial may help provide recommendations for those with ER/PR-positive and node-negative disease with an intermediate RS. In this study, a low-risk score was defined as less than 11, intermediate score was 11 to 25, and high-risk score was greater than 25. These cut points differ from those described above.

    Patients in this study with a low-risk score were found to have very low rates of recurrence at 5 years with endocrine therapy.[78] Primary endpoint results from this study are awaited.

    • Rate of invasive DFS was 93.8%.
    • Rate of freedom from recurrence of breast cancer at a distant site was 99.3%.
    • Rate of freedom from recurrence of breast cancer at a distant or local-regional site was 98.7%.
    • Rate of overall survival was 98.0%.

Results from the RxPONDER (NCT01272037) trial will help to determine if there is a benefit from adjuvant chemotherapy in patients with ER-positive, node-positive early breast cancer treated with endocrine therapy, and a RS below 25.

Many other gene-based assays may guide treatment decisions in patients with early breast cancer (e.g., Predictor Analysis of Microarray 50 [PAM50] Risk of Recurrence [ROR] score, EndoPredict, Breast Cancer Index).

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. (Refer to the Prognosis of BRCA1- and BRCA2-related breast cancer section of the PDQ Genetics of Breast and Gynecologic Cancerssummary for more information.)

Posttherapy Considerations

Hormone replacement therapy

After careful consideration, patients with severe symptoms may be treated with hormone replacement therapy. For more information, refer to the following PDQ summaries:

  • Breast Cancer Prevention
  • Hot Flashes and Night Sweats

Related Summaries

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

References
  1. American Cancer Society: Cancer Facts and Figures 2018. Atlanta, Ga: American Cancer Society, 2018. Available online. Last accessed August 3, 2018.
  2. Altekruse SF, Kosary CL, Krapcho M, et al.: SEER Cancer Statistics Review, 1975-2007. Bethesda, Md: Thailand Cancer Help, 2010. Also available online. Last accessed August 13, 2018.
  3. Johnson A, Shekhdar J: Breast cancer incidence: what do the figures mean? J Eval Clin Pract 11 (1): 27-31, 2005. [PUBMED Abstract]
  4. Haas JS, Kaplan CP, Gerstenberger EP, et al.: Changes in the use of postmenopausal hormone therapy after the publication of clinical trial results. Ann Intern Med 140 (3): 184-8, 2004. [PUBMED Abstract]
  5. Colditz GA, Kaphingst KA, Hankinson SE, et al.: Family history and risk of breast cancer: nurses’ health study. Breast Cancer Res Treat 133 (3): 1097-104, 2012. [PUBMED Abstract]
  6. Malone KE, Daling JR, Doody DR, et al.: Family history of breast cancer in relation to tumor characteristics and mortality in a population-based study of young women with invasive breast cancer. Cancer Epidemiol Biomarkers Prev 20 (12): 2560-71, 2011. [PUBMED Abstract]
  7. Cybulski C, Wokołorczyk D, Jakubowska A, et al.: Risk of breast cancer in women with a CHEK2 mutation with and without a family history of breast cancer. J Clin Oncol 29 (28): 3747-52, 2011. [PUBMED Abstract]
  8. Goodwin PJ, Phillips KA, West DW, et al.: Breast cancer prognosis in BRCA1 and BRCA2 mutation carriers: an International Prospective Breast Cancer Family Registry population-based cohort study. J Clin Oncol 30 (1): 19-26, 2012. [PUBMED Abstract]
  9. Mavaddat N, Barrowdale D, Andrulis IL, et al.: Pathology of breast and ovarian cancers among BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Cancer Epidemiol Biomarkers Prev 21 (1): 134-47, 2012. [PUBMED Abstract]
  10. Razzaghi H, Troester MA, Gierach GL, et al.: Mammographic density and breast cancer risk in White and African American Women. Breast Cancer Res Treat 135 (2): 571-80, 2012. [PUBMED Abstract]
  11. Key TJ, Appleby PN, Reeves GK, et al.: Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies. Br J Cancer 105 (5): 709-22, 2011. [PUBMED Abstract]
  12. Kaaks R, Rinaldi S, Key TJ, et al.: Postmenopausal serum androgens, oestrogens and breast cancer risk: the European prospective investigation into cancer and nutrition. Endocr Relat Cancer 12 (4): 1071-82, 2005. [PUBMED Abstract]
  13. Kaaks R, Berrino F, Key T, et al.: Serum sex steroids in premenopausal women and breast cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC). J Natl Cancer Inst 97 (10): 755-65, 2005. [PUBMED Abstract]
  14. Collaborative Group on Hormonal Factors in Breast Cancer: Menarche, menopause, and breast cancer risk: individual participant meta-analysis, including 118 964 women with breast cancer from 117 epidemiological studies. Lancet Oncol 13 (11): 1141-51, 2012. [PUBMED Abstract]
  15. Ritte R, Lukanova A, Tjønneland A, et al.: Height, age at menarche and risk of hormone receptor-positive and -negative breast cancer: a cohort study. Int J Cancer 132 (11): 2619-29, 2013. [PUBMED Abstract]
  16. Wolin KY, Carson K, Colditz GA: Obesity and cancer. Oncologist 15 (6): 556-65, 2010. [PUBMED Abstract]
  17. Kotsopoulos J, Chen WY, Gates MA, et al.: Risk factors for ductal and lobular breast cancer: results from the nurses’ health study. Breast Cancer Res 12 (6): R106, 2010. [PUBMED Abstract]
  18. Goldacre MJ, Abisgold JD, Yeates DG, et al.: Benign breast disease and subsequent breast cancer: English record linkage studies. J Public Health (Oxf) 32 (4): 565-71, 2010. [PUBMED Abstract]
  19. Kabat GC, Jones JG, Olson N, et al.: A multi-center prospective cohort study of benign breast disease and risk of subsequent breast cancer. Cancer Causes Control 21 (6): 821-8, 2010. [PUBMED Abstract]
  20. Worsham MJ, Raju U, Lu M, et al.: Risk factors for breast cancer from benign breast disease in a diverse population. Breast Cancer Res Treat 118 (1): 1-7, 2009. [PUBMED Abstract]
  21. Travis LB, Hill DA, Dores GM, et al.: Breast cancer following radiotherapy and chemotherapy among young women with Hodgkin disease. JAMA 290 (4): 465-75, 2003. [PUBMED Abstract]
  22. 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]
  23. 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]
  24. Blackwood MA, Weber BL: BRCA1 and BRCA2: from molecular genetics to clinical medicine. J Clin Oncol 16 (5): 1969-77, 1998. [PUBMED Abstract]
  25. 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]
  26. 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]
  27. Cancer risks in BRCA2 mutation carriers. The Breast Cancer Linkage Consortium. J Natl Cancer Inst 91 (15): 1310-6, 1999. [PUBMED Abstract]
  28. 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]
  29. 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]
  30. 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]
  31. 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]
  32. 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]
  33. Anderson GL, Limacher M, Assaf AR, et al.: Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the Women’s Health Initiative randomized controlled trial. JAMA 291 (14): 1701-12, 2004. [PUBMED Abstract]
  34. LaCroix AZ, Chlebowski RT, Manson JE, et al.: Health outcomes after stopping conjugated equine estrogens among postmenopausal women with prior hysterectomy: a randomized controlled trial. JAMA 305 (13): 1305-14, 2011. [PUBMED Abstract]
  35. Anderson GL, Chlebowski RT, Aragaki AK, et al.: Conjugated equine oestrogen and breast cancer incidence and mortality in postmenopausal women with hysterectomy: extended follow-up of the Women’s Health Initiative randomised placebo-controlled trial. Lancet Oncol 13 (5): 476-86, 2012. [PUBMED Abstract]
  36. Bernstein L, Henderson BE, Hanisch R, et al.: Physical exercise and reduced risk of breast cancer in young women. J Natl Cancer Inst 86 (18): 1403-8, 1994. [PUBMED Abstract]
  37. Thune I, Brenn T, Lund E, et al.: Physical activity and the risk of breast cancer. N Engl J Med 336 (18): 1269-75, 1997. [PUBMED Abstract]
  38. Adams-Campbell LL, Rosenberg L, Rao RS, et al.: Strenuous physical activity and breast cancer risk in African-American women. J Natl Med Assoc 93 (7-8): 267-75, 2001 Jul-Aug. [PUBMED Abstract]
  39. Kampert JB, Whittemore AS, Paffenbarger RS Jr: Combined effect of childbearing, menstrual events, and body size on age-specific breast cancer risk. Am J Epidemiol 128 (5): 962-79, 1988. [PUBMED Abstract]
  40. Pike MC, Krailo MD, Henderson BE, et al.: ‘Hormonal’ risk factors, ‘breast tissue age’ and the age-incidence of breast cancer. Nature 303 (5920): 767-70, 1983. [PUBMED Abstract]
  41. Lambe M, Hsieh C, Trichopoulos D, et al.: Transient increase in the risk of breast cancer after giving birth. N Engl J Med 331 (1): 5-9, 1994. [PUBMED Abstract]
  42. Col: Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50302 women with breast cancer and 96973 women without the disease. Lancet 360 (9328): 187-95, 2002. [PUBMED Abstract]
  43. Cuzick J, Sestak I, Bonanni B, et al.: Selective oestrogen receptor modulators in prevention of breast cancer: an updated meta-analysis of individual participant data. Lancet 381 (9880): 1827-34, 2013. [PUBMED Abstract]
  44. Goss PE, Ingle JN, Alés-Martínez JE, et al.: Exemestane for breast-cancer prevention in postmenopausal women. N Engl J Med 364 (25): 2381-91, 2011. [PUBMED Abstract]
  45. Cuzick J, Sestak I, Forbes JF, et al.: Anastrozole for prevention of breast cancer in high-risk postmenopausal women (IBIS-II): an international, double-blind, randomised placebo-controlled trial. Lancet 383 (9922): 1041-8, 2014. [PUBMED Abstract]
  46. Hartmann LC, Schaid DJ, Woods JE, et al.: Efficacy of bilateral prophylactic mastectomy in women with a family history of breast cancer. N Engl J Med 340 (2): 77-84, 1999. [PUBMED Abstract]
  47. Rebbeck TR, Levin AM, Eisen A, et al.: Breast cancer risk after bilateral prophylactic oophorectomy in BRCA1 mutation carriers. J Natl Cancer Inst 91 (17): 1475-9, 1999. [PUBMED Abstract]
  48. Kauff ND, Satagopan JM, Robson ME, et al.: Risk-reducing salpingo-oophorectomy in women with a BRCA1 or BRCA2 mutation. N Engl J Med 346 (21): 1609-15, 2002. [PUBMED Abstract]
  49. Rebbeck TR, Lynch HT, Neuhausen SL, et al.: Prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations. N Engl J Med 346 (21): 1616-22, 2002. [PUBMED Abstract]
  50. Kauff ND, Domchek SM, Friebel TM, et al.: Risk-reducing salpingo-oophorectomy for the prevention of BRCA1- and BRCA2-associated breast and gynecologic cancer: a multicenter, prospective study. J Clin Oncol 26 (8): 1331-7, 2008. [PUBMED Abstract]
  51. 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]
  52. Abbott A, Rueth N, Pappas-Varco S, et al.: Perceptions of contralateral breast cancer: an overestimation of risk. Ann Surg Oncol 18 (11): 3129-36, 2011. [PUBMED Abstract]
  53. Nichols HB, Berrington de González A, Lacey JV Jr, et al.: Declining incidence of contralateral breast cancer in the United States from 1975 to 2006. J Clin Oncol 29 (12): 1564-9, 2011. [PUBMED Abstract]
  54. 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]
  55. 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]
  56. 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]
  57. 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]
  58. 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]
  59. Morrow M: Magnetic resonance imaging in the breast cancer patient: curb your enthusiasm. J Clin Oncol 26 (3): 352-3, 2008. [PUBMED Abstract]
  60. 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]
  61. 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]
  62. 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]
  63. 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]
  64. 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]
  65. Wolff AC, Hammond ME, Hicks DG, et al.: Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update. J Clin Oncol 31 (31): 3997-4013, 2013. [PUBMED Abstract]
  66. Hammond ME, Hayes DF, Dowsett M, et al.: American Society of Clinical Oncology/College of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer. Arch Pathol Lab Med 134 (6): 907-22, 2010. [PUBMED Abstract]
  67. Buyse M, Loi S, van’t Veer L, et al.: Validation and clinical utility of a 70-gene prognostic signature for women with node-negative breast cancer. J Natl Cancer Inst 98 (17): 1183-92, 2006. [PUBMED Abstract]
  68. Wittner BS, Sgroi DC, Ryan PD, et al.: Analysis of the MammaPrint breast cancer assay in a predominantly postmenopausal cohort. Clin Cancer Res 14 (10): 2988-93, 2008. [PUBMED Abstract]
  69. Mook S, Knauer M, Bueno-de-Mesquita JM, et al.: Metastatic potential of T1 breast cancer can be predicted by the 70-gene MammaPrint signature. Ann Surg Oncol 17 (5): 1406-13, 2010. [PUBMED Abstract]
  70. Ishitobi M, Goranova TE, Komoike Y, et al.: Clinical utility of the 70-gene MammaPrint profile in a Japanese population. Jpn J Clin Oncol 40 (6): 508-12, 2010. [PUBMED Abstract]
  71. Knauer M, Mook S, Rutgers EJ, et al.: The predictive value of the 70-gene signature for adjuvant chemotherapy in early breast cancer. Breast Cancer Res Treat 120 (3): 655-61, 2010. [PUBMED Abstract]
  72. Fisher B, Jeong JH, Bryant J, et al.: Treatment of lymph-node-negative, oestrogen-receptor-positive breast cancer: long-term findings from National Surgical Adjuvant Breast and Bowel Project randomised clinical trials. Lancet 364 (9437): 858-68, 2004. [PUBMED Abstract]
  73. Paik S, Shak S, Tang G, et al.: A multigene assay to predict recurrence of tamoxifen-treated, node-negative breast cancer. N Engl J Med 351 (27): 2817-26, 2004. [PUBMED Abstract]
  74. Habel LA, Shak S, Jacobs MK, et al.: A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients. Breast Cancer Res 8 (3): R25, 2006. [PUBMED Abstract]
  75. Mamounas EP, Tang G, Fisher B, et al.: Association between the 21-gene recurrence score assay and risk of locoregional recurrence in node-negative, estrogen receptor-positive breast cancer: results from NSABP B-14 and NSABP B-20. J Clin Oncol 28 (10): 1677-83, 2010. [PUBMED Abstract]
  76. Paik S, Tang G, Shak S, et al.: Gene expression and benefit of chemotherapy in women with node-negative, estrogen receptor-positive breast cancer. J Clin Oncol 24 (23): 3726-34, 2006. [PUBMED Abstract]
  77. Albain KS, Barlow WE, Shak S, et al.: Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised trial. Lancet Oncol 11 (1): 55-65, 2010. [PUBMED Abstract]
  78. Sparano JA, Gray RJ, Makower DF, et al.: Prospective Validation of a 21-Gene Expression Assay in Breast Cancer. N Engl J Med 373 (21): 2005-14, 2015. [PUBMED Abstract]