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Hormonal Treatment of In-situ Breast Carcinoma Guideline Summary

(O): March 31, 2011 (R):
Date Signed:
May 23, 2012
Tumor Group:
Breast Disease Site Group
Issuing Authority:
Dr. Kara Laing, Clinical Chief,
Cancer Care Program
Adapted From:
New Zealand Guidelines Group "management of early breast cancer:evidence-based best practice guideline", 2009 (5).

Target Population:
These recommendations apply to patients with a diagnosis of ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS).

All patients, with no contraindications, deemed to be candidates for hormonal treatment for DCIS or LCIS will be offered tamoxifen 20mg/daily, taken orally, for five consecutive years.

Supporting Evidence:
The National Surgical Adjuvant Breast and Bowel Project (NSABP) B-24 clinical trial found that tamoxifen reduced the risk of both ipsilateral and contralateral breast recurrences (1). The proportional reduction of breast cancer events, in this study, was found to be approximately 38% with the addition of tamoxifen to standard treatment.

Qualifying Statements:

  • Patients with high grade DCIS, regardless of age should be considered for tamoxifen. Patients, including those less than 50 years of age, with low or moderate grade disease, may also be considered.
    Patients who have undergone bilateral mastectomies, do not require tamoxifen. Those who have undergone a unilateral mastectomy may derive a small benefit for the remaining breast.
  • The Breast Disease Site Group recommended that hormone receptor testing should not be performed on LCIS, since 99% are known to be estrogen and progesterone receptor positive (2).
  • Currently, testing for hormone receptor status on DCIS specimens is not standard practice in most centers across the country, and there is limited retrospective evidence to date to suggest that knowing this result will affect the outcome (3). The American Society of Clinical Oncology/College of American Pathologists, however, believes that the result of this one retrospective study is “…scientifically reasonable and consistent with previous studies of invasive and metastatic breast cancer” but does acknowledge that there are unlikely to be any validation studies performed, therefore the decision for testing should be left up to the patient and physician (4). Therefore, the group has decided to not recommend carrying out routine receptor testing on DCIS. However, if an individual physician requests it, the pathology department will refer the specimen for testing to an outside laboratory on a case-by-case basis following referral.

These guidelines are a statement of consensus of the Breast Disease Site Group regarding their views of currently accepted approaches to diagnosis and treatment. Any clinician seeking to apply or consult the guidelines is expected to use independent medical judgment in the context of individual clinical circumstances to determine any patient’s care or treatment.

Contact Information:
For more information on this guideline, please contact:
Dr. Joy McCarthy MD FRCPC
Dr. H. Bliss Murphy Cancer Center
St. John’s, NL
Telephone 709-777-8515.

For the complete guideline on this topic or for access to any of our guidelines, please visit our Cancer Care Program website

Literature Support:
  1. Fisher B, Dignam J, et al. Tamoxifen in treatment of intraductal breast cancer: National Surgical Adjuvant Breast and Bowel Project B-24 randomised controlled trial. The Lancet. 1999;353:1993-2000.
  2. Middleton LP, Perkins GH, et al. Expression of ERα and ERβ in lobular carcinoma in situ. Histopathology. 2007;50:875-880.
  3. Allred B, Bryant J, et al. Estrogen receptor expression as a predictive marker of the effectiveness of tamoxifen in the treatment  of DCIS: Findings from NSABP Protocol B-24 [meeting abstract]. Breast Cancer Res Treat. 2002;76(suppl 1):Abstract 30.
  4. Hammond MEH, Hayes DF, et al. American Society of Clinical Oncology/College of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer. J Clin Oncol. 2010;28(16):2784-2795.
  5. New Zealand Guidelines Group. Management of early breast cancer: Evidence-based best practice guideline. 2009.



Downloadable Documents:
Hormonal Treatment

Updated Apr 7, 2014