Patients with close or positive margins who decline re-excision should be advised that the risk of IBTR is increased. The relative risks/benefits of re-excision vs boost in the context of local control and cosmesis should be discussed.
Early consultation with a radiation oncologist is recommended if there is uncertainty about whether re-excision is recommended. This will facilitate a timely re-excision. Re-excision should be carried out prior to adjuvant radiation but does not need to occur prior to systemic therapy.
Lobular carcinoma in situ at the margins does not constitute a positive margin.
If a pathology report does not contain the necessary information to determine margin status, then the reading pathologist should be consulted or a BC Cancer pathology review should be obtained. If, after this, it is still not possible to accurately determine the margins, then the margins should be treated as unknown in which case a re-excision (or radiation boost) is generally recommended.
Total mastectomy (TM) is defined as the removal of entire breast. "Mastectomy requires the elevation of skin flaps sufficiently thin to remove all of the breast tissue, and extended to the anatomic limits of the breast (the sternal border medially, the clavicle superiorly, the latissimus laterally, and the rectus sheath/inframammary fold inferiorly)."10
Skin sparing mastectomy (SSM) is used in conjunction with immediate breast reconstruction and studies have shown no increased recurrence risk with use of this technique10. Nipple sparing mastectomy (NSM) is a viable option by the properly trained surgeon in women with small to moderate sized breasts, minimal ptosis, and favorable tumour features11 Evidence is accumulating that there is a low recurrence risk in properly selected patients. When assessing a patient for a NSM, considerations include location of the tumor, nodal status and need for radiotherapy, and tumor biology.11 A nipple margin (core) should be taken when a NSM is performed.11
Total Mastectomy (TM, SSM, NSM) is an option for patients with early stage breast cancer particularly for patients with contraindications to radiotherapy or desire to avoid radiotherapy, patients who would have a poor cosmetic outcome with breast-conserving therapy or those with multicentric disease or associated diffuse, extensive DCIS. Mastectomy should also be considered in those who continue to have positive margins of invasive disease after multiple breast-conserving surgeries.
Axillary surgery provides important prognostic information and can improve regional control for some patients with invasive breast cancer. Traditionally, level I and II axillary node dissection (ALND) had been the standard of care for all patients with invasive breast cancer. ALND has now been replaced by Sentinel Lymph Node biopsy (SLNB) for most patients with clinically N0 breast cancer12,13. Sentinel lymph node biopsy is associated with less morbidity than ALND12 and similar staging accuracy and oncologic outcomes in early breast cancer12,13,14,15 and should be offered to all eligible patients.
- Inflammatory breast cancer
- Occult breast cancer presenting as axillary node metastasis
- Clinically node positive axilla, confirmed by FNA or core biopsy in a patient for whom neoadjuvant chemotherapy is not planned
- Axillary nodes that remain positive after neoadjuvant chemotherapy
- Axillary recurrence following previous breast cancer treatment.
Axillary lymph node dissection should be considered12,13,14,15,16,17 (Surgical Breast Tumor group consensus 2016):
- Failed Sentinel node mapping in invasive cancer with high risk features
- Positive sentinel lymph nodes not meeting eligibility criteria for Z0011 study15* (multidisciplinary discussion recommended)
- Node positive disease prior to NAT (evidence evolving around the role of SLNB, multidisciplinary discussion recommended)
- Axillary staging required in the setting of previous mastectomy
Axillary lymph node dissection not recommended12,13,14,15,16,17 (Surgical Breast Tumor group consensus 2016):
- Clinically T1-T2 N0 breast cancer (sentinel node biopsy should be offered)
- Positive sentinel nodes meeting criteria for Z0011 study15*
* Z0011 Eligibility criteria: T1T2 Invasive breast cancer, no palpable axillary nodes, 1-2 Sentinel nodes positive, treated with BCS with clear margins (no tumour at ink), no matted nodes / gross extranodal disease / neoadjuvant hormonal or chemotherapy
Level 1 and 2 axillary dissection is generally recommended for those with three or more pathologically positive sentinel nodes and those at high risk for gross residual nodal disease after sentinel node procedure (e.g. those with three or more pathologically positive sentinel nodes, or gross extracapsular extension) to improve regional control, although the elevated risk of lymphedema of axillary dissection in the setting of regional radiotherapy must also be considered in the absence of a proven survival advantage.
Synoptic Reporting for Breast Cancer Surgery
The Surgical Breast Tumor group developed a Breast Cancer Checklist
(Synoptic Report) in conjunction with medical and radiation oncology. It is recommended that surgeons report breast cancer procedures using this template to facilitate communication of relevant details to other care providers.
Pathology considerations for Partial and Modified Radical Mastectomy
The specimen removed at partial mastectomy must be oriented by the surgeon. At least two boundaries should be marked with sutures of different color or length so that the specimen can be oriented in three dimensions (e.g. long suture = lateral, short suture = superior). With a correctly marked specimen the pathologist will then be able to make an accurate estimate of the size of the tumour-free margin and to identify the location of any margin thought to be inadequately excised. If the margin is inadequate in a location where it is possible to improve the situation surgically, then a re-excision should be carried out.
For a modified radical mastectomy, axillary end should be marked for orientation so that the location as well as the number of nodes removed and involved by malignancy can be ascertained.
Contralateral Prophylactic Mastectomy
Patients who require a mastectomy to treat unilateral breast cancer often enquire about contralateral prophylactic mastectomy (CPM). A detailed history and family history is required to assess the risk of a contralateral breast cancer (CBC). For the average woman the risk of CBC is less than 0.7% per year. CBC rate is increased in higher risk populations (eg BRCA mutation carriers). CPM reduces the risk of CBC but never eliminates it completely. Systemic treatments also reduce the risk of CBC. Rates of CPM are rising at more then 1% per year and have been known to almost double the risk of complications after surgery. CPM in an average risk woman does not improve cancer outcomes.
As such, CPM is not recommended for women with unilateral breast cancer. CPM may be considered in selective cases when a patient is deemed to be of moderate risk of CBC (e.g.very young age, strong family history of breast cancer, non-BRCA mutations, other high risk features such as atypical ductal hyperplasia or lobular carcinoma in-situ), or when issues arise surrounding asymmetry after unilateral mastectomy (with or without breast reconstruction).
High risk populations (BRCA mutation carriers, history of mantle field radiation) with unilateral breast cancer should be counseled on the risk of CBC and often CPM is recommended.
A Canadian expert consensus statement on this issue is a work in progress. The link will be posted here once it is available. Other groups, including the American Society of Breast Surgeons18 and Choosing Wisely19, have similar consensus statements discouraging the routine use of CPM.
All women undergoing mastectomy should be offered a reconstruction and referral to a plastic surgeon if they are clinically candidates. Reconstruction can be performed at the time of mastectomy (immediate reconstruction) or as a second procedure (delayed reconstruction). Options for reconstruction include autologous tissue vs implant reconstruction.20
- Fisher B, Anderson S, Bryant J et al Twenty year follow up of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. N Engl J Med 2002;347:1233-41
- Veronesi U, Cascinelli N Mariani L et al. Twenty year follow up of a randomized study comparing breast-conserving surgery with radical mastectomy for early breast cancer. N Engl J Med 2002; 1227-32.
- Eusoma http://www.eusoma.org/Engx/Guidelines/Other/OtherMT.aspx?cont=MT
- ACS breast centers: https://www.facs.org/~/media/files/quality%20programs/napbc/2014%20napbc%20standards%20manual.ashx
- Peters NH1, van Esser S, van den Bosch MA, Storm RK, Plaisier PW, van Dalen T, Diepstraten SC, Weits T, Westenend PJ, Stapper G, Fernandez-Gallardo MA, Borel Rinkes IH, van Hillegersberg R, Mali WP, Peeters PH. Preoperative MRI and surgical management in patients with nonpalpable breast cancer: the MONET - randomised controlled trial. Eur J Cancer. 2011 Apr;47(6):879-86. doi: 10.1016/j.ejca.2010.11.035. Epub 2010 Dec 30.
- Turnbull L1, Brown S, Harvey I, Olivier C, Drew P, Napp V, Hanby A, Brown J. Comparative effectiveness of MRI in breast cancer (COMICE) trial: a randomised controlled trial. Lancet. 2010 Feb 13;375(9714):563-71. doi: 10.1016/S0140-6736(09)62070-5.
- Meena S. Moran, Stuart J. Schnitt, Armando Giuliano et al. Society of Surgical Oncology–American Society for Radiation Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Stages I and II Invasive Breast Cancer. March 2014, Volume 21, Issue 3, pp 704–716
- Hughes KS, Schnaper LA, Berry D, et al. Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer. N Engl J Med 2004;351: 971: l
- Headon HL, Kasem A, Mokbel K.The Oncological Safety of Nipple-Sparing Mastectomy: A Systematic Review of the Literature with a Pooled Analysis of 12,358 Procedures. Arch Plast Surg. 2016 Jul;43(4):328-38. doi: 10.5999/aps.2016.43.4.328. Review.
- Krag DN, Anderson SJ, Julian TB et al. Sentinel lymph node resection compared with conventional axillary lymph node dissection in clinically node-negative patients with breast cancer: overall survival findings from the NSABP B-32 randomized phase 3 trial. Lancet Oncol 2010;11:927-33.
- Giuliano A, Ballman K, McCall L. Locoregional recurrence after sentinel lymph node dissection with or without axillary dissection in patients with sentinel lymph node metastases. Long term follow up from the ACOSOG Z0011
- Lyman et al. Sentinel lymph node biopsy for patients with early-stage breast cancer: American society of clinical oncology clinical practice guideline update. JCO. http://jco.ascopubs.org/cgi/doi/10.1200/JCO.2013.54.117. Accessed April 21, 2016
- Judy C. Boughey, Deanna J. Attai, Steven L. Chen et al. Contralateral Prophylactic Mastectomy (CPM) Consensus Statement from the American Society of Breast Surgeons: Data on CPM Outcomes and Risk. Annals of surgical oncology. October 2016, Volume 23, Issue 10, pp 3100–310
- https://www.breastsurgeons.org/docs/2016_asbrs_cw_recommendations.pdf. Accessed Sept 14, 2016
- Joon Y Choi, MD, Amy K Alderman, MD, Lisa Ann Newman, MD, MPH, FACS. Aesthetic and Reconstruction Considerations in Oncologic Breast Surgery. JACS 2006; 202:943-952.
Updated November 2017
Radiation Therapy following Breast Conserving Surgery (pT1T2;N0)
Patients treated with breast conserving surgery (BCS; lumpectomy, partial or segmental mastectomy) for stage I or II breast cancer should have a consultation with a Radiation Oncologist regarding the role of radiation therapy (RT).
RT to the breast following BCS reduces the risk of breast recurrence and lowers the risk of systemic recurrence and breast cancer death.1,2,3,4,5 At 10 years after diagnosis, a 20% absolute reduction in the risk of breast recurrence (from 30% to 10%) translates into a 4-5% reduction in the chance of dying from breast cancer. RT should follow BCS unless contraindicated due to patient comorbidites, limited patient life expectancy, patient desire to avoid RT, or in selected low recurrence risk situations (see below). In addition to breast RT, regional RT may be indicated in select node-negative patients, such as those with a number of high-risk features including large tumour, high grade, lymphovascular involvement, central/inner quadrant location, or those with triple-negative (i.e. ER/PR negative, her-2-neu negative) disease.
Timing of Adjuvant Radiotherapy
- I. RT should optimally start once healing from the BCS is complete and generally within 10 weeks of BCS
- II. If post-operative problems occur, including hematoma, large seroma, infection, breast edema with erythema, or wound dehiscence occur, the start of RT may be delayed to allow resolution. In such cases or to accommodate patient convenience, there is no randomised trial evidence showing detriment to delay the start of RT until 20 weeks after BCS. Longer intervals may be associated with reduced RT efficacy and inferior local control6
- III. If the patient receives adjuvant chemotherapy, then RT should follow the chemotherapy and start approximately 3-4 weeks after the last intravenous chemotherapy. Trastuzumab as a single agent may be delivered concurrently with radiation therapy. Adjuvant hormonal therapy may be commenced prior to or after RT.
Randomised trials have shown improved local control with a boost of RT to the surgical bed following tangential RT for selected patients.7,8,9
Indications for supplemental boost dose of RT:
- I. close or positive margins (less than or equal to 2 mm) post-breast conserving surgery, without possibility of further excision
- II. age 50 years or younger, even if the margins are greater than 2 mm
Patients who might be spared radiation therapy after breast conserving surgery
Radiation therapy consistently reduces the relative risk of local recurrence by 60-70%. Patients with a < 5% risk of local recurrence at 10 years are challenging to identify but might reasonably be considered for treatment with BCS alone. Women with all of the following factors likely have a 10 year risk of breast recurrence of 5% or less, if also prescribed adjuvant hormonal therapy: age >60 years, pN0, ER strongly positive, Grade 1 ductal carcinoma without lymphatic or vascular invasion and at least 5mm clear margins. Such women should be informed that RT will further decrease the risk of breast recurrence, but that the absolute benefit of RT on long-term survival is small.11,12,13
Accelerated partial breast radiation therapy following breast conserving surgery
Randomized trials of partial breast RT compared to whole breast RT have completed accrual but will not report cancer endpoints for several years. In the interim, the BC Cancer consensus is that:
- Whole breast RT remains the standard local treatment following breast conserving surgery.
- Partial breast RT using 4-5 external 3-D conformal external beam RT has been shown to increase the risk of breast pain and induration at the primary site.
- Where available, patients undergoing accelerated breast radiation therapy should be treated as part of a defined, clinical trial protocol.
- Partial breast RT may be considered in particular circumstances, e.g. previous breast RT with refusal of mastectomy for local recurrence
Radiation therapy following mastectomy (pT1,T2;N0)
Some patients treated with mastectomy with negative nodes may benefit from adjuvant RT. Those with close or positive margins with T2 tumour size plus other high risk features, such as grade 3 histology, lymphatic or vascular invasion, age<50 years, and central or inner quadrant tumours have a higher risk of locoregional recurrence and warrant a discussion of adjuvant radiotherapy.14 Adjuvant locoregional RT may benefit select node-negative patients with clear margins post-mastectomy or breast conserving therapy, such as those with central/inner quadrant tumours, or those with T2 tumour size with other high risk features, e.g. high grade, lymphovascular involvement, or triple-negative (i.e. ER/PR negative, her-2-neu negative) disease.15 Those with these high-risk features should be referred after mastectomy for discussion of adjuvant RT with a radiation oncologist.
Radiation therapy following mastectomy or breast conserving surgery (pT1,T2;N1, and T3;N0)
Locoregional RT improves outcomes following mastectomy for patients with node-positive breast cancer or node-negative T3 breast cancer (increased 15 year overall survival by 10% p=0.015)15,16,17,18,19,20. This benefit is significant, even for patients with only a moderate risk (e.g. 1-3 nodes positive) of loco-regional recurrence.16,17 Regional RT results in decreased risk of loco-regional recurrence and distant metastases and improved survival for patients with node-positive cancer.
Timing of Adjuvant Radiotherapy: Timing is as described
above post BCS for node-negative patients.
Details of radiotherapy planning and prescription in the post-breast conserving surgery and post-mastectomy setting are described
- EBCTCG (Early Breast Cancer Trialists' Collaborative Group), McGale P, Taylor C, Correa C, Cutter D, Duane F, Ewertz M, et al. Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet. 2011 Nov 12;378(9804):1707-16. doi: 10.1016/S0140-6736(11)61629-2. Epub 2011 Oct 19. Review. PMID: 22019144
- Fisher B, Bryant J, Dignam JJ, Wickerham DL, Mamounas EP, Fisher ER, et al. Tamoxifen, radiation therapy, or both for prevention of ipsilateral breast tumor recurrence after lumpectomy in women with invasive breast cancers of one centimeter or less. J Clin Oncol. 2002 Oct 15;20(20):4141-9.
- Vinh-Hung V, Verschraegen C. Breast-conserving surgery with or without radiotherapy: Pooled-analysis for risks of ipsilateral breast tumor recurrence and mortality. J Natl Cancer Inst. 2004 Jan 21;96(2):115-21.
- Veronesi U, Salvadori B, Luini A, Greco M, Saccozzi R, del Vecchio M, et al. Breast conservation is a safe method in patients with small cancer of the breast. long-term results of three randomised trials on 1,973 patients. Eur J Cancer. 1995 Sep;31A(10):1574-9.
- Whelan TJ, Olivotto IA, Parulekar WR, Ackerman I, Chua BH, Nabid A, et al. Regional Nodal Irradiation in Early-Stage Breast Cancer. N Engl J Med. 2015 Jul 23;373(4):307-16. doi: 10.1056/NEJMoa1415340.
- Olivotto IA, Lesperance ML, Truong PT, Nichol A, Berrang T, Tyldesley S, et al. Intervals longer than 20 weeks from breast-conserving surgery to radiation therapy are associated with inferior outcome for women with early-stage breast cancer who are not receiving chemotherapy. J Clin Oncol. 2009 Jan 1;27(1):16-23.
- Bartelink H, Horiot JC, Poortmans PM, Struikmans H, Van den Bogaert W, Fourquet A, et al. Impact of a higher radiation dose on local control and survival in breast-conserving therapy of early breast cancer: 10-year results of the randomized boost versus no boost EORTC 22881-10882 trial. J Clin Oncol. 2007 Aug 1;25(22):3259-65.
- Bartelink H1, Maingon P2, Poortmans P3, Weltens C4, Fourquet A5, Jager J, et al. Whole-breast irradiation with or without a boost for patients treated with breast-conserving surgery for earlybreast cancer: 20-year follow-up of a randomised phase 3 trial. Lancet Oncol. 2015 Jan;16(1):47-56. doi: 10.1016/S1470-2045(14)71156-8. Epub 2014 Dec 9.
- Romestaing P, Lehingue Y, Carrie C, Coquard R, Montbarbon X, Ardiet JM, et al. Role of a 10-gy boost in the conservative treatment of early breast cancer: Results of a randomized clinical trial in lyon, france. J Clin Oncol. 1997 Mar;15(3):963-8.
- Olivotto IA, Weir LM, Kim-Sing C, Bajdik CD, Trevisan CH, Doll CM, et al. Late cosmetic results of short fractionation for breast conservation. Radiother Oncol. 1996 Oct;41(1):7-13.
- Fyles AW, McCready DR, Manchul LA, Trudeau ME, Merante P, Pintilie M, et al. Tamoxifen with or without breast irradiation in women 50 years of age or older with early breast cancer. N Engl J Med. 2004 Sep 2;351(10):963-70.
- Hughes KS, Schnaper LA, Berry D, Cirrincione C, McCormick B, Shank B, et al. Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer. N Engl J Med. 2004 Sep 2;351(10):971-7.
- Kunkler IH, Williams LJ, Jack WJ, Cameron DA, Dixon JM; PRIME II investigators. Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breastcancer (PRIME II): a randomised controlled trial. Lancet Oncol. 2015 Mar;16(3):266-73. doi: 10.1016/S1470-2045(14)71221-5. Epub 2015 Jan 28
- Truong PT, Olivotto IA, Speers CH, Wai ES, Berthelet E, Kader HA. A positive margin is not always an indication for radiotherapy after mastectomy in early breast cancer. Int J Radiat Oncol Biol Phys. 2004 Mar 1;58(3):797-804.
- Poortmans PM., Collette S, Kirkove C., Van Limbergen, E, Budach V, Struikmans H, et al. Internal Mammary and Medial Supraclavicular Irradiation in Breast Cancer. N Engl J Med 2015; 373:317-327July 23, 2015DOI: 10.1056/NEJMoa141536
- Overgaard M, Hansen PS, Overgaard J, Rose C, Andersson M, Bach F, et al. Postoperative radiotherapy in high-risk premenopausal women with breast cancer who receive adjuvant chemotherapy.Danish Breast Cancer Cooperative Group 82b trial. N Engl J Med. 1997 Oct 2;337(14):949-55.
- Overgaard M, Jensen MB, Overgaard J, Hansen PS, Rose C, Andersson M, et al. Postoperative radiotherapy in high-risk postmenopausal breast-cancer patients given adjuvant tamoxifen: Danish Breast Cancer Cooperative Group DBCG 82c randomised trial. Lancet. 1999 May 15;353(9165):1641-8.
- Ragaz J, Olivotto IA, Spinelli JJ, Phillips N, Jackson SM, Wilson KS, et al. Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial. J Natl Cancer Inst. 2005 Jan 19;97(2):116-26.
- EBCTCG (Early Breast Cancer Trialists' Collaborative Group), McGale P, Taylor C, Correa C, Cutter D, Duane F, Ewertz M, et al. Effect of radiotherapy after mastectomy and axillary surgery on 10-year recurrence and 20-yearbreast cancer mortality: meta-analysis of individual patient data for 8135 women in 22 randomised trials. Lancet. 2014 Jun 21;383(9935):2127-35. doi: 10.1016/S0140-6736(14)60488-8. Epub 2014 Mar Erratum in: Lancet. 2014 Nov 22;384(9957):1848.
- Whelan TJ, Julian J, Wright J, Jadad AR, Levine ML. Does locoregional radiation therapy improve survival in breast cancer? A meta-analysis. J Clin Oncol. 2000 Mar;18(6):1220-9.
Revised 18 January 2013
Adjuvant systemic therapy has been demonstrated to reduce the risk of cancer recurrence and improve survival. Adjuvant systemic therapy with either chemotherapy or hormonal therapy should be offered to women according to the treatment policies as defined in Adjuvant Systemic Therapy. These policies are reviewed continuously by the provincial breast systemic policy group and updated accordingly. BC Cancer maintains current Chemotherapy Protocols
Systemic Management, Early Breast Cancer
The systemic management of invasive non-metastatic breast cancer is complex. The management of locally advanced and of metastatic breast cancer is discussed separately. The prognosis for a patient following treatment of early breast cancer varies according to their age, co-morbidities, and the stage and the biomarker profile of their cancer. The majority of patients with early breast cancer will be cured with appropriate multi-disciplinary therapy.
Invasive breast cancer can be divided into three broad groups that influence systemic treatment decisions:
- hormone receptor positive/her2 negative cancers;
- her2 positive cancers;
- and triple marker negative (ER-PR-her2-, "triple-negative") cancers.
Within each of these groups, treatment recommendations are also influenced by patient age, co-morbidity, and personal preferences, as well as the stage and other histopathologic features of the cancer.
The majority of advances in the management and improvements in the cure rates of early breast cancer have come from successful completion of scientifically rigorous clinical trials. Patients should be given the opportunity to participate in clinical trials if available for their stage and type of breast cancer.
Revised 18 January 2013
Hormone receptor positive breast cancers express estrogen receptors (ER) and or progesterone receptors (PR, PgR) on their nuclei, as evinced by immunohistochemical (IHC) assay. There are two main immunohistochemical scoring systems used by the province to describe the degree of ER and PR expression. The Allred score is made up of a measure of the intensity of the IHC stain and the percentage of cells which take up the stain for the receptor.1 The maximum score (strongest expression) is 8. A simpler scoring method is often used in which the hormone receptor staining strength is expressed from 0 (no staining) to 3 (strong, ubiquitous staining). Cancers with an IHC score of 0 or an Allred score of 2 or 0 do not benefit from hormone receptor targeted therapy. Cancers with an Allred score of 3 have weak staining in a small percentage of cells, and the benefit of therapy targeted at the receptor is debatable in this setting. An IHC score of 1+ is similar to an Allred score of 3 or 4. An IHC score of 2+ can be considered comparable to an Allred score of 5 or 6, and an IHC score of 3+ would be roughly equivalent to an Allred score of 7 or 8.
2. Hormone therapy
Hormone therapy for five years should be considered for all women with hormone receptor positive breast cancer (estrogen receptor [ER] and/or progresterone receptor [PR] Allred score 4-8/8; or 1+ , 2+ or 3+) based on robust large clinical trial data sets establishing a significant survival benefit.2 The absolute benefit depends on both the absolute recurrence risk and the relative strength of hormone receptor expression. The decision to treat cancers with an Allred score of 3 with hormone therapy should be individualized.
2A. Premenopausal women
For premenopausal women, the hormone therapy of choice is tamoxifen (BRAJTAM). An alternative for women with contraindications to tamoxifen is surgical oophorectomy (permanent) or medical menopause (LHRHa; reversible), with or without an aromatase inhibitor (BRAJLHRHT).3 For select low stage, non grade 3 disease, hormone therapy with both tamoxifen and an LHRHa may be an acceptable and/or superior alternative to chemotherapy.4
Duration of therapy:
The current standard of care for most premenopausal women is 5 years of hormone therapy. Women who remain premenopausal after 5 years of tamoxifen may derive a small additional survival benefit from continuing tamoxifen to a total of 10 years.5 Women becoming menopausal near the end of five years of tamoxifen should be considered for extended adjuvant therapy with an aromatase inhibitor for a further 3-5 years, based on evidence of disease free survival and, for node positive disease, modest overall survival benefits.6 When menopausal status is uncertain, extended adjuvant therapy should be with tamoxifen, given that aromatase inhibitors are not beneficial in premenopausal women.
2B. Postmenopausal women
For postmenopausal women, there are several hormone therapy options. They include 5 years of an aromatase inhibitor; 5 years of tamoxifen; and the sequential use over a total of 5 years of tamoxifen and aromatase inhibitor for about 2 and half years each (BRAJTAM, BRAJANAS, BRAJEXE, BRAJLET). Compared with 5 years of tamoxifen, the use of an aromatase inhibitor (for either five years, or for 2.5 years preceded or followed by tamoxifen) is associated with 3% fewer disease free survival events (defined as any of contralateral breast cancer, relapse of prior breast cancer, and death from any cause).7 Despite this, overall survival gains from the introduction of aromatase inhibitors in adjuvant therapy remain elusive.
Duration of therapy:
Menopausal women completing five years of tamoxifen should consider an additional 3-5 years of an aromatase inhibitor or of tamoxifen (if unable to tolerate aromatase inhibitors), depending on the recurrence risk of the original cancer. This is associated with a modest disease free survival improvement over stopping therapy at five years, and for women with node positive breast cancer, a small survival gain.5,6
Ongoing studies are examining whether longer than 5 years is beneficial if the first five years of therapy included an aromatase inhibitor.
The choice of treatment strategy must take into consideration patient co-morbidities and drug side effects, as well as the absolute recurrence risk associated with their cancer. As a guideline, the BC Cancer Breast Tumour group recommends the following:
Table 1. BC Cancer Breast Tumour Group guidelines for hormone therapy in menopausal non- metastatic hormone receptor positive breast cancer