Introduction
Breast cancer affects at least 1 in 10 women in the UK, but most present with primary operable disease, which has an 80% 5-year survival rate overall.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions after breast-conserving surgery for ductal carcinoma in situ? What are the effects of treatments for primary operable breast cancer? What are the effects of interventions in locally advanced breast cancer (stage 3B)? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found 83 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: adding chemotherapy (cyclophosphamide/methotrexate/fluorouracil and/or anthracycline and/or taxane-based regimens), or hormonal treatment to radiotherapy; adjuvant treatments (aromatase inhibitors, adjuvant anthracycline regimens, tamoxifen); axillary clearance; axillary dissection plus sentinel node dissection; axillary radiotherapy; axillary sampling; combined chemotherapy plus tamoxifen; chemotherapy plus monoclonal antibody (trastuzumab); extensive surgery; high-dose chemotherapy; hormonal treatment; less extensive mastectomy; less than whole-breast radiotherapy plus breast-conserving surgery; multimodal treatment; ovarian ablation; primary chemotherapy; prolonged adjuvant combination chemotherapy; radiotherapy (after breast-conserving surgery, after mastectomy, plus tamoxifen after breast-conserving surgery, to the internal mammary chain, and to the ipsilateral supraclavicular fossa, and total nodal radiotherapy); sentinel node biopsy; and standard chemotherapy regimens.
Key Points
Breast cancer affects at least 1 in 10 women in the UK, but most present with primary operable disease, which has an 80% 5-year survival rate overall.
In women with ductal carcinoma in situ (DCIS), radiotherapy reduces local recurrence and invasive carcinoma after breast-conserving surgery. The role of tamoxifen added to radiotherapy for DCIS remains unclear because of conflicting results.
In women with primary operable breast cancer, survival may be increased by full surgical excision, tamoxifen, chemotherapy, radiotherapy, ovarian ablation, or trastuzumab (in women who over-express HER2/neu oncogene).
Incomplete excision may increase the risk of local recurrence, but less-extensive mastectomy that excises all local disease is as effective as radical mastectomy at prolonging survival, with better cosmetic results.
Axillary clearance (removal of all axillary lymph nodes) achieves local disease control, but has not been shown to increase survival, and can cause arm lymphoedema.
Sentinel lymph node biopsy or 4-node sampling may adequately stage the axilla with less morbidity compared with axillary clearance.
Adjuvant tamoxifen reduces the risk of recurrence and death in women with oestrogen-positive tumours.
Primary chemotherapy may facilitate successful breast-conserving surgery instead of mastectomy. Adjuvant combination chemotherapy improves survival compared with no chemotherapy, with greatest benefit likely with anthracycline-based regimens at standard doses for 4 to 6 months.Radiotherapy decreases recurrence and mortality after breast-conserving surgery. Post-mastectomy radiotherapy for women who are node-positive or at high risk of recurrence decreases recurrence and mortality.
Adjuvant aromatase inhibitors improve disease-free survival compared with tamoxifen, but their effect on overall survival is unclear. Adjuvant taxane-based regimens may improve disease-free survival over standard anthracycline-based therapy.
In women with locally advanced breast cancer, radiotherapy may be as effective as surgery or tamoxifen at increasing survival and local disease control.
Adding tamoxifen or ovarian ablation to radiotherapy increases survival compared with radiotherapy alone, but adding chemotherapy may not reduce recurrence or mortality compared with radiotherapy alone.We don't know if chemotherapy alone improves survival in women with locally advanced breast cancer as we found few trials.