Table 2. Non-RCT comparative studies comparing BCS vs. mastectomy in terms of oncological safety.
| Author/year of publication | Centre/country | Treatment period | No. of patients | Type of study | Comparison of survival | Comparison of local control | BCT rate (%) | Conclusion, limitations & relevant comments |
|---|---|---|---|---|---|---|---|---|
| van Hezewijk et al. (12), 2013 | Multicentre trial, various countries (TEAM trial) | 2001–2006 | 9,231 ER, PR+ve | Prospective subgroup analysis | HR for death (P<0.001), BCStRT: 1.0, Mx: 1.22 (1.02e1.47), MxtRT: 1.41 (1.14_1.75) |
HR for LRR (P=0.1), BCStRT: 1.0, Mx: 1.53 (1.10e2.11) |
54.1 | Significantly higher LRR in patients with Mx only. Unrandomised for surgical therapy with possible selection bias |
| Abdulkarim et al. (13), 2011 | University of Alberta, Canada | 1998–2008 | 768 T1–2N0 TNBC |
Retrospective Single institution | NR | 5-year LRR-free survival: BCT, 94%; Mx, 85%; Mx t RT, 87% |
41.5 | BCT for T1–2N0 TNBC results in higher, 5-year LRR-free survival than Mx, (P=0.027). It is hypothesised that RT contributes to reduced LRR |
| van der Heiden-van der Loo et al. (14), 2015 | Netherlands Comprehensive Cancer Organisation | 2003–2006 | 40,892 | Retrospective The Netherlands Cancer Registry | NR | 5-year IBTR: BCStRT, 2.38%; Mx, 3.45% | 54.9 | IBTR rates may be used as an outcome indicator on a national level for international comparison |
| van Maaren et al. (15), 2016 | Netherlands Comprehensive Cancer Organisation | 2000–2004 | 37,207 | Retrospective The Netherlands Cancer Registry | HR for 10-year overall mortality: BCT, 0.81 (95% CI, 0.78e0.85); Mx, 1.0 (Reference) |
NR | 58 | Significantly higher 10-year distant metastasis-free survival for BCS t RT in T1N0 stage cancer, potentially confounded by factors unaccounted for |
| Plichta et al. (16), 2016 | Massachusetts General Hospital | 1996–2008 | 584 <40 years old | Retrospective Single Centre | 10-year DFS: BCT, 89%; Mx, 79% |
10 year LRR: BCT, 4%; Mx, 8.7% | 57.4 | BCT oncologically safe for young breast cancer patients |
BCS, breast conserving surgery/lumpectomy only; BCT, breast conservation treatment/lumpectomy with radiotherapy; DFS, disease-free survival; ER, oestrogen receptors; HR, hazard ratio; IBTR, ipsilateral breast tumour recurrence; LN, lymph node status; LRR, loco-regional recurrence; Mx, mastectomy; NR, not reported; OS, overall survival; PR, progesterone receptors; RT, radiotherapy/radiation treatment; SEER, Surveillance Epidemiology, and End Results database; TEAM, Tamoxifen Exemestane Adjuvant Multicentre trial; TNBC, triple negative breast cancer; USA, United States of America.