Comparison of Treatment Outcomes between Breast Conserving Surgery Followed by Radiotherapy and Mastectomy Alone in Patients with T1-2 Stage and 1-3 Axillary Lymph Nodes in the Era of Modern Adjuvant Systemic Treatments.
OBJECTIVE
The role of postmastectomy radiotherapy in the treatment of T1-2 primary tumor with 1-3 positive lymph nodes is controversial. We compared treatment outcomes between breast conserving surgery followed by radiotherapy (BCS+RT) and total mastectomy alone (TM) in the setting of modern adjuvant systemic treatments.


METHODS
Patients with T1-2 primary breast cancer and 1-3 positive lymph nodes who were treated between 2001 and 2011 were divided into 2 groups based on the treatment approach: BCS+RT (n = 169) and TM (n = 117). All patients received adjuvant chemotherapy including taxanes. Adjuvant endocrine therapy was administered to patients with positive hormone receptors according to their menstrual status.


RESULTS
During a median follow-up of 76.5 months, 21 patients (7.3%) experienced locoregional recurrence as the first event, including 7 patients (4.1%) in the BCS+RT group and 14 patients (12.0%) in the TM group. The 5-year cumulative incidence rate of locoregional recurrence was 2.5% for BCS+RT versus 9.5% for TM (p = 0.016). Competing risk regression analysis revealed that TM was associated with a relative risk for locoregional recurrence of 5.347 (p = 0.003). TM was also associated with a significantly lower 5-year disease-free survival rate compared with BCS+RT (hazard ratio, 2.024; 95% confidence interval, 1.090-3.759; p = 0.026).


CONCLUSIONS
To improve treatment outcomes for TM even after modern systemic treatments, postmastectomy radiotherapy might be required for patients with T1-2 primary breast cancer and 1-3 positive lymph nodes.
Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
Sang-Won
SW
Kim
Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
Mison
M
Chun
Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
Sehwan
S
Han
Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
Yong Sik
YS
Jung
Department of Hematology-Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
Jin Hyuk
JH
Choi
Department of Hematology-Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
Seok Yun
SY
Kang
Department of Radiation Oncology, Dongguk University Gyeongju Hospital, Gyeongju, Republic of Korea.
Hyunsoo
H
Jang
Department of Radiation Oncology, Haeundae Paik Hospital, Inje University School of Medicine, Busan, Republic of Korea.
Sunmi
S
Jo
Clin Oncol (R Coll Radiol). 2008 Feb;20(1):31-4
18345543
J Natl Cancer Inst Monogr. 2001;(30):5-15
11773285
Int J Radiat Oncol Biol Phys. 2003 Oct 1;57(2):336-44
12957243
Strahlenther Onkol. 2014 Aug;190(8):705-14
24888511
Lancet Oncol. 2013 Apr;14(4):297-305
23491275
Medicine (Baltimore). 2015 Aug;94(33):e1259
26287410
N Engl J Med. 2002 Oct 17;347(16):1233-41
12393820
Int J Radiat Oncol Biol Phys. 2014 Jun 1;89(2):392-8
24721590
N Engl J Med. 2015 Jul 23;373(4):307-16
26200977
J Natl Compr Canc Netw. 2015 Dec;13(12 ):1475-85
26656517
Ann Surg Oncol. 2013 Oct;20(10):3169-74
23975289
Ann Surg Oncol. 2014 May;21(5):1569-74
24488216
Int J Radiat Oncol Biol Phys. 2012 Aug 1;83(5):e577-81
22560546
N Engl J Med. 2002 Oct 17;347(16):1227-32
12393819
Int J Radiat Oncol Biol Phys. 2011 Aug 1;80(5):1446-52
20598451
J Clin Oncol. 2004 Nov 1;22(21):4247-54
15452182
J Clin Oncol. 2001 Mar 1;19(5):1539-69
11230499
J Natl Cancer Inst. 1998 Nov 4;90(21):1601-8
9811309
PLoS One. 2015 Dec 21;10(12):e0145463
26691445
Int J Radiat Oncol Biol Phys. 1999 Jul 15;44(5):989-90
10421530
Radiother Oncol. 2007 Mar;82(3):247-53
17306393
Lancet Oncol. 2014 Nov;15(12):1303-10
25439688
Int J Radiat Oncol Biol Phys. 2005 Apr 1;61(5):1337-47
15817335
Ann Oncol. 2015 Sep;26 Suppl 5:v8-30
26314782
Int J Radiat Oncol Biol Phys. 2008 Jul 15;71(4):1022-7
18234447
Cancer J Sci Am. 1997 Jan-Feb;3(1):6-12
9072310
Cancer Res Treat. 2013 Jun;45(2):103-11
23864843
Lancet. 2014 Jun 21;383(9935):2127-35
24656685