Radiotherapy can decrease locoregional recurrence and increase survival in mastectomy patients with T1 to T2 breast cancer and one to three positive nodes with negative estrogen receptor and positive lymphovascular invasion status.
OBJECTIVE
To define a subgroup of patients at high risk of locoregional recurrence (LRR) who might be benefit from postmastectomy radiotherapy in invasive breast cancer and tumor size <5 cm with one to three involved axillary lymph nodes (T1-2 N1).


METHODS
Between April 1991 and December 2005, 544 patients with T1-2 N1 invasive breast cancer were treated with modified radical mastectomy. Of the 544 patients, 383 patients (70.4%) had no radiotherapy, and 161 patients (29.6%) received radiotherapy. We retrospectively compared these two patient groups.


RESULTS
With a median follow-up of 40.3 months, LRR occurred in 40 (7.4%) of 544 patients. On univariate analysis, high nuclear grade (p = 0.04), negative estrogen receptor (ER) status (p = 0.001), presence of lymphovascular invasion (LVI) (p = 0.003), and no radiotherapy (p = 0.0015) were associated with a significantly higher rate of LRR. Negative ER status (hazard ratio = 5.1) and presence of LVI (hazard ratio = 2.5) were the risk factors for LRR with statistical significance in the multivariate analysis. Radiotherapy reduced the LRR in patients with the following characteristics: age <40 years, T2 stage, high nuclear grade, negative ER status, and presence of LVI. For 41 patients with negative ER and positive LVI status, radiotherapy can reduce LRR from 10 of 25 (40%) to 2 of 16 (12.5%) and increase the 5-year overall survival from 43.7% to 87.1%.


CONCLUSIONS
Radiotherapy can reduce LRR and increase survival in T1-2 N1 breast cancer patients with negative ER status and presence of LVI.
Yang
Po Sheng
PS
Department of Surgery, Sun Yat-Sen Cancer Center, Taipei, Taiwan. psyang@kfsyscc.org
Chen
Chi Ming
CM
Liu
Mei Ching
MC
Jian
Jer Min
JM
Horng
Cheng Fang
CF
Liu
Ming Jiung
MJ
Yu
Ben Long
BL
Lee
Ming Yuan
MY
Chi
Chin Wen
CW
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology; D015411:Mastectomy, Modified Radical / Q000401:mortality; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000517:prevention & control; D011960:Receptors, Estrogen / Q000378:metabolism; D012189:Retrospective Studies; D015996:Survival Rate; D047368:Tumor Burden
D011960:Receptors, Estrogen