Clinical relevance of lymph node ratio in breast cancer patients with one to three positive lymph nodes.
BACKGROUND
To test the hypotheses that breast cancer patients with one to three positive lymph nodes (pN1) consist of heterogeneous prognostic subsets and that the ratio of positive nodes to total nodes dissected (lymph node ratio, LNR) might discriminate patients with a higher risk as candidates for post-mastectomy radiation therapy (PMRT).


METHODS
Using information from 7741 node-positive patients, we first identified cutoff values of the LNR using the nonparametric bootstrap method. Focusing on 3477 patients with pN1 disease, we then evaluated the clinical relevance of the LNR categorised by the estimated cutoff values (categorised LNR, cLNR).


RESULTS
Among 3477 patients with pN1 disease, 3059 and 418 patients were assigned into the low and intermediate cLNR groups, respectively, based on a cutoff value of 0.18. The prognostic factors associated with poor overall survival (OS) included younger age, T2 stage, negative oestrogen/progesterone receptors, high histologic grade, and intermediate cLNR. Post-mastectomy radiation therapy significantly increased OS in patients assigned to the intermediate cLNR (hazard ratio, 0.39; 95% confidence interval, 0.17-0.89; P=0.0248), whereas patients in the low cLNR group derived no additional survival benefit from PMRT.


CONCLUSIONS
This study suggests that PMRT should be recommended for patients with pN1 disease and an intermediate cLNR.
Department of Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
S I
SI
Kim
S-H
SH
Cho
J S
JS
Lee
H-G
HG
Moon
W C
WC
Noh
H J
HJ
Youn
B K
BK
Ko
B-W
BW
Park
D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008408:Mastectomy; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone