Background: The ratio of involved to retrieved lymph nodes (LNR) is suggested as a prognostic factor in operable breast cancer. However, there are conflicting results regarding its clinical significance after neoadjuvant chemotherapy. We investigated the prognostic value of LNR with a thorough evaluation of potential prognostic factors in a large cohort constructed from Health Insurance Review and Assessment Service database of Korea.

Patients and method: This retrospective analysis is based on the data of 814 patients with clinical stage II/III breast cancer treated with four cycles of adriamycin/cyclophosphamide (AC) followed by four cycles of docetaxel (DOC) before surgery. We evaluated the clinical significance of the LNR (3 categories: Low, 0-0.20 vs. Intermediate, 0.21-0.65 vs. High, 0.66 -1.00) using Kaplan-Meier method, log-rank test, and Cox proportional hazard regression model.

Result: A total of 799 patients underwent breast surgery (Median age 45, range 16-74; Mastectomy 369, Lumpectomy 380, and Others 50). Axillary lymph node dissection was performed in 704 (88.1%) patients. Pathologic complete response (pCR, pT0/isN0) was achieved in 129 (16.1%) of 799 patients (HR+/HER2-, 34/373 [9.1%]; HER2+, 45/210 [21.4%]; TNBC 50/216 [23.1%]). The mean numbers of involved LN and retrieved LN were 2.70 (range 0-42) and 13.98 (range 1-64), respectively. The mean LNR was 0.17 (Low, 574 [71.8%]; Intermediate, 170 [21.3%]; High, 55 [6.9%]). In univariate analysis, LNR was significantly associated with worse relapse-free survival (3-yr RFS rate 84.8% in low vs. 66.2% in intermediate vs. 54.3% in high; P <0.0001, log-rank test). In multivariate analysis, LNR was not significantly associated with recurrence after adjustment of other clinical factors (Age, histologic grade, intrinsic subtype, ypT-stage, ypN-stage, lymphatic or vascular invasion, and pCR).

Multivariate analysis for relapse-free survival

  P-value HR 95%CI 
AGE (<50, ≥50) 0.157 - - 
ypT-stage <0.0001 - - 
ypN-stage 0.035 - - 
pCR (T0/isN0) 0.027 - - 
Lymphovascular invasion 0.040 - - 
Subtype <0.0001 - - 
Histologic grade 0.001 - - 
LNR Low (0-0.20) 0.954 1.00 - 
LNR Intermediate (0.21-0.65) 0.973 1.01 0.55-1.86 
LNR High (0.66-1.00) 0.797 1.12 0.48-2.59 
  P-value HR 95%CI 
AGE (<50, ≥50) 0.157 - - 
ypT-stage <0.0001 - - 
ypN-stage 0.035 - - 
pCR (T0/isN0) 0.027 - - 
Lymphovascular invasion 0.040 - - 
Subtype <0.0001 - - 
Histologic grade 0.001 - - 
LNR Low (0-0.20) 0.954 1.00 - 
LNR Intermediate (0.21-0.65) 0.973 1.01 0.55-1.86 
LNR High (0.66-1.00) 0.797 1.12 0.48-2.59 
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Conclusion: LNR is not superior to ypN-stage in predicting clinical outcome of breast cancer after neoadjuvant chemotherapy.

Citation Format: Se Hyun Kim, Jee Hyun Kim, Tae-Yong Kim, In Sil Choi, Yee Soo Chae, Sun Kyung Baek, Seok Yun Kang, In Hae Park, Yoon Ji Choi, Soohyeon Lee, Joo Hyuk Sohn, Yeon-Hee Park, Young-Hyuck Im, Jin-Hee Ahn, Sung-Bae Kim, Kyung Hae Jung. Prognostic value of axillary nodal ratio after neoadjuvant chemotherapy of AC followed by docetaxel: A multicenter retrospective cohort study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-33.