Objective: To evaluate factors affecting sentinel lymph node (SLN) identification after neoadjuvant chemotherapy (NAC) in patients with initial node-positive breast cancer.
Background: SLN surgery is increasingly used for nodal staging after NAC and optimal technique for SLN identification is important.
Methods: The American College of Surgeons Oncology Group Z1071 prospective trial enrolled clinical T0–4, N1–2, M0 breast cancer patients. After NAC, SLN surgery and axillary lymph node dissection (ALND) were planned. Multivariate logistic regression modeling assessing factors influencing SLN identification was performed.
Results: Of 756 patients enrolled, 34 women withdrew, 21 were ineligible, 12 underwent ALND only, and 689 had SLN surgery attempted. At least 1 SLN was identified in 639 patients (92.7%: 95% CI: 90.5%–94.6%). Among factors evaluated, mapping technique was the only factor found to impact SLN identification; with use of blue dye alone increasing the likelihood of failure to identify the SLN relative to using radiolabeled colloid +/− blue dye (P = 0.006; OR = 3.82; 95% CI: 1.47–9.92). The SLN identification rate was 78.6% with blue dye alone; 91.4% with radiolabeled colloid and 93.8% with dual mapping agents. Patient factors (age, body mass index), tumor factors (clinical T or N stage), pathologic nodal response to chemotherapy, site of tracer injection, and length of chemotherapy treatment did not significantly affect the SLN identification rate.
Conclusions: The SLN identification rate after NAC was higher when mapping was performed using radiolabeled colloid alone or with blue dye compared with blue dye alone. Optimal tracer use is important to ensure successful identification of SLN(s) after NAC.
Sentinel lymph node (SLN) identification rate after neoadjuvant chemotherapy is higher with use of radiolabeled colloid. Optimal tracer use is important to ensure successful identification of SLN(s) after neoadjuvant chemotherapy.
*Mayo Clinic, Rochester, MN
†Alliance Statistics and Data Center, Mayo Clinic, Rochester, MN
‡MD Anderson Cancer Center, Houston, TX
§University of Pittsburgh, Pittsburgh, PA
¶University of Wisconsin, Madison, WI
‖Columbia University Medical Center, New York, NY
**University of Texas Southwestern Medical Center, Dallas, TX
††Carolinas Medical Center, Charlotte, NC; and
‡‡Indiana University Medical Center, Indianapolis, IN.
Reprints: Judy C. Boughey, MD, Department of Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail: firstname.lastname@example.org.
Disclosure: There are no financial disclosures or potential conflicts of interest that we are aware of related to this manuscript. The clinical trial was funded by the National Cancer Institute, and some of the authors received reimbursement for travel to Alliance investigator meetings. This work was supported by National Cancer Institute grant U10 CA76001 to the American College of Surgeons Oncology Group (ACOSOG). The study was also supported, in part, by grants from the National Cancer Institute (CA31946) to the Alliance for Clinical Trials in Oncology (Monica M. Bertagnolli, MD, Chair) and to the Alliance Statistics and Data Center (Daniel J. Sargent, PhD, CA33601). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health. The National Cancer Institute (NCI) approved the study design and had a representative on the DSMC of this cooperative group study. It had no role in the collection, analysis, and interpretation of the data or the preparation, review, or approval of the manuscript.
Trial Registration clinicaltrials.gov; trial identifier NCT00881361.