Metastatic Tumor Volume and Extranodal Tumor Extension: Clinical Significance in Patients with Stage II Breast Cancer
Eva Drinka, Andrew McBride, Pamela Allen, Thomas Buchholz, Aysegul Sahin. MD Anderson Cancer Center, Houston, TX
Background: Lymph node status and number of positive lymph nodes (PLN) are the most important prognostic factors in breast cancer. Extranodal tumor extension (ENTE) has been used as a key histopathologic feature classifying patients into high versus low risk for local recurrence. Radiation oncologists also use ENTE when identifying patients who may benefit from post mastectomy radiation. However, in the current era of early detection and systemic therapy the prognostic significance of ENTE is not as well defined in patients with 1-3 PLN. We sought to determine if the amount of tumor burden in an axillary dissection, or the presence of ENTE provides any additional information regarding patient outcome in patents with 1-3 PLN.
Design: Clinical and pathologic factors were identified for 473 patients at MDACC with pT1 tumors and 1-3 PLN, treated by mastectomy with or without postmastectomy radiotherapy between 1978 and 2007. The total number of PLN was recorded for each patient, as well as the presence or absence of ENTE. A Kaplan-Meier analysis was generated to determine whether the number of PLN, and presence or absence of ENTE was an independent predictor of patient outcome.
Results: A total of 473 patients were identified with histology available for review. Out of these patients 266, 143 and 63 patients had 1, 2 or 3 PLN respectively. ENTE was present in 97 cases, and absent in the remaining 357 cases. Kaplan-Meier disease specific survival curves are seen below.
Conclusions: The number of positive axillary lymph nodes is statistically significant in regards to patient outcome. The presence of ENTE does not reach significance. 12 year disease specific survival for patients with stage II breast cancer approached 87%. When looking to stratify patients with stage II breast cancer who may benefit from radiation therapy, in our study the presence of ENTE did not show clear patient stratification.
Monday, March 4, 2013 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 20, Monday Morning