학술논문
Histologic Discordance Between Primary Tumor and Nodal Metastasis in Breast Cancer: Solving a Clinical Conundrum in the Era of Genomics
Precision Medicine Clinic: Molecular Tumor Board
Precision Medicine Clinic: Molecular Tumor Board
Document Type
Report
Author
Source
The Oncologist. December 2021, Vol. 26 Issue 12, p1000, 6 p.
Subject
Language
English
ISSN
1083-7159
Abstract
Key Points * A degree of molecular concordance is expected for tumors originating from a common stem or progenitor cell. Histological discordance and absence of any genomic overlap should raise [...]
Next-generation sequencing (NGS) technologies have become increasingly used for managing breast cancer. In addition to the conventional use of NGS for predicting recurrence risk and identifying potential actionable mutations, NGS can also serve as a powerful tool to understand clonal origin and evolution of tumor pairs and play a unique role in clarifying complex clinical presentations. We report an unusual case of early-stage breast cancer in which the primary tumor and draining axillary node were histologically discordant. The primary tumor was invasive lobular carcinoma, whereas the nodal metastasis was invasive ductal carcinoma. This discordance led us to question whether the tumors had the same origin. NGS performed on both specimens identified no overlapping variants, leading us to conclude that the patient had two separate primary breast cancers, with the nodal tumor representing metastasis from an occult breast cancer. DNA sequencing of the primary tumor and the nodal metastasis allowed us to predict the patient's recurrence risk, and we initiated adjuvant chemotherapy and hormonal therapy based on these results. This case illustrates the utility of NGS for successfully managing a rare and challenging case. The Oncologist 2021;26:1000-1005 Key Words. Breast cancer * Histologic discordance * Genomic sequencing * Next-generation sequencing * Occult breast cancer * Cancer stem cells
Next-generation sequencing (NGS) technologies have become increasingly used for managing breast cancer. In addition to the conventional use of NGS for predicting recurrence risk and identifying potential actionable mutations, NGS can also serve as a powerful tool to understand clonal origin and evolution of tumor pairs and play a unique role in clarifying complex clinical presentations. We report an unusual case of early-stage breast cancer in which the primary tumor and draining axillary node were histologically discordant. The primary tumor was invasive lobular carcinoma, whereas the nodal metastasis was invasive ductal carcinoma. This discordance led us to question whether the tumors had the same origin. NGS performed on both specimens identified no overlapping variants, leading us to conclude that the patient had two separate primary breast cancers, with the nodal tumor representing metastasis from an occult breast cancer. DNA sequencing of the primary tumor and the nodal metastasis allowed us to predict the patient's recurrence risk, and we initiated adjuvant chemotherapy and hormonal therapy based on these results. This case illustrates the utility of NGS for successfully managing a rare and challenging case. The Oncologist 2021;26:1000-1005 Key Words. Breast cancer * Histologic discordance * Genomic sequencing * Next-generation sequencing * Occult breast cancer * Cancer stem cells