Abstract
The human epidermal growth factor receptor 2 (HER2) gene is located on the long arm of chromosome 17 (Chr-17). While primary tumors with Chr-17 polysomy (polysomy 17) are histopathologically similar to HER2-negative tumors, the role of polysomy 17 in circulating tumor cells (CTCs) is still unknown. We report the detection rate of polysomy 17 in CTCs in patients with metastatic breast cancer (MBC). We determined the CTC count per 7.5 ml blood and polysomy 17 in CTCs at 3- to 4-week intervals up to 12 weeks in 52 patients. Polysomy was defined as Chr-17 ≥2.2. CTCs were detected in 40 of 52 patients (76.9%) during the study period, in 32 of the 52 patients (61.5%) at baseline, and in 21 of 49 patients (42.9%) at 3-4 weeks. Polysomy 17 in CTCs was present in 10 of 52 patients (19.2%) during the study period, in 5 of 52 patients (9.6%) at baseline, and in 7 of 49 patients (14.3%) at 3-4 weeks. The individual patient counts of polysomy 17 in CTCs/total count of CTCs examined for polysomy 17 at 3-4 weeks were 1/1, 1/7, 1/7, 2/27, 2/30, 2/50, and 3/50. Six of the 7 patients with polysomy 17 in CTCs had HER2-negative primary tumors. None of the CTCs displaying polysomy 17 themselves had HER2 amplification by FISH. In summary, polysomy 17 in CTCs was observed in only a small population of patients with MBC. We should prospectively evaluate its prognostic value in both HER2-positive and -negative metastatic breast cancer.
Original language | English (US) |
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Pages (from-to) | 596-600 |
Number of pages | 5 |
Journal | International Journal of Clinical Oncology |
Volume | 16 |
Issue number | 5 |
DOIs | |
State | Published - Oct 2011 |
Funding
The authors thank Bibari Nakamura, Keiko Shimizu, and all the staff from the Department of Breast Surgical Oncology, St. Luke’s International Hospital, for help in collecting clinical data; Masayuki Shimada, Takeshi Watanabe, and Yuki Matsuo from SRL Inc. for tissue analysis; and Sunita Patterson from the Department of Scientific Publications, MD Anderson Cancer Center, for editorial review. This research is supported in part by the National Institutes of Health through MD Anderson’s Cancer Center Support Grant, CA016672, and the Nellie B. Connally Breast Cancer Research Fund. G. N. Hortobagyi is a consultant to Merck, Novartis, and Sanofi-aventis, and received research funding from Novartis. Y. Shimada has employment with SRL Inc. The other authors have no conflict of interest.
Keywords
- Breast neoplasm
- Circulating tumor cell
- HER2
- Metastasis
- Polysomy
ASJC Scopus subject areas
- Hematology
- Oncology
- Surgery