Association between c-myc amplification and pathological complete response to neoadjuvant chemotherapy in breast cancer

作者：Yasojima Hiroyuki; Shimomura Atsushi; Naoi Yasuto; Kishi Kazuki; Baba Yousuke; Shimazu Kenzo; Nakayama Takahiro; Kim Seung Jin; Tamaki Yasuhiro; Noguchi Shinzaburo^*

来源：European Journal of Cancer, 2011, 47(12): 1779-1788.

DOI：10.1016/j.ejca.2011.06.017

• Breast cancer
• C-myc amplification
• Chemotherapy

Background: The aim of this study was to investigate whether c-myc amplification in human breast cancer is associated with response to neoadjuvant chemotherapy comprising paclitaxel followed by 5-FU/epirubicin/cyclophosphamide (P-FEC).
Methods: Tumour tissue samples were obtained before neoadjuvant chemotherapy (P-FEC) from 100 primary breast cancer patients (stage II/III). C-myc and HER2 amplification were examined by FISH, and oestrogen receptor (ER), progesterone receptor (PR), Ki67, and topoisomerase 2 alpha (TOP2A) expression were examined immunohistochemically. Pathological complete response (pCR) was defined by a complete loss of tumour cells in the breast without any lymph node metastasis.
Results: C-myc amplification was observed in 40% (40/100) of breast tumours, and was significantly associated with ER-negative tumours (23/40 for ER(-) versus 17/60 for ER(+), P = 0.004), high histological grade tumours (11/18 for grade 3 versus 29/82 for grades 1 + 2, P = 0.043) and TOP2A-positive tumours (28/51 for TOP2A(+) versus 12/49 for TOP2A(-), P = 0.002). pCR rate was 20% for total patients (10.0% for ER(+) and 35.0% for ER(-)). Further, breast tumours with c-myc amplification (c-myc(+)) showed a significantly (P = 0.041) higher pCR rate (12/40) than those without such amplification (c-myc(-)) (8/60). This association between pCR and c-myc amplification was observed in ER-positive tumours (4/17 for c-myc(+) versus 2/43 for c-myc(-), P = 0.048) but not in ER-negative tumours (8/23 for c-myc(+) versus 6/17 for c-myc(-), P = 0.973).
Conclusion: Our results suggest that c-myc amplification is significantly associated with a high pCR rate to P-FEC in breast tumours, especially in ER-positive tumours.

• 出版日期2011-8