BackgroundIn metastatic breast cancer, the status of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), as well as the Ki-67 index sometimes change between primary and metastatic lesions. However, the change in expression levels of enhancer of zeste homolog 2 (EZH2) between primary and metastatic lesions has not been determined in metastatic breast cancer.MethodsNinety-six metastatic breast cancer patients had biopsies or resections of metastatic lesions between September 1990 and February 2014 at the Kanagawa Cancer Center. We evaluated ER, PR, HER2, Ki-67, and EZH2 in primary lesions and their corresponding metastatic lesions using immunohistochemistry. We examined the change in expression of EZH2 between primary and metastatic lesions, the correlation between the expression of EZH2 and the expression of other biomarkers, and the relationship between EZH2 expression and patient outcome in metastatic breast cancer.ResultsEZH2 expression was significantly higher in metastatic lesions compared with primary lesions. EZH2 expression was highly correlated with Ki-67 expression in primary and metastatic lesions. High-level expression of EZH2 was associated with poorer disease-free survival (DFS) outcomes in patients with primary lesions (P < 0.001); however, high-level expression of EZH2 was not associated with poorer DFS outcomes in patients with metastatic lesions (P = 0.063). High-level expression of EZH2 was associated with poorer overall survival (OS) postoperatively in patients with primary (P = 0.001) or metastatic lesions (P = 0.005). High-level expression of EZH2 was associated with poorer OS outcomes after recurrence in patients with metastatic lesions (P = 0.014); however, high-level expression of EZH2 was not associated with poorer OS outcomes after recurrence in patients with primary lesions (P = 0.096). High-level expression of EZH2 in metastatic lesions was independently associated with poorer OS outcomes after recurrence.ConclusionsEZH2 expression was significantly increased in metastatic lesions compared with primary lesions. High-level expression of EZH2 in metastatic lesions was associated with poorer OS outcomes after primary surgery and recurrence.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3154-3) contains supplementary material, which is available to authorized users.

High Ki-67 immunohistochemical expression levels in distant metastatic lesions were independently associated with poorer overall survival outcomes after biopsy of recurrence lesion in breast cancer patients.

Background Internal mammary and/or supraclavicular (IM–SC) lymph node (LN) recurrence without distant metastasis (DM) in patients with breast cancer is rare, and there have been few reports on its clinical outcomes. Methods We enrolled 4237 patients with clinical stage I–IIIC breast cancer treated between January 2007 and December 2012. Clinicopathological features of patients with IM–SC LN recurrence and patients with DM were retrospectively reviewed. Results With a median follow-up time 78 (range, 13–125) months after the primary operation, 14 (0.3%) had IM–SC LN recurrence without DM and 274 (6.5%) had DM at the first recurrence among 4237 patients. No statistical differences were found in the baseline characteristics of the primary tumor between the two groups. The 5-year overall survival (OS) rate after recurrence in patients with IM–SC LN recurrence was 51% compared with 27% in patients with DM (P = 0.040). In patients with IM–SC LN recurrence, clinically positive axillary LN at diagnosis and pathologically positive axillary LN at primary surgery were poor prognostic factors for distant disease-free survival (DDFS) (P = 0.004 and 0.007, respectively). Clinical and pathological axillary nodal status at primary surgery was associated with OS (P = 0.011 and 0.001, respectively). Conclusions Patients with IM–SC LN recurrence without DM who had no clinical and pathological axillary LNs involved at primary surgery had a favorable prognosis. A larger validation study is required.

Breast cancer screening in Japanese women has led to increases in the rates of breast-conserving surgery, hormone receptor positivity, and survival rates along with reductions in axillary lymph node dissection and adjuvant chemotherapy administration.

The outcomes of the laparoscopic approach were comparable to those for open surgeries accompanied by radical lymph node dissection.