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Overexpression of the Six1 Homeobox Gene Is Associated with Diffuse Peritoneal Spread and Larger Residual Disease after Maximal Cytoreductive Effort in Advanced Ovarian Cancer

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DOI: 10.4236/jct.2015.614127    2,012 Downloads   2,262 Views  

ABSTRACT

Study Design: Between January 2003 and June 2009, we collected fresh tumor and extracted high-quality RNA from the omental/peritoneal metastases of 47 patients with stage IIB-IV ovarian cancer. Clinical data were abstracted from the patients’ medical records. Expression of Six1 level by quantitative RT-PCR was compared with preoperative factors and intraoperative findings using the χ2 test and the Fisher exact test. The effect of Six1 elevation on survival was assessed with the Kaplan/Meier method. Results: The mean age of patients enrolled was 60 (range 33 - 84). The histological subtypes were 77% serous (36/47), 11% endometrioid (5/47), 4% mucinous (2/47), and 4% clear cell (2/47). Eighty-one percent were optimally cytoreduced. Median Six1 expression for the samples was 114 fg/ng 18S rRNA and Six1 overexpression, defined as >300 fg/ng 18S rRNA, was observed in 19% of tumors. Six1 expression above sample median was associated with peritoneal disease (p = 0.049) and inability to optimally cytoreduce (p = 0.02). Six1 overexpression was associated with worsened survival in the high grade serous subgroup (43 months versus 71 months, p = 0.039 Log Rank test). Conclusions: Elevated levels of Six1 predict peritoneal disease and larger residual tumor after maximal cytoreductive effort. Prospective prediction of surgical cytoreduction using a combination of Six1 expression, included with other factors, is currently being evaluated.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Embry-Schubert, J. , Qamar, L. , Spillman, M. , Kelly, M. , Davidson, S. and Behbakht, K. (2015) Overexpression of the Six1 Homeobox Gene Is Associated with Diffuse Peritoneal Spread and Larger Residual Disease after Maximal Cytoreductive Effort in Advanced Ovarian Cancer. Journal of Cancer Therapy, 6, 1167-1175. doi: 10.4236/jct.2015.614127.

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