HOXA7 in epithelial ovarian cancer: interrelationships between differentiation and clinical features

Interrelationships between HOXA7 expression and ovarian cancer progression are investigated by cDNA array and by immunohistochemistry of normal ovaries and 538 epithelial ovarian tumor microarrays. Outcomes of patients and HOXA7 expression were compared by Kaplan-Meier survival curves. HOXA7 mRNA expression was higher in carcinomas than in benign tumors. HOXA7 protein was absent in normal surface epithelium but appeared in metaplastic regions. All carcinomas stained for HOXA7 protein, with staining intensities unrelated to histotype, grade, or patient outcome. There were significant associations of strong HOXA7 staining of stroma and tumor nuclei with the clear cell histotype (stroma: P = .0022, nuclei: P = .0003) and of weak/absent staining with serous carcinomas. Tumor E-cadherin expression correlated significantly with HOX7 staining in stroma (P = .0002) but not within tumors. HOXA7 staining of tumor cell nuclei is correlated significantly with improved disease-specific survival (P = .0104), which is suggestive of the biological and potentially clinical importance of subcellular HOXA7 localization.