Mesothelium expression of vascular cell adhesion molecule‐1 (VCAM‐1) is associated with an unfavorable prognosis in epithelial ovarian cancer (EOC)

BACKGROUND Mesothelium vascular cell adhesion molecule‐1 (VCAM‐1) expression in the metastatic epithelial ovarian cancer (EOC) microenvironment is induced by tumor and mediates tumor cell invasion. VCAM‐1 imaging suggests expression during treatment is an indicator of platinum resistance. Here, we assess the potential prognostic significance of mesothelium VCAM‐1 expression and prospectively evaluate whether soluble VCAM‐1 (sVCAM‐1) is a surrogate for mesothelium expression. METHODS A retrospective review of EOC patients was performed to evaluate outcomes with mesothelium VCAM‐1 expression determined by immunohistochemistry of peritoneum or omentum specimens. A prospective cohort of EOC patients was identified and followed through primary treatment. Serum for sVCAM‐1 evaluation, which was performed via enzyme‐linked immunosorbent assay, was collected before surgery or neoadjuvant chemotherapy and at each treatment cycle. Peritoneal specimens were obtained during debulking to assess mesothelial VCAM‐1 expression. RESULTS A retrospective review identified 54 advanced‐stage EOC patients. Patients expressing mesothelium VCAM‐1 had shortened overall survival (44 vs 79 months, P = 0.035) and progression‐free survival (18 vs 67 months, P = 0.010); the median time to platinum resistance was 36 months for VCAM‐1–expressing patients and not yet determined for the VCAM‐1–negative group. In our prospective observational cohort, 18 EOC patients completed primary treatment; 3 were negative for mesothelium VCAM‐1 expression, and sVCAM‐1 did not vary between groups. CONCLUSIONS Mesothelium VCAM‐1 expression is negatively associated with progression‐free and overall survival in EOC. This is especially compelling in light of previous data suggesting that persistent VCAM‐1 expression during treatment is an indicator of platinum resistance. Our pilot study had insufficient cases to determine whether sVCAM‐1 would substitute for mesothelium expression. Cancer 2017;123:977–84. © 2016 American Cancer Society. Expression of vascular cell adhesion molecule‐1 (VCAM‐1) on the mesothelium is a predictor of ovarian cancer treatment response and prognosis as its presence correlates with platinum sensitivity, progression of disease, and overall survival, affirming that the presence of VCAM‐1 in the tumor microenvironment of EOC appears to be pivotal in determining the biologic behavior of disease. Soluble serum VCAM‐1 does not correlate with mesothelium expression in this small pilot st