pRb2/p130 and VEGF expression in endometrial carcinoma in relation to angiogenesis and histopathologic tumor grade

Endometrial cancer is the most common gynecologic malignancy. Established prognostic factors are histologic grade, depth of myometrial invasion, and extrauterine spread including retroperitoneal lymph node metastases. Tumorigenesis is a multistep process involving different genetic changes resulting in uncontrolled cellular proliferation, inhibition of apoptosis, and enhanced vascular proliferation among other events. Angiogenesis, the formation of new blood vessels from a preexisting vascular network, is necessary for invasive tumor growth and metastasis and constitutes an important point in the control of cancer progression. The pathogenesis of the angiogenetic phenotype may involve the inactivation of different tumor suppressor genes.

We investigated the relationship between the expression levels of VEGF and the retinoblastoma family member pRb2/p130 in endometrial carcinoma in relation to histopathologic tumor grade in a cohort of 50 patients.

We found that VEGF and pRB2/p130 expression were inversely correlated. Additionally, high grade tumors presented a significantly lower number of cells expressing pRb2/p130 when compared to low grade tumors. A significant positive correlation was found, by means of the Spearman coefficient, between VEGF expression and binary grading (0.450, p-value < 0.005) which is an architectural grading system that uses low-magnification assessment of amount of solid growth, pattern of invasion, and presence of necrosis to divide endometrioid carcinomas into low- and high-grade tumors. Additionally, we also found a negative correlation between pRb2/p130 expression levels and binary grading (-0.595, p-value < 0.005). Interestingly, we also found that VEGF and pRb2/p130 expression levels were not related to staging (p-value > 0.005).

These results open up a new perspective including novel markers that, combined together, may be useful in patient screening for endometrial cancer aggressiveness.