Objective: The purpose of this study was to investigate the clinical usefulness of microvessel density (MVD) and an in vivo angiogenesis parameter, color Doppler vascularity index (CDVI), in patients with gastric cancer.
Summary background data: Many studies have reported a significant association between the degree of MVD-evaluated angiogenesis with the clinicopathologic factors and prognosis of patients with various solid tumors. All these studies were accomplished on tissue sections retrospectively obtained from surgical specimens. However, an in vivo method to assess tumor angiogenesis for human malignancies is highly desirable for diagnostic purpose, treatment planning, and follow-up. The CDVI is a new ultrasound parameter for evaluating in vivo angiogenesis, has a good correlation with status of lymph node metastasis in cervical carcinoma, and can predict distant metastasis and survival in colon cancer patients. Therefore, the CDVI may also be useful to assess in vivo angiogenesis in human gastric cancer.
Methods: A total of 79 patients with gastric cancer were enrolled in this study, and microvessel density was evaluated by using immunohistochemical staining of surgical specimens with anti-CD-34 antibody. Tumors were sonographically visible in 31 patients. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section, and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). Correlation between MVD, CDVI and clinicopathologic factors and patient survival was studied.
Results: The MVD was significantly correlated with vascular invasion by multiple linear regression analysis. Although the survival of patients with high MVD (> 32) was significantly worse than those with low MVD (< 32) by univariate analysis, vascular invasion was an independent prognostic factor by Cox proportional hazard model. There was a linear correlation between CDVI and MVD (r =.495, P =.005). Moreover, in patients with a high CDVI (> 11%), the survival rate was significantly lower than that in those with low CDVI (< or = 11%, P =.005). None of the patients with high CDVI (> 11%) survived 2 years after curative resection. In addition to vascular invasion, the CDVI was another independent prognostic factor in the patients with stage III gastric cancer.
Conclusions: Vascular invasion was an important prognostic indicator in gastric cancer. The high CDVI was a good preoperative indicator of early death in stage III gastric cancer patients. Thus, the CDVI may be helpful in selecting patients with gastric cancer for neoadjuvant chemotherapy and/or anti-angiogenic therapy.