Angiogenesis and apoptosis-related protein (p53, bcl-2, and bax) expression versus response of gastric adenocarcinomas to paclitaxel and carboplatin chemotherapy

The role of angiogenesis and apoptosis-related proteins in defining respons e to chemotherapy is poorly understood. We examined the microvessel density (MVD) and the expression of p53, bcl-2, and bax proteins in a series of 28 locally advanced gastric adenocarcinomas, treated with paclitaxel and carb oplatin A strong cytoplasmic reactivity in mon than 10% of cancer cells was recorded in 25% of cases for p53 protein, and in 14% and 64% of cases for bcl-2 and bax proteins, respectively. Microvessel density was assigned in t hree categories: low (<35), medium (35-60), and high (>60). Tumors of mediu m MVD showed a significantly higher response rate compared with those of hi gh or low MVD (p = 0.01 and 0.001, respectively), and prognosis was signifi cantly better in this group of patients with medium MVD tumors (p< 0.02). L oss of bax protein expression was somewhat more frequent in tumors resistan t to chemotherapy, but this difference was not of statistical significance. Nuclear p53 reactivity was associated with higher MVD (p = 0.02). The expr ession of p53 and bcl-2 did not influence the outcome of treatment. The pre sent study suggests that although apoptosis-related proteins may have a rol e in defining response to taxanes, parameters related to tumors' vasculatur e, such as drug availability or angiogenic tissue regeneration, may be equa lly important.