The expression of thymidine phosphorylase correlates with angiogenesis and the efficacy of chemotherapy using fluorouracil derivatives in advanced gastric carcinoma

The expression of thymidine phosphorylase (TP) and the density of microvessel in advanced gastric carcinoma were examined by immunohistochemistry to evaluate the significance of TP. The expression of TP was negative in 72 cases, positive in 54. The microvessel density correlated with the expression of TP. In total cases, patients with TP-positive tumours survived longer than those with TP-negative tumours. In patients treated with fluorouracil derivatives (FUs), the expression of TP significantly correlated with favourable prognosis and with unfavourable prognosis in those not treated with FUs. The patients with TP-positive tumours, the prognosis of patients treated with FUs was significantly better than that of those not treated with FUs. In patients with TP-positive tumours, treatment with FUs and lymph node metastasis were independent prognostic factors according to the Cox proportional hazards model. Depth of invasion and lymph node metastasis were independent prognostic factors in patients with TP-negative tumours. The determination of the expression of TP might be useful for predicting the efficacy of post-operative chemotherapy using FUs to prevent recurrence in advanced gastric carcinoma patients who undergo curative gastrectomy. © 1999 Cancer Research Campaig

Are high initial CEA and CA 19–9 levels associated with the presence of K-ras mutation in patients with metastatic colorectal cancer?

In certain cell culture studies, significant CEA expression was observed in K-ras mutant cells. However, the relationship between high CEA levels and K-ras status has not been sufficiently investigated. In the present study, we aimed to determine the prognostic role of initial CEA and CA 19-9 values in metastatic colorectal cancer patients according to the status of K-ras. Between 2000 and 2010, a total of 215 patients with metastatic colorectal cancer who were treated and followed up in our oncology center were analyzed. Smokers were excluded from the study. The clinicopathological findings and initial CEA and CA19-9 values were determined. K-ras mutation analysis was performed using quantitative PCR evaluation of the DNA from the tumor tissues. Eighty-two patients (38.1 %) were female and 133 (61.9 %) were male, with a median age of 59 years (range 27-83). Based on tumor localization, 127 patients (59 %) were classified as colon cancer patients and 88 patients (41 %) were classified as rectal cancer patients. The majority of patients (83.3 %) had pure adenocarcinoma histology, while 36 cases (16.7 %) had mucinous adenocarcinoma. The initial CEA levels were detected to be high (> 5 ng/mL) in 108 of the patients (50.2 %), while high levels of initial CA 19-9 (> 37 ng/mL) were found in 90 patients (41.8 %). K-ras mutations were detected in 99 of the patients (46 %). K-ras was found to be wild type in 116 patients (54 %). Significant differences were detected between the K-ras wild-type and mutant groups with respect to age and the initial serum CEA levels. Patients with K-ras mutations were younger (p = 0.04) and had higher initial CEA levels (p = 0.02) compared to patients with K-ras wild type. The median overall survival (OS) time and 3-year OS rate for patients with a high initial CEA level (> 5 ng/mL) were significantly shorter than those of patients with a low initial CEA level ( 37 ng/mL) (37.6 months and 55.7 %, p = 0.04). Multivariate analysis indicated that stage at the time of diagnosis (p < 0.001) and low initial serum CEA level (p = 0.037) were independent prognostic factors of OS. For K-ras mutant patients, the stage at diagnosis (p = 0.017), low initial serum CEA level (p = 0.001), and low initial serum CA 19-9 level were found to be independent prognostic indicators of OS. Our findings demonstrate for the first time that the presence of a K-ras mutation correlated with high initial CEA and CA 19-9 levels in patients with metastatic colorectal cancer. Patients with high initial CEA and CA 19-9 levels may potentially predict the presence of a K-ras mutation, and this prediction may guide targeted therapies in these patients