Recent research in molecular biology has identified a significant number of novel markers, which may have diagnostic, prognostic and therapeutic significance. High-throughput tissue array method facilitates the validation of novel markers by enabling the simultaneous analysis of hundreds or thousands of tissue specimens. Tissue array slides can be analyzed using techniques such as immunohistochemistry and in situ hybridization. In this review, we give a brief overview of tissue array method and its application to high throughput clinicopathologic research.
Citations
In spite of gastric cancer's decreasing incidence and mortality rates, it is still the most common cancer in Korea. In the present study, we examined the temporal trends of gastric cancer mortality during the past 20 years in Korea by using an age-period-cohort model, and we predicted the mortality rates for the next 10 years.
Data on the annual number of deaths due to gastric cancer and data on population statistics from 1984 to 2003 were obtained from the Korean National Statistical Office. A log-linear Poisson age-period-cohort model was used to estimate age, period and birth cohort effects. To project two periods (10 years) into the future, the new cohort values were estimated by performing linear regression that was applied to a chosen number of the most recent cohort values.
The trends of gastric cancer mortality were predominantly explained by the cohort effect; the risk of gastric cancer death decreased since the 1919 birth cohort for both genders. The predicted, expected age-adjusted mortality rates per 100,000 for males and females are 45.72 and 23.75, respectively, during 2004~2008, and 34.62 and 17.93 respectively, during 2009~2013. During 2004~2008 and 2009~2013, the predicted numbers of deaths due to gastric cancer in males are 36,922 and 27,959, respectively, whereas those in females are 19,698 and 14,869, respectively.
Not only the mortality, but also the incidence of gastric cancer in Korea is expected to further decrease in both men and women if the trends of the past 20 years continue.
Citations
Advanced gastric cancer patients have a poorer prognosis as compared to the patients with early gastric cancer. This study was conducted to define the prognostic factors for advanced gastric cancer.
606 patients with advanced gastric cancer who underwent curative gastric resection at our hospital were retrospectively examined. The patients were divided into two groups: group 1 was comprised of patients with a survival time <5 years, and group 2 patients had a survival time ≥5 years. We compared clinicopathological characteristics of the two groups by performing univariate and multivariate analysis. We also investigated the prognostic factors according to the stage.
On univariate analysis, 7 factors (age, tumor size, Borrmann type, resection type, distal resection margin, depth of invasion and lymph node status) were found to be different, and multivariate analysis revealed that patient age, depth of invasion and lymph node metastasis were the only significantly differences between the two groups. On the other hand, age and the Borrmann type for stage I b patients, age and the number of retrieved lymph nodes for stage II patients, tumor size for stage III patients, and the type of resection for stage IV patients were found to be the independent prognostic factors.
The age of patients had prognostic value in the early stages of advanced gastric cancers such as stage I b or II. The number greater than 20 retrieved lymph nodes affected the survival, particularly for the patients with stage II disease, and the tumor size was a significant prognostic factor for patients with stage III disease. Therefore, physicians are advised to pay special attention to lymph node dissection for those patients with stage II or III disease.
Citations
It has been reported that the overexpression of the excision repair cross-complementing 1 (ERCC1) gene, which is essential for the repair of cisplatin (CDDP)-DNA adducts, negatively influences the effectiveness of CDDP-based therapy for primary gastric cancer. We investigated whether the ERCC1 expression was associated with survival for gastric cancer patients in an adjuvant setting.
We retrospectively analyzed 44 patients who were diagnosed with stage II or higher disease after undergoing curative resection and they had also received cisplatin-based chemotherapy. The ERCC1 expression was examined by performing immunohistochemical (IHC) staining, and this was divided into two groups according to the percentage of IHC staining of the tumor cell nuclei (negative: 10% or less, positive: more than 10%).
Among the 44 patients (ERCC1-negative/ERCC1-positive group=16/28), 32 patients were male and their median age was 52 years. There was no difference for the baseline characteristics of the two groups. The median follow-up duration was 41 months. The median disease-free survival (DFS) and the overall survival (OS) for the ERCC1-positive group were significant higher than those of the ERCC1-negative group (DFS: 40.4 vs. 14.6 months, p=0.02, OS: undefined vs. 20.4 months, p=0.008).
The overall survival in gastric cancer patients who received cisplatin-based adjuvant chemotherapy after a curative resection is higher in those patients showing the overexpression of the ERCC1 gene. However, prospective studies using the ERCC1 gene expression as a prognostic marker for the DNA repair activity are needed.
Citations
The primary objective of the current study was to investigate the characteristics of synchronous cancers in gastric cancer patients.
We analyzed the 2,237 patients who were diagnosed between December 2000 and December 2003 with gastric cancer and synchronous cancers of organs other than the stomach.
73 (3.3%) of a total of 2,237 gastric cancer patients had synchronous primary cancers. Among these 73 patients, 71 had one synchronous cancer, and two patients had double synchronous cancers. Colorectal cancer (26 patients, 34.7%) was the most frequently encountered synchronous cancer, followed by cancer of the lung (16 patients, 21.3%), esophagus (13 patients, 17.2%), and liver (8 patients, 10.7%). Synchronous cancers were detected with increased frequency in the elderly, in the patients with multiple gastric cancers, in the patients with differentiated gastric cancer, and in the patients with early gastric cancer, as determined on univariate analysis, but the differentiation of gastric cancers was the only risk factor for synchronous cancers on the multivariate analysis.
The differentiation of gastric cancer cells may be a risk factor for synchronous cancers in gastric cancer patients. Careful surveillance by the physician for synchronous cancer is warranted for the patients suffering from gastric cancer.
Citations
Capecitabine is an oral fluoropyrimidine carbamate and it is known as an effective radiosensitizer. Capecitabine and its metabolite reach their peak concentration in the plasma at 1~2 hours after a single oral administration of capecitabine and the levels fall rapidly thereafter. To verify the radiosensitizing effect of capecitabine that is based on such pharmacokinetic characteristics, we performed a retrospective analysis on the optimal timing of capecitabine administration with performing preoperative chemoradiation for locally advanced rectal cancer.
Among 171 patients who were treated with preoperative radiotherapy and concurrent capecitabine administration for rectal cancer, 56 patients were administered capecitabine at 1~2 hours before radiotherapy (group A), and at other time in the other 115 patients (group B). Total mesorectal excision was done at 4 to 6 weeks after the completion of chemoradiation. The radiosensitizing effect of capecitabine was evaluated on the basis of the pathological response.
Complete pathological regression of the primary tumor was observed in 12 patients (21.4%) for group A and in 11 patients (9.6%) for group B (p=0.031). Residual disease less than 0.5 cm (a good response) was observed in 19 patients (33.9%) for group A and in 23 patients (20.0%) for group B (p=0.038). On multivariate analysis, the capecitabine ingestion time showed marginal significance.
When performing preoperative chemoradiation for locally advanced rectal cancer, the radiosensitizing effect of capecitabine was enhanced when it was administered 1 hour before radiotherapy.
Citations
The aim of study was to evaluate the usefulness of serum HER2 as a therapeutic response indicator in patients with HER2 positive metastatic breast cancer (MBC).
The levels of serum HER2 and CA15.3 were assayed in 148 serial serum samples from 50 HER2 positive MBC patients at both the baseline and follow-ups. The changes in the levels of serum HER2 and CA15.3 in relation to the tumor responses to the various chemotherapy regimens were monitored.
The levels of serum HER2 and CA15.3 were elevated in 82% and 62% of tissue HER2 positive patients, respectively, prior to therapies, with the changes in both tumor markers showing statistical significance in relation to the tumor responses (p<0.01) in patients with elevated baseline serum markers.
The level of serum HER2 could be a valuable response indicator, not only for trastuzumab containing therapy, but also for other common MBC chemotherapeutic agents. Also, as it is more frequently elevated, the serum level of HER2 may also be a more useful tumor marker than CA15.3 in HER2 positive MBC.
Citations
To evaluate the effect of the simulation method on recurrence among the patients who received radiotherapy after breast-conserving surgery (BCS) for early breast carcinoma.
Between 1995 and 2000, 70 patients with stage I-II breast carcinoma underwent breast-conserving surgery and adjuvant radiotherapy. Twenty nine patients (41.4%) were simulated with the 2D contour-based method (September 1995 to August 1997) and 41 patients (58.6%) were simulated with the 3D CT-based method (September 1997 to February 2000). To analyze the effect of the simulation method, the patient and treatment characteristics were compared.
The characteristics were similar for the patients between the 2D contour-based simulation group and the 3D CT-based simulation group. During a median follow-up period of 75 months, 4 (13.8%) of 29 patients who were treated with 2D simulation and 1 (2.4%) of 41 patients who were treated with 3D simulation group developed treatment failure. The five-year survival rates were 89.2% and 95.1% between the 2D and 3D simulation groups (p=0.196). The five-year disease free survival (
Although our data showed marginal significance for the DFS between the two groups, it is insufficient, due to the small number of patients in our study, to prove whether 3D CT-based simulation might improve the DFS and reduce the risk of recurrence when compared with 2D contour-based simulation. Further study is needed with a larger group of patients.
Resveratrol is a phenolic compound found in grapes and other food products. In order to assess the availability of resveratrol as an angio-inhibiting drug, we examined whether resveratrol plays an important role in bovine aortic endothelial cells (BAECs) for cell apoptosis and cell migration.
Endothelial cell apoptosis was observed as detected by the Hoechst staining and the caspase-3 activity. Additionally, Western blotting was performed for monitoring the activities of various cell signaling molecules.
Resveratrol was shown to act as a pro-apoptotic agent. The pro-apoptotic effect of resveratrol was as great as that of etoposide, a well-known anti-cancer drug. In addition, resveratrol had an inhibitory effect on endothelial cell migration. The demonstrated efficacy of resveratrol suggests that resveratrol may be utilized as an anti-angiogenic drug. To determine the underlying mechanisms, we further investigated which signaling molecules are activated by resveratrol. Extracellular signal-regulated kinase (ERK) was activated by the treatment with resveratrol in BAECs, whereas endothelial nitric oxide synthetase (eNOS), Akt, and Jun N-terminal kinase (JNK) were inhibited. The pretreatment with PD compound, an ERK inhibitor, had no effect on the pro-apoptosis induced by resveratrol.
Resveratrol plays an important role in endothelial cell apoptosis, indicating that resveratrol can be utilized as a potent anti-angiogenic drug.
Citations
Treatment with arsenic trioxide (As2O3) results in a wide range of cellular effects that includes induction of apoptosis, inhibition of cell growth, promotion or inhibition of cellular differentiation, and inhibition of angiogenesis through a variety of mechanisms. The mechanisms of As2O3-induced cell death have been mainly studied in hematological cancers, and those mechanisms in solid cancers have yet to be clearly defined. In this study, the mechanisms by which As2O3 induces apoptosis in human colorectal adenocarcinoma HT-29 cells were investigated.
To examine the levels of apoptosis, HT-29 cells were treated with As2O3 and then we measured the percentage of Annexin V binding cells, the amount of ROS production and the mitochondrial membrane potential. Western blot analysis was performed to identify the activated caspases after As2O3 exposure, and we compared the possible target molecules of apoptosis. As2O3 treatment induced the loss of the mitochondrial membrane potential and an increase of ROS, as well as activation of caspase-3, -7, -9 and -10.
As2O3 induced apoptosis via the production of reactive oxygen species and the loss of the mitochondrial membrane potential. As2O3 induced the activation of caspase-3, -7, -9 and -10. Furthermore, As2O3 treatment downregulates the Mcl-1 and Bcl-2 expressions, and the release of cytochrome c and an apoptosis-inducing factor (AIF). Pretreating the HT-29 cells with
Taken together, these results suggest that the generation of reactive oxygen species (ROS) by As2O3 might play an important role in the regulation of As2O3-induced apoptosis. This cytotoxicity is mediated through a mitochondria-dependent apoptotic signal pathway in HT-29 cells.
Citations