Labor resource use for endoscopic gastric cancer screening in Japanese primary care settings: a work sampling study

Potential capacity of endoscopic screening for gastric cancer in Japan

In 2016, the Japanese government decided to introduce endoscopic screening for gastric cancer as a national program. To provide endoscopic screening nationwide, we estimated the proportion of increase in the number of endoscopic examinations with the introduction of endoscopic screening, based on a national survey. The total number of endoscopic examinations has increased, particularly in clinics. Based on the national survey, the total number of participants in gastric cancer screening was 3 784 967. If 30% of the participants are switched from radiographic screening to endoscopic screening, approximately 1 million additional endoscopic examinations are needed. In Japan, the participation rates in gastric cancer screening and the number of hospitals and clinics offering upper gastrointestinal endoscopy vary among the 47 prefectures. If the participation rates are high and the numbers of hospitals and clinics are small, the proportion of increase becomes larger. Based on the same assumption, 50% of big cities can provide endoscopic screening with a 5% increase in the total number of endoscopic examinations. However, 16.7% of the medical districts are available for endoscopic screening within a 5% increase in the total number of endoscopic examinations. Despite the Japanese government's decision to introduce endoscopic screening for gastric cancer nationwide, its immediate introduction remains difficult because of insufficient medical resources in rural areas. This implies that endoscopic screening will be initially introduced to big cities. To promote endoscopic screening for gastric cancer nationwide, the disparity of medical resources must first be resolved.

Detection of gastric cancer using transabdominal ultrasonography is associated with tumor diameter and depth of invasion

Gastric cancer is occasionally diagnosed using transabdominal ultrasonography (US) during screening or investigation of patients with abdominal symptoms. Therefore, the present study analyzed the association of the tumor diameter, pathological T (pT) staging and depth of invasion with the detection of gastric cancer using US. Patient records were analyzed retrospectively and 13 patients were enrolled, who underwent US screening prior to endoscopic mucosal resection, endoscopic submucosal dissection or surgery. In total, 5 patients were diagnosed with gastric cancer using US (positive detection group), while US was unable to detect the gastric cancer in 8 patients (negative detection group). The tumor diameter and depth of invasion were determined by pathologists. One-way analysis of variance or the χ² test was performed. Wall thickness in gastric cancer cases ranged between 7 and 20 mm (mean, 12.2±5.9 mm), as measured using abdominal US. The hemoglobin level was significantly lower in the positive detection patients compared with the negative detection patients (P=0.0455). In addition, the diameters of the gastric wall in the negative and positive detection patients were 24.5±16.4 and 54.4±26.2 mm, respectively (P=0.0266). These results indicate that gastric cancer in the positive detection patients were at a more advanced-stage compared with that in the negative detection patients. Furthermore, gastric cancer with a stage over pT2 was diagnosed using abdominal US (P=0.0242), whereas stage pT1a gastric cancer was not detected by abdominal US. Gastric tumors invading deeper than the submucosa were diagnosed using US (P=0.0242). However, the gastric cancer cases limited to the mucosa remained undetected. In conclusion, the detection of gastric cancer correlated well with the tumor diameter, pT staging and depth of invasion.

When Is Rapid On-Site Evaluation Cost-Effective for Fine-Needle Aspiration Biopsy?

Background

Rapid on-site evaluation (ROSE) can improve adequacy rates of fine-needle aspiration biopsy (FNAB) but increases operational costs. The performance of ROSE relative to fixed sampling depends on many factors. It is not clear when ROSE is less costly than sampling with a fixed number of needle passes. The objective of this study was to determine the conditions under which ROSE is less costly than fixed sampling.

Methods

Cost comparison of sampling with and without ROSE using mathematical modeling. Models were based on a societal perspective and used a mechanistic, micro-costing approach. Sampling policies (ROSE, fixed) were compared using the difference in total expected costs per case. Scenarios were based on procedure complexity (palpation-guided or image-guided), adequacy rates (low, high) and sampling protocols (stopping criteria for ROSE and fixed sampling). One-way, probabilistic, and scenario-based sensitivity analysis was performed to determine which variables had the greatest influence on the cost difference.

Results

ROSE is favored relative to fixed sampling under the following conditions: (1) the cytologist is accurate, (2) the total variable cost ($/hr) is low, (3) fixed costs ($/procedure) are high, (4) the setup time is long, (5) the time between needle passes for ROSE is low, (6) when the per-pass adequacy rate is low, and (7) ROSE stops after observing one adequate sample. The model is most sensitive to variation in the fixed cost, the per-pass adequacy rate, and the time per needle pass with ROSE.

Conclusions

Mathematical modeling can be used to predict the difference in cost between sampling with and without ROSE.

Introducing biomarker panel in esophageal, gastric, and colon cancers; a proteomic approach

Cancer research is an attractive field in molecular biology and medicine. By applying large-scale tools such as advanced genomics and proteomics, cancer diagnosis and treatment have been improved greatly. Cancers of esophagus, gastric, and colon accounted for major health problem globally. Biomarker panel could bring out the accuracy for cancer evaluation tests as it can suggest a group of candidate molecules specified to particular malignancy in a way that distinguishing malignant tumors from benign, differentiating from other diseases, and identifying each stages with high specificity and sensitivity. In this review, a systematic search of unique protein markers reported by several proteomic literatures are classified in their specific cancer type group as novel panels for feasible accurate malignancy diagnosis and treatment. About thousands of introduced proteins were studied; however, a small number of them belonged to a specific kind of malignancy. In conclusion, despite the fact that combinatorial biomarkers appear to be hopeful, more evaluation of them is crucial to achieve the suitable biomarker panel for clinical application. This effort needs more investigations and researches for finding a specific and sensitive panel.