In recent years, rapid advancement in gene/protein analysis technology has resulted in target molecule identification that may be useful in cancer treatment. Therefore, \"Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition\" was published in Japan in September 2021. These guidelines were established to align the clinical usefulness of external diagnostic products with the evaluation criteria of the Pharmaceuticals and Medical Devices Agency. The guidelines were scoped for each tumor, and a clinical questionnaire was developed based on a serious clinical problem. This guideline was based on a careful review of the evidence obtained through a literature search, and recommendations were identified following the recommended grades of the Medical Information Network Distribution Services (Minds). Therefore, this guideline can be a tool for cancer treatment in clinical practice. We have already reported the review portion of \"Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition\" as Part 1. Here, we present the English version of each part of the Clinical Practice Guidelines for Molecular Tumor Marker, Second Edition.

Reports of low-value prostate-specific antigen (PSA) testing (testing in which the harms outweigh the benefits) generally employ population level data sources. While such results may be generalizable, they often lack the detail necessary to understand provider clinical decision making and guideline concordance. Using a retrospective study of PSA testing at our institution we intend to characterize the frequency and patterns associated with low-value PSA testing.
We leveraged the electronic health record to determine guideline-defined low-value testing in our health system from 07/01/2012 to 06/30/2017. Secondarily, we measured the between-testing interval for repeat tests and the rates of prostate cancer risk factors and comorbidities among men receiving screening.
Overall, 21,145 PSA tests were performed on 12,303 men. The rate of low-value testing ranged from 23.4 to 56.8%, depending upon the specific guideline. For repeat tests, the median between-testing interval was 12.6 months. Risk factors for prostate cancer were uncommon, but more frequent in men age <55 years compared to men age 55-69 years (17.6% vs. 13.5%, p < 0.001). Screened older men (age >70 years) were more likely to have a Charlson Comorbidity Index ≥ 3, compared to the 55-69 reference group (31.4% vs. 17.3%, p < 0.001).
Low-value prostate cancer testing is prevalent. Between-testing intervals were often times shorter than recommended. Screening among younger men was frequent despite low rates of risk factors. High rates of comorbidity may limit life expectancy among older men receiving screening. These findings highlight the need for improved guidance with prostate cancer screening.

OBJECTIVE: Presently, there is no scientific evidence supporting a definite role for follow-up after gastrectomy for cancer, and clinical practices are quite different around the globe. The aim of this consensus conference was to present an ideal prototype of follow-up after gastrectomy for cancer, based on shared experiences and taking into account the need to rationalize the diagnostic course without losing the possibility of detecting local recurrence at a potentially curable stage.
METHODS: On June 19-22, 2013 in Verona (Italy), during the 10th International Gastric Cancer Congress (IGCC) of the International Gastric Cancer Association, a consensus meeting was held, concluding a 6-month, Web-based, consensus conference entitled \"Rationale of oncological follow-up after gastrectomy for cancer.\"
RESULTS: Forty-eight experts, with a geographical distribution reflecting different health cultures worldwide, participated in the consensus conference, and 39 attended the consensus meeting. Six statements were finally approved, displayed in a plenary session and signed by the vast majority of the 10th IGCC participants. These statements are attached as an annex to the Charter Scaligero on Gastric Cancer.
CONCLUSIONS: After gastrectomy for cancer, oncological follow-up should be offered to patients; it should be tailored to the stage of the disease, mainly based on cross-sectional imaging, and should be discontinued after 5 years.

Biomarkers currently play an important role in the detection and management of patients with several different types of gastrointestinal cancer, especially colorectal, gastric, gastro-oesophageal junction (GOJ) adenocarcinomas and gastrointestinal stromal tumors (GISTs). The aim of this article is to provide updated and evidence-based guidelines for the use of biomarkers in the different gastrointestinal malignancies. Recommended biomarkers for colorectal cancer include an immunochemical-based fecal occult blood test in screening asymptomatic subjects ≥50 years of age for neoplasia, serial CEA levels in postoperative surveillance of stage II and III patients who may be candidates for surgical resection or systemic therapy in the event of distant metastasis occurring, K-RAS mutation status for identifying patients with advanced disease likely to benefit from anti-EGFR therapeutic antibodies and microsatellite instability testing as a first-line screen for subjects with Lynch syndrome. In advanced gastric or GOJ cancers, measurement of HER2 is recommended in selecting patients for treatment with trastuzumab. For patients with suspected GIST, determination of KIT protein should be used as a diagnostic aid, while KIT mutational analysis may be used for treatment planning in patients with diagnosed GISTs.

Tumor markers are assuming a growing role in all aspects of cancer care, starting from screening to follow-up after treatment, and their judicious application in clinical practice needs a thorough understanding of the basics of pathophysiology, techniques of identification or testing, reasons for out-of-range levels of tumor markers, as well as the knowledge of evidence of their role in any given malignancy. These are, at the most, just an adjunct to diagnosis, and establishing a diagnosis on the basis of tumor markers alone (especially a single result) is fraught with associated pitfalls because of the problem of nonspecificity. In reality an ideal tumor marker does not exist. Detection can be done either in tissue or in body fluids like ascitic or pleural fluid or serum. Clinical uses can be broadly classified into 4 groups: screening and early detection, diagnostic confirmation, prognosis and prediction of therapeutic response and monitoring disease and recurrence. In addition to variable sensitivity and specificity, the prevalence of a particular malignancy may be a major determinant in the application of a particular test as a screening tool. Serum levels, in certain situations, can be used in staging, prognostication or prediction of response to therapy. Monitoring disease is, perhaps, the most common clinical use of serum tumor markers. Rising trend in serum levels may detect recurrence of disease well before any clinical or radiological evidence of disease is apparent (\"biochemical recurrence\"). Sampling should ideally be repeated after 5-6 half-lives of the marker in question (or the marker with the longest half-life if multiple markers are being considered); but if found elevated, the next sampling after 2-4 weeks, for additional evidence, may be justified.