In patients with GIST, imatinib C(min) at steady state was significantly associated with albumin concentration, creatinine clearance, and previous major gastrectomy. Although its clinical impact is unclear at present time, monitoring of imatinib C(min) might be particularly important for optimal treatment with imatinib in patients who have undergone major gastrectomy.

Cancers with an advanced stage at diagnosis were associated with an increased risk of suicide within 1 year of diagnosis.

I n the era of cancer immunotherapy, the number of clinical trials for immunotherapeutic agents has been growing. Immune checkpoint inhibitors (ICIs) that target cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or its ligand (PD-L1) have been studied in clinical trials and applied in clinical practice (1).A subset of patients treated with ICI manifest an atypical pattern of tumor response either after an increase of tumor burden or appearance of new lesions, a phenomenon termed pseudoprogression, which is classified as progressive disease by conventional response criteria (2,3). This triggered efforts to develop criteria including immune-related response criteria (irRC) in 2009, immune-related Response Evaluation Criteria in Solid Tumors (RECIST; irRECIST) in 2013, and iRECIST in 2017 (2,(4)(5)(6).Along with increasing recognition of pseudoprogression and its importance, several studies evaluated its incidence and patterns (7-9). But a unifying definition of pseudoprogression is lacking. Although studies have raised the need for robust data on pseudoprogression (10,11), to our knowledge, there is no evidence-based systematic summary of definitions and incidence of pseudoprogression.We performed a systematic review and meta-analysis of published clinical trial reports to determine the incidence of pseudoprogression during treatment with ICI and Purpose: To evaluate by systematic review and meta-analysis the incidence of pseudoprogression in cancer treatment with ICIs, and compare the incidence according to response criteria, tumor types, and immunotherapeutic agents. Materials and Methods:Medline and Embase were searched to identify relevant studies published before December 31, 2018. Clinical trials, post hoc analysis of clinical trials, and prospective studies on ICI treatment in patients with malignant solid tumors were included. Pooled incidence of pseudoprogression for all included studies, per definition of pseudoprogression, cancer type, and drug type, was obtained by random-effects models with inverse variance weighting model. Results:Seventeen studies with 3402 patients were analyzed. The pooled incidence of pseudoprogression was 6.0% (95% confidence interval: 5.0%, 7.0%). The definition of pseudoprogression were divided into four categories: progressive disease followed by partial response (PR) or complete response (CR) but not stable disease (SD) with Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 (six studies); progressive disease followed by SD or PR or CR with RECIST 1.1 (five studies); progressive disease followed by SD or PR or CR with RECIST 1.0 (three studies); and progressive disease followed by SD or PR or CR with immunerelated response criteria (irRC) (three studies). Incidence of pseudoprogression varied from 4.5% to 8.0% per definition, ranged from 5.0% to 7.0% per cancer type, and was 5.6% with the monotherapy of programmed cell death-1 inhibitor. Conclusion:The overall incidence of pseudoprogression was 6.0% and was less than 10% in...