Cancer science
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Comparative Study
Prediction and prioritization of neoantigens: integration of RNA sequencing data with whole-exome sequencing.
The importance of neoantigens for cancer immunity is now well-acknowledged. However, there are diverse strategies for predicting and prioritizing candidate neoantigens, and thus reported neoantigen loads vary a great deal. To clarify this issue, we compared the numbers of neoantigen candidates predicted by four currently utilized strategies. ⋯ Without additional amplicon sequencing of cDNA, strategy IV was comparable to strategy III. We therefore propose strategy IV as a practical and appropriate strategy to predict candidate neoantigens fully utilizing currently available information. It is of note that different neoantigen loads were deduced from the same tumors depending on the strategies applied.
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Next-generation sequencing (NGS) and digital PCR technologies allow analysis of the mutational profile of circulating cell-free DNA (cfDNA) in individuals with advanced lung cancer. We have now evaluated the feasibility of cfDNA sequencing for mutation detection in patients with non-small cell lung cancer at earlier stages. A total of 150 matched tumor and serum samples were collected from non-small cell lung cancer patients at stages IA-IIIA. ⋯ Whereas the yield of cfDNA did not differ among tumor stages, the cfDNA mutations were detected in seven patients at stages IIA-IIIA and at T2b or T3. Tumor volume was significantly higher in the cfDNA mutation-positive patients than in the negative patients at stages T2b-T4 (159.1 ± 58.0 vs. 52.5 ± 9.9 cm3 , P = 0.014). Our results thus suggest that tumor volume is a determinant of the feasibility of mutation detection with cfDNA as the analyte.
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To assess the association of the programmed cell death ligand 1 (PD-L1) with cisplatin-based neo-adjuvant chemotherapy (NAC) response, we investigated the level of PD-L1 and found increased PD-L1 expression in chemo-resistant tumors compared with chemo-sensitive tumors according to RNA-Seq analysis. In a cohort of 92 patients with NAC, the positive staining of PD-L1 was correlated with TNM stage, lower sensitive-response rates and shorter overall survival rates. In another 30 paired tumor specimens pre- and post-chemotherapy, the patients with high PD-L1 expression post-chemotherapy had a worse outcome and higher stable disease rate. ⋯ When phosphatidylinositol 3-kinase/protein kinase B signaling was inhibited by corresponding inhibitors, PD-L1 expression was downregulated and apoptosis was upregulated in the cisplatin-treated cancer cells. These results suggest that the upregulation of PD-L1 promotes a resistance response in lung cancer cells that might be through activation of the phosphatidylinositol 3-kinase/protein kinase B pathway and suppression of tumor-infiltrating lymphocytes. The high expression of PD-L1 after NAC could be an indication of therapeutic resistance and poor prognosis in patients with non-small-cell lung cancer.
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Multicenter Study
Prognostic and predictive value of extended RAS mutation and mismatch repair status in stage III colorectal cancer.
The prognostic and predictive value of KRAS gene mutations in stage III colorectal cancer is controversial because many recent clinical trials have not involved a surgery-alone arm. Additionally, data on the significance of extended RAS (KRAS/NRAS) mutations in stage III cancer are not available. Hence, we undertook a combined analysis of two phase III randomized trials, in which the usefulness of adjuvant chemotherapy with tegafur-uracil (UFT) was evaluated, as compared with surgery alone. ⋯ The MMR status was neither prognostic nor predictive for adjuvant chemotherapy. An interaction analysis showed that there was better RFS among patients treated with UFT with RAS mutations, but not for those without RAS mutations. Extended RAS (KRAS/NRAS) mutations are proposed as predictive indicators with respect to the efficacy of adjuvant UFT chemotherapy in patients with resected stage III colorectal cancer.
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Multicenter Study
Lenalidomide and low-dose dexamethasone in Japanese patients with newly diagnosed multiple myeloma: a phase II study.
In the FIRST trial (MM-020), lenalidomide plus low-dose dexamethasone (Rd) reduced the risk of disease progression or death compared with combination melphalan-prednisone-thalidomide. As the FIRST trial did not include any Japanese patients, the efficacy and safety of continuous treatment with Rd was evaluated in 26 Japanese patients with newly diagnosed multiple myeloma (NDMM) in a single-arm, multicenter, open-label phase II trial (MM-025). Patients received lenalidomide on days 1-21 of each 28-day cycle, with a starting dose of 25 mg/day (dose adjusted for renal impairment), and 40 mg/day dexamethasone (dose adjusted for age) on days 1, 8, 15 and 22 of each 28-day cycle until disease progression or discontinuation for any reason. ⋯ Median durations of response, progression-free survival and overall survival have not been reached. The most common grade 3-4 adverse events were neutropenia (23%) and anemia (19%). The efficacy and safety of Rd were consistent with data from larger studies, including the FIRST trial, thereby supporting the use of Rd continuous in Japanese patients with NDMM who are ineligible for stem cell transplantation.