Potent molecular-targeted therapies for gastro-entero-pancreatic neuroendocrine carcinoma.

Neuroendocrine neoplasms (NENs), which are characterized by neuroendocrine differentiation, can arise in various organs. NENs have been divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) based on morphological differentiation, each of which has a distinct etiology, molecular profile, and clinicopathological features. While the majority of NECs originate in the pulmonary organs, extrapulmonary NECs occur most predominantly in the gastro-entero-pancreatic (GEP) system. Although platinum-based chemotherapy is the main therapeutic option for recurrent or metastatic GEP-NEC patients, the clinical benefits are limited and associated with a poor prognosis, indicating the clinically urgent need for effective therapeutic agents. The clinical development of molecular-targeted therapies has been hampered due to the rarity of GEP-NECs and the paucity of knowledge on their biology. In this review, we summarize the biology, current treatments, and molecular profiles of GEP-NECs based on the findings of pivotal comprehensive molecular analyses; we also highlight potent therapeutic targets for future precision medicine based on the most recent results of clinical trials.

Potent therapeutic strategy in gastric cancer with microsatellite instability-high and/or deficient mismatch repair.

Gastric cancer (GC) is a common malignancy that presents challenges in patient care worldwide. The mismatch repair (MMR) system is a highly conserved DNA repair mechanism that protects genome integrity during replication. Deficient MMR (dMMR) results in an increased accumulation of genetic errors in microsatellite sequences, leading to the development of a microsatellite instability-high (MSI-H) phenotype. Most MSI-H/dMMR GCs arise sporadically, mainly due to MutL homolog 1 (MLH1) epigenetic silencing. Unlike microsatellite-stable (MSS)/proficient MMR (pMMR) GCs, MSI-H/dMMR GCs are relatively rare and represent a distinct subtype with genomic instability, a high somatic mutational burden, favorable immunogenicity, different responses to treatment, and prognosis. dMMR/MSI-H status is a robust predictive biomarker for treatment with immune checkpoint inhibitors (ICIs) due to high neoantigen load, prominent tumor-infiltrating lymphocytes, and programmed cell death ligand 1 (PD-L1) overexpression. However, a subset of MSI-H/dMMR GC patients does not benefit from immunotherapy, highlighting the need for further research into predictive biomarkers and resistance mechanisms. This review provides a comprehensive overview of the clinical, molecular, immunogenic, and therapeutic aspects of MSI-H/dMMR GC, with a focus on the impact of ICIs in immunotherapy and their potential as neoadjuvant therapies. Understanding the complexity and diversity of the molecular and immunological profiles of MSI-H/dMMR GC will drive the development of more effective therapeutic strategies and molecular targets for future precision medicine.

Clinical outcomes and prognostic factors of concurrent chemoradiotherapy for anal squamous cell carcinoma in Japan.

BACKGROUND: Concurrent chemoradiotherapy (CCRT) is the standard treatment for locoregional anal squamous cell carcinoma (ASCC) in western countries. However, there have been few reports on the clinical outcomes of CCRT in Japan. This study aimed to evaluate the clinical outcomes of CCRT, prognostic factors, and the clinical impact of programmed cell death-ligand 1 (PD-L1) expression of ASCC in Japan. METHODS: Patients with locoregional ASCC were enrolled between 2007 and 2017. All patients received CCRT consisting of ≥ 45 Gy of radiation, 5-fluorouracil, and mitomycin C. Disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were estimated. Expression of p16 and PD-L1 were assessed by immunohistochemical staining (IHC). RESULTS: This study included 36 patients, of whom 30 (83.3%) were female. Among the participants, 32 (88.9%) achieved complete clinical remission, while six (16.7%) experienced recurrence. The five-year DFS and five-year OS were 72.2% and 84.7%, respectively. Grades ≥ 3 serious AEs included neutropenia in 10 (27.7%) and perianal dermatitis in eight (22.2%). In a univariate analysis, male sex, lymph node metastasis, and large tumor size were significantly associated with worse outcome. In a multivariate analysis, tumor size was an independent factor associated with short DFS. Of the 30 patients whose biopsy specimens were available for IHC, 29 (96.7%) were positive for p16, and 13 (43.3%) were positive for PD-L1. However, PD-L1 expression did not show any clinical impact. CONCLUSIONS: The comparative etiology, clinical outcomes, and prognostic factors of CCRT observed in Japanese patients with locoregional ASCC were consistent with western data.

Exploratory analysis of serum HER2 extracellular domain for HER2 positive gastric cancer treated with SOX plus trastuzumab.

BACKGROUND: The aim of this study was to explore the clinical utility of serum HER2 extracellular domain (sHER2 ECD) using data from a clinical trial evaluating trastuzumab combined S-1 plus oxaliplatin (SOX) in HER2 positive gastric cancer. METHODS: sHER2 ECD were prospectively measured at baseline and subsequent treatment courses. Based on each quantile point of baseline sHER2 ECD levels and its early changes, patients were divided into two groups and compared clinical outcomes. RESULTS: 43 patients were enrolled, and 17 patients (39.5%) were positive for baseline sHER2 ECD. Higher baseline sHER2 ECD levels tended to have lower hazard ratios (HRs). When divided into two groups by baseline sHER2 ECD of 19.1 ng/ml, median progression-free survival (PFS) and overall survival (OS) was longer in the higher group (mPFS: 16.8 vs 8.7 months, p = 0.359. mOS: 35.5 vs 20.6 months, p = 0.270), respectively. After initiation of treatment, sHER2 ECD significantly decreased up until the third cycle. Higher reduction rates of sHER2 ECD within 3 cycles also tended to have lower HRs. When divided into two groups by reduction rate of 42.5%, mPFS and mOS was longer in the higher reduced group (mPFS: 17.2 vs 8.7 months, p = 0.095. mOS: 65.0 vs 17.8 months, p = 0.047), respectively. Furthermore, higher reduction rates could surrogate higher objective response rates (ORR) (ORR: 90% vs 63.2% for 29.5%, p = 0.065. 100% vs 70% for 42.5%, p = 0.085), respectively. CONCLUSIONS: Baseline sHER2 ECD levels and its early decline may be useful biomarkers for SOX plus trastuzumab efficacy in HER2 positive gastric cancer.

Clinical utility of the carcinoembryonic antigen level in patients with stage III colon cancer after surgery and adjuvant chemotherapy.

PURPOSE: The association between perioperative and post-adjuvant carcinoembryonic antigen (CEA) levels and recurrence and prognosis remains unclear. We aimed to evaluate whether perioperative CEA levels are an integral component of the assessment of recurrence and prognosis of patients with stage III colon cancer (CC). METHODS: This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2005 to 2013. We enrolled patients with stage III CC who underwent complete resection of a primary tumor and received adjuvant chemotherapy. We analyzed the association between perioperative and post-adjuvant CEA levels and recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 564 consecutive patients were included in the analysis. The RFS and OS of patients with high postoperative CEA levels were significantly worse than those of patients with normal postoperative CEA levels. In the multivariate analysis, high postoperative CEA levels were associated with shorter RFS and OS. The number of risk factors, postoperative CEA levels, and T/N-stage all had a cumulative effect on RFS and OS. CONCLUSIONS: High postoperative CEA levels and the number of risk factors are associated with recurrence and worse prognosis for patients with stage III CC.

Single-organ pulmonary metastasis is a favorable prognostic factor in metastatic colorectal cancer patients treated with FOLFIRI and vascular endothelial growth factor inhibitors.

BACKGROUND: Few studies have focused on the impact of single-organ pulmonary metastases on progression-free survival and overall survival in patients with metastatic colorectal cancer. Recognizing differences in prognosis and chemotherapeutic efficacy based on metastasized organs may help in optimizing treatment strategies. The exploratory study was conducted to evaluate the comparative clinical outcomes and prognoses of patients with metastatic colorectal cancer presenting with single-organ pulmonary metastases and treated with folinic acid, 5-fluorouracil, irinotecan, and vascular endothelial growth factor inhibitors as second-line chemotherapy. METHODS: This retrospective study included 289 patients with metastatic colorectal cancer treated with second-line folinic acid, 5-fluorouracil, irinotecan, and vascular endothelial growth factor inhibitors. The response rate, disease control rate, progression-free survival, and overall survival were assessed in the participants. RESULTS: Among the 289 patients enrolled, 26 (9.0%) had single-organ pulmonary metastasis with left-sided primary locations, lower levels of tumor markers at the initiation point of chemotherapy, a significantly higher disease control rate (96.2% vs. 76.7%, P = .02), and a longer progression-free survival (median 29.6 months vs. 6.1 months, P < .001) and overall survival (median 41.1 months vs. 18.7 months, P < .001) than patients with other forms of metastatic colorectal cancer. Multivariate analysis showed that single-organ pulmonary metastasis was an independent predictor of longer progression-free survival (hazard ratio 0.35, P = .00075) and overall survival (hazard ratio 0.2, P = .006). CONCLUSION: Single-organ pulmonary metastasis was a strong predictor of progression-free survival and overall survival in patients with metastatic colorectal cancer treated with folinic acid, 5-fluorouracil, irinotecan, and vascular endothelial growth factor inhibitors as second-line chemotherapy; this provides preliminary evidence for medical guidelines and clinical decision-making on novel therapeutic strategies for these patients.

Treatment efficacy of ramucirumab-containing chemotherapy in patients with alpha-fetoprotein producing gastric cancer.

BACKGROUND: Alpha-Fetoprotein Producing Gastric Cancer (AFPGC) is an aggressive subgroup of gastric cancer. Recently ramucirumab has shown survival benefits in hepatocellular carcinoma, but only in those with higher Alpha-Fetoprotein (AFP) levels. However, the efficacy of ramucirumab-containing chemotherapy in AFPGC remains unclear. METHODS: We retrospectively assessed 352 patients who received ramucirumab-containing chemotherapy between June 2015 and December 2019. AFPGC was defined when serum AFP levels were elevated at diagnosis and correlated with the disease state during treatment. Non-AFPGC was defined when serum AFP levels were normal at diagnosis. RESULTS: Among the 352 patients, 28 patients were defined as AFPGC and 246 patients were defined as non-AFPGC. AFPGC was characterized by high frequency of liver metastasis and low frequency of peritoneal metastasis compared to non-AFPGC. Ramucirumab containing chemotherapy showed higher response rates in AFPGC (39.1% vs 24.8%, p = 0.198) and disease control rates (86.9% vs 61.5%, p = 0.028) than those of non-AFPGC, respectively. Median progression-free survival (PFS) was 5.5 months (95%CI 3.9-7.1) in AFPGC and 4.0 months (95%CI 3.6-4.6) in non-AFPGC (HR: 0.91, 95% CI 0.61-1.36, p = 0.66), and median overall survival (OS) was 10.7 months (95% CI 7.4-20.8) in AFPGC and 9.2 months (95% CI 8.1-10.4) in non-AFPGC (HR: 0.72, 95% CI 0.48-1.08, p = 0.11), respectively. In multivariate analysis, AFPGC was not a negative prognostic factor both for PFS and OS. CONCLUSION: Ramucirumab containing chemotherapy showed higher response and comparable survival in AFPGC compared to those of non-AFPGC. Considering the generally poor prognosis of AFPGC, ramucirumab-containing chemotherapy might be a promising treatment option in AFPGC.

Morphological response and tumor shrinkage as predictive factors in metastatic colorectal cancer treated with first-line capecitabine, oxaliplatin, and bevacizumab.

BACKGROUND: Morphologic response (MR) is a novel chemotherapeutic efficacy predictor of solid tumors, especially those treated with anti-vascular endothelial growth factor antibodies. Nevertheless, the importance of systemic chemotherapy MR for colorectal liver metastases (CLM) remains unclear. We aimed to evaluate the usefulness of MR as a factor associated with the therapeutic effects of chemotherapy plus bevacizumab for initially unresectable CLM cases. METHODS: We retrospectively evaluated the associations between MR and/or Response Evaluation Criteria in Solid Tumors (RECIST), progression-free survival (PFS), and overall survival (OS) in patients who received first-line capecitabine, oxaliplatin, and bevacizumab treatment for initially unresectable CLM using multivariate analysis. Patients who showed a complete or partial response based on the RECIST, or an optimal response based on MR, were defined as "responders." RESULTS: Ninety-two patients were examined, including 31 (33%) patients who responded optimally. PFS and OS estimates were comparable in MR responders and non-responders (13.6 vs. 11.6 months, p = 0.47; 26.6 vs. 24.6 months, p = 0.21, respectively). RECIST responders showed better PFS and OS than non-responders (14.8 vs. 8.6 months, p < 0.01; 30.7 vs. 17.8 months, p < 0.01, respectively). The median PFS and OS estimates of MR and RECIST responders were better than those of single responders or non-responders (p < 0.01). Histological type and RECIST response were independently associated with PFS and OS. CONCLUSION: MR predicts neither PFS nor OS; nevertheless, it may be useful when combined with the RECIST. The Ethics Committee of The Cancer Institute Hospital of JFCR approved this study in 2017 (No. 2017-GA-1123): retrospectively registered.

Clinical Progress in Inoperable or Recurrent Advanced Gastric Cancer Treatment from 1004 Single Institute Experiences Between 2007 and 2018.

BACKGROUND: In the past decade, several successful clinical trials provided new therapeutic agents approved for advanced gastric cancer (AGC). This study evaluated whether these practice-changing results actually altered the clinical practice. PATIENTS AND METHODS: We retrospectively reviewed medical records of treatment-naive AGC patients who received combination chemotherapy of fluoropyrimidine and platinum between 2007 and 2018 and divided them into three groups: Groups A (2007-10), B (2011-14), and C (2015-2018), respectively. We compared the clinicopathological features, treatment details, and clinical outcomes among the three groups. RESULTS: In total, 1004 consecutive patients were enrolled (A; n = 254, B; n = 300, and C; n = 450). The number of patients with poor performance status, older age, esophagogastric junction adenocarcinoma, and primary tumor increased during the study period. All groups had similar median overall survival (OS); ~16 months) without any statistical difference but steady prolongation of survival was observed in the adjusted with imbalance prognostic factors among groups (B/A; hazard ratio, HR 0.82, 95% C.I 0.68-0.98, C/A; HR 0.72, 95% CI 0.60-0.86); OS of HER2-positive AGC patients was clearly improved (HER2-positive vs HER2-negative in Group B, HR 0.80, 95% CI 0.60-1.06; Group C, HR 0.68, 95% CI 0.51-0.90) but that of diffuse-type AGC patients remained dismal. CONCLUSIONS: The increasing availability of chemotherapy options potentially contributed to improved survival of AGC patients, but expanded chemotherapeutic indications made the survival benefit inconspicuous in the whole population. Future therapeutic development for the AGC subset not adequately receiving benefit from previous clinical trials is warranted.

Clinical Usefulness of Postoperative Serum Carcinoembryonic Antigen in Patients with Colorectal Cancer with Liver Metastases.

BACKGROUND: Colorectal cancer with liver metastasis (CLM) has high postoperative recurrence rates; therefore, optimizing perioperative treatment is imperative. Postoperative carcinoembryonic antigen (CEA) can aid in detecting minimal residual disease in colon cancer following curative resection. This study aimed to identify the potential role of serum CEA following liver resection in patients with CLM. METHODS: This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2004 to 2018 and enrolled patients with CLM who underwent complete resection of primary tumors and CLM. Associations between perioperative CEA levels and characteristics of recurrence were investigated. RESULTS: Recurrence was detected during a median follow-up period of 90.1 months in 343 (54.2%) out of 633 analyzed patients. Patients in the postoperative CEA level > 5 ng/ml group had a significantly higher recurrence rate (75.7% versus 50.0%, p < 0.01) and shorter time until recurrence (4.4 versus 36.9 months, p < 0.01) than those in the postoperative CEA level ≤ 5 ng/ml group. Multivariate analysis revealed that postoperative CEA level > 5 ng/ml was an independent predictor, with hazard ratios of 2.77 (p < 0.01) for recurrence-free survival (RFS) and 3.18 (p < 0.01) for overall survival (OS). Additionally, RFS was significantly shorter among patients in the postoperative CEA level > 5 ng/ml group who did not have normalized CEA levels following adjuvant chemotherapy than among those in the normalized CEA group. CONCLUSIONS: The postoperative and post-adjuvant chemotherapy CEA levels in the CEA level > 5 ng/ml group may be predictors of RFS and OS.

Effect of DNA methylation status on first-line anti-epidermal growth factor receptor treatment in patients with metastatic colorectal cancer.

PURPOSE: The CpG island methylator phenotype (CIMP), important for carcinogenesis, is a predictor of prognosis and chemotherapy sensitivity in colorectal cancer (CRC). However, there is a lack of consensus on CIMP markers, and thus, more comprehensive methylation markers are required to reliably predict the clinical outcomes. This study aimed to clarify the effects of genome-wide DNA methylation status on clinical outcomes in patients with metastatic CRC (mCRC) treated with epidermal growth factor receptor (EGFR) inhibitors. METHODS: We enrolled 241 patients with mCRC, who received chemotherapy plus EGFR inhibitors as a first-line treatment. We analyzed the incidence and clinicopathological characteristics of highly methylated CRC (HMCC) and associations between genome-wide DNA methylation status and response rate (RR), progression-free survival (PFS), and overall survival (OS). RESULTS: In total, 169 patients were included in the final analyses. The frequency of HMCC was 8.9% (15/169). The characteristics of patients with HMCC included right-sided primary tumor location (P = 0.042), undifferentiated histology (P = 0.047), and BRAF V600E mutation (P < 0.0001). Patients with HMCC showed worse clinical outcomes than those with low-methylated CRC in terms of RR (P = 0.017), PFS (P = 0.004), and OS (P = 0.019). In the multivariate analysis, peritoneal metastasis (P = 0.017), methylation status (P = 0.037), and BRAF V600E mutations (P = 0.0001) were independent factors for shorter PFS. CONCLUSIONS: Genome-wide DNA methylation status is an independent factor associated with PFS in patients with mCRC treated with first-line EGFR inhibitors.

Managing a gastrointestinal oncology practice in Japan during the COVID-19 pandemic: single institutional experience in The Cancer Institute Hospital of Japanese Foundation for Cancer Research.

Coronavirus disease 2019 (COVID-19) was declared to be a global pandemic by the World Health Organization on March 11, 2020. On April 7, 2020, a state of emergency was declared in Japan, as had been by other nations worldwide. This unprecedented crisis has profound implications for patients undergoing chemotherapy and for practicing healthcare professionals. Various reports have shown data indicating that cancer patients with COVID-19 have high morbidity and mortality rates. In order to reduce the use of medical resources to avoid the risk of COVID-19 infections in both cancer patients and health care providers, oncologists now have to draw the line for cancer treatments by maintaining their efficacy while avoiding severe adverse events. In this article, we outlined the decisions made regarding the practice of gastrointestinal oncology in our institution during the COVID pandemic.

[Position of the Japanese Subgroup Data from Global Trial in Advanced Gastric Cancer].

Global studies have been planned to achieve early approval of the new agent especially in cancer chemotherapy. On the other hand, it is important to consider the difference in efficacy among each region. As medical approval in Japan means reimbursement of medical cost, new drug is required to show its effectiveness in the medical situation in Japan, and the Japanese subgroup data is important. Especially in the gastric cancer field, where there is a large difference in survival time and surgical outcome between Japan and outside Japan need to consider Japanese domestic data. But characteristic of Japanese subgroup is the number of target patients is small, high censored case due to longer survival and the background factors are not even. So the interpretation of the data requires caution because of these robustness.

Neoadjuvant Chemoradiotherapy with Cisplatin Plus Fluorouracil for Borderline Resectable Esophageal Squamous Cell Carcinoma.

BACKGROUND: The optimal treatment strategy for patients with borderline resectable (BR) esophageal squamous cell carcinoma (ESCC), in which tumors grow very close to the adjacent vital organs, remains unclear. This study evaluated the efficacy of neoadjuvant chemoradiotherapy (NACRT) with cisplatin plus fluorouracil (CF) and irradiation (40 Gy) for these patients. METHODS: The study cohort included 50 patients with BR-ESCC who received NACRT as the initial treatment and were allocated to one of two groups: patients who achieved curative resection (R0 group) or those who did not (Non-R0 group). The overall survival (OS), relapse-free survival (RFS), and pre-therapeutic predictive factors for Non-R0 were evaluated. RESULTS: Among the 50 patients, 22 (44%) achieved curative resection clinically. The median OS was significantly better in the R0 group than in the Non-R0 group (2.4 vs 0.8 years; hazard ratio [HR], 0.29; 95% confidence interval [CI], 0.12-0.67; p < 0.01). The independent predictive factors before NACRT for Non-R0 were higher serum SCC antigen level (p < 0.01) and clinical nodal involvement (p = 0.02). In addition, OS was significantly worse for the patients with higher levels of serum SCC antigen than for those with lower levels (p < 0.01). CONCLUSIONS: Curative resection was achieved for about 40% of the patients who received NACRT for BR-ESCC. Therefore, NACRT could be a useful neoadjuvant treatment option for BR-ESCC. However, a higher serum SCC antigen level before NACRT is predictive of treatment failure and poor survival.

A phase I study to determine the maximum tolerated dose of trifluridine/tipiracil and oxaliplatin in patients with refractory metastatic colorectal cancer: LUPIN study.

Background The effectiveness of reintroducing oxaliplatin for metastatic colorectal cancer (mCRC) refractory to both oxaliplatin and irinotecan was previously reported in a phase II study (RE-OPEN). We conducted a phase I study to determine the maximum tolerated dose of oxaliplatin plus trifluridine/tipiracil (FTD/TPI) in patients with refractory mCRC. Patients and Methods Three dosages of intravenous oxaliplatin (50, 65 and 85 mg/m2) on days 1 and 15 and a fixed dose of FTD/TPI 35 mg/m2 twice daily (bid) on days 1-5 and 15-19 every 4 weeks were investigated in patients with refractory mCRC using a 3 + 3 design. Eligible patients had received prior oxaliplatin-based treatment that achieved a response or stable disease followed by confirmed disease progression at least 6 months before entering the study. Results Twelve patients were enrolled in the study. Three of six patients in the oxaliplatin 85 mg/m2 cohort had dose-limiting toxicities (DLTs) with treatment delays during the second cycle at ≥8 days due to grade ≥ 2 neutropenia or grade 2 AST/ALT increased. No DLTs were observed in the other cohorts. Grade ≥ 3 AEs were neutropenia (n = 3), thrombocytopenia (n = 1), anorexia (n = 1), and nausea (n = 1). There was no evidence of allergic reaction to oxaliplatin or severe peripheral sensory neuropathy. Conclusions A combination of FTD/TPI 35 mg/m2 bid on days 1-5 and 15-19 and oxaliplatin 85 mg/m2 on days 1 and 15 every 4 weeks could be a suitable regimen for the recommended dose of FTD/TPI plus oxaliplatin in patients with refractory mCRC.

Clinical utility of polyethylene glycol conjugated granulocyte colony-stimulating factor (PEG-G-CSF) for preventing severe neutropenia in metastatic colorectal cancer patients treated with FOLFOXIRI plus bevacizumab: a single-center retrospective study.

BACKGROUND: This study aimed to evaluate the efficacy and the safety of polyethylene glycol conjugated granulocyte colony-stimulating factor (PEG-G-CSF) for preventing neutropenia in metastatic colorectal cancer (mCRC) patients that received fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus bevacizumab (Bev) in clinical practice. METHODS: We retrospectively analyzed mCRC patients who received FOLFOXIRI plus Bev between December 2015 and December 2017. We evaluated the efficacy of PEG-G-CSF as preventing or treating grade 3 or 4 neutropenia, the overall response rate (ORR) according to the Response Evaluation Criteria in Solid Tumors version 1.1, progression-free survival (PFS), overall survival (OS), and adverse events of FOLFOXIRI plus Bev based on the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: A total of 26 patients (median age 53.5 years) were included. The ORR rate was 65.3%, the median PFS was 9.6 months (7.2-16.9), and the median OS was 24.2 months (13.6-NA). Grade 3 or 4 neutropenia occurred in 53.8% of the patients, and febrile neutropenia occurred in 7.7%. PEG-G-CSF was given to 77.0% of the patients, including prophylactically (n = 9) and after the development of grade 3 or 4 neutropenia (n = 11). No patients experienced grade 3 or 4 neutropenia after the administration of PEG-G-CSF. In seven of the nine patients who received PEG-G-CSF prophylactically (77.8%), no dose adjustment was required. CONCLUSIONS: PEG-G-CSF is useful in preventing severe neutropenia in mCRC patients treated with FOLFOXIRI plus Bev.

Clinical outcomes of radical gastrectomy following trastuzumab-based chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer.

PURPOSE: Patients who receive trastuzumab (T-mab) plus chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer sometimes respond remarkably well and can undergo radical surgery. However, the clinical outcomes of preoperative T-mab combined chemotherapy with radical gastrectomy remain unclear. We conducted this study to investigate the clinical outcomes of this multimodal treatment. METHODS: From among a total of 199 patients who received T-mab-based chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer between 2011 and 2018, the subjects of this retrospective analysis were 20 patients who subsequently underwent radical gastrectomy. RESULTS: Seven patients had gastroesophageal junction cancer and 13 had gastric cancer. Eleven patients had unresectable stage IV cancer and 9 had resectable metastatic disease. Chemotherapy regimens included capecitabine, cisplatin + T-mab (11 patients), and S-1, oxaliplatin + T-mab (nine patients). The median number of chemotherapy cycles before surgery was three (range, 2-62). During preoperative chemotherapy, grade 3/4 adverse events developed in six patients. None suffered grade ≥ 3b postoperative complications. The 3-year relapse-free survival (RFS) and overall survival (OS) rates were 58.9% and 89.5%, respectively. CONCLUSION: Combined preoperative T-mab-based chemotherapy and surgery appears to be safe and effective for stage IV HER2-positive gastric or gastroesophageal junction cancer, with a clinically meaningful impact on RFS and OS.

Clinical impact of Epstein-Barr virus status on the incidence of lymph node metastasis in early gastric cancer.

Epstein-Barr virus-positive gastric cancer (EBVGC) comprises approximately 9% of all gastric cancers and is associated with a low prevalence of lymph node metastasis (LNM). Given that limited data concerning LNM in EBV-related early GC are available, EBV status is not considered an indicator for endoscopic submucosal dissection (ESD). In this review, we focused on pT1 EBVGC and on gastric carcinoma with lymphoid stroma (GCLS), and discuss expanded ESD indications and curative resection criteria. In pT1b EBVGC, the incidence of LNM was low (6/180 patients, 3.3%; 95% confidence interval [CI] 1.2-7.1), especially in lymphovascular invasion-negative EBVGC (1/109 patients, 0.9%). No patients with pT1a EBVGC had LNM (0/38 patients, 0%; 95% CI 0-7.6), even those who did not meet the current curative ESD criteria. Although the frequency of LNM in GCLS was low (5.0-10.6%), the incidence of LNM in non-EBV GCLS was relatively high (10.0-20.0%); therefore, EBV status can be considered a more important factor than GCLS. In summary, the clinicopathological characteristics of EBVGC differ from those of conventional GC, and EBV negativity is a risk factor for LNM in early GC. Therefore, patients in this group are likely to be promising candidates for ESD, and we recommend that EBV status evaluation be included in early GC treatment guidelines.

Non-V600E BRAF mutations and EGFR signaling pathway in colorectal cancer.

The Raf murine sarcoma viral oncogene homolog B (BRAFV600E ) mutation (MT) in metastatic colorectal cancer (CRC) is a well-known prognostic indicator and a negative predictive biomarker for antiepidermal growth factor receptor (EGFR) treatment. However, the clinical characteristics and significance of BRAFnon-V600E MTs remain unclear. Here, we evaluated the clinical characteristics of BRAFnon-V600E MTs vs. those of other MTs in the EGFR signaling pathway, including BRAFV600E . Consecutive CRC patients in our institute from June 2012 to November 2013 were enrolled in our study. Multiplex genotyping of the EGFR pathway was performed with archival samples using a Luminex Assay for BRAFV600E /BRAFnon-V600E , KRAS/NRAS exons 2-4, and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA). We analyzed correlations among the MT profiles, clinical data and primary tumor locations in CRC. All statistical analyses were performed using R software. CRC samples (824) from 374 (45.4%) male and 450 (54.6%) female patients were analyzed, of which 154 (18.7%), 202 (24.5%), 270 (32.8%) or 198 (24.0%) had Stages I, II, III or IV or recurrent CRC, respectively. The frequencies of BRAFV600E /BRAFnon-V600E , KRAS (including exons 2-4), NRAS and PIK3CA MTs were 5.3/1.7, 41.4, 3.3 and 9.6%, respectively. The characteristics of patients with the BRAFV600E MT were an age of ≥65 years old, a right-sided primary tumor location, poorly differentiated histology and an advanced disease stage. In contrast, the characteristics of patients with BRAFnon-V600E MTs were a left-sided primary tumor location and well-differentiated histology. BRAFnon-V600E MTs were relatively rare and showed different characteristics compared to the BRAFV600E MT. These results may contribute to future precision medicine.

Clinical utility of circulating tumor DNA for colorectal cancer.

Colorectal cancer (CRC) is currently the most common type of cancer in Japan, and its prognosis has improved because of development of diagnosis and advancement in treatments including surgery and chemotherapy. However, because of intratumor heterogeneity and clonal evolution, tumors often develop resistance to treatment. Genotyping tumor tissue in search of somatic genetic alterations for actionable information has become routine examination in clinical practice. However, the inherent molecular heterogeneity of metastatic tumors and the ability of cancer genomes to dynamically evolve are not properly captured by tissue specimens only. Circulating tumor DNA (ctDNA) carrying tumor-specific genetic or epigenetic alterations is released into the circulation from tumor cells undergoing apoptosis or necrosis. Analysis of ctDNA has the potential to change clinical practice by exploiting blood rather than tissue, as a source of information. Here, we provide an overview of the characteristics of ctDNA and focus on detection methods for ctDNA, and the feasibility of use of ctDNA to monitor tumor dynamics for patients with colorectal cancer.