Multicenter phase II study of capecitabine plus oxaliplatin in older patients with advanced gastric cancer: the Tokyo Cooperative Oncology Group (TCOG) GI-1601 study.

BACKGROUND: Capecitabine plus oxaliplatin (CapeOX) is a standard treatment option for advanced gastric cancer (AGC). We conducted a prospective multicenter phase II study to evaluate the efficacy and safety of CapeOX as a first-line therapy for AGC in older patients. METHODS: Chemotherapy-naive patients aged ≥ 70 years with AGC were eligible. Initial treatment comprised capecitabine (2000 mg/m2 on days 1-14) and oxaliplatin (130 mg/m2 on day 1) every 3 weeks. After the initial feasibility assessment, the dose was reduced considering toxicity (capecitabine, 1500 mg/m2 on days 1-14; and oxaliplatin, 100 mg/m2 on day 1 every 3 weeks). The primary endpoint was overall survival (OS). RESULTS: In total, 108 patients were enrolled, of whom 104 were evaluated. Thirty-nine patients received the original-dose treatment, whereas 65 received the reduced-dose treatment. The median OS, progression-free survival (PFS), and time to treatment failure (TTF) were 12.9 (95% CI 11.6-14.8), 5.7 (95% CI 5.0-7.0), and 4.3 (95% CI 3.9-5.7) months, respectively, for all patients; 13.4 (95% CI 9.5-16.0), 5.8 (95% CI 4.1-7.8), and 5.3 (95% CI 3.5-7.2) months in the original-dose group; and 12.8 (95% CI 11.3-15.3), 5.7 (95% CI 4.4-7.0), and 4.1 (95% CI 3.7-5.7) months in the reduced-dose group. The most common grade 3/4 toxicities were neutropenia (17.9%), anemia (12.8%), and thrombocytopenia (12.8%) in the original-dose group and neutropenia (13.8%) and anorexia (12.3%) in the reduced-dose group. CONCLUSIONS: These findings demonstrate CapeOX's efficacy and safety in older AGC patients.

MicroRNAs associated with postoperative outcomes in patients with limited stage neuroendocrine carcinoma of the esophagus.

Esophageal neuroendocrine carcinoma (E-NEC) is an aggressive disease with a poor prognosis. The present study aimed to assess the role of surgery in the treatment of patients with resectable E-NEC, and identify a microRNA (miRNA/miR) signature in association with positive postoperative outcomes. Between February 2017 and August 2019, 36 patients with E-NEC who underwent curative surgery at the Japan Neuroendocrine Tumor Society partner hospitals were enrolled in the study. A total of 16 (44.4%) patients achieved disease-free survival (non-relapse group), whereas 20 (55.6%) patients developed tumor relapse (relapse group) during the median follow-up time of 36.5 months (range, 1-242) after surgery with a 5-year overall survival rate of 100 and 10.8%, respectively (P<0.01). No clinicopathological parameters, such as histological type or TNM staging, were associated with tumor relapse. Microarray analysis of 2,630 miRNAs in 11 patients with sufficient quality RNA revealed 12 miRNAs (miR-1260a, -1260b, -1246, -4284, -612, -1249-3p, -296-5p, -575, -6805-3p, -12136, -6822-5p and -4454) that were differentially expressed between the relapse (n=6) and non-relapse (n=5) groups. Furthermore, the top three miRNAs (miR-1246, -1260a and -1260b) were associated with overall survival (P<0.01). These results demonstrated that surgery-based multidisciplinary treatment is effective in a distinct subpopulation of limited stage E-NEC. A specific miRNA gene set is suggested to be associated with treatment outcome.

Genomic characterization between HER2-positive and negative gastric cancer patients in a prospective trial.

BACKGROUND: We aimed to clarify the genomic characteristics of HER2-positive and negative gastric cancer cases that potentially affect tumor progression and treatment response in a prospective trial. METHODS: We collected 80 formalin-fixed paraffin-embedded (FFPE) samples (49 HER2+ and 31 HER2-) from gastric cancer patients who participated in the TROX-A1 trial (UMIN000036865). We queried a 435-gene panel (CANCERPLEX-JP) to generate comprehensive genomic profiling data, including the tumor mutation burden, somatic mutations, and copy number variations. In addition, the genomic differences between HER2+ and HER2- gastric cancer patients were analyzed. RESULTS: Mutational analyses showed that TP53 was the most frequently mutated gene regardless of HER2 status. ARID1A mutation was significantly enriched in HER2-negative patients. The number of total mutations in HER2-negative patients with ARID1A mutation was remarkably higher than that in HER2-positive patients. Next, copy number variation analyses showed that the number of amplified genes (such as CCNE1, PGAP3, and CDK12) in HER2-positive cases was significantly higher than that in HER2-negative cases. Moreover, PTEN deletion was more common in HER2-positive cases. Finally, we found that, compared with HER2-positive patients, HER2-negative patients tended to have a higher tumor mutation burden, particularly in patients with ARID1A mutation. Pathway analyses of the gene alterations showed an enrichment of several immune-related pathways in HER2-negative patients. CONCLUSIONS: According to the genomic profiling of HER2-positive and negative gastric cancer, several gene alterations in the HER2 pathway may be the potential mechanism underlying trastuzumab resistance. Relative to HER2-positive gastric cancer, HER2-negative gastric tumors with ARID1A mutation may be sensitive to immune checkpoint inhibitors.

Clinical Impact of Primary Tumor Location in Metastatic Colorectal Cancer Patients Under Later-Line Regorafenib or Trifluridine/Tipiracil Treatment.

BACKGROUND: Primary tumor location (PTL) is an important prognostic and predictive factor in the first-line treatment of metastatic colorectal cancer (mCRC). Although regorafenib (REG) and trifluridine/tipiracil (FTD/TPI) have been introduced recently, the clinical impact of PTL in these treatments is not well understood. MATERIALS AND METHODS: We retrospectively evaluated patients with mCRC who were registered in a multicenter observational study (the REGOTAS study). The main inclusion criteria were Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-2, refractory or intolerant to fluoropyrimidines, oxaliplatin, irinotecan, angiogenesis inhibitors, anti-epidermal growth factor receptor therapy (if RAS wild-type), and no prior use of REG and FTD/TPI. The impact of PTL on overall survival (OS) was evaluated using Cox proportional hazard models based on baseline characteristics. RESULTS: A total of 550 patients (223 patients in the REG group and 327 patients in the FTD/TPI group) were included in this study, with 122 patients with right-sided tumors and 428 patients with left-sided tumors. Although the right-sided patients had significantly shorter OS compared with the left-sided patients by univariate analysis (p = 0.041), a multivariate analysis revealed that PTL was not an independent prognostic factor (hazard ratio, 0.95; p = 0.64). In a subgroup analysis, the OS was comparable between the REG and FTD/TPI groups regardless of PTL (p for interactions = 0.60). CONCLUSIONS: In the present study, PTL is not a prognostic and predictive factor in patients with mCRC under later-line REG or FTD/TPI therapy.

Survival Benefit of Crossover Administration of Regorafenib and Trifluridine/Tipiracil Hydrochloride for Patients With Metastatic Colorectal Cancer: Exploratory Analysis of a Japanese Society for Cancer of the Colon and Rectum Multicenter Observational Study (REGOTAS).

Background: The survival benefits of regorafenib (REG) and trifluridine/tipiracil hydrochloride (TFTD) have been demonstrated in chemorefractory patients with metastatic colorectal cancer (mCRC). However, the effects of crossover administration of REG and TFTD on patient survival remain unclear. The present study evaluated the association between exposure to REG and TFTD and overall survival (OS) in patients with mCRC using data from the REGOTAS study. Patients and Methods: We analyzed patients registered in the REGOTAS study, which retrospectively compared the efficacy and safety of use of REG or TFTD as later-line chemotherapy for chemorefractory mCRC patients. We compared the survival outcomes of cohort A (treated using both REG and TFTD) and cohort B (treated using either REG or TFTD). Results: A total of 550 patients (cohort A, n = 252; cohort B, n = 298) met the inclusion criteria. The median OS was significantly increased in cohort A compared with cohort B [9.6 months (95% confidence interval (CI), 8.9-10.9 months) vs. 5.2 months (95% CI, 4.4-6.0 months), P < 0.001]. Multivariate analysis revealed that cohort A was independently associated with a significant increase in OS [A vs. B: Hazard ratios (HR), 0.58; 95% CI, 0.47-0.72; P < 0.001]. Subgroup analysis adjusted using multivariate Cox model revealed a consistently better trend in most subgroups for cohort A compared with cohort B. Conclusions: Our study revealed prolonged survival in patients treated with REG and TFTD. Therefore, all active agents, including REG and TFTD, should be made available to mCRC patients.

Safety and efficacy of S-1 plus oxaliplatin 130 mg/m2 combination therapy in patients with previously untreated HER2-negative unresectable, advanced, or recurrent gastric/gastroesophageal junction cancer: a phase II trial (KSCC1501A).

BACKGROUND: In a randomized pivotal global phase III study, S-1 and oxaliplatin 100 mg/m2 (SOX100) combination chemotherapy was as effective as S-1 and cisplatin for advanced gastric cancer (AGC) and showed a favorable safety profile. In this phase II study, we analyzed survival outcomes to assess the efficacy and safety of the SOX regimen with oxaliplatin 130 mg/m2 (SOX130) in AGC. METHODS: Patients with HER2-negative AGC received 80 mg/m2/day S-1 orally on days 1-14 and 130 mg/m2 oxaliplatin intravenously on day 1 of each 21-day cycle until the criteria for treatment withdrawal were fulfilled. The primary endpoint was the response rate (RR), and the null hypothesis of RR in the current trial was 45%. The secondary endpoints were progression-free survival (PFS) and overall survival (OS). Adverse events (AEs) were recorded according to CTCAE version 4.0. RESULTS: Seventy-one patients were enrolled from June 2015 to November 2016, but eight were excluded for ineligibility. Therefore, all final analyses were conducted with 63 patients. The confirmed RR was 46.0% (90% confidence interval [CI]: 36.1-56.3), and the disease control rate was 77.8% (90% CI: 68.1-85.1). The median PFS and OS were 4.9 (95% CI: 4.2-7.1) and 14.8 (95% CI: 11.1-18.9) months, respectively. Incidences of grade 3-4 AEs > 10% were anorexia (19.0%), peripheral neuropathy (12.7%), nausea (11.1%), and thrombocytopenia (11.1%). CONCLUSIONS: This study represents the first evaluation of SOX130 in patients with HER2-negative AGC. SOX130 showed an acceptable safety profile, but the prespecified statistical efficacy targets were not achieved.

Trifluridine/tipiracil plus bevacizumab as a first-line treatment for elderly patients with metastatic colorectal cancer (KSCC1602): A multicenter phase II trial.

BACKGROUND: A previous Phase I/II study demonstrated that TAS-102 (trifluridine/tipiracil [FTD/TPI]) plus bevacizumab (Bev) has encouraging efficacy and controllable safety for patients with previously treated metastatic colorectal cancer. Therefore, we designed for assessing the efficacy and safety of FTD/TPI plus Bev in elderly patients with previously untreated metastatic colorectal cancer. METHODS: This is a multicenter, single-arm Phase II study included patients ≥70 years old with previously untreated, unresectable metastatic colorectal cancer. Treatment consisted of FTD/TPI plus Bev given every 4 weeks. The primary endpoint was progression-free survival (PFS), assuming a null hypothesis of a PFS of 5 months. The secondary endpoints were the overall survival (OS), overall response rate (ORR), and adverse events (AEs). RESULTS: Between 5 January 2017 and 13 March 2018, 39 patients were enrolled from 18 institutions. The median patient age was 76.0 years (range, 70-88); the ECOG-PS was 0 in 24 patients and 1 in 15 patients. The median PFS was 9.4 months as a primary endpoint, and the median OS was 22.4 months. The ORR was 40.5% and the disease control rate was 86.5%. Grade 3-4 AEs included neutropenia (71.8%), leukopenia (51.3%), anorexia (15.4%), febrile neutropenia (10.3%), and fatigue (10.3%). CONCLUSIONS: FTD/TPI plus Bev is an effective and well-tolerated regimen for elderly patients with previously untreated metastatic colorectal cancer. Capecitabine/bevacizumab can be selected as a subsequent maintenance therapy without irinotecan and oxaliplatin because FTD/TPI has no cross-resistance with 5-fluorouracil. CLINICAL TRIAL REGISTRATION: UMIN clinical trials registry (UMIN000025241).

Phase II clinical trial of gemcitabine plus oxaliplatin in patients with metastatic pancreatic adenocarcinoma with a family history of pancreatic/breast/ovarian/prostate cancer or personal history of breast/ovarian/prostate cancer (FABRIC study).

BACKGROUND: A family/personal history of breast, ovarian, or pancreatic cancer is a useful predictive marker for response to platinum-based chemotherapy in treating patients with pancreatic cancer. These cancers, and prostate cancer, are known as BRCA-related malignancies. We evaluated the efficacy of gemcitabine plus oxaliplatin (GEMOX) in patients with metastatic pancreatic cancer with a family/personal history of these cancers. METHODS: Chemotherapy-naïve patients with metastatic pancreatic cancer with a family history of pancreatic/breast/ovarian/prostate cancer or a personal history of breast/ovarian/prostate cancer were included. Patients received fixed dose-rate gemcitabine (1000 mg/m2) and oxaliplatin (100 mg/m2) every 2 weeks. The primary endpoint was 1-year survival, and the threshold and expected values were set at 30 and 50%, respectively. The target sample size was determined to be 43, with a one-sided alpha value of 5% and power of 80%. A total of 45 patients were enrolled. RESULTS: Among the first 43 enrolled patients, the 1-year survival rate was 27.9% [90% confidence interval (CI) 17.0-41.3], which did not meet the primary endpoint. Median overall survival, progression-free survival, and response rates were 7.6 months (95% CI 6.0-10.7), 4.0 months (95% CI 2.0-4.6), and 26.7% (95% CI 14.6-41.9), respectively, in all registered patients. The GEMOX regimen was generally tolerated; the most common grade three or higher adverse events were hematological toxicities. CONCLUSION: GEMOX did not show the expected efficacy in patients with metastatic pancreatic cancer with a family or personal history of pancreatic/breast/ovarian/prostate cancer. Selection of GEMOX based on family/personal history is not recommended. TRIAL REGISTRATION NUMBER: UMIN000017894.

Randomized, Phase II Study of Trastuzumab Beyond Progression in Patients With HER2-Positive Advanced Gastric or Gastroesophageal Junction Cancer: WJOG7112G (T-ACT Study).

PURPOSE: This study evaluated the continuous use of trastuzumab beyond progression (TBP) in human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer. PATIENTS AND METHODS: Patients with HER2-positive advanced G/GEJ cancer refractory to first-line chemotherapy with trastuzumab in combination with fluoropyrimidine and platinum were eligible. Patients were randomly assigned to the paclitaxel (80 mg/m2, days 1, 8, and 15, every 4 weeks) or paclitaxel with trastuzumab (PT; initially 8 mg/kg followed by 6 mg/kg, every 3 weeks) arms. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), response rate, and safety. Biomarkers such as HER2 expression status in tumor tissue after first-line treatment, HER2 amplification evaluated in serum cell-free DNA, and soluble HER2 levels were analyzed. RESULTS: Overall, 91 patients were allocated to the paclitaxel (n = 46) and PT (n = 45) arms. The median PFS in the paclitaxel and PT arms was 3.2 and 3.7 months, respectively (hazard ratio [HR], 0.91; 80% CI, 0.67 to 1.22; P = .33), and the median OS in both arms was 10 months (HR, 1.2; 95% CI, 0.75 to 2.0; P = .20). The overall response rates in the paclitaxel and PT arms were 32% and 33%, respectively (P = 1.00), and safety was comparable between the 2 arms. On exploratory analyses, HER2 positivity of tumor tissues was lost after first-line chemotherapy in 11 (69%) of 16 patients whose tumor tissues were available, and circulating HER2 DNA amplification was detected in 41 (60%) of 68 patients. However, no biomarkers associated with efficacy of TBP were found. CONCLUSION: The TBP strategy failed to improve PFS in patients with HER2-positive advanced G/GEJ cancer, and no beneficial biomarkers were found.

Prognostic scores for evaluating the survival benefit of regorafenib or trifluridine/tipiracil in patients with metastatic colorectal cancer: an exploratory analysis of the REGOTAS study.

BACKGROUND: Although regorafenib or trifluridine/tipiracil (FTD/TPI) has been recognized as a later-line standard treatment in patients with metastatic colorectal cancer (mCRC), not all patients have beneficial outcomes. This study aimed to develop a prognostic scoring system for evaluating the overall survival (OS) benefit. METHODS: Patients included in the REGOTAS study, which comprised 489 patients (regorafenib group: 199; FTD/TPI group: 290 patients), were evaluated. OS was analyzed using multivariate Cox proportional model. The prognostic score was calculated using the worst four individual factors weighted by hazard ratio, and the total scores were categorized as low-, moderate-, and high-OS benefit. RESULTS: The worst four factors in the regorafenib group were AST > 40 IU/dL (point, + 3), CRP ≥ 1.0 mg/dL (+ 2), number of metastatic organ site ≥ 3 (+ 2), and duration from initiation of 1st-line chemotherapy < 18 months (+ 2), while they were AST (+ 2), CRP (+ 2), CA19-9 > 37.0 U/mL (+ 2), and ECOG PS ≥ 1 (+ 2) in the FTD/TPI group. These corresponded to a total prognostic score of > 5, 2-4, and 0 points in the regorafenib group and 8, 2-6, and 0 points in the FTD/TPI group. The median OS in the low, moderate, and high OS benefit group was 3.3 (95% CI 3.0-3.7), 8.1 (95% CI 6.4-9.7), and 12.6 months (95% CI 10.6-14.6) in the regorafenib group and 2.8 (95% CI 2.0-3.5), 7.5 (95% CI 6.6-8.3), and 15.4 months (95% CI 9.7-21.2) in the FTD/TPI group. CONCLUSION: These prognostic scores are useful for identifying patients with mCRC who will obtain survival benefits from these drugs.

Multicenter phase II study of SOX plus trastuzumab for patients with HER2+ metastatic or recurrent gastric cancer: KSCC/HGCSG/CCOG/PerSeUS 1501B.

BACKGROUND: Trastuzumab (T-mab) combined with cisplatin and fluoropyrimidines is a standard first-line treatment for HER2+ advanced gastric cancer (AGC). We conducted the first phase II trial among four Japanese study groups to assess the efficacy and safety of T-mab + S-1 and oxaliplatin (T-SOX130) for HER2+ AGC or recurrent gastric cancer. METHODS: Patients with IHC 3+ or IHC 2+/FISH+ tumors received 80 mg/m2 (80-120 mg/day) oral S-1 on days 1-14, 130 mg/m2 intravenous oxaliplatin on day 1, and intravenous T-mab (8 mg/kg loading dose, 6 mg/kg thereafter) on day 1 of a 21-day cycle. The primary endpoint was centrally assessed response rate (RR). Adverse events were based on the Common Terminology Criteria for Adverse Events (CTCAE) Ver.4.0. RESULTS: We enrolled 42 patients from June 2015 to May 2016. Efficacy and safety analyses were conducted for 39 patients. The data cutoff was May 31, 2018. The confirmed RR was 82.1% (32/39; 90% CI 70.0-90.0); the disease control rate was 87.2% (34/39; 95% CI 73.3-94.4). Nine patients underwent curative surgery after T-SOX130. Median Time to treatment failure (TTF), Progression-free survival (PFS) and Overall survival (OS) was 5.7 (95% CI 4.6-7.0), 7.0 (95% CI 5.5-14.1), and 27.6 (95% CI 15.6-Not reached) months, respectively. Incidences of grade 3-4 adverse events > 10% were thrombocytopenia (17.9%), anorexia (17.9%), anemia (12.8%), neutropenia (10.3%), and hyponatremia (10.3%). CONCLUSIONS: T-SOX130 showed promising response and survival with a favorable safety profile and should be considered for patients with HER2+ AGC.

Re-evaluation of HER2 status in patients with HER2-positive advanced or recurrent gastric cancer refractory to trastuzumab (KSCC1604).

BACKGROUND: Anti-HER2 therapy has not demonstrated a survival advantage in the second-line setting of patients with HER2-positive gastric cancer. We conducted this study to assess changes in HER2 status and to identify possible biomarkers for acquired resistance after the use of trastuzumab as the first-line therapy. PATIENTS AND METHODS: Patients with advanced or recurrent HER2-positive gastric adenocarcinoma who were diagnosed with progressive disease after the first-line trastuzumab-based therapy and developed pathologically confirmed adenocarcinoma within 3 months after completion of trastuzumab-based therapy were enrolled in this study. We collected re-biopsied samples from the HER2-positive patients who had developed resistance to trastuzumab and re-evaluated their HER2 status. Amplification of EGFR and c-met, as well as PIK3CA mutation, were comparatively analysed when samples were available. RESULTS: Among 33 eligible patients, loss of HER2 was identified in 20 patients (60.6%) with refractory disease. Immunohistochemistry showed that the rate of HER2 overexpression was greatly reduced after therapy (pre-HER2 3+: 24 [72.7%] vs. post-HER2 3+: 13 [39.4%]). We found that the use of fixatives other than 10% neutral buffered formalin significantly reduced the HER2-positive rate. EGFR amplification, c-met amplification and PIK3CA mutation before and after trastuzumab-based therapy were observed in 10.3% and 3.8%, 17.9% and 4.2% and 4.0% and 4.2% of cases, respectively. CONCLUSION: Re-evaluation of HER2 status is needed to determine the appropriate use of anti-HER2-targeted therapy after disease progression. Our results also highlight the importance of formalin fixation conditions for HER2 testing.

Role of Predictive Value of the Modified Glasgow Prognostic Score for Later-line Chemotherapy in Patients With Metastatic Colorectal Cancer.

BACKGROUND: Assessment of patient factors is essential for selecting later-line chemotherapy in patients with metastatic colorectal cancer (mCRC). The efficacy, prognosis, and safety of each treatment regimen according to nutritional and inflammatory status still remain to be elucidated. PATIENTS AND METHODS: A total of 550 patients with mCRC who were registered in the REGOTAS study (Regorafenib versus TAS-102 as Salvage-line in patients with colorectal cancer refractory to standard chemotherapies: a multicenter observational study, UMIN 000020416) and treated with trifluridine/tipiracil (TFTD) or regorafenib as a later-line therapy were retrospectively stratified according to the modified Glasgow Prognostic Score (mGPS), which divided patients into mGPS 0 to 2 by serum albumin and C-reactive protein, and compared. RESULTS: The median overall survival (OS) of patients with mGPS 0, 1, and 2 was 10.0 months (95% confidence interval [CI], 9.2-11.6 months), 6.5 months (95% CI, 5.3-7.1 months), and 3.9 months (95% CI, 3.3-4.9 months), respectively. The median progression-free survival (PFS) with mGPS 0, 1, and 2 was 2.5 months (95% CI, 2.1-3.0 months), 2.0 months (95% CI, 1.9-2.3 months), and 1.7 months (95% CI, 1.4-1.9 months), respectively. There were significant differences by mGPS in both OS and PFS (all P < .001). No significant differences in OS and PFS were observed between the patient groups treated with TFTD and regorafenib in each mGPS group. In patients aged ≥ 65 years with mGPS 2, the OS and PFS were worse with regorafenib than with TFTD (OS: hazard ratio, 1.45; 95% CI, 0.93-2.25; P = .097; PFS: hazard ratio, 1.57, 95% CI, 1.01-2.44; P = .047), but there were no consistent trends observed as mGPS increased. The frequency of grade 3 and more adverse events was generally similar in each mGPS group. The multivariate analyses showed that mGPS was the strongest predictive factor for OS. CONCLUSIONS: The mGPS before later-line chemotherapy is strongly correlated with survival in patients with mCRC.

First-line chemotherapy with S-1 alone or S-1 plus cisplatin for elderly patients with advanced gastric cancer: a multicenter propensity score matched study.

BACKGROUND: Fluoropyrimidine and platinum combination is the standard treatment for advanced or recurrent gastric cancer (AGC). However, fluoropyrimidine monotherapy is commonly used for elderly patients with AGC because of its good tolerability. METHODS: In this multicenter retrospective study, we collected clinical data of AGC patients aged 70 years or older, treated with S-1 alone or S-1 plus cisplatin (SP) as the first-line treatment between January 2009 and December 2011. Propensity score matched cohorts (PSMC) were used for reducing the confounding effects to compare efficacy and safety between the two treatment groups. Cox regression analysis was performed to clarify the prognostic factors. RESULTS: PSMC (n = 109 in each group) were selected from among 444 eligible patients (S-1 group, 210; SP group, 234); the S-1 group included more patients deemed unfit for intensive chemotherapy than the SP group (e.g., higher age, poorer PS, poor renal function). In the PSMC, patients' characteristics were comparable between groups, except the male ratio (S-1 group, 64.2%; SP group, 77.1%; p = 0.04). No significant differences were observed in either overall survival [hazard ratio (HR) 0.93, p = 0.63] or progression-free survival (HR 1.09, p = 0.61). Severe adverse events (AEs) and hospitalization due to AEs were more frequent in the SP group than in the S-1 group (p < 0.001 each). CONCLUSION: Our findings do not support the survival benefit of SP over S-1 in elderly patients with AGC. We are now conducting a prospective comparative study to optimize treatment strategy and explore applicability of the geriatric assessment for these patients.

Propensity Score Analysis of Regorafenib Versus Trifluridine/Tipiracil in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapy (REGOTAS): A Japanese Society for Cancer of the Colon and Rectum Multicenter Observational Study.

BACKGROUND: This study compared the efficacy of regorafenib and trifluridine/tipiracil (TFTD) in patients with metastatic colorectal cancer (mCRC) who are refractory to standard chemotherapy, because despite their clinical approval, it still remains unclear which of these two drugs should be used as initial treatment. MATERIALS AND METHODS: The clinical data of patients with mCRC who were treated with regorafenib or TFTD and those of drug-naive patients, between June 2014 and September 2015, were retrospectively collected from 24 institutions in Japan. Overall survival (OS) was evaluated using the Cox's proportional hazard models based on propensity score adjustment for baseline characteristics. RESULTS: A total of 550 patients (223 patients in the regorafenib group and 327 patients in the TFTD group) met all criteria. The median OS was 7.9 months (95% confidence interval [CI], 6.8-9.2) in the regorafenib group and 7.4 months (95% CI, 6.6-8.3) in the TFTD group. The propensity score adjusted analysis showed that OS was similar between the two groups (adjusted hazard ratio [HR], 0.96; 95% CI, 0.78-1.18). In the subgroup analysis, a significant interaction with age was observed. Regorafenib showed favorable survival in patients aged <65 years (HR, 1.29; 95% CI, 0.98-1.69), whereas TFTD was favored in patients aged ≥65 years (HR, 0.78; 95% CI, 0.59-1.03). CONCLUSION: No significant difference in OS between regorafenib and TFTD was observed in patients with mCRC. Although the choice of the drug by age might affect survival, a clearly predictive biomarker to distinguish the two drugs should be identified in further studies. IMPLICATIONS FOR PRACTICE: Previous studies of patients with metastatic colorectal cancer refractory to standard chemotherapy had demonstrated that both regorafenib and trifluridine/tipiracil could result in increased overall survival compared with placebo, but there are no head-to-head trials. This large, multicenter, observational study retrospectively compared the efficacy of regorafenib and trifluridine/tipiracil in 550 patients with metastatic colorectal cancer refractory to standard chemotherapy who had access to both drugs. Although no difference in overall survival was found between the two drugs in adjusted analysis using propensity score, regorafenib showed favorable survival in patients aged <65 years, whereas trifluridine/tipiracil was favored in patients aged ≥65 years in the subgroup analysis.

Detection of KRAS Mutations in Plasma DNA Using a fully Automated Rapid Detection System in Colorectal Cancer Patients.

KRAS mutations have been recognized as predictive markers of primary resistance to anti-EGFR-antibodies in colorectal cancer patients. In addition, newly detected KRAS mutations have been reported to be related with acquired resistance to chemotherapy containing anti-EGFR antibody. Considering this evidence, monitoring of KRAS mutations is indispensable for making treatment decisions, and the method should be non-invasive allowing repeated examinations. Recently, we established a novel automated sensitive detection system for KRAS mutations, named mutation-biased PCR quenching probe system (MBP-QP). The goal of our study was to investigate the potential for monitoring KRAS mutations during treatment with anti-EGFR antibodies. The detection limit of MBP-QP using a control plasmid containing KRAS mutations was 1-9 copies, and 0.05-0.3% mutant plasmid was detectable in a mixture of wild type and mutants. One-hundred twenty colorectal cancer patients were genotyped for KRAS mutations with MBP-QP as well as polymerase chain reaction reverse sequence-specific oligonucleotide (PCR-rSSO), which has already been applied to cancer tissue samples in the clinical setting. Concordance rates between plasma DNA and cancer tissues were 68% with MBP-QP and 66% with PCR-rSSO, indicating that these systems are equivalent in terms of detecting KRAS mutations with plasma DNA. KRAS mutations in plasma DNA were frequently observed in systemic metastatic cancer patients, and in three patients KRAS mutations appeared after chemotherapy containing anti-EGFR antibody. A prospective study is needed for clarifying whether KRAS mutations detected in plasma DNA are predictive markers of treatment efficacy with anti-EGFR antibody.

Pharmacokinetic dose adjustment of 5-FU in modified FOLFOX7 plus bevacizumab for metastatic colorectal cancer in Japanese patients: a-JUST phase II clinical trial.

PURPOSE: Dose adjustment of 5-fluorouracil (FU) based on pharmacokinetic monitoring has been shown to reduce toxicities and increase efficacy compared with dosing based on body surface area in patients with metastatic colorectal cancer (mCRC). We evaluated the efficacy and safety of pharmacokinetic dose adjustment of FU in a modified FOLFOX7 (mFOLFOX7) plus bevacizumab regimen in Japanese patients with previously untreated mCRC. METHODS: This single-arm, multicenter phase II trial enrolled 48 patients with mCRC. Treatment consisted of 5 mg/kg intravenous bevacizumab followed by mFOLFOX7 (oxaliplatin 85 mg/m2 on day 1, infused leucovorin 200 mg/m2, followed by a 2400 mg/m2 infusion of FU for 46 h starting on day 1), repeated every 2 weeks. FU concentrations were measured by immunoassay between 18 and 36 h after the start of continuous FU infusion, and the FU dose was then adjusted if required in subsequent cycles. The primary endpoint was response rate. RESULTS: The median initial area under the concentration-time curve for FU was 23 mg h/L. Twenty-nine patients (60%) achieved the target concentration at the first cycle, and all 48 achieved it within the fourth cycle. The overall frequency of grade 3/4 adverse effects was 38%, with no significant difference between patients who did and not require dose adjustments. The overall response rate was 48% (95% confidence intervals = 34-62%). The median progression-free and overall survival rates were 11.3 and 24.1 months, respectively. CONCLUSIONS: Pharmacokinetic dose adjustment of FU in mFOLFOX7 plus bevacizumab can optimize FU concentrations promptly and is safe in Japanese patients with mCRC.