Eiji Shinozaki

Dlk-1, a cell surface antigen on foetal hepatic stem/progenitor cells, is expressed in hepatocellular, colon, pancreas and breast carcinomas at a high frequency.

Delta-like 1 protein (Dlk-1), also known as preadipocyte factor 1 (Pref-1), is a transmembrane and secreted protein with epidermal growth factor (EGF)-like repeats. Dlk-1 is known to be expressed in foetal liver, but absent in neonatal and adult liver in mice and rats. Dlk-1 is also expressed in a subpopulation of hepatic oval cells, which are considered as stem/progenitor cells in rat adult liver. In this study, we generated monoclonal antibodies against human Dlk-1 (hDlk-1) and investigated hDlk-1 expression in human liver and hepatocellular carcinoma (HCC). Like rodent livers, hDlk-1 was detected in foetal liver, but not in adult liver. In HCC, hDlk-1 was positive for 20.5% of the cases examined and was localized in both cytoplasm and cell membrane, whereas hDlk-1 was undetected in viral hepatitis, nodular cirrhosis. Interestingly, hDlk-1 positive HCC was found more frequently in younger patients and its expression was correlated with alpha-fetoprotein expression. Furthermore, hDlk-1 was also detected frequently in colon adenocarcinomas (58%), pancreatic islet carcinoma (50%), and small cell lung carcinoma (50%). Thus, hDlk-1 is a cell surface protein expressed in many carcinomas including HCC and may be a potential target for monoclonal antibody therapy for carcinomas.

Circulating tumor cells as a surrogate marker for determining response to chemotherapy in patients with advanced gastric cancer

The purpose of this study was to quantify circulating tumor cells (CTCs) in advanced gastric cancer (AGC) patients, and to demonstrate the role of CTCs in cancer therapy. This study investigates the hypothesis that CTCs can predict clinical outcomes in patients with AGC. From November 2007 to June 2009, 52 patients with AGC were enrolled into a prospective study. The chemotherapy regimen was an S‐1‐based regimen (S‐1 with or without cisplatin) or paclitaxel. CTCs of whole blood at baseline, 2 weeks, and 4 weeks after initiation of chemotherapy, were isolated and enumerated using immunomagnetics. Patients with ≥4 CTCs at 2‐week points and 4‐week points had a shorter median progression‐free survival (PFS) (1.4, 1.4 months, respectively) than those with the median PFS of <4 CTCs (4.9, 5.0 months, respectively) (log‐rank test; P < 0.001, P < 0.001, respectively). Patients with ≥4 CTCs at 2‐week points and 4‐week points had shorter median overall survival (OS) (3.5, 4.0 months, respectively) than those with the median PFS of <4 CTCs (11.7, 11.4 months, respectively) (log‐rank test; P < 0.001, P = 0.001, respectively). In conclusion, this study demonstrates that CTC measurement may be useful as a surrogate marker for determining response to S‐1‐based or paclitaxel regimens in AGC.

Irinotecan plus cisplatin for therapy of small-cell carcinoma of the esophagus: report of 12 cases from single institution experience.

BACKGROUND Esophageal small-cell cancer is a rare disease, and standard therapy has not yet been established. METHODS A total of 12 esophageal small-cell carcinoma patients were treated with CPT-11 (70 mg/m(2)) on Days 1 and 15 and CPT-11 plus CDDP (80 mg/m(2)) on Day 1 with each cycle repeated every 4 weeks at our institution. RESULTS A total of 46 chemotherapy courses were given (median, 3.5). There were two complete responses and eight partial responses. The median survival time was 417 (97-1626) days, and three patients were still alive for >40 months. Grade 4 neutropenia was observed in two patients, Grade 4 anemia in one patient, Grade 3-4 diarrhea in three patients and Grade 3-4 hyponatremia in three patients. Other adverse reactions seen were mild with no treatment-related deaths observed. CONCLUSIONS To our knowledge, this is the first report of the series of more than 10 patients with small-cell carcinoma of the esophagus treated with the same chemotherapy regimen. The combination of CPT-11 and CDDP appears to be effective therapy of this disease with acceptable toxicity profile. We believe that this regimen is one of the options to be considered for treatment of esophageal small-cell carcinoma.

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

BACKGROUND FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab. PATIENTS AND METHODS WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396. RESULTS Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months. CONCLUSION FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC. CLINICAL TRIALS NUMBER UMIN000001396.

Chemotherapy for small-bowel Adenocarcinoma at a single institution

PurposeSmall-bowel adenocarcinoma (SBA) is rare. No standard chemotherapy for this type of cancer has yet been established. At Cancer Institute Hospital (CIH), the chemotherapy regimen used for colorectal cancer is initially used for patients with SBA, followed by that used for gastric cancer.MethodsPatients with advanced or recurrent SBA who had been treated with chemotherapy in CIH were retrospectively analyzed. The first-line treatments were fluoropyrimidines used alone or in combination with other drugs, such as 5-fluorouracil plus leucovorin (FL), UFT-E, or TS-1. The second-line treatment was irinotecan (CPT-11) monotherapy.ResultsFluoropyrimidine-based regimens, mainly FL, were used for 10 patients. Seven patients received the second-line CPT-11 regimen. Disease control was seen in five patients (50%) with the first-line chemotherapy and in three (43%) with the second-line. The median overall survival time was 12 months (range 3–39). The treatments were generally tolerated. Gastrointestinal symptoms were the most common adverse effects.ConclusionsFluoropyrimidines as the first-line and CPT-11 as the second-line chemotherapy yielded low response, although the adverse effects were mild. The FOLFOX and FOLFIRI regimens such as those used for metastatic colorectal cancer are potential alternative strategies. Extensive trials are needed to develop standard chemotherapy with new drugs.

Predictors of the Efficacy of FOLFIRI plus Bevacizumab as Second-Line Treatment in Metastatic Colorectal Cancer Patients

PurposeFluoropyrimidine-based chemotherapy plus bevacizumab (BV) is the standard treatment for metastatic colorectal cancer (mCRC). The aim of this study was to investigate the efficacy of BV plus FOLFIRI (5-fluorouracil, leucovorin, irinotecan) as second-line treatment in mCRC patients refractory to first-line oxaliplatin-based chemotherapy, and determine potential predictive factors affecting survival.MethodsThirty-four consecutive patients were included in this retrospective study. All patients received FOLFIRI plus 5 mg/kg BV until progression or unmanageable toxicity occurred. Clinical factors and KRAS status were evaluated as potential biomarkers of efficacy.ResultsThe overall response was 23.5%. The median progression-free survival (PFS) and time-to-treatment failure (TTF) were 248 and 221 days, respectively. The median overall survival (OS) was 651 days. A univariate analysis revealed that normal thrombin antithrombin complex, alkaline phosphatase, lactate dehydrogenase, and carbohydrate antigen 125 (CA125) levels at baseline were associated with better PFS, TTF, and OS. A multivariate analysis showed that only the CA125 level at baseline was an independent negative predictor of both PFS and OS. KRAS status was not identified as a predictor.ConclusionsThe results of this study suggest that FOLFIRI plus BV is a viable option in second-line treatment for mCRC refractory to first-line FOLFOX (5-fluorouracil, leucovorin, oxaliplatin) alone, and indicate that CA125 might be a predictive biomarker for the outcome.

Serum VEGF-A and CCL5 levels as candidate biomarkers for efficacy and toxicity of regorafenib in patients with metastatic colorectal cancer.

Regorafenib is an oral multi-kinase inhibitor used as salvage therapy for metastatic colorectal cancer (mCRC). We tested whether serum cytokine levels are associated with clinical outcome in the mCRC patients receiving regorafenib. Serum samples were collected before treatment start, day 21, and progressive disease, and eleven angiogenic and inflammatory cytokine serum levels were examined. Fifty-four patients of a total of 62 enrolled patients were eligible for the analyses. The chemokine ligand 5 (CCL5) levels ≤ cut-off value (59959 pg/ml) at baseline was associated with relative tumor shrinkage (P = 0.021), better progression-free survival (PFS) (P = 0.036) and overall survival (OS) (P = 0.019). Vascular endothelial growth factor A (VEGF-A) levels showing a decrease on day 21 were significantly associated with a better PFS (P = 0.021). CCL5 levels ≤ cut-off was associated with any grade hand-foot skin reaction (HFSR) (P = 0.025) and thrombocytopenia (P = 0.013). Low chemokine ligand 2 levels at baseline were associated with grade 2 ≤ HFSR. High angiopoietin-2 and basic fibroblast growth factor (bFGF) levels at baseline were associated with grade 3 ≤ total bilirubin increase and transaminases increase, respectively. Low bFGF levels at baseline were associated with grade 3 ≤ hypertension. No correlation with severe events was observed. Baseline serum CCL5 levels and decrease of the serum VEGF-A levels may serve as potential predictive markers for survival or treatment-specific toxicities in mCRC patients receiving regorafenib.

RAS mutation is a prognostic biomarker in colorectal cancer patients with metastasectomy.

Studies have demonstrated a relationship between clinical outcomes after curative resection for colorectal cancer (CRC) and gene mutations of the EGFR pathway; however, no studies have examined metastatic CRC (mCRC) patients with metastasectomy. The aim of this study was to evaluate the relationship between gene mutations of EGFR pathway and clinical outcomes after metastasectomy in mCRC patients. A total of 1,053 patients histopathologically confirmed CRC received a genotyping test for the EGFR pathway from February 2012 to October 2013. Detailed information was obtained through review of medical records. Gene mutations of EGFR pathway were analyzed by Luminex assay. Overall survival (OS) and recurrence free survival were estimated by the Kaplan‐Meier method and the log‐rank test was used to compare the survival outcomes by gene mutation status. A total of 132 patients received metastasectomy. The frequencies of KRAS exon 2, KRAS exon 3.4, NRAS, BRAF, and PIK3CA mutations were 38.6% (51/132), 3.6% (5/132), 5.1% (7/132), 5.1% (7/132), and 8.7% (12/132), respectively. With a median follow‐up of 84.1 months (57.2—NA) for a survivor, the 4‐year OS rate was 65.6% for mCRC with RAS mutation, and 81.3% for mCRC with wild‐type RAS (p < 0.05). We observed a statistically significant correlation for only the RAS mutation and OS. In multivariate analysis, RAS mutation and liver metastasis were independent factors for shorter OS. There were no significant differences between gene mutations of EGFR pathway and recurrence free survival. RAS mutation in mCRC metastasectomy patients was associated with shorter overall survival.

Phase II study of reintroduction of oxaliplatin for advanced colorectal cancer in patients previously treated with oxaliplatin and irinotecan: RE-OPEN study

Background The effectiveness of reintroducing oxaliplatin in patients with metastatic colorectal cancer refractory to standard chemotherapy has not been verified. We performed a single-arm, open-label, Phase II study to evaluate the safety and efficacy of reintroducing oxaliplatin. Methods Eligible patients had received prior chemotherapy including oxaliplatin and irinotecan that achieved a response or stable disease followed by confirmed disease progression ≥6 months previously during prior oxaliplatin-based therapy. The primary endpoint was the disease control rate (DCR) after 12 weeks of treatment starting. The DCR was defined as the sum of patients with complete response, partial response, and stable disease. Results Thirty-three patients were enrolled. The median age was 62 (range: 35–77) years and the male/female ratio was 19/14. Eastern Cooperative Oncology Group performance status was 0 in 84.8%. Fourteen primary tumors were in the colon and 19 were in the rectum. All patients received modified FOLFOX6 as the protocol treatment. After 12 weeks of treatment starting, the DCR was 39.4% (95% confidence interval 21.8–57.0) and the response rate (complete response and partial response) was 6.1%. The median number of chemotherapy cycles was five and the median total dose of oxaliplatin was 425 mg/m2. Median progression-free survival time was 98 days and median overall survival was 300 days. The incidence of grade ≥1 and grade ≥3 allergic reactions was 28.1% and 3.1%, respectively. The incidence of grade ≥1 and grade ≥3 peripheral sensory neuropathy was 53.1% and 0%, respectively. There were no other severe adverse events and no treatment-related deaths. Conclusion Reintroducing oxaliplatin can be both safe and effective. This may be a salvage option for patients with metastatic colorectal cancer who achieved a response or stable disease with prior oxaliplatin-based therapy followed by disease progression ≥6 months previously during prior oxaliplatin-based therapy.

Clinical significance of BRAF non-V600E mutations on the therapeutic effects of anti-EGFR monoclonal antibody treatment in patients with pretreated metastatic colorectal cancer: the Biomarker Research for anti-EGFR monoclonal Antibodies by Comprehensive Cancer genomics (BREAC) study

Background:Patients with BRAFV600E-mutated metastatic colorectal cancer (mCRC) have a poorer prognosis as well as resistance to anti-EGFR antibodies. However, it is unclear whether BRAF mutations other than BRAFV600E (BRAFnon-V600E mutations) contribute to anti-EGFR antibody resistance.Methods:This study was composed of exploratory and inference cohorts. Candidate biomarkers identified by whole exome sequencing from super-responders and nonresponders in the exploratory cohort were validated by targeted resequencing for patients who received anti-EGFR antibody in the inference cohort.Results:In the exploratory cohort, 31 candidate biomarkers, including KRAS/NRAS/BRAF mutations, were identified. Targeted resequencing of 150 patients in the inference cohort revealed 40 patients with RAS (26.7%), 9 patients with BRAFV600E (6.0%), and 7 patients with BRAFnon-V600E mutations (4.7%), respectively. The response rates in RAS, BRAFV600E, and BRAFnon-V600E were lower than those in RAS/BRAF wild-type (2.5%, 0%, and 0% vs 31.9%). The median PFS in BRAFnon-V600E mutations was 2.4 months, similar to that in RAS or BRAFV600E mutations (2.1 and 1.6 months) but significantly worse than that in wild-type RAS/BRAF (5.9 months).Conclusions:Although BRAFnon-V600E mutations identified were a rare and unestablished molecular subtype, certain BRAFnon-V600E mutations might contribute to a lesser benefit of anti-EGFR monoclonal antibody treatment.