Exploratory randomized phase II trial for optimizing treatment dosage and duration of adjuvant S‐1 plus oxaliplatin in patients with stage III colon cancer: YCOG1402 (SOAP trial)

Abstract Introduction Conventionally, the recommended duration of adjuvant chemotherapy of colon cancer had been 6 months. The IDEA Collaboration suggested that shortening capecitabin and oxaliplatin (CAPOX) adjuvant chemotherapy may be possible. S‐1 and oxaliplatin (SOX) treatment is standard treatment in metastatic colorectal cancer in Japan. The aim of this study was to optimize treatment dosage and duration of adjuvant SOX in stage III colon cancer. Methods This trial was as open‐label multi‐center randomized phase II study. Patients with stage III colon cancer were randomly assigned to 3 months or 6 months of adjuvant SOX treatment in different doses: 130 mg/m2 (3 months) or 100 mg/m2 (6 months) of oxaliplatin. The primary endpoint was 3‐year disease‐free survival (DFS) and the null hypothesis for the primary endpoint was that the 3‐year DFS was ≤72% in each arm and was tested with a one‐sided significance level of 10%. Results Eighty‐two patients were assigned to the 6 months arm and 81 to the 3 months arm. The 3‐year DFS was 75.0% (80% CI 67.95–80.72, p = 0.282) in the 6 months arm and 76.9% (80% CI 70.1–82.38, p = 0.171) in the 3 months arm. Treatment completion rate and relative dose intensity (RDI) were higher in 3 months than 6 months arm. The adverse events (AE) were similar in both arms. Conclusions The 3‐year DFS was not significantly superior to null hypothesis in both 3 months and 6 months arms for the stage III colon cancer. Primary endpoint was not achieved. The SOX regimen was not feasible in long‐term outcomes

Fenton reaction induced cancer in wild type rats recapitulates genomic alterations observed in human cancer.

Iron overload has been associated with carcinogenesis in humans. Intraperitoneal administration of ferric nitrilotriacetate initiates a Fenton reaction in renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC) after repeated treatments. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of this oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletions. Deletions and amplifications were numerous and sometimes fragmented, demonstrating that a Fenton reaction is a cause of such genomic alterations in vivo. Frequency plotting indicated that two of the most commonly altered loci corresponded to a Cdkn2a/2b deletion and a Met amplification. Tumor sizes were proportionally associated with Met expression and/or amplification, and clustering analysis confirmed our results. Furthermore, we developed a procedure to compare whole genomic patterns of the copy number alterations among different species based on chromosomal syntenic relationship. Patterns of the rat RCCs showed the strongest similarity to the human RCCs among five types of human cancers, followed by human malignant mesothelioma, an iron overload-associated cancer. Therefore, an iron-dependent Fenton chemical reaction causes large-scale genomic alterations during carcinogenesis, which may result in distinct genomic profiles. Based on the characteristics of extensive genome alterations in human cancer, our results suggest that this chemical reaction may play a major role during human carcinogenesis

Features of 13 cases of Fe-NTA-induced renal cell carcinomas.

<p>Fe-NTA: ferric nitrilotriacetate; HD: homozygous deletion.</p

Frequent wide-ranging amplifications over a long pericentromeric region of chromosome 4 with the <i>Met</i> oncogene residing in the most overlapping section.

<p>(A) The bar chart represents the amplification regions along a 65 Mb pericentrometic region of chromosome 4 for 13 RCC tumors and two RCC cell lines. Four grades of amplification are indicated by bar color gradation; the darker the red, the larger the amplitude. (B) A magnified view of the bar chart above shows the vicinity of the most overlapping region. The genomic regions of all of the RefSeq genes included in the displayed range of the chromosome are depicted as vertical bars in the background. (C) Expression analysis of <i>Met</i> for 13 RCC tumors and two RCC cell lines by real-time PCR. The values on the <i>y</i>-axis indicate relative mRNA expression level compared to an average of those in normal kidneys of three control rats.</p