Ken Ando

Significance of definitive concurrent chemoradiotherapy for vulvar cancer: a Japanese Gynecologic Oncology Group nationwide survey study

Abstract Objective This study aimed to show the results of radical radiation therapy (RT) and concurrent chemoradiotherapy (CCRT) for vulvar cancer (VC) based on data from a Japanese nationwide survey. Materials and methods We collected data from 108 institutions on cases of VC diagnosed between January 2001 and December 2010. Patients with histologically proven squamous cell carcinoma and adenocarcinoma with curative intent were selected, and 172 patients with VC were included in this study. The collected data were analyzed for overall survival (OS) using the Kaplan–Meier method. Univariate and multivariate analyses were performed to examine the prognostic factors for patients with VC. Results The median follow-up period was 16.8 (range; 3.2–154.8) months. Fifty-five patients received CCRT, and 117 patients received RT alone. The 2-year OS rates (95% confidence interval [CI]) for stages I, II, III, and IV were 77.9% (55.8–100.0), 71.9% (53.8–89.9), 55.4% (42.5–68.3), and 41.5% (27.3–55.7) respectively. Univariate analyses showed that the FIGO stage (p = 0.001), tumor diameter (p = 0.005), and lymph node (LN) status (p = 0.001) were associated with OS. The concurrent use of chemotherapy resulted in a significantly longer OS in Stage III (p = 0.013). Multivariate analysis showed that the hazard ratios (95% CI) for tumor diameter, positivity for LN metastasis, and RT alone (no concurrent chemotherapy) were 1.502 (1.116–2.021), 1.801 (1.287–2.521), and 1.936 (1.187–3.159), respectively. Conclusions Our analysis revealed that CCRT should be recommended, especially for Stage III VC patients. Further studies are warranted to determine who benefits from CCRT, considering primary tumor size and LN status. The study was registered at the University Hospital Medical Information Network (protocol number: UMIN000017080) on April 8th, 2015.

Mutation Analysis of Radioresistant Early-Stage Cervical Cancer

Radiotherapy is a definitive treatment for early-stage cervical cancer; however, a subset of this disease recurs locally, necessitating establishment of predictive biomarkers and treatment strategies. To address this issue, we performed gene panel-based sequencing of 18 stage IB cervical cancers treated with definitive radiotherapy, including two cases of local recurrence, followed by in vitro and in silico analyses. Simultaneous mutations in KRAS and SMAD4 (KRASmt/SMAD4mt) were detected only in a local recurrence case, indicating potential association of this mutation signature with radioresistance. In isogenic cell-based experiments, a combination of activating KRAS mutation and SMAD4 deficiency led to X-ray resistance, whereas either of these factors alone did not. Analysis of genomic data from 55,308 cancers showed a significant trend toward co-occurrence of mutations in KRAS and SMAD4. Gene Set Enrichment Analysis of the Cancer Cell Line Encyclopedia dataset suggested upregulation of the pathways involved in epithelial mesenchymal transition and inflammatory responses in KRASmt/SMAD4mt cancer cells. Notably, irradiation with therapeutic carbon ions led to robust killing of X-ray-resistant KRASmt/SMAD4mt cancer cells. These data indicate that the KRASmt/SMAD4mt signature is a potential predictor of radioresistance, and that carbon ion radiotherapy is a potential option to treat early-stage cervical cancers with the KRASmt/SMAD4mt signature.