Toshifumi Wakai

Actionable Gene Alterations in an Asian Population With Triple-Negative Breast Cancer

PurposenIt has been suggested that the biological characteristics of breast cancer may differ among different geographic or ethnic populations. Indeed, triple-negative breast cancer (TNBC), the most lethal breast cancer subgroup, has been reported to show a higher incidence in Japan than in the US. However, most genomic studies of these tumors are from Western countries and the genomic landscape of TNBC in an Asian population has not been thoroughly investigated. Here, we sought to elucidate the geographic and ethnic diversity of breast cancer by examining actionable driver alterations in TNBC tumors from Japanese patients and comparing them with The Cancer Genome Atlas (TCGA) database, which gather data primarily from non-Asian patients.nnnMaterials and MethodsnWe performed comprehensive genomic profiling, including an analysis of 435 known cancer genes on Japanese TNBC patients (N=53) and compared the results to independent data obtained from TCGA (N=123).nnnResultsnDriver alterations were identified in 51 out of 53 Japanese patients (96%). Although the overall alteration spectrum of Japanese patients was similar to that of the TCGA, we found significant differences in the frequencies of alterations in MYC and PTK2. We identified three patients (5.7%) with a high tumor mutation burden, although no microsatellite instability was observed in any of the Japanese patients. Importantly, pathway analysis revealed that 66.0% (35/53) of Japanese patients, as well as 66.7% (82/123) of the TCGA cohort, had alterations in at least one actionable gene targetable by an FDA-approved drug.nnnConclusionnOur study identified actionable driver alterations in Japanese patients with TNBC, revealing new opportunities for targeted therapies in Asian patients.

Surgical management of carcinoma in situ at ductal resection margins in patients with extrahepatic cholangiocarcinoma

Recent advances in dimensional imaging, surgical technique, and perioperative patient care have resulted in increased rates of complete resection with histopathologically negative margins and improved surgical outcomes in patients with extrahepatic cholangiocarcinoma. However, achieving cancer‐free resection margins at ductal stumps in surgery for this disease remains challenging because of longitudinal extension, which is one of the hallmarks of extrahepatic cholangiocarcinoma. When the ductal resection margins are shown to be positive on examination of frozen sections, discrimination between carcinoma in situ and invasive carcinoma is clinically important because residual carcinoma in situ may lead to late local recurrence whereas residual invasive carcinoma is associated with early local recurrence. Residual invasive carcinoma at the ductal margins should be avoided whenever technically feasible. Residual “carcinoma in situ” at the ductal margins appears to be allowed in resection for the advanced disease because it has less effect on survival than other adverse prognostic factors (pN1 and/ or pM1). However, in surgery for early‐stage (pTis‐2N0M0) extrahepatic cholangiocarcinoma, residual carcinoma in situ at the ductal margins may have an adverse effect on long‐term survival, so should be avoided whenever possible. In this review, we focus on the histopathological term “carcinoma in situ,” the biological behavior of residual carcinoma in situ at ductal resection margins, intraoperative histological examination of the ductal resection margins, outcome of additional resection for positive ductal margins, and adjuvant therapy for patients with positive margins.

Sorafenib-Inhibited Signaling: Emerging Evidence of RAFIndependent Pathways as Potential Therapeutic Targets in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide [Serag et al., 2007, Liovet et al., 2003, Yang et al., 2010]. More than 500,000 people are diagnosed with HCC every year, and it remains the leading cause of death among patients with hepatitis B virus (HBV), hepatitis C virus (HCV) and alcohol-induced liver cirrhosis. One of the main obstacles for treating HCC is late diagnosis of patients. Many unresectable HCC patients are treated with loco-regional therapies such as radiofrequency ablation and transarterial chemo‐ embolization (TACE), but the prognosis remains poor [Bruix et al., 2005]. A recent study in multiple clinical facilities in Japan reported that 5-year survival of patients treated with TACE was less than 30% [Takayasu et al., 2006]. Moreover, HCC is poorly responsive to chemother‐ apeutic drugs and radiotherapy [Arii et al., 2000, Kuwahara et al., 2009]; thus, effective therapeutic tools for HCC are long-awaited.