Jae Ho Jeong

HER2 Amplification and Cetuximab Efficacy in Patients With Metastatic Colorectal Cancer Harboring Wild-type RAS and BRAF

Background: Cetuximab has shown clinical benefit in patients with metastatic colorectal cancer (mCRC) harboring wild‐type RAS. Human epidermal growth factor receptor 2 (HER2) amplification may be a mechanism of cetuximab resistance. We evaluated the association between HER2 amplification and cetuximab efficacy in patients with mCRC harboring wild‐type RAS and BRAF. Patients and Methods: Between December 2003 and June 2013, we identified 142 patients with mCRC whose tumors harbored both wild‐type exons 2, 3, and 4 in KRAS and NRAS, and wild‐type exon 15 in BRAF using high throughput sequencing (OncoMap version 4.0). All patients received cetuximab after oxaliplatin, irinotecan, and fluoropyrimidine failure. HER2 status was determined using immunohistochemistry and silver in situ hybridization (SISH) and correlated with cetuximab efficacy. Results: Of 142 RAS and BRAF wild‐type tumors, we observed 7 cases (4.9%) of HER2 amplification by SISH. After a median follow‐up of 13.2 months (range, 1.4‐78.1 months), median progression‐free survival (PFS) was significantly different according to HER2 status: 3.1 months in patients with HER2 amplification compared with 5.6 months in those with non‐amplified HER2 (hazard ratio, 2.73; 95% confidence interval, 1.18‐6.31; P = .019). Overall survival (OS) was not significantly different between groups, although there was a tendency towards shorter OS in patients with HER2‐amplified tumors (hazard ratio, 1.31; 95% confidence interval, 0.61‐2.82; 10.1 vs. 13.5 months; P = .488). Conclusions: HER2 amplification is predictive of shorter PFS after cetuximab treatment in patients with mCRC harboring wild‐type RAS and BRAF. Further study is warranted for this patient population. &NA; Human epidermal growth factor receptor 2 (HER2) amplification may be a mechanism of cetuximab resistance. We evaluated the association between HER2 amplification and cetuximab efficacy in 142 patients with metastatic colorectal cancer harboring wild‐type RAS and BRAF. We found that HER2 amplification is predictive of shorter progression‐free survival after cetuximab treatment in patients with metastatic colorectal cancer harboring wild‐type RAS and BRAF.

Prognostic implications of hepatitis B virus infection in intrahepatic cholangiocarcinoma treated with first-line gemcitabine plus cisplatin

Purpose: Hepatitis B virus infection is a well-known risk factor for intrahepatic cholangiocarcinoma. However, its prognostic impact has rarely been investigated in advanced intrahepatic cholangiocarcinoma. Methods: Between April 2010 and May 2015, 296 patients with unresectable or metastatic intrahepatic cholangiocarcinoma who received gemcitabine plus cisplatin (GemCis) were categorized into a hepatitis B virus group (n=62; 21%) and a non-hepatitis B virus group (n=234; 79%). Clinicopathological features and survival outcomes were retrospectively reviewed and analyzed. Results: The median age of patients was 59 years (range, 27–78). The median overall survival with first-line GemCis was 9.4 months (95% CI 8.4, 10.4). Compared to the non-hepatitis B virus group, the hepatitis B virus group was younger (median age, 57 vs. 61 years, P = 0.001), mainly male (74% vs. 57%, P = 0.02), and had lower frequency of elevated cancer antigen (CA) 19-9 (34% vs. 59%, P = 0.001) and alkaline phosphatase (43% vs. 61%, P = 0.01). In a univariate analysis, the hepatitis B virus infection showed a marginal relationship with poor overall survival compared to the non-hepatitis B virus infection (median, 8.3 vs. 10.0 months; P=0.13). A multivariate analysis of potential prognostic factors revealed a significant association with poor overall survival in the hepatitis B virus group (hazard ratio (HR) =1.50, P = 0.02). Initial metastatic disease (vs. recurrent/unresectable disease; HR=1.50), metastatic sites ⩾ 2 (vs. 0–1; HR=1.51), Eastern Cooperative Oncology Group performance status ⩾ 2 (vs. 0–1; HR=1.93), elevated total bilirubin (vs. normal; HR=1.83), and low albumin (vs. normal; HR=1.52) were significantly related to an unfavorable overall survival. Conclusions: This study suggests that the hepatitis B virus infection may be associated with distinctive clinicopathological characteristics and poor outcome in advanced intrahepatic cholangiocarcinoma treated with GemCis.

Clinical Benefit of Maintenance Therapy for Advanced Biliary Tract Cancer Patients Showing No Progression after First-Line Gemcitabine Plus Cisplatin

Purpose Gemcitabine plus cisplatin (GemCis) is the standard first-line chemotherapy for patients with advanced biliary tract cancer (BTC). In ABC-02 study, the BTC patients received up to 6-8 cycles of 3-weekly GemCis; however, those without progression often receive more than 6-8 cycles. The clinical benefit of maintenance treatment in patients without progression is uncertain. Materials and Methods Advanced BTC patients treated with GemCis between April 2010 and February 2015 at Asan Medical Center, Seoul, Korea, were retrospectively analysed. The patients without progression after 6-8 cycles were stratified according to further treatment i.e., with or without further cycles of GemCis (maintenance vs. observation groups). The primary endpoint was overall survival (OS) and progression-free survival (PFS). Results Among the 740 BTC patients in the initial screen, 231 cases (31.2%) were eligible for analysis (111 in the observation group, 120 in the maintenance group). The median OS from the GemCis initiation was 20.5 months (95% confidence interval [CI], 15.4 to 25.6) and 22.4 months (95% CI, 17.0 to 27.8) in the observation and maintenance groups, respectively (p=0.162). The median PFS was 10.4 months (95% CI, 7.0 to 13.8) and 13.2 months (95% CI, 11.3 to 15.2), respectively (p=0.320). Conclusion sGemCis maintenance is not associated with an improved survival outcome.

Multicenter Phase II Study of Oxaliplatin, Irinotecan, and S-1 as First-line Treatment for Patients with Recurrent or Metastatic Biliary Tract Cancer

Purpose Although gemcitabine plus cisplatin has been established as the standard first-line chemotherapy for patients with advanced biliary tract cancer (BTC), overall prognosis remains poor. We investigated the efficacy of a novel triplet combination of oxaliplatin, irinotecan, and S-1 (OIS) for advanced BTC. Materials and Methods Chemotherapy-naive patientswith histologically documented unresectable or metastatic BTC were eligible for this multicenter, single-arm phase II study. Patients received 65 mg/m2 oxaliplatin (day 1), 135 mg/m2 irinotecan (day 1), and 40 mg/m2 S-1 (twice a day, days 1-7) every 2 weeks. Primary endpoint was objective response rate. Targeted exome sequencing for biomarker analysis was performed using archival tissue. Results In total, 32 patients were enrolled between October 2015 and June 2016. Median age was 64 years (range, 40 to 76 years), with 24 (75%) male patients; 97% patients had metastatic or recurrent disease. Response rate was 50%, and median progression-free survival and overall survival (OS) were 6.8 months (95% confidence interval [CI], 4.8 to 8.8) and 12.5 months (95% CI, 7.0 to 18.0), respectively. The most common grade 3-4 adverse events were neutropenia (32%), diarrhea (6%), and peripheral neuropathy (6%). TP53 and KRAS mutations were the most frequent genomic alterations (42% and 32%, respectively), and KRAS mutations showed a marginal relationship with worse OS (p=0.07). Conclusion OIS combination chemotherapy was feasible and associated with favorable efficacy outcomes as a first-line treatment in patients with advanced BTC. Randomized studies are needed to compare OIS with gemcitabine plus cisplatin.

Treatment of Refractory Colorectal Cancer: Regorafenib vs. TAS-102

Purpose of ReviewThis paper reviews the development, mechanism of action, clinical efficacy, and safety of regorafenib and TAS-102. Through this review, we aimed to help clinicians make an appropriate choice in patients who progressed after standard therapies.Recent FindingsRegorafenib and TAS-102 have shown superior survival results compared with placebo in refractory metastatic colorectal cancer (mCRC). In the phase III CORRECT study, regorafenib showed significant improvement in overall survival (OS) and progression-free survival (PFS). TAS-102 was associated with OS and PFS benefit as well in the phase III RECOURSE study. However, the toxicity profiles were quite different between the two agents.SummaryRegorafenib and TAS-102 are approved for the management of refractory mCRC. Optimal treatment sequence for using these two novel agents is not defined yet. Safety profiles and patient’s condition should be considered before using these two agents in clinical settings. Further investigation is needed to identify the predictive biomarkers of both agents. These results will allow patients to benefit more from regorafenib and TAS-102.

Safety and feasibility of adjuvant chemotherapy with S-1 in Korean patients with curatively resected advanced gastric cancer.

121 Background: Adjuvant chemotherapy with S-1 has been proven effective for patients with curatively resected advanced gastric cancer with D2 lymph node dissection in Japan. We assessed the safety and feasibility of adjuvant S-1 chemotherapy in Korean patients with stage II, III or IV(M0) gastric cancer. METHODS A total of 305 patients with stage II, III or IV(M0) gastric cancer received adjuvant S-1 chemotherapy following curative gastrectomy with D2 lymph node dissection in Asan Medical Center between October 2007 and December 2009. Adjuvant chemotherapy with S-1 was started 3-6 weeks after surgery and it was administered orally twice daily at the dose of 40 mg/m2 for 4 weeks followed by 2 weeks of rest, every 6 weeks 8 times for 1 year. We retrospectively reviewed the medical records of the patients and evaluated the safety and feasibility of adjuvant S-1 chemotherapy in Korean patients. RESULTS Among the 305 patients, 248 (81.3%) and 198 (64.9%) patients completed 4 and 8 cycles of adjuvant chemotherapy, respectively. The most common reasons for discontinuation of treatment were adverse event (43.9%) and recurrence (26.2%). Among the 305 patients, 75 (24.6%) patients required dose reduction because of toxicities. The most common grade 3/4 toxicities were neutropenia (12.8%), diarrhea (5.3%), abdominal pain (3.8%), and anemia (3.3%). Multivariate analysis showed that total gastrectomy (H.R. 2.50; 95% C.I. 1.32-4.72, p=0.005) and female gender (H.R. 1.95; 95% C.I. 1.03-3.66, p=0.039) were independent risk factors for grade 3/4 hematologic toxicities, and old age (>65 years) (H.R. 2.92; 95% C.I. 1.50-5.69, p=0.002) was an independent risk factor for grade 3 non-hematologic toxicities. CONCLUSIONS Adjuvant chemotherapy with S-1 for 1 year was safe and feasible in Korean patients. Old age, female gender, and total gastrectomy were independent risk factors for severe toxicities of adjuvant S-1 chemotherapy.