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Background/aim The aim of the study was to evaluate gemcitabine plus nanoparticle albumin-bound paclitaxel (GnP) and FOLFIRINOX for recurrent pancreatic cancer (rPC) after resection. Patients and methods Forty-four patients with rPC and 211 with de novo metastatic pancreatic cancer (mPC) who received GnP or FOLFIRINOX as first-line chemotherapy were retrospectively analyzed. Results On crude analysis, the median overall survival (OS) was significantly longer in the rPC group than in the mPC group (14.0 vs. 10.6 months, respectively; p=0.02). However, the difference was not significant on adjusted analysis using the Cox proportional hazards model (adjusted p=0.90). Patients receiving FOLFIRINOX (n=10) and GnP (n=34) in the rPC group had comparable OS (medians, 12.2 vs. 14.4 months, respectively; p=0.82) even after adjusting for covariates using the Cox model (adjusted p=0.18). Conclusion The outcomes of patients in the rPC and mPC groups were comparable following chemotherapy. Both FOLFIRINOX and GnP may be reasonable options for treating rPC.

Introduction: Original FOLFIRINOX (oFFX) is more toxic than other regimens for patients with metastatic pancreatic cancer (mPC); therefore, a modified FFX (mFFX) regimen with a reduced dosage has been used in Japanese clinical practice. However, very few studies have compared these two regimens. Methods: This study was conducted as part of a multicenter retrospective study of 318 patients with mPC across 14 centers in Japan (NAPOLEON study). To control for potential bias and confounders, we conducted a propensity score-adjusted analysis of patient characteristics and clinical outcomes. Results: oFFX and mFFX were administered to 48 and 54 patients. More patients with younger age and poorer performance status were included in the oFFX group. The overall survival (OS; median, 11.6 vs. 11.3 months; hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.60–1.40; p = 0.67), progression-free survival (PFS) (median, 6.3 vs. 5.7 months; HR, 0.85; 95% CI, 0.56–1.28; p = 0.44), and overall response rate (29 vs. 26%, p = 0.71) were not significantly different for the oFFX and mFFX groups. Thrombopenia and liver dysfunction were significantly more frequent with oFFX than with mFFX. The median received dose intensity of CPT-11 was higher with oFFX than with mFFX (299 vs. 270 mg/m2/week, p < 0.01). The propensity score-adjusted analysis revealed no statistically significant differences in OS and PFS between the two groups. Conclusion: In our data, there was no significant difference in efficacy between mFFX and oFFX, and mFFX has fewer adverse events.

Fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX, FFX) and gemcitabine plus nab-paclitaxel (GnP) are considered standard treatments for patients with metastatic pancreatic cancer. Direct comparisons are not available that establish which is optimal. We conducted a propensity score-adjusted analysis of patients with metastatic pancreatic cancer to identify the therapeutic advantages of these standard therapies. We used clinical data as part of a multicenter retrospective study of patients with unresectable or recurrent pancreatic cancer treated with FFX or GnP (NAPOLEON study). FFX and GnP were initially administered to 102 and 153 patients, respectively. The GnP group comprised more patients of advanced age, worse performance status, lower body mass index, recurrence, and lower albumin concentrations. Median overall survival (OS) and progression-free survival (PFS) were 11.5 months and 5.8 months in the FFX group and 11.1 months and 5.9 months in the GnP group, respectively. Propensity score-adjusted analysis indicated that the administration of FFX or GnP was not independently associated with OS (adjusted hazard ratio [HR] 1.06; 95% confidence interval [CI] 0.76–1.47; P = 0.73). Similarly, the difference in PFS was not significant between groups (adjusted HR 0.93; 95% CI 0.68–1.26; P = 0.62). Gastrointestinal disorders were more common in the FFX group, whereas the frequencies of hematological, nervous system, and skin disorders were higher in the GnP group. The efficacies of FFX and GnP were comparable, although safety profiles differed and should be considered in selecting treatment.

There are several reports of pleural adenomatoid (microcystic) mesothelioma, but peritoneal adenomatoid mesothelioma is extremely rare. A 64-year-old Japanese woman presented with no symptoms and no asbestos exposure history. An abdominal computed tomography scan revealed multiple hypervascular masses on the liver surface, pelvic cavity and anterior peritoneum. Over 10 pieces of the multiple resected tumors showed numerous microcysts composed of a bland mesothelial cell background with rich capillary vessels. Focally, atypical cells with bizarre nuclei with prominent nucleoli were observed. Adenomatoid mesothelioma was suspected based on histochemical, immunohistochemical and fluorescence in situ hybridization findings. The tumors relapsed 4 years later and metastasized to the lung, but the patient remains alive 7 years after the first tumor resection surgery. Although the prognosis of adenomatoid mesothelioma of pleural origin is poor, the progression of this peritoneal case is slow.

Objectives FOLFIRINOX (FFX, a combination of oxaliplatin, irinotecan, fluorouracil, and leucovorin) and gemcitabine plus nab-paclitaxel (GnP) have been used as standard, first-line treatments for advanced pancreatic cancer. However, no study has compared the efficacy of the 2 regimens. This study retrospectively compared the efficacy and safety of the 2 regimens in patients with locally advanced pancreatic cancer. Methods We reviewed the records of patients with locally advanced pancreatic cancer who started FFX or GnP as first-line chemotherapy as part of a multicenter retrospective study in patients with unresectable pancreatic cancer treated with FFX or GnP (NAPOLEON study). Results Sixteen of the 63 patients were treated with FFX, and the other 47 patients were treated with GnP between December 2013 and March 2017. There were no significant differences in median overall survival rate between the GnP (15.5 months) and FFX (14.3 months, P = 0.60) groups or median progression-free survival rate between the GnP (8.8 months) and FFX (8.1 months, P = 0.51) groups. Both treatments were generally well tolerated, although anorexia was more severe in the FFX group than in the GnP group. Conclusions The effects of FFX and GnP were similar but resulted in different toxicities, which could guide agent choice.

The aim of the study was to evaluate gemcitabine plus nanoparticle albumin-bound paclitaxel (GnP) and FOLFIRINOX for recurrent pancreatic cancer (rPC) after resection.Forty-four patients with rPC and 211 with de novo metastatic pancreatic cancer (mPC) who received GnP or FOLFIRINOX as first-line chemotherapy were retrospectively analyzed.On crude analysis, the median overall survival (OS) was significantly longer in the rPC group than in the mPC group (14.0 vs. 10.6 months, respectively; p=0.02). However, the difference was not significant on adjusted analysis using the Cox proportional hazards model (adjusted p=0.90). Patients receiving FOLFIRINOX (n=10) and GnP (n=34) in the rPC group had comparable OS (medians, 12.2 vs. 14.4 months, respectively; p=0.82) even after adjusting for covariates using the Cox model (adjusted p=0.18).The outcomes of patients in the rPC and mPC groups were comparable following chemotherapy. Both FOLFIRINOX and GnP may be reasonable options for treating rPC.

Background No reliable nomogram has been developed until date for predicting the survival in patients with unresectable pancreatic cancer undergoing treatment with gemcitabine plus nab-paclitaxel (GnP) or FOLFIRINOX (FFX).Methods This analysis was conducted using clinical data of patients with unresectable pancreatic cancer undergoing GnP or FFX treatment obtained from a multicenter study (NAPOLEON study). A Cox proportional hazards model was used to identify the independent prognostic factors. A nomogram to predict 6-, 12-, and 18-month survival probabilities was generated, validated by using the concordance index (C-index), and calibrated by the bootstrapping method. And then, we attempted risk stratification for survival by classifying the patients according to the sum of the scores on the nomogram (total nomogram points; TNP).Results A total of 318 patients were enrolled. A prognostic nomogram was generated using data on the Eastern Cooperative Oncology Group performance status, liver metastasis, serum LDH, serum CRP, and serum CA19-9. The C-indexes of the nomogram were 0.77, 0.72 and 0.70 for 6-, 12-, and 18-month survival, respectively. The calibration plot showed optimal agreement at all points. Risk stratification based on tertiles of the TNP yielded clear separations of the survival curves. The median survival times in the low-, moderate-, and high-risk groups were 15.8, 12.8 and 7.8 months (PConclusions: Our nomogram is a convenient and inexpensive tool to accurately predict survival in patients with unresectable pancreatic cancer undergoing treatment with GnP or FFX, and will help clinicians in selecting appropriate therapeutic strategies for individualized management.

This study was designed to assess the tolerability, efficacy, and safety of tri-weekly irinotecan plus S-1 (IRIS) and weekly cetuximab in patients with metastatic colorectal cancer (mCRC). The main eligibility criteria were RAS wild-type mCRC with no prior chemotherapy. S-1 was given orally at a dose of 40 mg/m2 (40–60 mg) twice for 2 weeks, followed by a 1-week rest. Irinotecan was given on day 1 of each cycle at a dose of 150 mg/m2. Cetuximab was administered on days 1 (400 mg/m2), 8 (250 mg/m2), and 15 (250 mg/m2), and then once weekly (250 mg/m2) thereafter. A standard 3 + 3 phase I dose de-escalation design was used to determine the maximum tolerated dose and the recommended dose (RD) of irinotecan. The primary end point of the Phase II study was overall response rate (ORR). Between December 2014 and September 2017, 4 and 54 patients were enrolled in phase I and phase II studies, respectively. No dose-limiting toxicity was observed in the phase I study, and the RD of irinotecan was 150 mg/m2. In the phase II study, the ORR was 56.9% (90% confidence interval 44.4%–68.7%). The safety profile revealed that the most common grade 3/4 adverse events were neutropenia (31.4%), appetite loss (27.5%), hypokalemia (11.8%), and diarrhea (11.8%). Grade 3/4 hand–foot skin syndrome occurred in nine patients (9.8%). This study showed that the efficacy and safety of IRIS combined with cetuximab were comparable to those for other first-line treatments. This regimen is a good candidate for first-line treatment of RAS wild-type mCRC.

[Background] Medical staff have many occasions to be exposed to anticancer drugs (ACDs) in the process of performing cancer chemotherapy. Although guidelines for the safe handling of ACDs have been published, actual measures against exposure to ACDs differ between hospitals, and no surveillance data regarding the conditions of each hospital in relation to performing chemotherapy in Japan are available. [Methods] To understand current measures against exposure to ACDs and problems related to cancer chemotherapy at outpatient departments, we conducted a questionnaire survey on doctors, pharmacists, and nurses in 10 leading hospitals for cancer chemotherapy in Japan. [Results] Responses were received from all 10 institutions. The hospital pharmacists prepared all ACDs for outpatients in each institution. All hospitals took basic measures against ACD exposure, such as using personal protective equipment and penetration-resistant waste containers. Conditions against exposure to ACDs generally improved between 2012 and 2015, especially in terms of conveyance of ACDs and use of a closed-system drug transfer device. However, no measures linking ACDs with administration routes or injection sites were commonly taken in any of the hospitals in 2015. [Conclusions] Conditions against ACD exposure improved between 2012 and 2015, possibly because new guidelines were issued. To improve measures for ACD exposure in Japan, preparing more appropriate manuals and offering more opportunities to medical staff for continuing education are considered important.

661 Background: Gemcitabine plus nab-paclitaxel (GnP) and FOLFIRINOX (FFX) have been established as standard first-line combination chemotherapy (CTx) for patients with metastatic pancreatic cancer (MPC). However, the efficacy of second-line CTx and the significance of combination CTx in clinical practice are unclear. We therefore investigated the efficacy of second-line CTx in patients with MPC. Methods: Data were collected from CTx-naive MPC patients treated with first-line combination CTx at 14 hospitals in the Kyushu area of Japan from December 2013 to June 2018. The median overall survival (mOS) from second-line treatment was compared between patients who received second-line CTx (CT group) and those who received best supportive care (BSC group). Furthermore, in the CT group, the mOS was compared between the patients who received combination CTx and those who received mono-CTx. To control potential bias in the selection of second-line treatment, we also conducted a propensity score-adjusted analysis. Results: A total of 255 patients received GnP or FFX as first-line CTx. Of these, there were 156 (61%) in the CT group and 77 (30%) in the BSC group. The number of patients who received FFX/GnP as first-line CTx was 79 (51%)/77 (49%) in the CT group and 15 (20%)/62 (80%) in the BSC group, respectively (P < 0.01). The mOS in the CT group was significantly longer than that in the BSC group (5.2 vs. 2.7 months; hazard ratio [HR] 0.42; 95% confidence interval [CI] 0.31-0.57; p < 0.01 and 5.2 vs. 2.6 months; adjusted HR 0.39; 95% CI 0.28-0.55; p < 0.01). In the CT group, 89 (57%) patients received combination CTx, and 67 (43%) received mono-CTx. There was no significant difference in the mOS between the combination CTx and mono-CTx patients (5.5 vs. 4.4 months; HR 0.88; 95% CI 0.62-1.26; p = 0.88 and 5.6 vs. 4.4 months; adjusted HR 0.85; 95% CI 0.56-1.30; p = 0.47). Conclusions: Among patients with MPC receiving second-line treatment, the CT group had a significantly longer mOS than the BSC group, but combination CTx conferred no improvement in the survival duration compared with mono-CTx.

Pemetrexed is a key anticancer agent for treatment of advanced non-small cell lung cancer (NSCLC). Pemetrexed is generally well tolerated, but individual-patient differences exist in severity of adverse events. Our study aimed to characterize the adverse events of pemetrexed that result in discontinuation of chemotherapy and to identify risk factors associated with those adverse events. We retrospectively studied the incidence of adverse events in 257 patients with NSCLC who received pemetrexed (P) with or without bevacizumab (B) and/or carboplatin (C): P, PB, CP, or CPB. Patients whose chemotherapy was discontinued were divided into two groups according to adverse events and disease progression. Grade 2/3 nausea, fatigue with P and PB, and rash with CP and CPB occurred more frequent in the adverse events group than in the disease progression group. Multivariate analysis indicated that grade 2/3 nausea [odds ratio (OR) 9.94; 95% confidence interval (CI) 1.46-67.37; p = 0.01] and fatigue (OR 10.62; CI 1.60-70.20; p = 0.01) with P or PB, and rash (OR 6.12; CI 1.34-27.88; p = 0.01) with CP or CPB, were independent risk factors for discontinuation of chemotherapy. Administration of dexamethasone at doses less than 4 mg after the day of pemetrexed administration was associated with nausea following P or PB (OR 11.08; 95% CI 1.02-119.95; p = 0.04). Grade 2/3 nausea and fatigue with P or PB, and rash with CP or CPB, were associated with discontinuation of chemotherapy.

Background GEM plus nab-PTX (GnP) and FOLFIRINOX (FFX) have been shown to improve overall survival for advanced pancreatic cancer patients. However, clinical utility of C-reactive protein/albumin ratio (CAR) as prognostic factor for the patients treated with GnP or FFX remains unclear. We conducted the exploratory analysis to elucidate prognostic impact of CAR using a multicenter retrospective study (the NAPOLEON study) cohort which examined the efficacy and safety of GnP and FFX in clinical practice. Methods Between December 2013 to March 2017, 255 patients with unresectable advanced or recurrent pancreatic cancer who received GnP or FFX as 1st-line chemotherapy at 14 centers participating in the NAPOLEON study were examined. Patient characteristics at the start of 1st and 2nd line chemotherapy including age, gender, ECOG performance status, primary tumor site, disease status, metastatic site, underwent biliary drainage or not, treatment regimen at 1st line chemotherapy, LDH and CAR were analyzed to investigate correlation with prognosis by Cox regression model. The cut-off value of CAR adopted 0.54 based on a previous study. Patients were divided into groups according to CAR level less than 0.54 (CAR-low) and 0.54 or greater (CAR-high). Results Cox regression analysis of OS identified underwent biliary drainage (HR: 1.76, 95%CI: 1.19–2.61), CAR-high (HR: 1.52, 95%CI: 1.05–2.21), and higher LDH level (HR: 2.10, 95%CI: 1.36–3.22) as significant factors at the start of 1st-line chemotherapy. Similarly, Cox regression analysis of OS identified a poor PS (HR: 1.62, 95%CI: 1.07–2.47), a high level of CA19-9 (HR: 2.14, 95%CI: 1.07–4.29) and CAR-high (HR: 2.15, 95%CI: 1.32–3.49) as significant factors at the start of 2nd-line chemotherapy. Eighty-six of 140 patients (82.7%) with CAR-high at the start of 1st-line chemotherapy still remained CAR-high at the start of 2nd-line chemotherapy. Conclusions CAR may be useful prognostic factor at the start of both 1st and 2nd-line treatment. Almost all the patients with CAR-high before 1st line treatment still remained CAR-high after 1st line treatment. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background Gemcitabine plus nab-paclitaxel (GnP) and FOLFIRINOX (FFX) are both considered as standard chemotherapy for patients with metastatic pancreatic cancer (mPC). However, there are no prospective clinical trials that directly compare these two therapies. We investigate and compare them to support the treatment selection for mPC. Methods: We retrospectively analyzed the patients with mPC who had received GnP or FFX as first-line chemotherapy at 14 institutions in Kyushu. In this study, patient characteristics and clinical outcomes; overall survival (OS), progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR) and adverse events (AEs) were compared. Results: A total of 211 pts were included; GnP 119 pts (73 males and 46 females) and FFX 92 pts (55 males and 37 females). The median age of the FFX group was younger than that of GnP (GnP 68 vs. FFX 61 years). There was neither significant difference in the OS (median: 10.2 vs. 11.1 months, HR 0.98, 95%CI 0.72-1.34, p = 0.91) nor the PFS (median: 5.5 vs. 5.7 months, HR 1.05, 95%CI 0.79-1.40, p = 0.75) between the GnP and FFX group, respectively. Moreover, neither significant difference in the ORR (29% vs. 27%, p = 0.72) nor the DCR (81% vs. 79%, p = 0.25) was seen. There were no significant differences in grade 3/4 neutropenia (55% vs. 58%) and febrile neutropenia (10% vs. 13%). Grade 3/4 peripheral sensory neuropathy (12% vs. 3%) and fatigue (4% vs. 0%) were more frequent with GnP. All grades of rash and alopecia were more frequent with GnP. Otherwise, grade 3/4 anorexia (6% vs. 20%), diarrhea (0% vs. 11%) and nausea (3% vs. 11%) were more with FFX. 64% of the patients with FFX received GnP as second-line, but the rate of patients with FFX followed by GnP was only 10%. Conclusions: There was no significant difference in the effectiveness between GnP and FFX statistically. We need to select the appropriate treatment for each patient, considering that the toxicity profiles differ.

585 Background: Several previous reports indicated that cetuximab (Cmab) rechallenge may be efficacious in some patients for whom Cmab was previously effective. Liquid biopsy can detect the some emerging mutations for resistance with Cmab. Considering the plasticity and elasticity of sensitive clone, we assumed we could identify the patients with benefit from Cmab rechallenge by liquid biopsy. This current study investigates the predictability of efficacy for Cmab rechallenge by liquid biopsy in the E-Rechallenge Trial. Methods: The E-Rechallenge Trial is a multicenter phase II study in mCRC patients who have become refractory to fluoropyrimidines, L-OHP, CPT-11, Cmab, and bevacizumab, and in whom previous treatment with Cmab was effective in any earlier line (achieving CR, PR, or SD that persisted for ≥ 6 months). The other main eligibility criteria are; RAS wild type, measurable disease, aEFI ≥ 16 weeks between the last dose of Cmab during previous treatment and the start of Cmab rechallenge. Protocol treatment is the combination of weekly Cmab with biweekly CPT-11. Additional research of ctDNA was conducted optionally. Baseline plasma samples were analyzed for KRAS, NRAS, BRAF and EGFR S492R mutations using digital PCR (LBx probe, RIKEN GENESIS). A cut-off of the mutation allele frequency was > 0.1%. Results: Between Dec. 2014 and Oct. 2017, 33 patients were enrolled. The primary endpoint; the rates of PR/SD/PD were PR 15.6%/SD 40.6%/PD 43.8%. Twenty-four of 33 patients participated in the additional research. In the additional cohort, the rates of PR/SD/PD were PR 12.5%/SD 50.0%/PD 37.5%. The mutations were detected at the baseline of Cmab rechallenge as followings; KRAS exon 2 29.2%, exon 3,4 33.3%, BRAF V600E 12.5%, EGFR S492R 12.5%. In wild type of these genes the PR and SD rate increased to 25% and 50%, respectively. Conclusions: Cmab rechallenge showed some activity in the salvage setting, in patients for whom Cmab was previously effective. KRAS, BRAF, and EGFR S492R screening by liquid biopsy may contribute to identify patients with benefit from Cmab rechallenge. The additional data of ctDNA may be provided in the conference. Clinical trial information: UMIN 000016439.

KRAS mutations have been recognized as predictive markers of primary resistance to anti-EGFR-antibodies in colorectal cancer patients. In addition, newly detected KRAS mutations have been reported to be related with acquired resistance to chemotherapy containing anti-EGFR antibody. Considering this evidence, monitoring of KRAS mutations is indispensable for making treatment decisions, and the method should be non-invasive allowing repeated examinations. Recently, we established a novel automated sensitive detection system for KRAS mutations, named mutation-biased PCR quenching probe system (MBP-QP). The goal of our study was to investigate the potential for monitoring KRAS mutations during treatment with anti-EGFR antibodies. The detection limit of MBP-QP using a control plasmid containing KRAS mutations was 1-9 copies, and 0.05-0.3% mutant plasmid was detectable in a mixture of wild type and mutants. One-hundred twenty colorectal cancer patients were genotyped for KRAS mutations with MBP-QP as well as polymerase chain reaction reverse sequence-specific oligonucleotide (PCR-rSSO), which has already been applied to cancer tissue samples in the clinical setting. Concordance rates between plasma DNA and cancer tissues were 68% with MBP-QP and 66% with PCR-rSSO, indicating that these systems are equivalent in terms of detecting KRAS mutations with plasma DNA. KRAS mutations in plasma DNA were frequently observed in systemic metastatic cancer patients, and in three patients KRAS mutations appeared after chemotherapy containing anti-EGFR antibody. A prospective study is needed for clarifying whether KRAS mutations detected in plasma DNA are predictive markers of treatment efficacy with anti-EGFR antibody.

The need for examinations of single nucleotide polymorphisms (SNPs) on drug metabolizing enzymes is accelerating. Especially, SNPs of UTG1A1 and CYP2C19 are important for patients who are treated with irinotecan and proton pump inhibitors, respectively. Thus, a method for the rapid, fully automated, and accurate measurement of these SNPs is desired. We genotyped 109 Japanese volunteers for UGT1A1 * 6, UGT1A1 * 28, CYP2C19 * 2, and CYP2C19 * 3 with the quenching probe (QP) method. Only 90 min after whole blood was applied, QP method enabled to detect these SNPs automatically. The results obtained by QP method were absolutely identical to those examined by the conventional direct sequencing. These findings indicate that the QP method will enable point-of-care testing in clinical laboratories and patient-oriented therapy with its convenience and speed for patients who are treated with irinotecan or proton pump inhibitors.

KRAS mutations are detected in tumors of various organs, and they are also markers of resistance for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and monoclonal antibodies against the EGFR. Thus, the accurate and rapid detection of KRAS mutations is crucial, not only for screening, but also for the prediction of the efficacy of molecular-targeted therapy. The aim of the present study was to establish a novel automated detection system for KRAS mutations. One hundred and thirty-six lung adenocarcinoma patients were genotyped for KRAS mutations with both the conventional direct sequence (DS) method and with the newly developed quenching probe (QP) method that obtains data automatically within 60 min. The detection limit of the QP method using a control plasmid containing the KRAS mutation was 50 copies, and 10% mutant plasmid was detected in the mixture of wild-type and mutants. The results obtained by the QP and DS methods were identical in all but two of the 136 cases. The two differentially identified samples, which consisted of substantially fewer lung cancer cells, were positive according to the QP method but negative as determined by DS for KRAS mutations. These findings characterize the QP method as an accurate and rapid detection system for KRAS mutations.

Purpose Gene polymorphism and genetic mutation are related to the therapeutic effect of many drugs, and a simple genetic test method is preferred. To meet this demand, we have developed a platform for genetic testing called i-densy, which can complete fully automated gene polymorphism analysis from whole blood in approximately 90 minutes, and compared it with the existing test method. Also, recent reports indicate that DNA derived from cancer cells are liberated in blood (it is called “circulating cell-free DNA”). Using the i-densy, we here tested EGFR gene T790M mutation in circulating cell-free DNA from a sample derived from advanced lung cancer patient with EGFR-TKI aquired resistance, and then compared with the existing test method. Methods The i-densy newly developed can perform fully automated gene polymorphism testing from 70μL of whole blood and allows typing of 3 polymorphisms or mutations in a single reaction. Four samples can be tested at once with this instrument, and testing is also possible using oral mucosa or purified nucleic acid instead of whole blood. In addition to the i-densy, circulating cell-free DNA was also tested using Mutation Biased PCR (MBP) method that can preferentially amplify mutation sequence. Results As a result of using the i-densy with whole blood for gene testing on 1236C>T, 3435C>T and 2677 G>(T/A) polymorphism of ABCB1 gene related to toxicity and pharmacokinetics of EGFR-TKI erlotinib, results of 1236C>T and 3435C>T matched with that of Taqman assay method and 2677 G>(T/A) matched with Direct sequencing method for all 20 samples. We also extracted free DNA from peripheral blood plasma of a patient, and tested EGFR T790M mutation using Mutation Biased PCR (MBP) method, PNA-LNA PCR clamp method and Cycleave method. Among 19 patients with acquired resistance to EGFR-TKI, number of patients tested positive for T790M were 10 (53%) using MBP method, 3 (16%) using PNA-LNA PCR method and 5 (26%) using Cycleave method. Also, when using MBP method, there was not a single case with T790M mutation detected among cases with continued therapeutic effect or which EGFR-TKI is not used. Conclusion The i-densy newly developed has been identified to be simple and fast that allows accurate gene polymorphism from whole blood, and also confirmed to be useful in clinical practice. As a result of EGFR gene T790M mutation testing from circulating cell-free DNA using the i-densy and MBP method, appearance ratios of acquired resistance mutation were very close to each other (approximately 50%), indicating the high detection performance compared to other methods. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2089. doi:1538-7445.AM2012-2089

e13561 Background: EGFR tyrosine kinase inhibitors (EGFR-TKIs) are widely used to treat lung adenocarcinomas with EGFR activating mutations. However, half of patients acquire resistance because of ...

Although EGFR tyrosine kinase inhibitors (EGFR-TKIs) have great response to lung adenocarinoma with EGFR activating mutations, acquired resistance eventually developed. The half of these patients has the gatekeeper T790M mutation of EGFR in lung cancer tissue. A non-invasive mutation detection system is desired considering the difficulty in obtaining tissue specimens during disease progression_the majority of lung cancer recurrences occur in distant sites. We report a novel non-invasive monitoring system, MBP-QP (mutation-biased PCR and quenching probe) method, to detect the mutation using plasma DNA. The MBP-QP method is combined with mutated biased PCR and genotyping based on the analysis of a melting curve of probe DNA which is bound to the target mutated site using a fluorescence quenching probe. The detection limit was 2 copies of control plasmid, and 0.2 ng of genomic DNA isolated from a lung caner cell line harboring T790M. 0.3 % mutant plasmid could be detected in the mixture of plasmids inserted with EGFR exon 20 with or without T790M. With this method, T790M mutations were detected in plasma DNA of 50% of patients who acquired resistance, but not in primary EGFR-TKI non-responders, patients responding to treatment, or patients not treated with EGFR-TKI, which is consistent with the clinical course. The non-invasive MBP-QP method enabled us to monitor T790M repeatedly and will be useful for determining appropriate lung cancer treatment strategies in practice. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4117. doi:10.1158/1538-7445.AM2011-4117