Establishment of a platform of non-small-cell lung cancer patient-derived xenografts with clinical and genomic annotation.

BACKGROUND: Preclinical models that can better predict therapeutic activity in clinical trials are needed in this era of personalized cancer treatment. Herein, we established genomically and clinically annotated patient-derived xenografts (PDXs) from non-small-cell lung cancer (NSCLC) patients and investigated whether these PDXs would faithfully recapitulate patient responses to targeted therapy. METHODS: Patient-derived tumors were implanted in immunodeficient mice and subsequently expanded via re-implantation. Established PDXs were examined by light microscopy, genomic profiling, and in vivo drug testing, and the successful engraft rate was analyzed with the mutation profile, histology, or acquisition method. Finally, the drug responses of PDXs were compared with the clinical responses of the respective patients. RESULTS: Using samples from 122 patients, we established 41 NSCLC PDXs [30 adenocarcinoma (AD), 11 squamous cell carcinoma (SQ)], among which the following driver mutation were observed: 13 EGFR-mutant, 4 ALK-rearrangement, 1 ROS1-rearrangement, 1 PIK3CA-mutant, 1 FGFR1-amplification, and 2 KRAS-mutant. We rigorously characterized the relationship of clinical features to engraftment rate and latency rates. The engraft rates were comparable across histologic type. The AD engraft rate tended to be higher for surgically resected tissues relative to biopsies, whereas similar engraft rates was observed for SQ, irrespective of the acquisition method. Notably, EGFR-mutants demonstrated significantly longer latency time than EGFR-WT (86 vs. 37days, P = 0.007). The clinical responses were recapitulated by PDXs harboring driver gene alteration (EGFR, ALK, ROS1, or FGFR1) which regressed to their target inhibitors, suggesting that established PDXs comprise a clinically relevant platform. CONCLUSION: The establishment of genetically and clinically annotated NSCLC PDXs can yield a robust preclinical tool for biomarker, therapeutic target, and drug discovery.

A pilot study of S-1 plus cisplatin versus 5-fluorouracil plus cisplatin for postoperative chemotherapy in histological stage IIIB-IV (M0) gastric cancer.

BACKGROUND: Although its efficacy is unproven, 5-fluorouracil plus cisplatin (FP) is used to prevent postoperative relapse in gastric cancer. We investigated the safety and feasibility of S-1 plus cisplatin (SP) vs. FP for stage IIIB-IV (M0) gastric cancer. METHODS: Following curative resection, 41 stage IIIB-IV (M0) gastric cancer patients were assigned to SP (eight 14-day cycles of S-1 [40 mg/m(2) twice daily] plus cisplatin [60 mg/m(2) day 1] administered every 3 weeks) or FP (six 3-day cycles of FU [1 g/m(2) per day] plus cisplatin [80 mg/m(2) day 1] every 4 weeks). Doses were reduced based on predefined criteria. RESULTS: Patient characteristics were balanced between the two arms. In total, 124 cycles of SP (N = 20, median = 7, range 1-8) and 113 cycles of FP (N = 21, median 6, range 1-6) were administered. The median relative dose intensity per patient was 75% (49.99-100%) for S-1, 100% (75-100%) for cisplatin in SP, and 100% (64-100%) for 5-FU, 100% (60-100%) for cisplatin in FP. The relative dose intensity of FP was stable, while that of SP decreased during treatment. After median follow-up of 7.9 months (3.8-14.55), the median RFS was not reached. Relapse occurred in two (10%) patients on SP and five (23.8%) in the FP arm (P = 0.24). The incidence of grade 3-4 granulocytopenia was 36.8% with SP and 14.3% with FP. Grade 3-4 non-hematologic toxicities included fatigue (5.2% with SP vs. 4.8% with FP), vomiting (10.5% with SP vs. 0% with FP), and infection (5.2% with SP vs. 0% FP). CONCLUSION: S-1 plus cisplatin was feasible and tolerable as adjuvant treatment for stage IIIB-IV (M0) gastric cancer. However, because of decreased relative dose intensity during treatment, further study is warranted to determine optimal dosage and combination.

Capecitabine and cisplatin chemotherapy (XP) alone or sequentially combined chemoradiotherapy containing XP regimen in patients with three different settings of stage IV esophageal cancer.

BACKGROUND: The 1997 staging system for esophageal carcinoma subdivided distant metastatic disease (M1) into nonregional lymph node metastases (M1a) and other metastases (M1b). To determine the relevance of this classification system, we investigated the efficacy and toxicity of capecitabine/cisplatin (XP) chemotherapy alone or in combination with radiotherapy. METHODS: We identified 74 patients with M1 disease treated at Asan Medical Center from January 2003 to December 2005. Of these patients, 19 (25.7%) were classified as M1a, 29 (39.2%) as M1b (nonvisceral lymph node metastases), and 26 (35.1%) as M1b (visceral metastases). All patients were treated with first two cycles of XP induction chemotherapy, consisting of capecitabine 1000 mg/m(2) twice daily on days 1-14, and i.v. cisplatin 60 mg/m(2) on day 1, every 3 weeks. Patients classified as M1a and M1b (nonvisceral lymph node metastases) were treated with 54 Gy of radiotherapy, concurrently with weekly capecitabine 800 mg/m(2) twice daily on days 1-5 and i.v. cisplatin 30 mg/m(2) on day 1 during radiation. Patients classified as M1b (visceral metastases) were treated with chemotherapy only until disease progression or intolerance to chemotherapy. RESULTS: In response to the first two cycles of chemotherapy, 3/18 (16.7%) M1a nonregional lymph node (LN), 4/27 (14.8%) M1b nonvisceral LN metastases and 5/25 (20%) M1b visceral metastases patients attained partial responses. After definitive chemoradiation in the setting of M1a, M1b nonvisceral LN metastases and maximum cycles of chemotherapy in the M1b visceral metastases setting, the response rates were 77.8, 62.9 and 36.0% respectively. With median follow-up of 12.5 months (range 0.5-22.8), 50 of 74 patients (67.5%) died. The median time to progression (TTP) was 7.8 months (95% CI, 6.0-9.5 months) and the median overall survival (OS) was 12.0 months (95% CI, 9.0-15.0 months). Median TTP in the M1a, M1b nonvisceral LN metastases and M1b visceral metastases were 10.3, 6.5 and 5.9 months, respectively (P = 0.087), whereas median OS in these groups was 13.8, 13.8, and 8.2 months, respectively (P = 0.134). Median TTP was 8.4 months (95% CI, 5.5-11.3 months) in the 48 patients with M1a and M1b nonvisceral LN metastases and 5.9 months (95% CI, 2.7-9.0 months) in the 26 patients with M1b visceral metastases (P = 0.03), and median OS in these two groups was 13.8 months (95% CI, 10.4-17.3 months) and 8.2 months (95% CI, 5.7-10.7 months), respectively (P = 0.04). CONCLUSION: The similar OS in patients with M1a and M1b nonvisceral LN metastases suggests that concurrent chemoradiotherapy might contribute in the latter. Our findings indicate that sequentially combined chemoradiotherapy containing XP regimen was active and well tolerated as first-line treatment for M1a as well as M1b esophageal cancer.

A randomized comparison of peripheral blood hematopoietic progenitor cell level of 5/mm3 versus 50/mm3 as a surrogate marker to initiate efficient autologous blood stem cell collection.

We previously showed that at least 5/mm(3) hematopoietic progenitor cells (HPCs) could be used as a marker for initiating autologous blood stem cell collection (ABSCC). However, the timing of efficient ABSCC following mobilization is still to be determined. We conducted a prospective, randomized comparison of 5/mm(3) versus 50/mm(3) peripheral blood (PB) HPCs as a surrogate marker to initiate efficient ABSCC. Forty-five consecutive patients, 26 with multiple myeloma (MM) and 19 with non-Hodgkin's lymphoma (NHL), were enrolled between October 2004 and October 2006. Chemotherapy was cyclophosphamide 4 g/m(2) for MM and ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin), with or without Rituximab, for NHL. Circulating HPCs were monitored daily with the Sysmex SE9000 automated hematology analyzer, and harvested CD34+ cells were counted by flow cytometry. ABSCC was initiated when HPC levels reached at least 5/mm(3) (HPC5 group) or 50/mm(3) (HPC50 group). The median number of harvested CD34+ cells was 15.0 x 10(6)/kg and 21.0 x 10(6)/kg in the HPC5 and HPC50 groups, respectively (P = 0.23). Optimal collection (>5 x 10(6) CD34+ cells/kg) in a single session (day 1) was attained in 15 HPC5 patients (63%) and in 14 HPC50 patients (67%), and targeted collection of 5 x 10(6) CD34+ cells/kg was achieved in 100 and 95% of HPC5 and HPC50 patients, respectively (P = 0.47), with a median number of 1 apheresis in both groups (P = 0.58). There were no between group differences in optimal collection rate on day 1, median number of aphereses to achieve optimal collection, and overall optimal collection rate. HPC > or = 5/mm(3) and > or =50/mm(3) are both reliable indices for the timing of ABSCC.