Pharmacogenetic Analysis of INT 0144 Trial: Association of Polymorphisms with Survival and Toxicity in Rectal Cancer Patients Treated with 5-FU and Radiation

PURPOSE

We tested whether 18 polymorphisms in 16 genes (GSTP1, COX2, IL10, EGFR, EGF, FGFR4, CCDN1, VEGFR2, VEGF, CXCR2, IL8, MMP3, ICAM1, ERCC1, RAD51, and XRCC3) would predict disease-free survival (DFS), overall survival (OS), and toxicity in the INT0144 trial, which was designed to investigate different postoperative regimens of 5-fluorouracil (5-FU)-based chemoradiation (CRT) in locally advanced rectal cancers: Arm 1 consisted of bolus 5-FU followed by 5-FU protracted venous infusion (PVI) with radiotherapy; arm 2 was induction and concomitant PVI 5-FU with radiotherapy and arm 3 was induction and concomitant bolus 5-FU with radiotherapy.

EXPERIMENTAL DESIGN

DNA from 746 stage II/III rectal patients enrolled in the Southwest Oncology Group (SWOG) S9304 phase III trial was analyzed. Genomic DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue. The polymorphisms were analyzed using direct DNA-sequencing or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

GSTP1-Ile105Val (rs1695) was significantly associated with DFS and OS and its effect did not vary by treatment arm. The five-year DFS and OS were 53% and 58%, respectively, for G/G, 66% and 72% for G/A, and 57% and 66% for A/A patients. In arm 2, IL8-251A/A genotype (rs4073) was associated with a lower risk of toxicities (P = 0.04). The VEGFR2 H472Q Q/Q genotype (rs1870377) was associated with a higher risk of grade 3-5 proximal upper gastrointestinal tract (PUGIT) mucositis (P = 0.04) in arm 2. However, in arm 1, this genotype was associated with a lower risk of PUGIT mucositis (P = 0.004).

CONCLUSION

rs1695 may be prognostic in patients with rectal cancer treated with adjuvant CRT. rs4073 and rs1870377 may exhibit different associations with toxicity, according to the 5-FU schedule.

SWOG 0941: A phase II study of sorafenib and erlotinib in patients (pts) with advanced gallbladder cancer or cholangiocarcinoma

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Background: The treatment of pts with advanced biliary cancers represents a therapeutic challenge. The vascular endothelial growth factor and epidermal growth factor receptor pathways play an important role in biliary carcinogenesis, as evidenced by their up-regulation and prognostic impact. Methods: The primary objective was progression free survival (PFS) (improvement in PFS from 4 to 8 months); secondary endpoints included overall survival (OS), objective response rate, and toxicity. A two-stage design was used; if 13 or more eligible pts of the 25 initially accrued were alive without progression at 4 months, an additional 25 were to be accrued. Eligibility criteria included no prior treatment for advanced or metastatic disease, histologic diagnosis of gallbladder cancer or cholangiocarcinoma, presence of measurable disease, Zubrod performance status 0-1, AST/ALT ≤ 5 IULN, total bilirubin ≤1.5 IULN, adequate hematologic function. Pts were treated with sorafenib 400 mg PO BID and erlotinib 100 mg PO q daily continuously. Restaging scans were performed every 8 weeks. Results: 32 eligible pts were accrued. 30 pts were evaluable for response. 2 patients (7 %) had an unconfirmed partial response (95% CI:1%-23%), and 8 pts (27%) had stable disease. Median PFS was 2 months (95% CI: 2-3 months). 22/32 patients progressed or died within 4 months of registration. Median OS was 6 months (95% CI: 3 -7 months). The study failed to meet its primary endpoint to proceed to the second stage of accrual. There were 3 deaths on study, 1 of which was possibly related to treatment. 19 patients (59%) had grade 3 or 4 toxicities: AST/ALT (22%), bilirubin (16%), alkaline phosphatase (16%), hypertension (16%), diarrhea (9%), hepatic infection (6%). Conclusions: This multicenter study was the first to evaluate the combination of sorafenib and erlotinib in pts with advanced biliary cancers. Despite manageable toxicity, the study failed to meet its primary endpoint. Correlative studies on collected tissue and blood are ongoing; improved pt selection based on tumor biology and molecular markers is necessary for future evaluation of targeted therapies in this disease.

SWOG 0514: a phase II study of sorafenib in patients with unresectable or metastatic gallbladder carcinoma and cholangiocarcinoma

OBJECTIVES

Gallbladder and cholangiocarcinomas represent a heterogeneous group of malignant diseases that commonly present at an advanced stage and have limited therapeutic options. Based on the role of the Ras-Raf-Mek-Erk pathway and the VEGF axis in biliary carcinomas, we conducted a phase II study of sorafenib in patients with advanced biliary cancers.

METHODS

Eligible patients had no prior therapy for metastatic or unresectable disease. Sorafenib was administered at 400 mg po twice daily continuously.

RESULTS

The study was terminated after the first stage of accrual due to failure to meet the primary objective. A confirmed response rate of 0% (0%-11%) was observed. Thirty-nine percent of patients demonstrated stable disease (including 2 with unconfirmed PR). PFS was 3 months (95% CI: 2-4 months) and OS 9 months (95% CI: 4-12 months). The most common grade 3 and 4 toxicities included hand-foot skin reaction (13%), bilirubin elevation (13%), venous thromboembolism (10%), AST/ALT elevation (10%) and elevated alkaline phosphatase (10%).

CONCLUSION

While treatment with sorafenib did not result in objective responses, patients with biliary cancers receiving this drug had some therapeutic benefit. Additional studies with sorafenib in combination with chemotherapy or other targeted agents may be warranted.

Imatinib mesylate in advanced dermatofibrosarcoma protuberans: pooled analysis of two phase II clinical trials

PURPOSE

Dermatofibrosarcoma protuberans (DFSP) is a dermal sarcoma typically carrying a translocation between chromosomes 17 and 22 that generates functional platelet-derived growth factor B (PDGFB).

PATIENTS AND METHODS

Two distinct phase II trials of imatinib (400 to 800 mg daily) in patients with locally advanced or metastatic DFSP were conducted and closed prematurely, one in Europe (European Organisation for Research and Treatment of Cancer [EORTC]) with 14-week progression-free rate as the primary end point and the other in North America (Southwest Oncology Group [SWOG]) with confirmed objective response rate as the primary end point. In the EORTC trial, confirmation of PDGFB rearrangement was required, and surgery was undertaken after 14 weeks if feasible. The SWOG study confirmed t(17;22) after enrollment.

RESULTS

Sixteen and eight patients were enrolled onto the EORTC and SWOG trials, respectively. Tumor size ranged from 1.2 to 49 cm. DFSP was located on head/neck, trunk, and limb in seven, 11, and six patients, respectively, and was classic, pigmented, and fibrosarcomatous DFSP in 13, one, and nine patients, respectively. Metastases were present in seven patients (lung involvement was present six patients). Eleven patients (4%) had partial response as best response, and four patients had progressive disease as best response. Median time to progression (TTP) was 1.7 years. Imatinib was stopped in 11 patients because of progression, one patient because of toxicity, and two patients after complete resection of disease. Median overall survival (OS) time has not been reached; 1-year OS rate was 87.5%.

CONCLUSION

Imatinib is active in DFSP harboring t(17;22) including fibrosarcomatous DFSP, with objective response rate approaching 50%. Response rates and TTP did not differ between patients taking 400 mg daily versus 400 mg twice a day.

A simple fluorescent biosensor for theophylline based on its RNA aptamer

Theophylline is a potent bronchodilator with a narrow therapeutic index. A simple fluorescent biosensor that detects clinically relevant theophylline concentrations has been developed using the well-characterized theophylline binding RNA aptamer. Hybridization of the RNA aptamer to a fluorescently labeled DNA strand (FL-DNA) yields a fluorescent RNA:DNA hybrid that is sensitive to theophylline. The biosensor retains the remarkable selectivity of the RNA aptamer for theophylline over caffeine and is sensitive to 0-2 muM theophylline, well below the clinically relevant concentration (5-20 mg/L or approximately 10-50 muM). Adding a dabcyl quenching dye to the 3'-terminus of the fluorescently labeled DNA strand yielded a dual-labeled DNA strand (FL-DNA-Q) and increased the dynamic range of this simple biosensor from 1.5-fold to 4-fold.

Using technology to help rural practice

Health care providers in rural settings are faced with the same issues as those in urban areas, write Susan Dymond, M.B.A., and Christopher Rankin, but those issues are compounded by the isolation of distance. One answer to this problem is to use telecommunications and satellite technology to bridge these distances and that's just what Texas Tech University is doing.