Search

Background: National guidelines have advocated broad molecular profiling as a part of the standard diagnostic evaluation for advanced non-small cell lung cancer (NSCLC), with the goal of identifying driver mutations for which effective therapies or clinical trials are available. However, adherence to genomic testing guidelines could present challenges to community oncologists., Patients and Methods: We performed a retrospective review of genomic testing patterns in patients with nonsquamous NSCLC treated by 89 oncologists at 15 sites throughout New Jersey and Maryland from January 2013 to December 2015., Results: A total of 814 patients (89% with stage IV; 11% with stage IIIB) were identified in the COTA Inc database. Of the 814 patients, 479 (59%) met the guideline recommendations for EGFR (epidermal growth factor receptor) and ALK (anaplastic lymphoma kinase) biomarker testing; 63 (8%) underwent comprehensive genomic profiling for all 4 major types of alterations (point mutations, indels, fusions, and copy number amplifications). Gender, age, race, site of care (referral vs. community center), and practice size did not influence comprehensive genomic profiling frequency. Active smokers and patients who died within 30 days were tested less frequently (P < .05). Among those not tested for EGFR and ALK, 52% received chemotherapy without documented reasons for no testing, 32% did not receive antineoplastic therapy, and 13% had insufficient tissue for genotyping., Conclusion: Genomic testing presents multiple logistical challenges for the community-based oncologist, including coordination of sample handling, long turnaround times, test reimbursement, access to targeted therapies, insufficient tissue, and patient harm from the repeat biopsies necessary if the tissue sample is insufficient. Opportunities exist for improvement in guideline adherence, possibly through new technologies such as "liquid biopsies," which obviates the need tissue biopsy samples in select settings., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate pharmacologically guided addition of etoposide to a weekly irinotecan/cisplatin chemotherapy., Patients and Methods: Patients with advanced nonhematologic malignancies were eligible. Treatment consisted of i.v. administration of 50 mg/m(2) irinotecan and 20 mg/m(2) cisplatin on days 1, 8, 15, and 22 of a 42-day cycle or on days 1 and 8 of a 21-day cycle. Etoposide was administered in a dose-escalating fashion 2 days after each dose of irinotecan/cisplatin, either i.v. as a single dose or p.o. as two doses administered 12 h apart. Pharmacologic analyses included measurement of plasma concentrations of irinotecan, SN-38, and SN-38 glucuronide, as well as quantitation of topoisomerase protein levels in peripheral blood mononuclear cells (PBMNCs)., Results: A total of 40 patients with a variety of malignancies received 122 cycles of therapy. Dose-limiting toxicities included neutropenia and diarrhea, with the 21-day cycle tolerated better than the 42-day cycle. For the 21-day cycle, the maximum tolerated dose was 75 mg/m(2) for i.v. etoposide and 85 mg/m(2) for oral etoposide. Objective responses were observed in four patients with previously treated mesothelioma, gastric, breast, and ovarian cancer, respectively. PBMNC levels of topoisomerase IIalpha were increased at the time of etoposide administration in two patients, with these patients having the highest SN-38 glucuronide peak-plasma-concentration and area-under-the-curve values among 15 patients with available pharmacokinetic data. One of these patients had a partial response to therapy., Conclusions: Pharmacologically guided administration of etoposide in combination with irinotecan/cisplatin using a 21-day cycle is associated with acceptable toxicity and significant antitumor activity. The finding that PBMNC topoisomerase IIalpha protein levels increased after irinotecan/cisplatin treatment in two of six patients supports the continued development of sequential topoisomerase targeting in the treatment of malignancy.

The efficacy of chemotherapeutic agents may be determined by a number of different factors, including the genotype of the tumor cell. The p53 tumor suppressor gene frequently is mutated in human tumors, and this may contribute to chemotherapeutic resistance. We tested the requirement for wild-type p53 in the response of tumor cells to treatment with paclitaxel (trade name Taxol), an antineoplastic agent that stabilizes cellular microtubules. Although paclitaxel is broadly effective against human tumor xenografts in mice, including some known to carry p53 mutations, we found that p53-containing mouse tumor cells were significantly more sensitive to direct treatment with this drug than were p53-deficient tumor cells. In an attempt to reconcile this apparent discrepancy, we examined the requirement for p53 in the cytotoxic effects of tumor necrosis factor alpha (TNF-alpha), a cytokine released from murine macrophages upon paclitaxel treatment. Conditioned medium from paclitaxel-treated macrophages was capable of inducing p53-independent apoptosis when applied to transformed mouse embryonic fibroblasts and was inhibitable by antibodies against TNF-alpha. Furthermore, in response to direct treatment with TNF-alpha, both wild-type and p53-deficient tumor cells underwent apoptosis to similar extents and with similar kinetics. Our results suggest that the efficacy of paclitaxel in vivo may be due not only to its microtubule-stabilizing activity, but its ability to activate local release of an apoptosis-inducing cytokine.

Small ligand-receptor interactions underlie many fundamental processes in biology and form the basis for pharmacological intervention of human diseases in medicine. We report herein a genetic system, named the yeast three-hybrid system, for detecting ligand-receptor interactions in vivo. This system is adapted from the yeast two-hybrid system with which a third synthetic hybrid ligand is combined. The feasibility of this system was demonstrated using as the hybrid ligand a heterodimer of covalently linked dexamethasone and FK506. Yeast expressing fusion proteins of the hormone binding domain of the rat glucocorticoid receptor fused to the LexA DNA-binding domain and FKBP12 fused to a transcriptional activation domain activated reporter genes when plated on medium containing the dexamethasone-FK506 heterodimer. The reporter gene activation is completely abrogated in a competitive manner by the presence of excess FK506. Using this system, we screened a Jurkat cDNA library fused to the transcriptional activation domain in yeast expressing the hormone binding domain of rat glucocorticoid receptor-LexA DNA binding domain fusion protein in the presence of dexamethasone-FK506 heterodimer. We isolated overlapping clones of human FKBP12. These results demonstrate that the three-hybrid system can be used to discover receptors for small ligands and to screen for new ligands to known receptors.