Purpose Information about symptomatic toxicities of anticancer treatments is not based on direct report by patients, but rather on reports by clinicians in trials. Given the potential for under-reporting, our aim was to compare reporting by patients and physicians of six toxicities (anorexia, nausea, vomiting, constipation, diarrhea, and hair loss) within three randomized trials. Patients and Methods In one trial, elderly patients with breast cancer received adjuvant chemotherapy; in two trials, patients with advanced non–small-cell lung cancer received first-line treatment. Toxicity was prospectively collected by investigators (graded by National Cancer Institute Common Toxicity Criteria [version 2.0] or Common Terminology Criteria for Adverse Events [version 3]). At the end of each cycle, patients completed the European Organisation for Research and Treatment of Cancer quality-of-life questionnaires, including toxicity-related symptom items. Possible answers were “not at all,” “a little,” “quite a bit,” and “very much.” Analysis was limited to the first three cycles. For each toxicity, agreement between patients and physicians and under-reporting by physicians (ie, toxicity reported by patients but not reported by physicians) were calculated. Results Overall, 1,090 patients (2,482 cycles) were included. Agreement between patients and physicians was low for all toxicities. Toxicity rates reported by physicians were always lower than those reported by patients. For patients who reported toxicity (any severity), under-reporting by physicians ranged from 40.7% to 74.4%. Examining only patients who reported “very much” toxicity, under-reporting by physicians ranged from 13.0% to 50.0%. Conclusion Subjective toxicities are at high risk of under-reporting by physicians, even when prospectively collected within randomized trials. This strongly supports the incorporation of patient-reported outcomes into toxicity reporting in clinical trials.
Purpose: The resistance to selective EGFR inhibitors involves the activation of alternative signaling pathways, and Akt activation and VEGF induction have been described in EGFR inhibitor–resistant tumors. Combined inhibition of EGFR and other signaling proteins has become a successful therapeutic approach, stimulating the search for further determinants of resistance as basis for novel therapeutic strategies.
Experimental Design: We established human cancer cell lines with various degrees of EGFR expression and sensitivity to EGFR inhibitors and analyzed signal transducers under the control of EGFR-dependent and EGFR-independent pathways.
Results: Multitargeted inhibitor vandetanib (ZD6474) inhibited the growth and the phosphorylation of Akt and its effector p70S6 kinase in both wild-type and EGFR inhibitor–resistant human colon, prostate, and breast cancer cells. We found that the resistant cell lines exhibit, as common feature, VEGFR-1/Flt-1 overexpression, increased secretion of VEGF and placental growth factor, and augmented migration capabilities and that vandetanib is able to antagonize them. Accordingly, a new kinase assay revealed that in addition to VEGF receptor (VEGFR)-2, RET, and EGFR, vandetanib efficiently inhibits also VEGFR-1. The contribution of VEGFR-1 to the resistant phenotype was further supported by the demonstration that VEGFR-1 silencing in resistant cells restored sensitivity to anti-EGFR drugs and impaired migration capabilities, whereas exogenous VEGFR-1 overexpression in wild-type cells conferred resistance to these agents.
Conclusions: This study shows that VEGFR-1 contributes to anti-EGFR drug resistance in different human cancer cells. Moreover, vandetanib inhibits VEGFR-1 activation, cell proliferation, and migration, suggesting its potential utility in patients resistant to EGFR inhibitors.
Inhibition of a single transduction pathway is often inefficient due to activation of alternative signalling. The mammalian target of rapamycin (mTOR) is a key intracellular kinase integrating proliferation, survival and angiogenic pathways and has been implicated in the resistance to EGFR inhibitors. Thus, mTOR blockade is pursued to interfere at multiple levels with tumour growth. We used everolimus (RAD001) to inhibit mTOR, alone or in combination with anti-EGFR drugs gefitinib or cetuximab, on human cancer cell lines sensitive and resistant to EGFR inhibitors, both
in vitro
and
in vivo
. We demonstrated that everolimus is active against EGFR-resistant cancer cell lines and partially restores the ability of EGFR inhibitors to inhibit growth and survival. Everolimus reduces the expression of EGFR-related signalling effectors and VEGF production, inhibiting proliferation and capillary tube formation of endothelial cells, both alone and in combination with gefitinib. Finally, combination of everolimus and gefitinib inhibits growth of GEO and GEO-GR (gefitinib resistant) colon cancer xenografts, activation of signalling proteins and VEGF secretion. Targeting mTOR pathway with everolimus overcomes resistance to EGFR inhibitors and produces a cooperative effect with EGFR inhibitors, providing a valid therapeutic strategy to be tested in a clinical setting.
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