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Background: The mechanism of resistance to human epidermal growth factor receptor 2 (HER2)-targeted agents has not been fully understood. We investigated the influence of PIK3CA mutations on sensitivity to HER2-targeted agents in naturally derived breast cancer cells. Materials and methods: We examined the effects of Calbiochem (CL)-387,785, HER2 tyrosine kinase inhibitor, and trastuzumab on cell growth and HER2 signaling in eight breast cancer cell lines showing HER2 amplification and trastuzumab-conditioned BT474 (BT474-TR). Results: Four cell lines with PIK3CA mutations (E545K and H1047R) were more resistant to trastuzumab than the remaining four without mutations (mean percentage of control with 10 μg/ml trastuzumab: 58% versus 92%; P = 0.010). While PIK3CA-mutant cells were more resistant to CL-387,785 than PIK3CA-wild-type cells (mean percentage of control with 1 μM CL-387,785: 21% versus 77%; P = 0.001), CL-387,785 retained activity against BT474-TR. Growth inhibition by trastuzumab and CL-387,785 was more closely correlated with changes in phosphorylation of S6K (correlation coefficient, 0.811) than those of HER2, Akt, or ERK1/2. Growth of most HER2-amplified cells was inhibited by LY294002, regardless of PIK3CA genotype. Conclusions: PIK3CA mutations are associated with resistance to HER2-targeted agents. PI3K inhibitors are potentially effective in overcoming trastuzumab resistance caused by PIK3CA mutations. S6K phosphorylation is a possibly useful pharmacodynamic marker in HER2-targeted therapy. [ABSTRACT FROM AUTHOR]

Background: Many patients with non-small-cell lung cancer (NSCLC) who achieve radiographic responses to treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors gefitinib and erlotinib have somatic mutations in the EGFR tyrosine kinase domain. However, little is known about the efficacy of cetuximab, an antibody against the EGFR extracellular domain, in EGFR mutant NSCLC.Methods: NSCLC cell lines carrying wild-type EGFR (A549, H441, and H1666) or mutant EGFR (H3255, DFCILU-011, PC-9, and HCC827) were treated with various dilutions of gefitinib or cetuximab relative to maximal achievable serum concentration. Cell growth was analyzed by the MTS assay, with differences between dose-response curves analyzed nonparametrically. Apoptosis was analyzed by propidium iodide staining and immunoblotting for PARP. Phosphorylation of EGFR and the downstream signaling components ERK1/2 and Akt were analyzed by immunoblotting. Statistical tests were two-sided.Results: Growth of NSCLC lines with wild-type EGFR was slightly (A549 and H441) or moderately (H1666) inhibited by gefitinib and cetuximab, and the effects of the two agents were similar. Both agents also induced no (H441) or moderate (H1666) apoptosis in NSCLC cells with wild-type EGFR. By contrast, gefitinib was statistically significantly more effective than cetuximab at inhibiting growth of EGFR mutant cells (H3255: P = .003, DFCILU-011: P = .011, and PC-9: P = .003), and gefitinib-treated EGFR mutant cells had higher levels of apoptosis than cetuximab-treated cells (mean fold increase in apoptosis by 1 microM of gefitinib and 10 microg/mL of cetuximab relative to control, H3255: 8.3 [95% confidence interval {CI} = 4.8 to 11.8] and 2.1 [95% CI = 2.0 to 2.2], respectively, P = .025; DFCILU-011: 5.7 [95% CI = 5.1 to 6.3] and. 0.9 [95% CI = 0.3 to 1.5], respectively, P < .001). Gefitinib treatment decreased EGFR, ERK1/2, and Akt phosphorylation in EGFR mutant cell lines whereas cetuximab had relatively little effect. Both gefitinib and cetuximab inhibited the growth of HCC827 cells, but gefitinib inhibited growth to a greater extent (P = .003).Conclusions: EGFR mutations in NSCLC cells are associated with sensitivity to gefitinib but not to cetuximab. [ABSTRACT FROM AUTHOR]

To determine the maximum-tolerated dose (MTD) and the recommended dose (RD) of paclitaxel administered weekly with a fixed dose of cisplatin, and to assess the toxicity and activity of this combination, we conducted a phase I/II trial in patients with advanced non-small-cell lung cancer (NSCLC). In this study, patients with stage IIIB/IV NSCLC were eligible. Paclitaxel, at a starting dose of 40?mg?m-2?week-1 on days 1, 8, and 15, was combined with a fixed dose of cisplatin 80?mg?m-2 on day 1. Chemotherapy was given in a 4-week cycle. In this phase I/II study, 38 patients were enrolled. Dose-limiting toxicities (DLT) were neutropenia, fatigue, and omission of treatment due to leucopenia, thrombocytopenia, or febrile neutropenia. The MTD and RD were estimated to be 70?mg?m-2. Of the 37 assessable patients, 23 had a partial response and one had a complete response. Overall response rate was 62.1% (95% confidence interval (CI): 46.5-77.7%). The progression-free survival, the median survival time, and the 1-year survival rate were 5.5 months, 13.7 months, and 56.9%, respectively. This regimen is tolerable and very active against advanced NSCLC, and its efficacy should be confirmed in a phase III study.British Journal of Cancer (2004) 90, 1184-1189. doi:10.1038/sj.bjc.6601672 www.bjcancer.com Published online 24 February 2004 [ABSTRACT FROM AUTHOR]

The article discusses the case of a 50-year-old woman who presented with a large nodule on her abdomen. Topics covered include the findings of the magnetic resonance imaging of the tumor, results of various examinations which led to the diagnosis of cutaneous endometrial cancer arising from heterotopic endometriosis in the abdominal caesarean section scar, and patient outcome following Mohs surgery, oral medroxyprogesterone and local radiotherapy.