Metabolic activation of 4-ipomeanol in human lung, primary pulmonary carcinomas, and established human pulmonary carcinoma cell lines.

4-Ipomeanol (IPO) is a pulmonary-specific toxin that is metabolically activated by a cytochrome P450 pathway in lung tissue. In this study, IPO metabolism, as determined by measurement of [14C]IPO covalent binding, was evaluated in a diverse sampling of 18 established, human lung cancer cell lines as well as in normal lung tissue and primary lung carcinoma tissue obtained at the time of thoracotomy from 56 patients with lung cancer. [14C]IPO covalent binding in lung cancer cell lines ranged from 248 to 1,047 pmol of bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 547 +/- 62.2). IPO metabolism in normal lung tissue ranged from 12 to 2,007 pmol of covalently bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 549 +/- 60). In lung cancer tissue, values ranged from 0 to 2.566 pmol of covalently bound [14C]IPO per milligram of protein per 30 minutes (mean +/- SE = 547 +/- 60, P greater than .3). When patients were divided into smokers and current non-smokers (no tobacco products smoked for greater than 6 mo), no effects of cigarette smoking were observed for either normal lung tissue or lung tumor tissue (P greater than .1 in all instances). A wide range of IPO metabolic activity was observed among different histological classifications of lung cancer cell lines and of fresh lung cancer tissues. IPO metabolism was simultaneously compared in normal lung tissue and lung cancer tissue from individual patients, but no positive correlation was observed (r = .10; P greater than .30). The results clearly demonstrate a wide range of IPO metabolism in both normal and lung cancer cells and indicate that a wide diversity of human lung cancers possess the metabolic enzyme system(s) necessary for the bioactivation of IPO to a potentially cytotoxic intermediate. Therefore, the continued exploration for any possible therapeutic potential of IPO in patients with lung cancer appears warranted.

Pre-operative systemic (neo-adjuvant) therapy with trastuzumab and docetaxel for HER2-overexpressing stage II or III breast cancer: results of a multicenter phase II trial.

BACKGROUND: Trastuzumab plus chemotherapy has become the standard of care for women with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. Trastuzumab-based pre-operative systemic (neo-adjuvant) therapy (PST) also appears promising, warranting further investigation. PATIENTS AND METHODS: Patients with HER2-positive, stage II/III non-inflammatory, operable breast cancer requiring a mastectomy (but who wished to conserve the breast) received weekly trastuzumab and 3-weekly docetaxel for six cycles before surgery. The primary end point was pathological complete response (pCR) rate, determined from surgical specimens. RESULTS: Thirty-three patients were enrolled. The majority (79%) had T2 tumors, with 42% being N1/2. Twenty-nine patients completed six cycles of therapy and one patient withdrew prematurely due to progressive disease. A complete or partial objective clinical response was seen in 96% (73% and 23%, respectively) of patients. Surgery was performed in 30 patients, breast conserving in 23 (77%). In an intention-to-treat analysis, tumor and nodal pCR was seen in 14 (47%) patients. Treatment was generally well tolerated. Grade 3/4 neutropenia occurred in 85% of patients while febrile neutropenia was encountered in 18%. Only three patients withdrew prematurely due to toxicity. No symptomatic cardiac dysfunction was reported. CONCLUSIONS: PST with trastuzumab plus docetaxel achieved promising efficacy, with a high pCR rate and good tolerability, in women with stage II or III HER2-positive breast cancer.