Oncology
-
Human epidermal growth factor receptor-2 (HER2/erbB-2) belongs to a family of four transmembrane receptors involved in signal transduction pathways that regulate cell growth and differentiation. Overexpression/amplification of HER2 is associated with malignancy and a poor prognosis in breast cancer. HER2 acts as a networking receptor that mediates signaling to cancer cells, causing them to proliferate. ⋯ Removal of HER2 from the cell surface or inhibition of its intrinsic enzymatic activity may reduce oncogenicity. Our research suggests that the antitumor efficacy of HER2-specific antibodies such as Herceptin relates to their ability to direct HER2 to a Cbl- dependent endocytosis and degradation pathway. The reported clinical therapeutic efficacy of anti-HER2 monoclonal antibodies in breast cancer highlights the importance of understanding the biology of HER2.
-
Preclinical and phase I/II studies of Herceptin demonstrated a dose-related, non-linear pharmacokinetic profile. The results of a dose-finding study supported a regimen comprising an initial intravenous (i.v.) dose of 4 mg/kg with subsequent weekly doses of 2 mg/kg. However, pharmacokinetic and safety data suggested that increased dose and reduced frequency of Herceptin administration are feasible. ⋯ Subcutaneous (s.c.) administration of Herceptin would further simplify administration and studies are also underway to clinically evaluate s.c. administration of Herceptin in combination with paclitaxel. With the recent development of oral taxanes, it is predicted that combinations including an oral taxane, Xeloda and either 3-weekly or possibly s.c. Herceptin may become future therapies for breast cancer patients.
-
To define the maximum tolerated dose (MTD) of irinotecan (CPT-11) given on days 1 and 8 with mitomycin C (MMC) given on day 1 in a monthly cycle, and to assess the toxicity and activity of this regimen in patients with previously treated colorectal carcinoma. ⋯ CPT-11 175 mg/m2 on days 1 and 8 associated with MMC 10 mg/m2 on day 1, every 4 weeks, is a safe and moderately active regimen in heavily pretreated patients with advanced colorectal carcinoma. The role of MMC in this combination is doubtful, and further attempts with other new agents should be made to improve the outcome in these patients.
-
In HER2-positive breast cancer patients, the humanized anti-HER-2 monoclonal antibody trastuzumab (Herceptin) may improve overall survival. No reports exist regarding the application of trastuzumab in patients with cytotoxically induced cardiac failure and decreased left ventricular ejection fraction or about locally recurrent and advanced disease. In this case report, trastuzumab resulted in a complete and long-lasting response of recurrent and locally advanced breast cancer and was well tolerated in a severely cytotoxically pretreated patient with cardiac failure. We encourage other oncologists to offer trastuzumab also to severely cytotoxically pretreated patients with conditions after cardiac insufficiency or with locally advanced breast cancer.
-
Somatostatin (SST) analogues are cornerstones in the symptomatic management of patients suffering from carcinoid tumors, and antiproliferative activity has also been reported for these agents. The most commonly applied SST analogues are octreotide (OCT) and lanreotide (LAN), which are both available in a slow release formulation. To the current knowledge, both OCT and LAN are thought to be equally effective for the management of various disorders. We report the case of a patient with a disseminated carcinoid, who progressed during dose-intensified treatment with slow-release LAN in combination with interferon-alpha, but developed a pronounced response after treatment was switched to the application of a depot formulation of OCT. ⋯ To our knowledge, this is the first case demonstrating both a symptomatic as well as objective response to OCT following progression during therapy with LAN in a patient with a carcinoid tumor. Our results suggest that refractoriness to treatment including a long-acting SST analogue does not automatically imply resistance to a related agent and should alert clinicians to the potential of non-cross-resistance between SST analogues in neuroendocrine malignancies.