Doxorubicin (adriamycin) has a very wide antitumour spectrum, compared with other anticancer drugs; however, except for Hodgkin's disease, it is not associated with curative chemotherapy. Doxorubicin has been in clinical use for more than 2 decades, and only recently has it been recognised that the cytotoxic effect is produced at the cellular level by multiple mechanisms which have not yet been conclusively identified. Key factors are a combination of doxorubicin-induced free radical formation due to metabolic activation, deleterious actions at the level of the membrane, and drug-intercalation into DNA. Multiple aspects of the clinical pharmacokinetics of this drug have been described. Wide interpatient variations in plasma pharmacokinetics have been noted, but without firm relation to clinical outcome. An apparent volume of distribution of approximately 25 L/kg points to extensive uptake by tissues. Up to several weeks after administration, significant concentrations of doxorubicin have been found in haematopoietic cells and in several other tissues. The maximum cellular doxorubicin concentrations reached in vivo remain significantly below those at which all clonogenic leukaemic cells are killed in vitro. Doxorubicin has been administered as frequent (weekly) low doses, single high doses, and as a continuous infusion. The optimal schedule with respect to tumour cytotoxicity and dose-limiting side effects such as myelosuppression or cardiotoxicity, has never been investigated in a prospective, randomised manner. Clinical trials large enough to study optimal, and possibly individualised, doxorubicin chemotherapy need to be performed. This review summarises pharmacological and pharmacodynamic data of doxorubicin, and discusses these in relation to possible improvement of its therapeutic index. Furthermore, drug interactions, dose-response relationships, mechanisms of action, multidrug resistance, and treatment scheduling are discussed in the perspective of the development of novel treatment strategies.
The first purpose of this study was to evaluate the saddle prosthesis in patients with periacetabular tumors in terms of the functional results obtained after several postoperative intervals. The second purpose was to evaluate the complications and how they might be prevented in the future. Functional results according to the MSTS functional rating system were evaluated at several postoperative intervals in 15 patients treated with internal hemipelvectomy and reconstruction with the saddle prosthesis because of periacetabular primary (n = 9) or secondary (n = 6) malignancies. All complications were evaluated. Three months postoperatively, 7/9 patients with a primary tumor and 2/4 patients with a secondary tumor were able to walk outside without pain. Median functional results 3 and 6 months postoperatively were 40% and 50%, respectively. Deep infection occurred in 4 patients and fracture of the iliac remnant in 2. Heterotopic ossifications along the interpositional component were seen in 5 patients, but they did not negatively influence the functional outcome. Three (relative) contraindications to reconstruction with the saddle prosthesis could be ascertained: osteoporosis, extended involvement of the iliac wing by tumor, and insufficient soft-tissue quality after previous procedures. (Short-term) functional results after reconstruction with the saddle prosthesis are satisfactory if the above-mentioned contraindications are taken into consideration.
Benefit from chemotherapy treatment in breast cancer patients is determined by the molecular make-up of the tumour. In a retrospective analysis, we determined the molecular subtypes of breast cancer originally defined by expression microarrays by immunohistochemistry in tumours of patients who took part in a randomised study of adjuvant high-dose chemotherapy in breast cancer. In addition, the topoisomerase IIa (TOP2A) amplification status was determined by fluorescence in situ hybridisation and chromogenic in situ hybridisation. 411 of the 753 tumours (55%) were classified as luminal-like, 137 (18%) as basal-like and 205 (27%) as human epithelial receptor type 2 (HER2) amplified. The basal-like tumours were defined as having no expression of ER and HER2; 98 of them did express epidermal growth factor receptor and/or cytokeratin 5/6. The luminal-like tumours had a significantly better recurrence free and overall survival than the other two groups. From the 194 HER2-positive tumours, 47 (24%) were shown to harbour an amplification of TOP2A. Patients with an HER2-amplified tumour randomised to the high-dose therapy arm did worse than those in the conventional treatment arm, possibly caused by the lower cumulative anthracycline dose in the high-dose arm. The tumours with a TOP2A amplification contributed hardly to this difference, suggesting that TOP2A amplification is not the cause of the steep dose -response curve for anthracyclines in breast cancer. Possibly, the difference of the cumulative dose of only 25% between the treatment arms was insufficient to yield a survival difference.
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