The regulation and inhibition of 17beta-hydroxysteroid dehydrogenase in breast cancer.

17Beta-hydroxysteroid dehydrogenase Type 1 (17beta-HSD1) has a pivotal role in regulating the synthesis of oestradiol (E2) within breast tumours. In whole body studies in postmenopausal women with breast cancer the conversion of oestrone (E1) to E2 (4.4+/-1.1%) was much lower than the inactivation of E2 to E1 (17.3+/-5.0%). In contrast, an examination of in vivo oestrogen metabolism within breast tumours revealed that whereas little metabolism of E2 occurred, E1 was converted to E2 to a much greater extent in malignant (48+/-14%) than in normal (19+/-6%) breast tissue. Findings from these studies originally suggested that oestrogen metabolism within breast tumours may differ from the mainly oxidative direction found in most other body tissues and that the activity of 17beta-HSD1 might be regulated by tumour-derived factors. Several growth factors (e.g. IGF-I, IGF-II) and cytokines (e.g. IL-6, TNFalpha) have now been identified which can markedly stimulate the activity of 17beta-HSD1 and such a mechanism may account for the high concentrations of E2 found in most breast tumours. Cells of the immune system, which can infiltrate breast tumours, are thought to be a major source of the growth factors and cytokines which can modulate 17beta-HSD1 activity. Given the central role that 17beta-HSD1 has in regulating breast tumour E2 concentrations the development of potent inhibitors of this enzyme has recently attracted considerable attention. Our initial studies in this area explored the use of derivatives of E1 as inhibitors, with 2-ethyl- and 2-methoxy E1 being found to inhibit 17beta-HSD1 activity in T-47D breast cancer cells by 96+/-2 and 91+/-1% respectively at 10 microM, but with a lack of specificity. Using the E1 scaffold a number of potent, selective 17beta-HSD1 inhibitors have now been identified including E1- and 2-ethyl-E1 containing a side chain with a m-pyridylmethylamidomethyl functionality extending from the 16beta position of the steroid nucleus. At 10 microM these compounds both inhibited 17beta-HSD1 activity by >90%, however some inhibition of 17beta-HSD2 activity was exhibited by the E1 derivative (25%) but not the 2-ethyl analogue. It is now apparent that 17beta-HSD1 activity contributes to the high E2 concentrations found in most breast tumours. The identification of potent, selective novel 17beta-HSD1 inhibitors will allow their efficacy to be tested in in vitro and in vivo studies.

Improving the cancer chemotherapy use process.

PURPOSE: Reports of the tragic consequences of erroneous cancer chemotherapy overdoses at a prominent cancer center and a university hospital prompted a review of our institution's practices and those of 123 other hospitals to ascertain for each the current in-house process to prevent chemotherapy errors. METHODS: A multidisciplinary committee of oncologists, nurses, and pharmacists reviewed the chemotherapy use process and identified opportunities for improvement. A 1-page facsimile survey was answered by 150 of 215 members of the American Society of Clinical Oncology (ASCO) who received it. RESULTS: We further restricted the writing of cytotoxic chemotherapy orders to physicians who were board-certified or -eligible in hematology or medical, pediatric, and gynecologic oncology and their approved fellows. Dispensation of drugs is limited to oncology-certified pharmacists, and administration to chemotherapy-certified nurses. Standard orders are used either on special oncology forms or designated order sets in the computer. Procedures to regulate the ordering of antineoplastic drugs for nonmalignant indications by nononcology specialists are outlined. A process to prevent chemotherapy errors is in place in 95% of hospitals. Dedicated medical oncology units are ubiquitous, and most cancer centers and university hospitals have dedicated gynecologic and pediatric oncology units. Chemotherapy orders are generally written by oncology fellows and countersigned by an attending oncologist in cancer centers and university hospitals, whereas private oncology attending physicians write them in most community hospitals. Drugs are administered by oncology-certified nurses in most institutions. CONCLUSIONS: These recommendations should improve the safety and effective use of chemotherapy and reduce the error rate to as close to zero as human fallibility will allow.

Observations on ethical problems and terminal care.

Progress in medical diagnosis and therapy has raised new problems with far-reaching ethical implications. Medicine must remain a profession and not become a business. Textbooks must address ethical problems in the context of health care decisions and not restrict themselves to pathophysiology and practical therapeutics alone. The relative roles of the principles of autonomy, non-maleficence, beneficence, and justice must be balanced and appropriately applied to individual situations in biomedical ethics. When therapy becomes futile and the suffering of the patient does not justify any anticipated benefit, the patient (and/or patient surrogate) may request withholding or even withdrawing life-prolonging interventions. In the persistent vegetative state, even nutritional support by an unnatural (tube) route may ethically be denied at the patient's (or surrogate's) informed decision. New areas of ethical evaluation have been raised by the desire of some individuals to prolongation of their lives at high expense to the society such that other individuals are denied services because of limitation of available resources. There has been a long-standing conflict of interest between the acceptance by physicians and/or medical institutions of money or gifts from pharmaceutical companies whose drugs they prescribe, stock, or sell. This practice increases the cost of the drugs and is, in effect, a "sick tax," which is morally wrong.

High-dose pulse chlorambucil in advanced, low-grade non-Hodgkin's lymphoma.

High-dose pulse chlorambucil was given orally at a dose of 16 mg/m2 daily for 5 consecutive days each month, as reported by Cadman et al. It was used to treat 33 patients with advanced, low-grade non-Hodgkin's lymphoma. With median follow-up of 4.2+ years, 70% of the patients achieved objective response. Eleven of 24 patients with follicular small cleaved cell lymphoma (FSCL) had pathological complete response; nine of 24 with FSCL and three of seven with small lymphocytic lymphoma had partial response. Median disease-free survival was 28 months. Actuarial survival for all patients was 60% at 5 years from initiation of therapy. Treatment toxicity was minimal. Pulse chlorambucil is an effective and minimally toxic palliative therapy for advanced FSCL.

A randomized study of low and high doses of leukocyte alpha-interferon in metastatic renal cell carcinoma: the American Cancer Society collaborative trial.

A prospective randomized trial of low versus high doses of human leukocyte alpha-interferon (1 X 10(6) units/day for 28 days versus 10 X 10(6) units/day for 28 days) was carried out in 30 patients with metastatic renal cell carcinoma, to test the tolerance and relative antitumor effects of these interferon doses. Both doses were tolerated well, and responses to the human leukocyte alpha-interferon were observed overall in seven individuals, including complete, partial, and minimal tumor regressions. Six of the seven responses occurred in patients who received the high dosage, and three of these responses were major responses. While not statistically significant, this result suggested a dose-response relationship. One minimal response was observed in a patient treated at low dosage. Nine individuals who were stable after 1 month of therapy at low dosage were randomized to a further month of therapy at low or high dosage, during which one of four at high dosage had a partial response, and none of five at low dosage manifested response. Regression of pulmonary disease in one individual was delayed, occurring 3 months after therapy at the high dose and enduring for a period of 28 months. Major objective responses in other patients were of 4 and 15 months duration. Human leukocyte alpha-interferon is an active agent in renal cell carcinoma at the dosage of 10 million units daily. No relationship of toxicity to response was evident in this trial. Optimum dosage and duration of treatment have yet to be established.

Circulating factor XI antibody and disseminated intravascular coagulation.

Association of a circulating factor XI anticoagulant and disseminated intravascular coagulation (DIC) is described in a 33-year-old woman. Although the patient had rheumatoid arthritis and a bacterial infection treated with antibiotics, the anticoagulant was thought to be secondary to systemic lupus erythematosus. Curiously, the low levels of factor XI did not prevent the DIC from developing.

Abdominal paracentesis for malignant ascites.

Abdominal paracentesis for malignant ascites may be performed safely for several hours by insertion of a plastic tube through an intracatheter needle. The system is closed and sterile for up to 9 liters of drainage.

Asymptomatic eyebrow mass. A rare presenting sign of malignant non-Hodgkin's lymphoma.

A 60-year-old woman had a solitary mass in her left eyebrow that was first thought to be a dermoid cyst and following excision and histological examination was found to be a localized, malignant, non-Hodgkin's lymphoma of the mixed lymphocytic and histiocytic type. Subsequent lymphangiography after excisional biopsy of the left eyebrow mass demonstrated extensive para-aortic and inguinal lymph node involvement.