Toxicity of antineoplastic agents in man, chromosomal aberrations antifertility effects, congenital malformations, and carcinogenic potential

O Risco Genético das Terapias do Câncer

O presente artigo descreve as conseqüências de algumas terapias utilizadas para o câncer sobre o material genético de pacientes com neoplasias. O objetivo é ressaltar a importância da avaliação da relação risco/ benefício dos diferentes tratamentos utilizados para o câncer, e da continuidade de pesquisas para o desenvolvimento de novas formas de terapia e de novas drogas antineoplásicas. Faremos breve exposição sobre o processo de carcinogênese de múltiplas etapas, destacando o conceito geral de que o câncer é uma doença genética. São apresentados os efeitos mutagênicos das radiações ionizantes e de algumas classes de quimioterápicos sobre o material genético. Além dos efeitos deletérios desses agentes para o paciente, são também relatados efeitos nocivos para os indivíduos que manipulam ou que são responsáveis pela condução dos tratamentos. Abordaremos de modo geral, os danos genéticos induzidos por agentes antineoplásicos mutagênicos tanto para o paciente como para os indivíduos que os manipulam, predispondo-os ao desenvolvimento de um segundo tumor ou de um tumor primário, respectivamente.

Measures to prevent the risks associated with exposure to cytostatic drugs in glaucoma filtering surgery

INTRODUCTION

The use of cytostatic drugs such as Mitomycin C and 5-Fluorouracil is well-known in glaucoma filtering surgery, as well as the management of its complications. However, there is a lack of information regarding the preventive measures to be taken by the professional that handles these types of substances.

OBJECTIVE

Raise awareness among professionals of the risks associated with the use of cytostatic drugs without adequate prevention measures.

RESULTS

Review of the available literature and legislation on preventive measures in the management of cytostatic drugs in the medical and ophthalmological field.

CONCLUSIONS

The prevention and awareness of the risks of the qualified professionals that handle these substances is the most important measure to prevent the possible risks. Coordination is necessary with the Occupational Health teams of the Hospital, as well as the professionals and staff involved in the different phases of the process, from the preparation in Hospital Pharmacy to its elimination.

Rapid Analysis of Normal and Abnormal Cell Types in Human Semen and Testis Biopsies by Flow Cytometry

A simple, rapid procedure is described that quantitates RNA content and DNA content/chromatin condensation for each of many possible cell types and differentiation levels of the cells present in human semen. A fresh semen sample (1-6 hr postemission) or frozen sample (allowing samples to be accumulated and sent to a laboratory) is treated with a detergent solution, stained with acridine orange (AO), and measured by flow cytometry (FCM); approximately 10 minutes are required to measure 5,000 cells per sample and analyze the data with computer assistance. The following can be learned from a single measurement: a) the percentage of each cell type in semen including, i) mature sperm, ii) immature sperm precursor cells, representing all stages of development from spermatogonia to mature sperm, iii) somatic cells, e.g., leukocytes; b) normality/abnormality of sperm nuclear chromatin condensation. These measurements can be correlated with cell types in testis biopsies identified by two-parameter FCM measurements (RNA versus DNA) using AO as the fluorescent probe.

Genotoxic Monitoring of Nurses Handling Cytotoxic Drugs

OBJECTIVE

Several biomarkers may be used to detect harmful exposure and individual susceptibility to cancer. Monitoring of biomarkers related to exposure may have a significant effect on early detection of cell transformation, thereby aiding the primary prevention of various chronic and malignant diseases. Nurses who handle cytotoxic drugs are exposed to carcinogenic agents, which have the potential to interrupt the cell cycle and to induce chromosomal aberrations. The presence of high chromosomal aberrations indicates the need for intervention even when exposure to these carcinogens is low.

METHODS

Nationally representative samples of 552 nurses were investigated by a follow-up monitoring system. The measured biomarkers were clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations [CAs] and sister chromatid exchanges [SCEs]) and immunotoxicological monitoring (ratio of lymphocyte subpopulations and lymphocyte activation markers) measured on peripheral blood lymphocytes. Results were compared to the data of 140 healthy, age-matched controls.

RESULTS

In nurses exposed to cytostatics, we observed a significantly increased frequency of CAs and SCEs compared with those in the controls. Cytostatic drug exposure also manifested itself in an increased frequency of helper T lymphocytes. Genotoxicological and immunotoxicological changes, as well as negative health effects (i.e., iron deficiency, anemia, and thyroid diseases), increased among cytostatic exposed subjects.

CONCLUSIONS

These results raised concerns about the protection of nursing staff from chemical carcinogens in the working environment.

Occupational health and staff monitoring: A genetic toxicologist's viewpoint

This is a summary of some of the points raised in a round table discussion on occupational health and in two workshops on staff monitoring, held as part of ISOPP IV. It is not intended as a comprehensive review on these issues. It is, however, intended to focus discussion on some of the controversial areas from the perspective of a genetic toxicologist. Pharmacists who have points to add or disagree with, or who wish to discuss or debate these issues further might address such comments as "Letters to the editor" in this journal.

Review : Infertility after chemotherapy: A review of the risks and strategies for prevention

Purpose. Infertility as a late complication of cancer chemotherapy, focusing on specific drug-related ef fects, effects observed in the treatment of certain malignancies, and strategies for prevention is re viewed.

Data Sources. A MEDLINE search of articles from 1966 to present was conducted using the terms infertility, antineoplastics, amenorrhea, azospermia, oogenesis, and spermatogenesis. Additional refer ences were identified using review articles and phar macology textbooks.

Study Selection. All human studies reported in English language were included. Animal studies were included when human data were insufficient or un available.

Data Synthesis. Data on the infertility effects of individual antineoplastic agents are difficult to inter pret for several reasons, including small sample sizes, lack of prechemotherapy fertility assessment, inade quate long-term follow-up, and use of regimens in cluding multiple agents. In general, the incidence and severity of antifertility effects are dependent on the total dosage delivered, duration of therapy, and age at exposure. The alkylating agents have the most signif icant effects on fertility. Fertility outcomes have been reported for several different malignancies, especially in patients cured of Hodgkin's disease and testicular cancer. Information on specific antineoplastic agents and cancers are reviewed. Several methods have been employed to decrease gonadotoxic effects, but none have been effective.

Conclusions. Infertility is a common late com plication of cancer chemotherapy that is receiving increasing attention as the number of cancer survi vors increases. Health care professionals should be aware of infertility risks associated with antineoplastic agents and certain malignancies, and patients should be informed of these risks as treatment decisions are made.

Acute myeloid leukemia in the pregnant patient

Although acute myeloid leukemia (AML) mostly occurs in older patients, it could be seen in women of childbearing age. It is therefore not surprising that in some patients, the management of AML will be complicated by a coexistent pregnancy. However, the association of leukemia and pregnancy is uncommon. Its incidence is estimated to be 1 in 75,000-100,000 pregnancies. During pregnancy, most leukemias are acute: two-thirds are myeloid and one-third are lymphoblastic. There is no standard approach for this clinical dilemma, in part because of variables such as the type of AML, the seriousness of the symptoms, and the patient's personal beliefs. In many cases, the diagnostic workup has to be altered because of the pregnancy, and often available treatments have varying risks to the fetus. While chemotherapy is reported to have some risks during the first trimester, it is admitted that it can be administered safely during the second and the third trimesters.

Lymphohematopoietic cancers induced by chemicals and other agents and their implications for risk evaluation: An overview

Lymphohematopoietic neoplasia are one of the most common types of cancer induced by therapeutic and environmental agents. Of the more than 100 human carcinogens identified by the International Agency for Research on Cancer, approximately 25% induce leukemias or lymphomas. The objective of this review is to provide an introduction into the origins and mechanisms underlying lymphohematopoietic cancers induced by xenobiotics in humans with an emphasis on acute myeloid leukemia, and discuss the implications of this information for risk assessment. Among the agents causing lymphohematopoietic cancers, a number of patterns were observed. Most physical and chemical leukemia-inducing agents such as the therapeutic alkylating agents, topoisomerase II inhibitors, and ionizing radiation induce mainly acute myeloid leukemia through DNA-damaging mechanisms that result in either gene or chromosomal mutations. In contrast, biological agents and a few immunosuppressive chemicals induce primarily lymphoid neoplasms through mechanisms that involve alterations in immune response. Among the environmental agents examined, benzene was clearly associated with acute myeloid leukemia in humans, with increasing but still limited evidence for an association with lymphoid neoplasms. Ethylene oxide and 1,3-butadiene were linked primarily to lymphoid cancers. Although the association between formaldehyde and leukemia remains controversial, several recent evaluations have indicated a potential link between formaldehyde and acute myeloid leukemia. The four environmental agents examined in detail were all genotoxic, inducing gene mutations, chromosomal alterations, and/or micronuclei in vivo. Although it is clear that rapid progress has been made in recent years in our understanding of leukemogenesis, many questions remain for future research regarding chemically induced leukemias and lymphomas, including the mechanisms by which the environmental agents reviewed here induce these diseases and the risks associated with exposures to such agents.

Modulatory effects of gentisic acid against genotoxicity and hepatotoxicity induced by cyclophosphamide in Swiss albino mice

Objectives

This study evaluated the protective effects of gentisic acid (GA) against genotoxicity and hepatotoxicity induced by cyclophosphamide (CP) in Swiss albino mice.

Methods

Mice were pretreated with GA orally at doses of 50 and 100 mg/kg for 14 consecutive days before the administration of a single intraperitoneal dose of 50 mg/kg CP. The ameliorative effect of GA on genotoxicity was studied using the in-vivo bone marrow micronuclei induction test, DNA integrity and alkaline unwinding assay. The activity of various oxidative stress enzymes were estimated in hepatic tissue.

Key findings

A single intraperitoneal administration of CP in mice increased the malondialdehyde level, depleted the glutathione content and antioxidant enzyme activity (glutathione peroxidase, glutathione reductase, catalase and quinone reductase), and induced DNA strand breaks and micronuclei induction. Oral pretreatment with GA at both doses caused a significant reduction in malondialdehyde and glutathione levels, restoration of antioxidant enzyme activity, reduction in micronuclei formation and DNA fragmentation. Serum toxicity marker enzymes such as aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase were increased after CP treatment but restored in GA pretreated groups.

Conclusion

The results support the protective effect of GA against CP induced genotoxicity and hepatotoxicity.

Amifostine reduces the seminiferous epithelium damage in doxorubicin-treated prepubertal rats without improving the fertility status

BACKGROUND

Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.

METHODS

Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). "Standard One Way Anova" parametric and "Anova on Ranks" non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.

RESULTS

The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.

CONCLUSIONS

These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models.

Effect of methotrexate administration on status of some essential trace elements and antioxidant enzymes in pregnant rats in late gestation

OBJECTIVE

Folate antagonists are widely used in the treatment of various cancerous states. Paucity of data on effect of administration of one such widely used drug, methotrexate (MTX), on the status of essential trace elements and antioxidant enzymes in pregnant women or in pregnant animals prompted us to undertake this study.

METHODS

MTX at a concentration of 5 mg/kg body weight was administered intraperitoneally as single dose to pregnant Sprague-Dawley rats for three consequitive days from day 17 of pregnancy. Control group of pregnant rats received single dose of saline instead of the anti-cancer drug on all the 3 days. After receiving the third dose of drug, the treated rats and control group rats were sacrificed, 1 h after intraperitoneal injection of a cocktail of essential trace elements namely, Cu, Se and Zn administered as a single bolus dose. Blood samples were collected 30 min of trace element cocktail injection, after decapitation and concentrations of trace elements in serum samples were determined by atomic absorption spectrophotometry. Concentrations of antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase and total antioxidant status were determined by specific analytical kits, using spectrophotometry.

RESULTS

In control group(n = 6), serum concentrations of Cu, Se and Zn averaged 2330.5, 614.8 and 2773.2 microg/l, while in study group (n = 6) the concentrations of trace elements averaged 2294, 596 and 2713 microg/l, respectively. Student's t-test did not show any statistical significance (p > 0.05) between various trace element concentrations in control and treated groups. Cu:Zn ratios of control and treated group of rats did not vary significantly as well. Concentrations of superoxide dismutase, glutathione peroxidase in whole blood samples in control rats averaged 165 and 43,260 U/ml, respectively, while in MTX-treated group of animals the corresponding antioxidant enzymes averaged 330.6 and 67,101 U/ml respectively. SOD and GPX values were significantly higher in drug-treated animals compared to controls (Student's t-test, p < 0.05) However, total antioxidant activity was shown to be significantly lower (Student's t-test; p < 0.05) in the drug-treated group compared to control.

CONCLUSIONS

We report for the first time that effect of MTX administration in pregnancy is not associated with significant alteration in disposition of essential trace elements. However, the effect of drug administration on antioxidant enzyme status in pregnant women cannot be excluded while using the drug in clinical states.

Maternal–fetal transport kinetics of methotrexate in perfused human placenta:In vitrostudy

OBJECTIVE

Folate antagonists are widely used in the treatment of diverse cancerous states. A paucity of data on transport characteristics of one such widely used drug, methotrexate, in the human placenta, prompted us to study its permeation characteristics in vitro.

METHODS

Placentas from normal pregnancies were collected post-partum. Methotrexate, along with antipyrine as reference marker were injected as a single bolus (100 microL) into the maternal arterial circulation of isolated perfused placental lobules; perfusate samples were collected from both maternal and fetal circulations over a study period of five minutes. National Culture and Tissue Collection medium, diluted with Earle's buffered salt solution was used as the perfusate. The concentration of methotrexate in various samples was determined by high performance liquid chromatography, while antipyrine concentration was assayed by spectrophotometry. Transport and pharmacokinetic data of study and reference substances were computed using standard parameters.

RESULTS

Differential transport rate of methotrexate for 10, 25, 50, 75 and 90% efflux fractions in fetal venous effluent averaged 0.52, 1.30, 2.37, 3.57 and 4.43 minutes in 12 perfusions, representing 1.01 + 0.08, 1.03 + 0.06, 0.95 + 0.03, 0.93 + 0.03, 0.93 + 0.03 respectively times antipyrine reference value. Student's t-test showed varying differences between the control and study group data. Transport Fraction (TF) of methotrexate, expressed as fraction of the drug appearing in fetal vein, during study period of 5 minutes averaged 24.00 + 2.50% of bolus dose while antipyrine TF averaged 68.73 + 2.01% of injected bolus dose, representing 24.00 percent of reference marker value. Student's t-test showed methotrexate and reference marker TF values to be significantly different (p < 0.05). Pharmacokinetic parameters such as area under the curve, clearance, time for maximum response, absorption and elimination rates of study and reference substances showed varying differences.

CONCLUSIONS

We report for the first time that the transport of methotrexate from maternal to fetal circulation is not negligible in human placenta at term. It is reasonable to assume that a direct risk for the fetus from methotrexate use in pregnancy cannot be excluded, and caution is warranted when it is used in emergency clinical situations.

Conflicting priorities in surgical intervention for cancer in pregnancy

Cancer in pregnancy is uncommon, with an incidence of about one to two cases in every 1000 pregnancies. There are no randomised trials on any aspect of the management of cancer in pregnancy. Stage for stage cancer outcomes are similar in women who are pregnant compared with those who are not. Misdiagnosis and delayed diagnosis are common where the index of suspicion by the mother and health carers is low. Surgical interventions pose some risk to the fetus, especially laparotomy for abdominal tumours and procedures undertaken during the first trimester. Chemotherapy is teratogenic in the early stages, but seems to be safe in later pregnancy, and radiotherapy can be used for localised tumours remote from the uterus, such as head and neck or limb neoplasms. Suspicious symptoms should be appropriately investigated during pregnancy, and recent advances in non-ionising-radiation staging techniques, such as MRI and ultrasound, are especially helpful. Surgical interventions can be safely undertaken with minimum risk, although there is almost always some element of maternal-fetal conflict.

Chemical safety and health conditions among Hungarian hospital nurses

In the present study genotoxicological and immunotoxicological follow-up investigations were made on 811 donors including 94 unexposed controls and 717 nurses with various working conditions from different hospitals (The Hungarian Nurse Study). The nurses were exposed to different chemicals: cytostatic drugs, anesthetic, and sterilizing gases, such as ethylene oxide (ETO) and formaldehyde. The measured biomarkers were: clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations [CA], sister chromatid exchange [SCE]), and immune-toxicological monitoring (ratio of lymphocyte subpopulations, lymphocyte activation markers, and leukocyte oxidative burst). The highest rate of genotoxicologically affected donors (25.4%) was found in the group of cytostatic drug-exposed nurses. Comparing geno- and immunotoxicological effect markers, we found that among genotoxicologically affected donors the frequency of helper T cell (Th) lymphocytes, the ratio of activated T and B cells increased, whereas the oxidative burst of leukocytes decreased. In hospitals with lack of protective measures increased CA yields were observed compared to those with ISO 9001 quality control or equivalent measures. Anemia, serum glucose level, thyroid dysfunctions, benign, and malignant tumors were more frequent in the exposed groups than in controls. The hygienic standard of the working environment is the basic risk factor for the vulnerability of nurses. On the basis of these results, it is suggested, that the used cytogenetic and immunological biomarkers are appropriate to detect early susceptibility to diseases. The Hungarian Nurse Study proved that the use of safety measures could protect against occupational exposure at work sites handling cytostatic drugs, anesthetic, and sterilizing gases.

In vivo micronucleus assay and GST activity in assessing genotoxicity of plumbagin in Swiss albino mice

Information available on the mutagenicity of a large number of indigenous drugs commonly employed in the Siddha and Ayurveda systems of medicine is scanty. In this context, the current investigation on plumbagin, 5-hydroxy-2methyl-1,4-napthoquinone, an active principle in the roots of Plumbago zeylanica used in Siddha and Ayurveda for various ailments, was carried out; 16 mg/kg b.w. (LD(50)) was fixed as the maximum dose. Subsequent dose levels were fixed as 50% and 25% of LD(50) amounting to 8 mg and 4 mg/kg b.w., respectively, and given orally for 5 consecutive days in 1% Carboxyl Methyl Cellulose (CMC) to Swiss albino mice weighing 25-30 g. The micronucleus assay was done in mouse bone marrow. Plumbagin was found to induce micronuclei at all the doses studied (4 mg/kg, 8 mg/kg, 16 mg/kg b.w.), and it proves to be toxic to bone marrow cells of Swiss albino mice. Animal treated with cyclophosphamide (40 mg/kg b.w.) served as positive control. In addition, glutathione S-transferase (GST) activity was observed in control, plumbagin (4 mg, 8 mg, 16 mg/kg b.w., respectively), and genotoxin-treated experimental group of animals. No significant change in GST activity was observed with plumbagin dose of 4 mg/kg b.w., whereas GST activity was significantly inhibited by higher doses of plumbagin (8 mg and 16 mg/kg b.w.) and cyclophosphamide.

A de novo, apparently balanced reciprocal translocation in a child with developmental delay whose mother was being treated with low-dose methotrexate at the time of conception

BACKGROUND

Methotrexate is a proven teratogen and its use periconceptually is strongly advised against. Concerns about possible chromosomal effects in the offspring of women treated with this agent have been raised, but they have not been reported. In vivo and in vitro studies have supported this possibility, however.

CASE

A 32-year-old primigravida was treated with low-dose methotrexate for rheumatoid arthritis from prior to conception until six weeks postconception. Her child was born without congenital malformations but subsequently developed seizures and was diagnosed with developmental delay. He was found to have a de novo, apparently balanced, reciprocal translocation between chromosomes 5 and 20 (46,XY,t(5:20)(q15;p12)). Other investigations failed to reveal another cause for his developmental delay.

CONCLUSIONS

The possible association between maternal methotrexate exposure and a de novo chromosomal anomaly in an offspring supports the recommendation that women should be advised to cease taking this drug for at least six months prior to conception.

Fertility and outcomes of pregnancy after chemotherapy in a sample of childbearing aged women

The aim of the study was to review the characteristics and outcomes of pregnancies occurring in women of childbearing age after chemotherapy for malignant disease. Between November 1998 and October 1999, a total of 16 patients who were treated for ovary (three), mole (one), vaginal (one), breast (four), Hodgkin's disease (four), lung (one), melanoma (one) and osteosarcoma (one) carcinoma were identified and retrospectively questioned about their fertility status. All the 16 women included in this study received at least one alkylating agent. Five patients (31%) experienced anomalies of hormonal cycle during and after the treatment. All of them recovered normal cycle without consequence of fertility. Caesarean section was performed in seven of 20 (35%) pregnancies with known outcomes. No obstetrical events were reported. The 16 women had 21 pregnancies resulting in 18 normal infants, one newborn with a minor abnormality (tallus foot), one spontaneous abortion and one lost of follow-up to 6 months of pregnancy. The present survey suggests that cytotoxic drug exposure had no deleterious effects on subsequent pregnancies. A prospective and systemic survey would be the only means able to clarify the actual cancer therapy on reproductive outcome and to investigate the long-term effects in the progeny.

Pregnancy outcome in non-gynecologic cancer

OBJECTIVE

The objective was to determine the prevalence of non-gynecologic cancer in pregnancy and its maternal and fetal outcome in a single tertiary center in the Eastern Province of Saudi Arabia.

METHOD

Retrospective chart review was done of 54 patients with a diagnosis of non-gynecologic cancer in pregnancy at Dhahran Health Center from January 1990 to December 2001 using the Dhahran Health Information database. Maternal and fetal outcome were determined for 17 women with active cancer during pregnancy (Group I, 18 pregnancies) and for 44 women in cancer remission (Group II, 96 pregnancies). Seven women were pregnant during active cancer and during cancer remission.

RESULTS

There were 114 pregnancies in 54 women with cancer. The prevalence in pregnancy was 1.5:1,000 (54 cancer in 70,987 pregnancies). Thyroid (33) and breast (11) cancer accounted for 75% of all cancer. Induced abortion, spontaneous abortion, stillbirth and low birth weights in Group I were: 5 (28%), 0 (0%), 1 (6%) and 2 (11%), respectively, and in Group II were: 1 (1%), 11 (11%), 0 (0%) and 3 (3%), respectively. Live births for Group I, II and all patients with cancer were 12 (66.7%), 84 (87.5%) and 96 (84.2%), respectively, with p =0.025 There were three maternity deaths among 17 women in Group I. None of 44 women in Group II died.

CONCLUSION

The diagnosis of active cancer in pregnancy carries a significant increase in perinatal and maternal mortality. However, pregnancy during cancer in remission has favorable outcome, pregnancy in this group should not be discouraged.

Induction of developmental toxicity in mice treated withAlstonia scholaris (Sapthaparna) In utero

BACKGROUND

The teratogenic effect of hydroalcoholic extract of Alstonia scholaris (ASE) was studied in the pregnant Swiss albino mice administered with 0, 60, 120, 240, 360, and 480 mg/kg ASE on Day 11 of gestation.

METHODS

Females were allowed to complete the term and parturiate. The litters were monitored regularly for mortality, growth retardation, congenital malformations, and appearance of physiological markers up to 7 weeks post-parturition (p.p.).

RESULTS

The administration of 60, 120, 180, and 240 mg/kg ASE to the pregnant mice on Day 11 did not induce mortality, congenital malformations, or alter the normal growth patterns. A further increase in the herbal extract dose up to 360 or 480 mg/kg resulted in a dose dependent increase in the mortality, growth retardation, and congenital malformations, characterized mainly by bent tails and syndactyly. The administration of higher doses (360 or 480 mg) of ASE also caused a significant delay in the morphological parameters such as fur development, eye opening, pinna detachment, and vaginal opening. The incisor eruption and testes decent were found to be delayed in litters born to the mothers treated with 240-480 mg/kg ASE.

CONCLUSIONS

Our study indicates clearly that ASE treatment caused teratogenic effect only at doses above 240 mg/kg (>20% of LD(50)). Lower doses had no developmental toxicity.

Modulation of antineoplastic activity of cyclophosphamide byAlstonia scholarisin the Ehrlich ascites carcinoma-bearing mice

Alterations in the neoplastic activity of cyclophosphamide (CPA) by the extract of Alstonia scholaris(ASE) were studied in mice transplanted with Ehrlich ascites carcinoma (EAC). The tumor-bearing animals were injected with various doses of ASE and 25 mg/kg of CPA (1/10th of the LD50 dose). The combination of 120 mg/kg of ASE with 25 mg/kg of CPA was most effective, as it caused the highest tumor regression and enhanced the mean survival time (MST) and the average survival time (AST) up to 42 and 40.7, as against the 29 and 27.5 of CPA alone, respectively. Similarly, when 120 mg/kg of ASE was combined with different doses of CPA (3.125 to 50 mg/kg), a dose-dependent increase in the anticancer activity was observed up to 25 mg/kg of CPA. However, a further increase in the CPA dose up to 37.5 or 50 mg/kg resulted in toxic side effects and death. The best effect was observed when 120 mg/kg of ASE was combined with 25 mg/kg followed by 12.5 mg/kg of CPA, as evident by the greater tumor remission, when compared with the concurrent doses of either drug alone. The administration of 120 mg/kg of ASE 6 h before the administration of 25 mg/kg of CPA resulted in a drastic decline in the glutathione levels and increased the lipid peroxidation considerably when compared with either drug alone.

Germ cell transplantation in the male: animal studies with a human perspective

Germ cell transplantation has been developed in rodent models. The transfer of donor germ cells into the seminiferous tubules of mice leads to re-initiation of donor spermatogenesis in the host testis and restoration of fertility. Furthermore, cryopreservation of donor cells or culture of germ cells before the transfer is feasible. Xenologous transfer of rat and hamster germ cells results in the production of foreign gametes in the mouse testis. From a clinical perspective, this methodology has the potential to restore fertility in patients whose testes have been damaged due to oncological therapy. This review summarizes the existing data on animal models and introduces the first preclinical attempts for preserving germ cells in patients undergoing oncological treatment. As improved therapeutic regimens have markedly increased the life expectancy of oncological patients, it seems timely to develop improved strategies for restoring the maximum quality of life after recovery from the disease. The loss of fertility is one of the most problematic negative side effects in young male oncological patients. Germ cell transplantation offers the potential for protection of the male germ line during gonadotoxic therapy and restoration of fertility.

The effect of early pregnancy following chemotherapy on disease relapse and foetal outcome in women treated for gestational trophoblastic tumours

Little literature exists on the safety of early pregnancy following chemotherapy. Here we assess the rate of relapse and foetal outcome in women who have completed single and multi-agent chemotherapy for gestational trophoblastic tumours. The records of 1532 patients treated for persistent gestational trophoblastic tumours at Charing Cross Hospital between 1969 and 1998 were reviewed. Patients were defined as receiving single agent or multi-agent treatment. Relapse rates and foetal outcome were reviewed in the 230 patients who became pregnant within 12 months of completing chemotherapy. In the single agent group 153 (22%) of 691 patients conceived early. Three subsequently relapsed. In the multi-agent group, 77 (10%) of 779 patients conceived early, two then relapsed. Relapse rates were 2% (3 out of 153) and 2.5% (2 out of 77) for each group compared to 5% and 5.6% in the comparative non-pregnant groups. Outcomes of 230 early pregnancies: 164 (71%) delivered at full term, 35 (15%) terminations, 26 (11%) spontaneous abortions, three (1.3%) new hydatidiform moles and two (1%) stillbirths. Early pregnancies were more common in the single agent group (P<0.001), but spontaneous miscarriages and terminations were more likely to occur in the multi-agent group (P=0.04 and 0.03, respectively). Of the full-term pregnancies, three (1.8%) babies were born with congenital abnormalities. Patients in either group who conceive within 12 months of completing chemotherapy are not at increased risk of relapse. Though, we still advise avoiding pregnancy within 12 months of completing chemotherapy, those that do conceive can be reassured of a likely favourable outcome. DOI: 10.1038/sj/bjc/6600041 www.bjcancer.comCopyright 2002 The Cancer Research Campaign

Follow-up genotoxicological monitoring of nurses handling antineoplastic drugs

Most of the antineoplastic drugs used in the treatment of tumors are carcinogenic to humans. Hospital nurses are often subject to possible occupational carcinogen exposure. Exposure may occur during handling and administration of infusion solutions containing cytostatics. A genotoxicological monitoring system to detect genotoxic changes was developed in our laboratory, helping to improve working conditions and subserving primary prevention. Multiple-endpoint follow-up genotoxicological monitoring was performed in peripheral blood lymphocytes (PBLs) among 4 groups of 95 nurses (152 investigations) occupationally exposed to cytostatics. The results were compared to those of historical and industrial controls. The genotoxicological endpoints were the determination of the frequency of sister chromatid exchanges (SCEs) and the cells with high-frequency SCEs (HFC), the frequency of structural and numerical chromosome aberrations. and the measurement of ultraviolet-light-induced unscheduled DNA-repair synthesis (UDS). In Hospital 1, where nurses worked without a safety cabinet, the percentage of cells with chromosome aberrations (AC) was significantly higher than that of the controls. In Hospital 2, where nurses used inadequate safety cabinets (with horizontal airflow), significantly elevated levels of AC, SCE, HFC, and UDS were detected. During follow-up, in Hospital 2 at the time of the second investigation AC was still significantly higher, although safety conditions had been improved. The results indicate the presence of genotoxic damage in hospital nurses working with no or inadequate safety equipment. In Hospitals 3 and 4 where nurses using biological safety cabinets, the results were lower than those in the previous two groups. In Hospital 3 in the first year of the study AC was as at the level of industrial controls. During follow-up in the course of the repeated investigations a fluctuation in AC above the control level and an increase in HFC in yr 4 and 6 of the study were observed. In this group, the fluctuation in AC and HFC during the study points to the possibility of genotoxic exposure with cytostatics despite of the use of suitable safety cabinets, drawing attention to other possible routes of exposure. In Hospital 4, both AC and HFC were elevated. These data corroborate the need to maintain safety measures to avoid exposure, and the necessity of intervention in the case of exposure when using and handling hazardous carcinogenic agents. The results also indicate a certain expression time for genotoxic changes, which can lead to late somatic mutations as well as to a possible higher risk of cancer.

Correlation between cell survival and micronuclei formation in V79 cells treated with vindesine before exposure to different doses of gamma-radiation

Effect of 20 nM vindesine sulphate (VDS) treatment was studied on cell survival, growth kinetics and micronuclei induction in V79 cells exposed to 0-300 cGy of gamma-radiation at 16, 22 and 28 h post-irradiation. Treatment of V79 cells with VDS before exposure to different doses of gamma radiation resulted in a significant decline in cell survival and growth kinetic when compared with the concurrent PBS+irradiation group. The decline in cell survival and growth kinetics was dose related. Similarly, the cell proliferation indices also declined in a dose dependent manner in both PBS+irradiation and VDS+irradiation groups and this decline was higher in VDS+irradiation group in comparison with the PBS+irradiation group. In contrast, the frequency of micronuclei increased in a dose related manner in both PBS+irradiation and VDS+irradiation groups. However, the frequency of micronuclei was significantly greater in the VDS+irradiation group when compared to the PBS+irradiation group at all the post-irradiation time periods studied and the dose response for both groups was linear for all the scoring time periods. The biological response was determined by plotting surviving fraction and micronuclei frequencies on X- and Y-axes, respectively. The plot between surviving fraction and micronuclei induction showed a close correlation. The surviving fraction of V79 cells reduced with the increasing frequency of micronuclei in both groups and the relationship between micronuclei induction and cell survival could be fitted on a linear quadratic model.

Nurses' and pharmacists' exposure to antineoplastic drugs: findings from industrial hygiene scans and urine mutagenicity tests

Data from 83 nurses and pharmacists handling antineoplastic drugs and 35 nurse/pharmacist controls who participated in a national study of antineoplastic drug-handling risks were examined to investigate antineoplastic drug exposure. Measures of external exposure included self-completion drug logs and industrial hygiene scans conducted in clinical settings. Internal exposure was measured by urine mutagenicity tests on end-of-week 24-hour urine specimens. To control for potential confounders, the staff was asked to complete food and hobby diaries and to avoid identified mutagenic substances for 1 week before collection of 24-hour urine samples. On the scans of the drug handlers, 13% showed one or more spots of drug contamination on gloved and ungloved hands, gowns, or shoes. Of the 24-hour urine samples, 15% were mutagenic for Salmonella typhimurium: Rates did not differ significantly for drug handlers and controls. Among nurses who both prepared and administered antineoplastics, those with positive mutagenicity tests handled more doses of the drugs, used less skin protection, and had more skin contact with the drugs than those with negative tests. Nurses who only administered the drugs and had positive mutagenicity tests handled fewer doses of drugs than those with negative tests, but they also reported less use of protection and more skin contact. For both groups of nurses, skin contact with antineoplastics was associated with positive mutagenicity test results (p < 0.01).

Lymphoma in patients with rheumatoid arthritis: association with the disease state or methotrexate treatment

Although long-term clinical studies have shown no excessive risk of lymphoma in rheumatoid arthritis (RA) patients treated with methotrexate (MTX), an increasing number of reports of this association continue to appear. We describe two cases, review the cases in the world's literature, and summarize their important characteristics. Possible oncogenic mechanisms are discussed. Most lymphoproliferation cases presented here have features of immunosuppression-associated lymphoma. The immunosuppressed state is attributable to a combination of factors, such as RA itself and the actions of MTX. The risk factors for RA patients to develop lymphoma while on MTX include severe disease, intense immunosuppression, genetic predisposition, and an increased frequency of latent infection with prooncogenic viruses such as Epstein-Barr virus (EBV). The spontaneous remission of lymphomas in eight RA patients after MTX was stopped highlights the likely causative role of the drug in the development of these malignancies. If the clinical situation permits, a period of observation for spontaneous remission after MTX is stopped is advisable. The physicians caring for RA patients on MTX should maintain a high surveillance for signs and symptoms suggestive of lymphoma.

Infertility in women with pemphigus vulgaris and other autoimmune diseases

BACKGROUND

Pemphigus vulgaris (PV) is an autoimmune disease. Autoimmune diseases may adversely affect reproductive function and could result in infertility.

OBJECTIVE

Our purpose was to describe nine young women with PV and infertility.

METHODS

A retrospective study was performed. Clinical characteristics, immunopathologic features, treatment, clinical course, and long-term follow-up were determined.

RESULTS

Eight of nine patients were unable to become pregnant. One patient became pregnant during a period of remission. In eight of the nine patients, the cause of infertility was ovarian. Anti-sperm antibodies were present in two of the patients.

CONCLUSION

Some patients with PV may have infertility. No definitive conclusion about the frequency of infertility in these patients or its relation to PV can be drawn. However, these observations indirectly demonstrate that there may be important interactions between the immune and hormonal systems.

Inhibitors of thymine nucleotide biosynthesis: antimetabolites that provoke genetic change via primary non-DNA targets

Folate antagonists and direct-acting inhibitors of thymidylate synthase are potent genotoxic antimetabolites. These agents induce genetic change not by attacking DNA, but by interfering with the control of DNA precursor metabolism. This review surveys the genetic effects attributable to selected representatives of this class of antimetabolites.

Cytogenetic damage measured in human sperm following cancer chemotherapy

Germ-line cytogenetic damage is well documented in laboratory animals exposed to anti-cancer agents, but has been harder to verify in the human. This paper reviews published studies demonstrating cytogenetic damage in human sperm following exposure to anti-cancer chemicals, as measured by the human-sperm/ hamster-egg cytogenetic technique and fluorescence in situ hybridization. These two assays have provided important information on one step in the pathway leading to induced, transmissible germ line damage in the human. By way of introduction, a short review of the traditional human endpoints used to address the question of induced, transmissible genetic damage in human germ cells (mutation epidemiology) related to anti-cancer chemicals is presented.

Risk of acute myelogenous leukaemia and myelodysplasia following cancer treatment

Now that a substantial group of cancer patients has such a favourable prognosis, it has become increasingly important to evaluate the long-term complications of treatment. Of all late effects of treatment, secondary leukaemia is one of the most serious. Increased risk of AML has been observed both after RT and after CT; however, several types of CT have much stronger leukaemogenic properties than RT. Limited field radiation in the therapeutic dose range is associated with very little or no increased risk of leukaemia, which has been attributed to cell killing at the higher radiation doses. With respect to CT, two different syndromes of treatment-related AML have been recognized. Risk of alkylating agent-related AML is highest in the 5-10 year follow-up period and seems to decrease afterwards. This type of leukaemia is often preceded by MDS, and is characterized by deletions of chromosomes 5 and 7. Leukaemias related to treatment with the topoisomerase II inhibitors are characterized by a short induction period, presentation as myelomonocytic or monocytic leukaemia (rather than MDS) and balanced chromosomal translocations involving bands 11q23 and 21q22. This review addresses the risk of secondary AML and MDS following treatment of HD, NHL, testicular cancer, ovarian cancer, breast cancer and paediatric malignancies. In patients with HD, the risk of AML is higher with an increasing number of mechlorethamine-procarbazine-containing cycles, a greater number of CT episodes, and after splenectomy. The majority of data shows that RT does not add to the leukaemia risk from CT, but this issue is still surrounded by some controversy. ABV(D)-treated patients have a very low risk of AML. Generally, patients with NHL, testicular cancer and breast cancer experience much lower risk of AML than patients with HD. NHL and breast cancer treatment regimens with cumulative cyclophosphamide doses of 20 g or less do not confer an appreciable increase of AML. Recently, strongly increased AML risk has been observed following autologous bone marrow transplantation and other dose intensification strategies. Risk factors for this excess remain to be defined. PVB treatment for testicular cancer is not followed by increased leukaemia risk, but modern etoposide-containing regimens do confer excess risk, of which the magnitude at conventional drug doses is not yet well known. High risk of leukaemia has been reported in children treated with epipodophyllotoxins. The leukaemogenic hazards of cancer treatment should be weighed against their therapeutic benefits.

Renal cell carcinoma associated with cyclophosphamide therapy for Wegener's granulomatosis

Cyclophosphamide therapy may be associated with the subsequent development of malignacies in many organs including the urinary tract. The main site in the urinary tract for development of these malignancies is the urinary bladder. Carcinoma of the kidney associated with cyclophosphamide therapy has previously been reported only in transplant recipients. The present case describes, for the first time, the development of renal cell carcinoma after treatment with cyclophosphamide in a patient with Wegener's granulomatosis.

Ovarian cancer in pregnancy

A pelvic mass in pregnancy is a relatively common entity, especially considering the increased use of ultrasound or early fetal evaluation. These masses can derive from multiple gynecologic and nongynecologic origin, and fortunately the majority will resolve with observation into the second trimester. Masses persisting into the second trimester should be surgically evaluated given the decreased risk to both mother and fetus at this time. For masses persisting into the third trimester, a 2% to 5% risk of malignancy is to be expected. Documentation of disease (FIGO stage) is critically important in defining need for adjuvant cytotoxic chemotherapy. Above all, potentially lifesaving therapy should not be withheld from patients because they are pregnant, especially considering that chemotherapy is apparently safe in the second and third trimesters.

Evaluation of a metaphase chromosome finder: potential application to chromosome-based radiation dosimetry

An automated metaphase chromosome finder is described which combines a microscope, state-of-the-art computer technology and a simple decision-making algorithm. A microscope slide is systematically scanned under computer control and the location of each positive 'signal' placed into memory for later recall and review by a human operator. The software identifies two events, positives (the presence of a 'signal') and negatives (the absence of a 'signal'). The performance of the metaphase finder was evaluated using receiver operating characteristic curve analysis. At the optimum decision threshold, the detection rates for true positives (metaphase spreads) was about 74%, false positives (type I error) about 6%, and false negatives (type II error) about 26%. The overall accuracy, which accounts for differences in the sensitivity of the detector to positive and negative events, was 89.4% (+/- 0.01%; standard error of the mean, n = 8). Potential applications to radiation dosimetry are discussed.

International Commission for Protection Against Environmental Mutagens and Carcinogens. Deoxyribonucleoside triphosphate levels: a critical factor in the maintenance of genetic stability

DNA precursor pool imbalances can elicit a variety of genetic effects and modulate the genotoxicity of certain DNA-damaging agents. These and other observations indicate that the control of DNA precursor concentrations is essential for the maintenance of genetic stability, and suggest that factors which offset this control may contribute to environmental mutagenesis and carcinogenesis. In this article, we review the biochemical and genetic mechanisms responsible for regulating the production and relative amounts of intracellular DNA precursors, describe the many outcomes of perturbations in DNA precursor levels, and discuss implications of such imbalances for sensitivity to DNA-damaging agents, population monitoring, and human diseases.

Evaluation of spermatogenic response of mice to the induction of mutations by combined treatment with X rays and antineoplastic drugs

Combined treatment with low doses of X-rays plus cyclophosphamide (0.25 Gy + 25 mg/kg body weight) or X-rays plus mitomycin C (0.25 Gy + 1.75 mg/kg body weight) did not induce significant dominant lethal effects in any stage of spermatogenesis when a parameter representing pre- and postimplantation loss, such as the decrease of live implants per female, was applied. After combined exposure to high dose of X-rays plus cyclophosphamide (1.00 Gy + 100 mg/kg body weight) an increase of dominant lethal mutations (DLMs) was observed in differentiating spermatogonia, spermatids, and spermatozoa with the same parameter. Combined treatment with high doses of X-rays plus mitomycin C (1.00 Gy + 5.25 mg/kg body weight) produced DLMs in differentiating spermatogonia and late spermatocytes. A calculation of "enhanced risk" was applied to the data of DLMs from the combined treatment regimen and was based on the proportion of dead implants (postimplantation loss only). Enhanced risk could be shown not only after high but also after low combined exposure to X-rays plus cyclophosphamide and X-rays plus mitomycin C. With low doses this enhanced risk was observed in spermatids for X-rays plus cyclophosphamide and in differentiating spermatogonia to early spermatocytes for X-rays plus mitomycin C.

Genetic toxicity studies of gossypol

Gossypol, a polyphenolic compound extracted from cotton plants, shows promise for use as a male contraceptive, as well as a treatment for gynecological disorders, cancer, and certain microbial diseases. Before gossypol can be considered safe for widespread human use, particularly by healthy people of childbearing age, its effect on normal genetic processes should be understood. Characterization of gossypol's genotoxic potential has not been approached systematically, although numerous clinical and laboratory studies have addressed issues relating to genetic effects of gossypol. This review summarizes results of relevant studies and offers recommendations for the emphasis of future efforts to understand gossypol's genotoxicity potential. Evidence suggesting that gossypol has any genotoxic effects in mammals under normal physiologic conditions so far is weak, at best. However, several unresolved issues that are important for establishing long-term genetic safety of gossypol were uncovered by this analysis. These include the need for a better understanding of the significance of weak increases in SCE frequency seen in a number of laboratory exposure studies, and more definitive, comprehensive animal tumor bioassay data.

Chromosomal aberrations in peripheral lymphocytes of nurses and physicians handling antineoplastic drugs

The frequencies of structural chromosome aberrations of persons occupationally exposed to antineoplastic drugs without adequate protection were measured in peripheral blood lymphocytes of 106 persons from five oncological units and in an adequate control population. The observed chromosomal aberration frequencies were 3.3 +/- 0.1 aberrations per 100 cells in the exposed group and 0.6 +/- 0.1 aberrations per 100 cells in the controls. Chromosomal aberration frequencies were not correlated with age, duration of exposure and smoking habits. The results stress the necessity to protect hospital staff against the potential risk related to the handling of antineoplastic drugs.