Urinary cyclophosphamide excretion and chromosomal aberrations in peripheral blood lymphocytes after occupational exposure to antineoplastic agents

Occupational exposure to cytotoxic drugs: the importance of surface cleaning to prevent or minimise exposure

Healthcare workers who prepare or administer cytotoxic agents run the risk of exposure, and the risks for health are real even at doses lower than those applied in cancer patients, because, in theory, no dose is safe. The most common and problematic route of exposure is through the skin, especially as work surfaces can remain contaminated even after cleaning. This pilot study aimed to demonstrate the importance of having an effective surface decontamination protocol by determining surface contamination with cyclophosphamide, 5-fluorouracil, and paclitaxel as the most common cytotoxic drugs in an oncology day service. Samples were collected before and after drug handling and analysed with high performance liquid chromatography with diode array detection (HPLC-DAD). Of the 29 samples collected before drug handling 23 were contaminated, five of which with more than one drug. Of the 30 samples collected after drug handling 25 were contaminated, eight of which with more than one drug. The two time points did not significantly differ, which evidences a widespread contamination and ineffective cleaning. This calls for revising the cleaning protocol and handling procedure to place contamination under control as much as possible.

Surface contamination of counting tools after mock dispensing of cyclophosphamide in a simulated outpatient pharmacy

PURPOSE

The primary aim was to determine if dispensing of cyclophosphamide tablets resulted in accumulated residue on pharmacy counting tools during a simulated outpatient dispensing process. Secondary objectives included determining if cyclophosphamide contamination exceeded a defined threshold level of 1 ng/cm² and if a larger number of prescriptions dispensed resulted in increased contamination.

METHODS

Mock prescriptions of 40 cyclophosphamide 50 mg tablets were counted on clean trays in three scenarios using a simulated outpatient pharmacy after assaying five cleaned trays as controls. The three scenarios consisted of five simulated dispensings of one, three, or six prescriptions dispensed per scenario. Wipe samples of trays and spatulas were collected and assayed for all trays, including the five clean trays used as controls. Contamination was defined as an assayed cyclophosphamide level at or above 0.001 ng/cm² and levels above 1 ng/cm² were considered sufficient to cause risk of human uptake. Mean contamination for each scenario was calculated and compared using one-way analysis of variance. P-values of < 0.05 implied significance.

RESULTS

Mean cyclophosphamide contamination on trays used to count one, three, and six cyclophosphamide prescriptions was 0.51 ± 0.10 (p=0.0003), 1.02 ± 0.10 (p < 0.0001), and 1.82 ± 0.10 ng/cm² (p < 0.0001), respectively. Control trays did not show detectable cyclophosphamide contamination. Increasing the number of prescriptions dispensed from 1 to 3, 1 to 6, and 3 to 6 counts increased contamination by 0.51 ± 0.15 (p = 0.0140), 1.31 + 0.15 (p < 0.0001), and 0.80 ± 0.15 ng/cm² (p = 0.0004), respectively.

CONCLUSION

Dispensing one or more prescriptions of 40 cyclophosphamide 50 mg tablets contaminates pharmacy counting tools, and an increased number of prescriptions dispensed correlates with increased level of contamination. Counting out three or more prescriptions leads to trays having contamination that surpasses the threshold at which worker exposure may be increased. Pharmacies should consider devoting a separate tray to cyclophosphamide tablets, as cross-contamination could occur with other drugs and the efficacy of decontamination methods is unclear. Employee exposure could be minimized with the use of personal protective equipment, environmental controls, and cleaning trays between uses. Future investigation should assess the extent of drug powder dispersion, the effects of various cleaning methods, and the potential extent of contamination with different oral cytotoxic drugs.

Genotoxicity assessment of a selected cytostatic drug mixture in human lymphocytes: A study based on concentrations relevant for occupational exposure

Cytostatic drugs are highly cytotoxic agents used in cancer treatment and although their benefit is unquestionable, they have been recognized as hazardous to healthcare professionals in occupational settings. In a working environment, simultaneous exposure to cytostatics may occur creating a higher risk than that of a single substance. Hence, the present study evaluated the combined cyto/genotoxicity of a mixture of selected cytostatics with different mechanisms of action (MoA; 5-fluorouracil, cyclophosphamide and paclitaxel) towards human lymphocytes in vitro at a concentration range relevant for occupational as well as environmental exposure. The results suggest that the selected cytostatic drug mixture is potentially cyto/genotoxic and that it can induce cell and genome damage even at low concentrations. This indicates not only that such mixture may pose a risk to cell and genome integrity, but also that single compound toxicity data are not sufficient for the prediction of toxicity in a complex working environment. The presence of drugs in different amounts and with different MoA suggests the need to study the relationship between the presence of genotoxic components in the mixture and the resulting effects, taking into account the MoA of each component by itself. Therefore, this study provides new data sets necessary for scientifically-based risk assessments of cytostatic drug mixtures in occupational as well as environmental settings.

Meta-analysis of chromosomal aberrations as a biomarker of exposure in healthcare workers occupationally exposed to antineoplastic drugs

Many antineoplastic drugs used to treat cancer, particularly alkylating agents and topoisomerase inhibitors, are known to induce genetic damage in patients. Elevated levels of chromosomal aberrations, micronuclei, and DNA damage have been documented in cancer patients. Elevations in these same biomarkers of genetic damage have been reported in numerous studies of healthcare workers, such as nurses and pharmacists, who routinely handle these drugs, but results vary across studies. To obtain an overall assessment of the exposure effect, we performed a meta-analysis on data obtained from peer-reviewed publications reporting chromosomal aberration levels in healthcare workers exposed to antineoplastic drugs. A literature search identified 39 studies reporting on occupational exposure to antineoplastic drugs and measurement of chromosomal aberrations in healthcare workers. After applying strict inclusion criteria for data quality and presentation, data from 17 studies included in 16 publications underwent meta-analysis using Hedges' bias-corrected g and a random-effects model. Results showed the level of chromosomal aberrations in healthcare workers exposed to antineoplastic drugs was significantly higher than in controls. The standardized mean differences (difference of means divided by within sd) from all studies were pooled, yielding a value 1.006 (unitless) with p<0.001. Thus, in addition to the documented genotoxic effects of antineoplastic drugs in cancer patients, this meta-analysis confirmed a significant association between occupational exposure to antineoplastics during the course of a normal work day and increases in chromosomal aberrations in healthcare workers. Based on the studies reviewed, we were unable to accurately assess whether appropriate use of protective measures might reduce the incidence of genetic damage in healthcare workers. However, given the potential for increased cancer risk linked to increases in chromosomal aberrations, the results of this study support the need to limit occupational exposure of healthcare workers to antineoplastic drugs as much as possible.

Evaluation of the PhaSeal Hazardous Drug Containment System

PhaSeal is a containment system designed to ensure the safe preparation and administration of cytostatic drugs and thus reduce environmental contamination to work areas and to medical and support staff. The PhaSeal system was tested in an outpatient setting in Sweden for 1 year during the preparation and administration of cyclophosphamide, fluorouracil, and similar cytostatic drugs. The study was designed to determine the effectiveness of PhaSeal in preventing the leakage of cytostatic drugs frequently reported in a number of studies. Cytostatic drugs were prepared and administered using standard safety procedures, except that a biological safety cabinet was not used. At the conclusion of the study period, environmental contamination was determined from wiping samples of objects and surfaces in the drug preparation room. Neither cyclophosphamide nor fluorouracil was found in any of these samples. Results show that use of the PhaSeal system alone is sufficient to prevent environmental contamination during the preparation of cytostatic drugs.

A review of surface wipe sampling compared to biologic monitoring for occupational exposure to antineoplastic drugs

The potential for adverse health effects from occupational exposure to antineoplastic drugs (AD) is well known. Control measures recommended by the NIOSH Alert ^[3] include medical and biologic monitoring, and environmental monitoring where available. At present no guidelines or published best practices exist to guide EHS managers on how to carry out this biologic or environmental monitoring. Studies investigating surface wipe sampling for AD have been numerous in the past decade, but very limited research exists to correlate surface contamination with actual absorption by pharmacists and nurses. This article reviews the studies with concurrent surface wipe sampling and urine monitoring for the same AD, and tests their correlation. Methodologic limitations are reviewed. Twenty-one studies were identified that concurrently measured surface contamination by AD by wipe sampling and AD absorption by urine monitoring. Two studies directly evaluated the AD by wipe sampling and urine levels and neither found a statistically significant correlation. Six studies reported a decrease in both surface and urine levels following interventions to reduce contamination or exposure. Only one study directly evaluated the personal protective equipment and handling techniques employed by the studied workers, which can be viewed as a major confounder of absorption. While no statistically significant correlation was found between wipe sampling and urine monitoring for AD, decreases in urine and wipe levels following interventions to reduce exposure were noted. Limitations in the data and recommendations for future research are reviewed.

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.

How to protect environment and employees against cytotoxic agents, the UZ Ghent experience

Objective. To compare two different systems for the reconstitution and preparation of cytotoxic drug-containing infusion bags. The Classical System (open) uses Luer lock syringes and needles, and the PhaSealA System (closed) uses special devices.

Methods. Both wipe samples of the Biological Safety Cabinet (BSC) plus surroundings and urine analysis of technicians and pharmacists involved in the preparatory activities were used. Analyses were performed using gas chromatography in tandem with mass spectroscopy.

Results. An important difference has been found in the surface contamination rate and in the number, periods and values of contaminated urine samples in favour of the closed PhaSealA System. J Oncol Pharm Practice (2001) 6, 146-152.

Occupational exposure to chemotherapy of pharmacy personnel at a single centre

BACKGROUND

Cyclophosphamide is one of the most commonly used chemotherapy drugs worldwide. Data concerning environmental contamination and biological exposure of pharmacy personnel to this and other chemotherapy drugs are limited.

OBJECTIVES

To determine whether pharmacy personnel involved in preparing and checking cyclophosphamide doses were more likely to have detectable levels of this drug in their urine than non-oncology pharmacy personnel with no known contact with the drug, and to compare the degree of surface contamination with cyclophosphamide, methotrexate, and ifosfamide in the oncology pharmacy of a tertiary care pediatric hospital, where chemotherapy doses were prepared, and the main (control) pharmacy in the same institution, where no chemotherapy was prepared.

METHODS

Biological exposure to cyclophosphamide was compared between pharmacy personnel who did and did not handle this drug by determining whether participants had detectable amounts of cyclophosphamide in their urine. Environmental exposure to chemotherapy drugs was assessed by using surface wipes to determine the degree of surface contamination with various chemotherapy agents in the oncology pharmacy and the main (control) pharmacy.

RESULTS

On initial testing, cyclophosphamide was detected in the urine of all pharmacy personnel (n = 7 oncology personnel, n = 5 control personnel). However, it was determined that all control personnel had been exposed to the oncology pharmacy on the day of testing. Repeat testing of these individuals revealed no positive samples among those not exposed to the oncology pharmacy on the day of repeat testing. The sole positive result on retesting of control personnel was for a participant who had been exposed to the oncology pharmacy on the retest day. Surface wipe testing revealed contamination of the oncology pharmacy with cyclophosphamide and methotrexate before and after cleaning, as well as contamination with ifosfamide after cleaning. The main (control) pharmacy showed no evidence of contamination with cyclophosphamide, methotrexate, or ifosfamide.

CONCLUSIONS

The findings suggest that environmental contamination plays a role in biological exposure to cyclophosphamide. Measures to reduce environmental contamination from chemotherapy and biological exposure of pharmacy personnel when handling chemotherapy agents should be identified and implemented as a priority.

Occupational exposure to cyclophosphamide in nurses at a single center

OBJECTIVE

To evaluate biological and environmental exposure to cyclophosphamide in nurses at a single institution.

METHODS

Biological exposure to cyclophosphamide in nurses administering cyclophosphamide compared with two control groups: nononcology nurses not administering cyclophosphamide and community members without recent hospital exposure. Environmental exposure to chemotherapy was measured using surface wipes taken from oncology and nononcology areas in the hospital.

RESULTS

More than one third of all nurses and no community controls tested positive for urinary cyclophosphamide. Oncology and nurse controls tested positive in equal numbers. Surface wipes were positive only in the oncology ward.

CONCLUSION

We have demonstrated elevated levels of cyclophosphamide in one third of all nurses and cyclophosphamide contamination of surfaces within the oncology patient environment. This suggests that environmental contamination plays a major role in biological exposure to cyclophosphamide.

Environmental contamination, product contamination and workers exposure using a robotic system for antineoplastic drug preparation

Environmental contamination, product contamination and technicians exposure were measured following preparation of iv bags with cyclophosphamide using the robotic system CytoCare. Wipe samples were taken inside CytoCare, in the clean room environment, from vials, and prepared iv bags including ports and analysed for contamination with cyclophosphamide. Contamination with cyclophosphamide was also measured in environmental air and on the technicians hands and gloves used for handling the drugs. Exposure of the technicians to cyclophosphamide was measured by analysis of cyclophosphamide in urine. Contamination with cyclophosphamide was mainly observed inside CytoCare, before preparation, after preparation and after daily routine cleaning. Contamination outside CytoCare was incidentally found. All vials with reconstituted cyclophosphamide entering CytoCare were contaminated on the outside but vials with powdered cyclophosphamide were not contaminated on the outside. Contaminated bags entering CytoCare were also contaminated after preparation but non-contaminated bags were not contaminated after preparation. Cyclophosphamide was detected on the ports of all prepared bags. Almost all outer pairs of gloves used for preparation and daily routine cleaning were contaminated with cyclophosphamide. Cyclophosphamide was not found on the inner pairs of gloves and on the hands of the technicians. Cyclophosphamide was not detected in the stationary and personal air samples and in the urine samples of the technicians. CytoCare enables the preparation of cyclophosphamide with low levels of environmental contamination and product contamination and no measurable exposure of the technicians.

Reduction in Surface Contamination With Cyclophosphamide in 30 US Hospital Pharmacies Following Implementation of a Closed-System Drug Transfer Device

PURPOSE

In a follow-up to a previous study, surface contamination with the antineoplastic drug cyclophosphamide was compared in 30 US hospital pharmacies from 2004 to 2010 following preparation with standard drug preparation techniques or the PhaSeal closed system drug transfer device (CSTD).

METHODS

Wipe samples were taken from biological safety cabinet (BSC) surfaces, BSC airfoils (the front leading edge of the BSC), floors in front of BSCs, and countertops in the pharmacy, and they were analyzed for contamination with cyclophosphamide. Contamination was reassessed after a minimum of 6 months following the implementation of the CSTD. Surface contamination (ng/cm(2)) was compared between the 2 techniques and between the previous and current test periods and evaluated with the Kruskal-Wallis test.

RESULTS

With the use of CSTD compared to the standard preparation techniques, a significant reduction in levels of contamination with cyclophosphamide was observed (P < .0001). Median values for surface contamination with cyclophosphamide were reduced by 86% compared to 95% in the previous study.

CONCLUSIONS

The CSTD significantly reduced, but did not totally eliminate, surface contamination with cyclophosphamide. In addition to other protective measures, increased usage of CSTDs should be employed to help protect health care workers from exposure to hazardous drugs.

Non-invasive quantification of 5 fluorouracil and gemcitabine in aqueous matrix by direct measurement through glass vials using near-infrared spectroscopy

Fourier transform near infrared spectroscopy (NIRS) was used for quantitative analysis of two cytotoxic drugs used in pharmaceutical infusion, 5-fluorouracil (5FU) and gemcitabine (GEM), at therapeutic concentrations in aqueous matrix. Spectra were collected from 4000 cm(-1) to 13,000 cm(-1) by direct measurement through standard glass vials and calibration models were developed for 5FU and GEM using partial least-squares regression. NIR determination coefficient (R(2)) greater than 0.9992, root-mean-square-error of cross-validation (RMESCV) of 0.483 mg/ml for 5FU and 0.139 mg/ml for GEM and the root mean square error of prediction (RMSEP) of 0.519 for 5FU and 0.108 mg/ml for GEM show a good prediction ability of NIR spectroscopy to predict 5FU and GEM concentrations directly through a glass packaging. According to accuracy profile, the linearity was validated from 7 to 50mg/ml and 2 to 40 mg/ml for 5-fluorouracil and gemcitabine respectively. This new approach for cytotoxic drugs control at hospital has shown the feasibility of near infrared spectroscopy to quantify antineoplastic drugs in aqueous matrix by a direct measurement through glass vial in less than 1 min and by non-invasive measurement perfect to limit exposure of operator to cytotoxic drugs.

Exposure of family members to antineoplastic drugs via excreta of treated cancer patients

Purposes:

(a) To measure the urinary excretion of antineoplastic drugs of three patients during 48 h after the administration of cyclophosphamide (two patients) and 5-fluorouracil (one patient). (b) To evaluate environmental contamination with antineoplastic drugs via excreta of patients in the home setting. (c) To evaluate exposure of family members to antineoplastic drugs by measuring the drugs in their urine during the 48 h after completion of the chemotherapy by the patients.

Methods:

Two patients were administered cyclophosphamide by i.v. bolus injection. One patient was administered 5-fluorouracil by i.v. bolus injection and thereafter immediately administered the same drug by continuous infusion for 46 h. Urine samples from the patients administered cyclophosphamide and their family members, and wipe samples from their home environment, were analysed for the unchanged form of cyclophosphamide. For 5-fluorouracil, the urine samples from the patient and the family member were analysed for the 5-fluorouracil metabolite α-fluoro-β-alanine. Wipe samples were analysed for 5-fluorouracil. Drugs were detected and quantified with gas chromatography in tandem with mass spectroscopy-mass spectroscopy or by high-performance liquid chromatography with ultraviolet-light detection.

Results:

A total of 35 and 16 urine samples were collected from the three patients and their family members, respectively. The drugs were detected in all samples. Cyclophosphamide was detected at levels of 0.03–7.34 ng/cm2 in 8 of the 12 wipe samples obtained from the homes of the patients administered cyclophosphamide. For the patient administered 5-fluorouracil, drug levels in his home environment were below the limit of detection.

Conclusion:

We demonstrated contamination of the home setting and exposure of family members to cyclophosphamide via the excreta of outpatient receiving chemotherapy. Exposure of the family member of the patient administered 5-fluorouracil was also demonstrated. These findings indicate the importance of strict precautions by the members of treated cancer patients as well as healthcare workers, to reduce the risk of exposure to antineoplastic drugs.

A study protocol for the evaluation of occupational mutagenic/carcinogenic risks in subjects exposed to antineoplastic drugs: a multicentric project

Background

Some industrial hygiene studies have assessed occupational exposure to antineoplastic drugs; other epidemiological investigations have detected various toxicological effects in exposure groups labeled with the job title. In no research has the same population been studied both environmentally and epidemiologically. The protocol of the epidemiological study presented here uses an integrated environmental and biological monitoring approach. The aim is to assess in hospital nurses preparing and/or administering therapy to cancer patients the current level of occupational exposure to antineoplastic drugs, DNA and chromosome damage as cancer predictive effects, and the association between the two.

Methods/Design

About 80 healthy non-smoking female nurses, who job it is to prepare or handle antineoplastic drugs, and a reference group of about 80 healthy non-smoking female nurses not occupationally exposed to chemicals will be examined simultaneously in a cross-sectional study. All the workers will be recruited from five hospitals in northern and central Italy after their informed consent has been obtained.

Evaluation of surface contamination and dermal exposure to antineoplastic drugs will be assessed by determining cyclophosphamide on selected surfaces (wipes) and on the exposed nurses' clothes (pads). The concentration of unmetabolized cyclophosphamide as a biomarker of internal dose will be measured in end-shift urine samples from exposed nurses.

Biomarkers of effect and susceptibility will be assessed in exposed and unexposed nurses: urinary concentration of 8-hydroxy-2-deoxyguanosine; DNA damage detected using the single-cell microgel electrophoresis (comet) assay in peripheral white blood cells; micronuclei and chromosome aberrations in peripheral blood lymphocytes. Genetic polymorphisms for enzymes involved in metabolic detoxification (i.e. glutathione S-transferases) will also be analysed.

Using standardized questionnaires, occupational exposure will be determined in exposed nurses only, whereas potential confounders (medicine consumption, lifestyle habits, diet and other non-occupational exposures) will be assessed in both groups of hospital workers.

Statistical analysis will be performed to ascertain the association between occupational exposure to antineoplastic drugs and biomarkers of DNA and chromosome damage, after taking into account the effects of individual genetic susceptibility, and the presence of confounding exposures.

Discussion

The findings of the study will be useful in updating prevention procedures for handling antineoplastic drugs.

Multicenter study for environmental and biological monitoring of occupational exposure to cyclophosphamide in Japan

Purpose. A multicenter field survey of environmental contamination and exposure of healthcare professionals to anticancer drugs were performed.

Setting. Three university hospitals, one cancer specialty hospital and two corporate hospitals from across Japan.

Method. The environmental contamination with cyclophosphamide (CP) was investigated. A wipe examination was performed at six sites apiece in two divisions. The urinary excretion of the CP over 24 h was determined. The subjects of the survey included physicians, pharmacists, and nurses, for a total of seven at each facility irrespective of job title. The wipe samples were collected at 12 sites within two divisions at each facility. For the exposure survey, the total urine volume was determined, and a portion of the urine sample was then collected from each participants at each facility. Urine was collected for 24 h. The samples were determined by using the GC-MS method.

Results. Wipe examination: contamination with CP was identified at 50% of the sites. The concentration was high (CP > 1.00 ng/cm2) in the general environment in two hospitals and in the safety cabinet in one hospital. In the survey for the exposure of staff to anticancer drugs, 276 samples were obtained from 41 healthcare professionals. CP was detected in 90 samples obtained from 23 subjects. The amount of exposure was greatly different among the facilities. The urinary excretion of CP per subject was between 2.7 and 462.8 ng/24 h. The range of urinary excretion for each hospital was between 4.6 and 211.2 ng/24 h.

Antineoplastic Drugs as a Potential Risk Factor in Occupational Settings: Mechanisms of Action at the Cell Level, Genotoxic Effects, and Their Detection Using Different Biomarkers

U članku je prikazana osnovna podjela antineoplastičnih lijekova prema mehanizmima djelovanja na razini stanice. Objašnjeni su mehanizmi genotoksičnosti najvažnijih vrsta lijekova koji se primjenjuju u okviru uobičajenih protokola za liječenje zloćudnih novotvorina. Navedena je važeća klasifikacija antineoplastika prema kancerogenom potencijalu, podaci o mutagenom potencijalu te je prikazana njihova podjela u skladu s anatomsko-terapijsko-kemijskim sustavom klasifikacije. Sustavno su prikazani najvažniji rezultati svjetskih i hrvatskih istraživanja na populacijama radnika izloženih antineoplasticima, provedenih u razdoblju 1980.-2009. s pomoću četiri najčešće primjenjivane metode: analize izmjena sestrinskih kromatida, analize kromosomskih aberacija, mikronukleus-testa i komet-testa. Objašnjena su osnovna načela navedenih metoda te raspravljene njihove prednosti i nedostaci. Biološki pokazatelji daju važne podatke o individualnoj osjetljivosti profesionalno izloženih ispitanika koji mogu poslužiti unaprjeđenju postojećih uvjeta rada i upravljanju rizicima pri izloženosti genotoksičnim agensima. Na osnovi prednosti i nedostataka citogenetičkih metoda zaključeno je da je mikronukleus-test, koji podjednako uspješno dokazuje klastogene i aneugene učinke, jedna od najboljih metoda dostupnih za otkrivanje štetnih djelovanja antineoplastičnih lijekova koji su u aktivnoj primjeni.

Reduction in surface contamination with antineoplastic drugs in 22 hospital pharmacies in the US following implementation of a closed-system drug transfer device

PURPOSE

Surface contamination with the antineoplastic drugs cyclophosphamide, ifosfamide, and 5-fluorouracil was compared in 22 US hospital pharmacies following preparation with standard drug preparation techniques or the PhaSeal® closed-system drug transfer device (CSTD).

METHODS

Wipe samples were taken from biological safety cabinet (BSC) surfaces, BSC airfoils, floors in front of BSCs, and counters and analyzed for contamination with cyclophosphamide, ifosfamide, and 5-fluorouracil. Contamination was reassessed several months after the implementation of the CSTD. Surface contamination (ng/cm(2)) was compared between the two techniques and evaluated with the Signed Rank Test.

RESULTS

Using the CSTD compared to the standard preparation techniques, a significant reduction in levels of contamination was observed for all drugs (cyclophosphamide: p < 0.0001; ifosfamide: p < 0.001; 5-fluorouracil: p < 0.01). Median values for surface contamination with cyclophosphamide, ifosfamide, and 5-fluorouracil were reduced by 95%, 90%, and 65%, respectively.

CONCLUSIONS

Use of the CSTD significantly reduces surface contamination when preparing cyclophosphamide, ifosfamide, and 5-fluorouracil as compared to standard drug preparation techniques.

Cytotoxic drug residues in urine of dogs receiving anticancer chemotherapy

BACKGROUND

The presence of cytotoxic drug residues in urine of dogs may represent an exposure risk for pet owners and other people as well as a potential environmental contaminant. However, studies on cytotoxic drug residues in excretions of clinical patients are lacking in veterinary oncology.

HYPOTHESIS

Variable concentrations of cytotoxic residues are present in urine samples, depending on sampling time and substance.

ANIMALS

Client-owned dogs with lymphoma or mast cell tumors treated with standard chemotherapy protocols.

METHODS

Urine samples were collected before, directly after, and on days after administration of chemotherapy. Measurement of vincristine, vinblastine, cyclophosphamide, and doxorubicin residues in canine urine was performed by a quantitative liquid chromatography tandem mass spectrometry (LC/MS/MS) method.

RESULTS

Median cyclophosphamide residue concentration was 398.2 microg/L directly after treatment (d0) and was below the level of detection on days 1-3 (d1, d2, d3). Median vincristine residue concentration was 53.8 microg/L directly after treatment and was 20.2, 11.4, and 6.6 microg/L on days 1, 2, and 3. Median vinblastine residues were 144.9 (d0), 70.8 (d1), 35.6 (d2), and 18.7 microg/L (d3) with low concentrations detectable for 7 days after treatment. Median urine doxorubicin concentrations were 354.0 (d0), 165.6 (d1), 156.9 (d2), and 158.2 microg/L (d3). Low concentrations of doxorubicin were measurable up to 21 days after administration.

CONCLUSIONS AND CLINICAL IMPORTANCE

Variable concentrations of chemotherapeutics were measured in urine samples, depending on sampling time point and drug. Findings may inform current chemoprotection guidelines and help minimize exposure risks.

Occupational exposure to antineoplastic agents induces a high level of chromosome damage. Lack of an effect of GST polymorphisms

The aim of our study was to investigate whether occupational exposure to antineoplastic drugs (AND) resulted in genetic damage, possibly indicative of adverse health effects in the long term. We performed a chromosomal aberrations (CA) analysis in peripheral blood lymphocytes (PBL) of a group of 76 trained nurses occupationally exposed to AND. Furthermore, we analysed whether genetic polymorphisms in four metabolic genes of the glutathione S-transferase (GST) family involved in antineoplastic drugs detoxification (GSTM1, GSTT1, GSTP1, GSTA1) had any effect on the yield of chromosomal aberrations in nurses exposed to antineoplastic agents. The exposed group showed a very significant increase of genetic damage (p<0.0001) potentially indicative of an increased risk of cancer. Unexpectedly, besides the elevated level of chromatid-type aberrations usually related to exposure to chemical agents, we found also severe chromosome damages such as chromosome deletions and dicentric chromosomes, usually related to radiation exposure. No significant association was detected between all GSTs genotypes and chromosome damage. In conclusion, our data show how the occupational exposure to AND is associated to a potential cancer risk, suggesting that current prevention methods do not completely eliminate opportunities for exposure and supporting the need to improve the actual safety practices.

Inhalation and dermal exposure to eight antineoplastic drugs in an industrial laundry facility

OBJECTIVES

The aims of the study were to quantify levels of dermal and inhalation exposure to antineoplastic drugs in an industrial laundry service in the Netherlands and to test the removal efficiency of the washing procedure for removal of antineoplastic drugs.

METHODS

During four workdays dermal and inhalation exposure to eight frequently used antineoplastic drugs (cyclophosphamide, ifosfamide, methotrexate, 5-fluorouracil, etoposide, cytarabine, gemcitabine and chlorambucil) were measured for all job titles involved in handling unwashed laundry. To test the removal efficiency of the washing procedure, 10 x 10 cm sections were excised before and after the washing procedure. These sections were taken from 15 bed sheets that were collected in hospitals of patients who were treated with one of the selected antineoplastic drugs.

RESULTS

During none of the four measurement days, detectable levels of any of the eight antineoplastic drugs (cyclophosphamide, ifosfamide, methotrexate, 5-fluorouracil, etoposide, cytarabine, gemcitabine, or chlorambucil) were found on workers' skin of hands or in any of the air samples. Only four out of the 15 bed sheets from patients that were treated with antineoplastic drugs appeared to be contaminated with detectable levels of antineoplastic drugs before the washing procedure (range 13.0-3,060 ng/100 cm(2)). After the pre-washing and after the complete washing procedure, no detectable levels of any of the eight antineoplastic drugs were found anymore in the selected bed sheets.

CONCLUSIONS

The implementation of guidelines for working with antineoplastic drugs seems to be successful in reducing exposure to antineoplastic drugs of workers in this laundry facility to an acceptable, non-detectable level and to remove antineoplastic drug contamination from bed linen.

Organizational safety culture/climate and worker compliance with hazardous drug guidelines: lessons from the blood-borne pathogen experience

BACKGROUND

The health risks posed to health care workers (HCW) handling antineoplastic and other hazardous drugs (HDs) are well established. However, despite nearly 20 years of professional practice standards, compliance with safe handling procedures is poor.

METHOD

We present documentation of undercompliance with recommended safety procedures for HDs. Then, we examine a similar problem, HCW compliance with blood-borne pathogen universal precautions (UP) and its partial solution tied to the strength of a facility's safety culture. Lessons learned here may be applicable to the HD issue.

RESULTS

It is proposed that analyzing a facility's safety culture may enlarge our understanding of the barriers contributing to HD under-compliance and suggest strategies to improve it.

CONCLUSION

The Safety Culture paradigm offers many targets for intervention to enhance and promote worker compliance with safe HD handling practices thus mitigating internal exposure.

Investigating genetic damage in workers occupationally exposed to methotrexate using three genetic end-points

Genetic damage in workers occupationally exposed to an antineoplastic drug was studied using the micronucleus (MN) test, the comet assay, the hprt gene mutation assay and the TCR gene mutation assay. The subjects were divided into two groups: (i) 21 workers from a plant producing methotrexate (MTX); (ii) 21 controls were matched according to age, gender and smoking. Fresh blood samples were collected from the workers and controls. The results of the MN test showed that the mean micronuclei rate (MNR) and mean micronucleated cell rate (MCR) in workers were 10.10 +/- 0.95 per thousand and 8.05 +/- 0.75 per thousand, respectively, which were significantly higher than those (5.48 +/- 0.82 per thousand and 4.38 +/- 0.58 per thousand) in controls (P < 0.01). It was found in the comet assay that the mean tail length (MTL) of workers and controls were 1.30 +/- 0.06 microm and 0.07 +/- 0.01 microm, respectively. There was a significant difference between workers and controls for MTL (P < 0.01), but the difference between the mean tail moment (MTM, 0.23 +/- 0.03) of workers and MTM (0.17 +/- 0.04) of controls was not significant (P > 0.05). The results of hprt gene mutation assay showed that the average mutation frequency (Mf-hprt) of hprt in workers was 1.00 +/- 0.02 per thousand, which was significantly higher than that (0.86 +/- 0.01 per thousand) in controls (P < 0.01). Meanwhile, the results of TCR gene mutation assay indicated that Mfs-TCR gene mutation frequencies of workers and controls were 6.87 +/- 0.52 x 10(-4) and 1.67 +/- 0.14 x 10(-4), respectively, which were significantly different (P < 0.01). The results of our experiment suggest that genetic damage is detectable in the 21 workers occupationally exposed to methotrexate.

Surface contamination of chemotherapy drug vials and evaluation of new vial-cleaning techniques: results of three studies

PURPOSE

The results of three studies that describe the external contamination of chemotherapy drug vials are presented. New techniques for the improved decontamination of vials containing cisplatin are also described.

SUMMARY

Study 1 evaluated the external contamination of drug vials with cyclophosphamide and ifosfamide in a pharmacy setting. Widespread contamination of the outside of drug vials was found with each drug. Study 2 evaluated the surface contamination of drug vials with cyclophosphamide and fluorouracil in three pharmacies. Sporadic contamination with fluorouracil was detected, while cyclophosphamide was found on most vials. In study 3, investigators compared the decontamination abilities of a standard decontamination procedure at the manufacturer level with an improved decontamination procedure and the use of sleeves to further decrease contamination. Though the methods of each study reported herein differed, the outcomes were similar. All chemotherapy drug vials studied demonstrated levels of contamination with the drug well above the limit of detection. Improved decontamination procedures, combined with the use of protective sleeves, reduced the level of platinum contamination by 90%, suggesting that standard decontamination procedures should be reconsidered.

CONCLUSION

The results of these studies are consistent with several others that have reported contamination of the outside surface of drug vials for a number of chemotherapy drugs. Contamination can be reduced by using decontamination equipment and protective sleeves during the manufacturing process.

Dermal exposure to cyclophosphamide in hospitals during preparation, nursing and cleaning activities

OBJECTIVES

To determine levels of potential and actual dermal exposure to cyclophosphamide (CP) during performance of oncology-related tasks in hospitals and to investigate the relationship with potential sources and surface contamination levels of CP.

METHODS

Dermal exposure to CP was determined for tasks with potential exposure to CP: preparation of CP, decanting of patients' urine, washing of the patient, removal of bed sheets of treated patients and cleaning of patients' toilets on oncology wards. Exposure was assessed by the collection of nitrile and latex protective medical gloves (potential exposure), washing of hands (actual exposure), from cotton pads attached to (un)covered forearms (potential or actual exposure) and a wipe sample of the forehead (actual exposure). Bulk samples (i.e. application fluids and patients' excreta) and possible contact surfaces were monitored to assess the amount of CP available for dermal exposure.

RESULTS

Pharmacy technicians, oncology nurses and cleaning personnel showed actual and potential dermal exposure to CP during performance of their daily duties. Exposure occurred predominantly on the hands and sporadically on the forehead and forearms. Although all nurses used gloves during handling of patients' urine and sometimes during the other nursing tasks, skin underneath gloves was repeatedly contaminated. Results of tests on bulk and surface contamination samples confirmed that patients intravenously treated with CP excrete the unmetabolised drug, which could subsequently lead to dermal exposure of hospital personnel. A clear relationship was found between dermal exposure levels and direct sources of exposure for all tasks, except for handling patients' urine.

CONCLUSIONS

We demonstrated for the first time that actual dermal exposure to CP is common among oncology nurses working with patients treated with this anti-neoplastic drug. Pharmacy technicians and cleaning personnel, on the other hand, are potentially exposed to CP, and protection provided by gloves seemed to be sufficient.

Highly sensitive high-performance liquid chromatography/selective reaction monitoring mass spectrometry method for the determination of cyclophosphamide and ifosfamide in urine of health care workers exposed to antineoplastic agents

In recent years, the potential for exposure of health care workers to antineoplastic agents has led to the establishment of more restrictive government and professional standards and procedures for handling cytotoxic drugs. Therefore, the detection of low exposure levels is a new and important aim of biological monitoring. In the present paper we report an assay for the simultaneous determination of cyclophosphamide (CP) and ifosfamide (IF) in urine, using electrospray ionization liquid chromatography/tandem mass spectrometry with selective reaction monitoring (HPLC/SRM-MS). A rapid sample preparation procedure uses a solid-phase extraction stage with C18 columns. The urine assay is linear over the range 0.02 to 0.4 microg/L, with lower limits of quantification (LLOQs) of 0.02 and 0.04 microg/L for CP and IF. The accuracy and precision have been carried out through the validation study. The intra-day precision, expressed as relative standard deviation (RSD), is found to be always less than 14.7% for both analytes. The overall precision, assessed on three different days, is less than 15.0%. The recovery of ozaxaphosphorines ranges from 83.5% (CP) to 88.5% (IF) with a RSD always less than 14.6%. The uncertainty of the overall method was also evaluated, to identify possible sources of error. The combined uncertainty was less than 25% over all the days of the validation study. This method is selective and sensitive enough to determine trace levels of CP and IF in a range of urine concentrations relevant to performing low exposure assessment.

Osteryoung square wave stripping voltammetry at mercury film electrode for monitoring ultra trace levels of Tarabine PFS and its interaction with ssDNA

The electrochemical oxidation and reduction behaviour of adsorbed species of antimetabolic antineoplastic agent Tarabine PFS (Cytosar-U) in Sorensen buffer solution of different pH values at an in situ-mercury film electrode (MFE) is studied using cyclic voltammetry (CV) and Osteryoung square-wave stripping voltammetry (OSWSV). Optimal experimental and operational parameters have been selected for the drug preconcentration and determination in aqueous medium. Based on the adsorption and accumulation of Tarabine PFS using Osteryoung square-wave anodic stripping voltammetry (OSWASV) at MFE, the drug is easily detected as 0.134 ng/ml (5.51 x 10(-10) M). Calibration plots have been constructed at different accumulation times. The standard deviation (n=10) at a concentration level of 6 x 10(-8) M Tarabine PFS is 0.062. The interaction of ssDNA with the drug under the optimal conditions at pH 7.7 has been studied. The formal potentials E degrees and E degrees ' and the equilibrium constants K(1) and K(2) have been calculated for the free form of Tarabine PFS and the bonded form with ssDNA, respectively. It was found that K(2) value for the bonded oxidized form is 298 times than that of K(1) for the bonded reduced form. Therefore, ssDNA has been found to interact strongly with the oxidized form of the drug. The method has been used for the nanogram determination of ssDNA with 1.9% variation coefficient. Detection limit of 3 ng/ml ssDNA has been achieved. Possible interfering organic compounds, cations and anions have been tested. The method has been applied for the drug determination in urine samples, down to 0.23 ng/ml could be easily achieved in such samples.

Biological and environmental monitoring of hospital personnel exposed to antineoplastic agents: a review of analytical methods

In order to assess occupational exposure of hospital personnel involved in the preparation and administration of antineoplastic drugs, biological and environmental monitoring are essential to identify the main exposure routes and to quantify potential health risks. If workplace contamination cannot be completely avoided, it is of utmost importance to reduce exposure to the lowest possible levels. To this aim, not only do education and training of the exposed subjects play an important role, but accurate standardized sampling techniques and analytical methods are also required. A critical overview of the most significant methods available in the literature is presented and their value is discussed, especially with respect to their sensitivity and specificity. In addition, attention is given to validation procedures and, consequently, to their reliability. The results from the most important surveys carried out at hospital departments are also discussed, with a view to improving both monitoring strategies and moreover working conditions.

Exposure to anti-cancer drugs during preparation and administration. Investigations of an open and a closed system

Systems for the preparation and administration of drugs are designed to ensure that the drug is not contaminated. They do not necessarily consider the work environment for the medical staff and new techniques are therefore desirable. The aim of this work is to compare a new closed system for the preparation and administration of drugs with the traditional technique with regard to airborne emission and surface spillage of drugs. Platinum, determined using adsorptive voltammetry, was used as the tracer for airborne emission. Air samples were collected during the preparation and administration, and the collected platinum on the filters was determined by adsorptive voltammetry. For determination of spills and leakage onto surfaces the radioisotope 99m-technetium was used as a tracer. The radiation from the isotope was determined on protective gloves and bench covers after preparation and administration. The mean airborne emission was 6 ng m(-3) with the closed system and 15 ng m(-3) with the traditional pump technique. The average surface spillage using the closed technique was 0.005 microL. This is significantly smaller than with the traditional technique, which resulted in an average spillage of 64 microL. Our results also show that the dominant part of the leakage is surface spillage. Inexperienced nurses could also adequately handle the closed system.

Assessment of genotoxic damage in nurses occupationally exposed to antineoplastics by the analysis of chromosomal aberrations

To estimate the genotoxic risk of occupational exposure to antineoplastic drugs, chromosomal aberration (CAs) frequencies in peripheral lymphocytes were determined for 20 nurses handling antineoplastics and 18 referents matched for age and sex. Urinary cyclophosphamide (CP) excretion rates, which are used as a marker for drug handling, were also measured on these nurses. We have observed significant frequencies of CAs (about 2.5-fold increase) including chromatid breaks, gaps, and acentric fragments for nurses handling antineoplastics as compared to control subjects (p < 0.05, p < 0.01, excluding and including gaps, respectively). The mean value of CP excretion rate for 12 nurses was 1.63 microg/24 h, suggesting that when the nurses handled CP (and other antineoplastic drugs) this particular compound was absorbed. Our study has shown that increased genetic damage was evident in nurses, at population level, due to occupational exposure to antineoplastics. Until the effects of handling antineoplastics from low-level exposure are known, it will be important to keep the exposure to a minimum.

The genotoxic risk of hospital, pharmacy and medical personnel occupationally exposed to cytostatic drugs--evaluation by the micronucleus assay

The aim of this study was to evaluate the genotoxicity of cytostatic drugs in hospital and pharmacy employees (n=100), occupationally exposed. The micronucleus assay was used to study lymphocytes in 247 peripheral blood samples. Samples were collected at "baseline level" without any cytostatic drugs exposure before recruiting or after at least 3 weeks without cytostatic drugs contact and at three times (cycle 1-3) post-exposure. Samples from 60 office employees served as controls. Furthermore, our results were compared to urinary analyses of cytostatic drugs (oxazaphosporines, anthracyclines, platinum) which were collected in parallel to the cytogenetic investigation. Statistical analyses were performed under consideration of age, gender and X-ray exposure. The frequency of micronuclei was significantly related to the age of the subjects (r(Spearman)=0.16; P<0.05). However, there were no significant differences in micronucleus rates between controls and exposed hospital workers. Similarly, micronucleus rates were not significantly different at the various sampling time points and there was no correlation between duration of employment and micronucleus rates. Furthermore, no correlation between current biomonitoring data of exposure (urine tests) and micronuclei frequency was found. Therefore, significantly increased genotoxic damage of the lymphocytes investigated in this study could not be demonstrated.

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.

Assessment of DNA damage in nurses handling antineoplastic drugs by the alkaline COMET assay

The widespread use of chemotherapy in the treatment of cancer has led to anxiety about the possible hazards to staff involved in the preparation and administration of cytotoxic agents. Careless handling of antineoplastic drugs may lead to exposure in detectable amounts by means of chemical or biological methods in the body fluids or cell samples but the information about the mutagenic effects of these agents on nurses is limited and inconsistent. DNA damage in peripheral lymphocytes of 30 professional nurses employed in the oncology departments for at least 6 months were examined by the alkaline single cell gel electrophoresis, 'COMET' technique. The results were compared to that of 30 controls with comparable age, sex and smoking habits, not practising in the chemotherapy services. Work characteristics of the exposed nurses and the use of personal protective equipment were also investigated. The DNA damage observed in the lymphocytes of the nurses was significantly higher than the controls (p<0.001). The observed DNA damage was found to be significantly lower (p<0.001) in nurses applying the necessary individual safety protections during their work. Cigarette smoking was not related to increases in DNA damage, also a significant association was not found between the duration of occupational exposure to antineoplastic drugs and the DNA damage.

Urinary cyclophosphamide excretion and micronuclei frequencies in peripheral lymphocytes and in exfoliated buccal epithelial cells of nurses handling antineoplastics

In this study, urinary cyclophosphamide (CP) excretion rate, as well as micronuclei (MN) in peripheral lymphocytes and in buccal epithelial cells were determined for 26 nurses handling antineoplastics and 14 referents matched for age and sex. In urine samples of 20 out of 25 exposed nurses CP excretion rate was found in a range of 0.02-9.14 microg CP/24 h. Our results of the analyses of CP in urine demonstrates that when the nurses were handling CP (and other antineoplastic drugs) this particular compound was observed in urine. The mean values (+/-SD) of MN frequencies (%) in peripheral lymphocytes from the nurses and controls were 0.61 (+/-0. 32) and 0.28 (+/-0.16), respectively (p<0.01). The mean value (+/-SD) of MN frequency (%) in buccal epithelial cells of nurses was 0.16 (+/-0.19) and also mean MN frequency in buccal epithelial cells for controls was found to be as 0.08 (+/-0.08), (p>0.05). Age, sex and smoking habits have not influenced the parameters analyzed in this study. Handling time of antineoplastics, use of protective equipment and handling frequency of drugs have no effect on urinary and cytogenetic parameters analyzed. No correlation was found between the urinary CP excretion and the cytogenetic findings in nurses. Neither could we find any relationship between two cytogenetic endpoints. Our results have identified the possible genotoxic damage of oncology nurses related to occupational exposure to at least one antineoplastic agent, which is used as a marker for drug handling. As a whole, there is concern that the present handling practices of antineoplastic drugs used in the several hospitals in Ankara will not be sufficient to prevent exposure.

Biological effect markers for exposure to carcinogenic compound and their relevance for risk assessment

In this review data are summarized on biomarkers that are used for biological effect monitoring of human populations exposed to genotoxic carcinogens. The biomarkers are DNA and protein adducts and cytogenetic effects. Most of these biomarkers are relevant for the process of carcinogenesis. Emphasis is on providing information on the properties of the biomarkers and on their relevance for predicting cancer risk. Overviews are presented of: (1) studies on effects of exposure in target tissues of human origin obtained by surgical biopsies or autopsies, (2) epidemiological studies on healthy (cancer-free) individuals, correlating the putative occupational, lifestyle or environmental exposure with increased levels of biomarkers in blood cells, and (3) studies with animal models on the relation between biomarkers and cancer. Finally, on the basis of epidemiological data the possibilities were explored to use biomarker data to estimate the risk of death due to cancer. For several biomarkers the increment of the cancer mortality risk was calculated on the basis of a lifetime doubling of the biomarker level.