ABSTRACT
INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has caused extensive disruption of public health worldwide. There were reports of COVID-19 patients having multiple complications. This study investigated COVID-19 from a genetic perspective. METHODS: We conducted RNA sequencing (RNA-Seq) analysis of respiratory tract samples from 24 patients with COVID-19. Eight patients receiving mechanical ventilation or extracorporeal membrane oxygenation were regarded as severe cases; the remaining 16 patients were regarded as non-severe cases. After quality control, statistical analyses were performed by logistic regression and the Kolmogorov-Smirnov test to identify genes associated with disease severity. RESULTS: Six genes were associated with COVID-19 severity in both statistical tests, namely RPL15, BACE1-AS, CEPT1, EIF4G1, TMEM91, and TBCK. Among these genes, RPL15 and EIF4G1 played roles in the regulation of mRNA translation. Gene ontology analysis showed that the differentially expressed genes were mainly involved in nervous system diseases. CONCLUSION: RNA sequencing analysis showed that severe acute respiratory syndrome coronavirus 2 infection is associated with the overexpression of genes involved in nervous system disorders.
Subject(s)
COVID-19 , Humans , COVID-19/genetics , Amyloid Precursor Protein Secretases , SARS-CoV-2/genetics , Hong Kong/epidemiology , Aspartic Acid Endopeptidases , Sequence Analysis, RNAABSTRACT
BACKGROUND: Early-stage nasopharyngeal carcinoma (NPC) evades detection when the primary tumor is hidden from view on endoscopic examination. Therefore, in a prospective study of subjects being screened for NPC using plasma Epstein-Barr virus (EBV) DNA, we conducted a study to investigate whether magnetic resonance imaging (MRI) could detect endoscopically occult NPC. PATIENTS AND METHODS: Participants with persistently positive EBV DNA underwent endoscopic examination and biopsy when suspicious for NPC, followed by MRI blinded to the endoscopic findings. Participants with a negative endoscopic examination and positive MRI were recalled for biopsy or surveillance. Diagnostic performance was assessed by calculating sensitivity, specificity and accuracy, based on the histologic confirmation of NPC in the initial study or in a follow-up period of at least two years. RESULTS: Endoscopic examination and MRI were performed on 275 participants, 34 had NPC, 2 had other cancers and 239 without cancer were followed-up for a median of 36 months (24-60 months). Sensitivity, specificity and accuracy were 76.5%, 97.5% and 94.9%, respectively, for endoscopic examination and 91.2%, 97.5% and 96.7%, respectively, for MRI. NPC was detected only by endoscopic examination in 1/34 (2.9%) participants (a participant with stage I disease), and only by MRI in 6/34 (17.6%) participants (stage I = 4, II = 1, III = 1), two of whom had stage I disease and follow-up showing slow growth on MRI but no change on endoscopic examination for 36 months. CONCLUSION: MRI has a complementary role to play in NPC detection and can enable the earlier detection of endoscopically occult NPC.
Subject(s)
Epstein-Barr Virus Infections/diagnosis , Nasopharyngeal Carcinoma/diagnosis , Nasopharyngeal Neoplasms/diagnosis , Adult , DNA, Viral/blood , DNA, Viral/genetics , Early Detection of Cancer/methods , Endoscopy/methods , Epstein-Barr Virus Infections/blood , Epstein-Barr Virus Infections/pathology , Epstein-Barr Virus Infections/virology , Follow-Up Studies , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/isolation & purification , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Carcinoma/surgery , Nasopharyngeal Carcinoma/virology , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/surgery , Nasopharyngeal Neoplasms/virology , Prognosis , Prospective Studies , Viral LoadABSTRACT
Three epidemic waves of human influenza A(H7N9) were documented in several different provinces in China between 2013 and 2015. With limited understanding of the potential for human-to-human transmission, it was difficult to implement control measures efficiently or to inform the public adequately about the application of interventions. In this study, the human-to-human transmission rate for the epidemics that occurred between 2013 and 2015 in Zhejiang Province, China, was analysed. The reproduction number (R), a key indicator of transmission intensity, was estimated by fitting the number of infections from poultry to humans and from humans to humans into a mathematical model. The posterior mean R for human-to-human transmission was estimated to be 0·27, with a 95% credible interval of 0·14-0·44 for the first wave, whereas the posterior mean Rs decreased to 0·15 in the second and third waves. Overall, these estimates indicate that a human H7N9 pandemic is unlikely to occur in Zhejiang. The reductions in the viral transmissibility and the number of poultry-transmitted infections after the first epidemic may be attributable to the various intervention measures taken, including changes in the extent of closures of live poultry markets.
Subject(s)
Disease Transmission, Infectious , Epidemics , Influenza A Virus, H7N9 Subtype/isolation & purification , Influenza, Human/transmission , Influenza, Human/virology , Basic Reproduction Number , China/epidemiology , Humans , Influenza, Human/epidemiology , Models, TheoreticalABSTRACT
BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis. We performed an individual patient data meta-analysis to study whether magnesium is effective when given within different time frames within 24 hours after the SAH. METHODS: Patients were divided into categories according to the delay between symptom onset and start of the study medication: <6, 6 to 12, 12 to 24, and >24 hours. We calculated adjusted risk ratios with corresponding 95% confidence intervals for magnesium versus placebo treatment for poor outcome and DCI. RESULTS: We included 5 trials totaling 1981 patients; 83 patients started treatment<6 hours. For poor outcome, the adjusted risk ratios of magnesium treatment for start <6 hours were 1.44 (95% confidence interval, 0.83-2.51); for 6 to 12 hours 1.03 (0.65-1.63), for 12 to 24 hours 0.84 (0.65-1.09), and for >24 hours 1.06 (0.87-1.31), and for DCI, <6 hours 1.76 (0.68-4.58), for 6 to 12 hours 2.09 (0.99-4.39), for 12 to 24 hours 0.80 (0.56-1.16), and for >24 hours 1.08 (0.88-1.32). CONCLUSIONS: This meta-analysis suggests no beneficial effect of magnesium treatment on poor outcome or DCI when started early after SAH onset. Although the number of patients was small and a beneficial effect cannot be definitively excluded, we found no justification for a new trial with early magnesium treatment after SAH.
Subject(s)
Brain Ischemia/prevention & control , Calcium Channel Blockers/administration & dosage , Intracranial Aneurysm , Magnesium Sulfate/administration & dosage , Subarachnoid Hemorrhage/drug therapy , Time-to-Treatment/statistics & numerical data , Vasospasm, Intracranial/prevention & control , Aneurysm, Ruptured/complications , Calcium Channel Blockers/therapeutic use , Early Medical Intervention , Humans , Magnesium Sulfate/therapeutic use , Subarachnoid Hemorrhage/etiology , Treatment OutcomeABSTRACT
BACKGROUND AND PURPOSE: Our previous nasopharyngeal carcinoma detection study, comparing MR imaging, endoscopy, and endoscopic biopsy, showed that MR imaging is a highly sensitive test that identifies nasopharyngeal carcinomas missed by endoscopy. However, at the close of that study, patients without biopsy-proved nasopharyngeal carcinoma nevertheless had shown suspicious abnormalities on endoscopy and/or MR imaging. The aim of this study was to determine whether there were any patients with undiagnosed nasopharyngeal carcinoma by obtaining long-term follow-up and to use these data to re-evaluate the diagnostic performance of MR imaging. MATERIALS AND METHODS: In the previous study, 246 patients referred to a hospital ear, nose, and throat clinic with suspected nasopharyngeal carcinoma, based on a wide range of clinical indications, had undergone MR imaging, endoscopy, and endoscopic biopsy, and 77 had biopsy-proved nasopharyngeal carcinoma. One hundred twenty-six of 169 patients without biopsy-proved nasopharyngeal carcinoma underwent re-examination of the nasopharynx after a minimum of 3 years, including 17 patients in whom a previous examination (MR imaging = 11; endoscopy = 7) had been positive for nasopharyngeal carcinoma, but the biopsy had been negative for it. Patients with nasopharyngeal carcinoma were identified by biopsy obtained in the previous and this follow-up study; patients without nasopharyngeal carcinoma were identified by the absence of a tumor on re-examination of the nasopharynx. The sensitivity and specificity of the previous investigations were updated and compared by using the Fisher exact test. RESULTS: One patient with a previous positive MR imaging finding was subsequently proved to have nasopharyngeal carcinoma. Nasopharyngeal carcinomas were not found in the remaining 125 patients at follow-up, and the previous positive findings for nasopharyngeal carcinoma on MR imaging and endoscopy were attributed to benign lymphoid hyperplasia. The diagnostic performances for the previous MR imaging, endoscopy, and endoscopic biopsy were 100%, 88%, and 94%, respectively, for sensitivity, and 92%, 94%, and 100%, respectively, for specificity; the differences between MR imaging and endoscopy were significant for sensitivity (P = .003) but not specificity (P = .617). CONCLUSIONS: MR imaging detected the 12% of nasopharyngeal carcinomas that were endoscopically invisible, including 1 cancer that remained endoscopically occult for several years. Lymphoid hyperplasia reduced the specificity of MR imaging.
Subject(s)
Magnetic Resonance Imaging/methods , Nasopharyngeal Neoplasms/diagnosis , Adult , Aged , Biopsy/methods , Carcinoma , Female , Follow-Up Studies , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma , Otorhinolaryngologic Surgical Procedures/methods , Prospective Studies , Sensitivity and SpecificityABSTRACT
Metabolic disorders including type 2 diabetes, obesity and hypertension have growing prevalence globally every year. Genome-wide association studies have successfully identified many genetic markers associated to these diseases, but few studied their interaction effects. In this study, twenty candidate SNPs from sixteen genes are selected, and a lasso-multiple regression approach is implemented to consider the SNP-SNP interactions among them in an Asian population. It is found out that the main effects of the markers are weak but the interactions among the candidates showed a significant association to diseases. SNPs from genes CDKN2BAS and KCNJ11 are significantly associated to risk for developing diabetes, and SNPs from FTO and APOA5 might interact to play an important role for the onset of hypertension.
Subject(s)
Asian People/genetics , Carcinoma, Hepatocellular/genetics , Carrier State/virology , HLA Antigens/genetics , Hepatitis B virus/genetics , Liver Neoplasms/genetics , Alleles , Antigens, Viral/blood , Carcinoma, Hepatocellular/virology , Case-Control Studies , Hepatitis B/complications , Hepatitis B virus/immunology , Hong Kong , Humans , Liver Neoplasms/virology , Polymorphism, Genetic , Risk Assessment , Tumor Necrosis Factor-alpha/geneticsABSTRACT
BACKGROUND: We aimed to evaluate the safety and efficacy of single-agent sunitinib in nasopharyngeal carcinoma (NPC). METHODS: Eligible patients had progressive disease after prior platinum-based chemotherapy. Sunitinib was given as continuous once-daily dosing of 37.5 mg in 4-week cycles until progression. RESULTS: Thirteen patients were enrolled. Recruitment was stopped after two patients died of hemorrhagic events. All patients had previously received curative radiotherapy (RT) to nasopharynx/neck (including nine patients who had chemoradiotherapy). Patients received a median of three cycles of sunitinib. One patient was still on sunitinib with stable disease after 24 cycles. Hemorrhagic events occurred in nine patients (64%), including epistaxis in six, hemoptyses in three and hematemesis in two patients. Prior RT to thorax was significantly associated with hemoptyses (P = 0.03). Two patients with local tumor invasion into the carotid sheath developed fatal epistaxis/hematemesis within the first cycle of sunitinib, likely due to internal carotid blowout after tumor shrinkage. CONCLUSIONS: Sunitinib demonstrated modest clinical activity in heavily pretreated NPC patients. However, the high incidence of hemorrhage from the upper aerodigestive tract in NPC patients who received prior high-dose RT to the region is of concern. Direct vascular invasion by tumors appeared to increase the risk of serious bleeding.
Subject(s)
Antineoplastic Agents/adverse effects , Hematemesis/chemically induced , Hemoptysis/chemically induced , Indoles/adverse effects , Nasopharyngeal Neoplasms/therapy , Pyrroles/adverse effects , Adult , Aged , Antineoplastic Agents/therapeutic use , Carcinoma , Chemoradiotherapy , Epistaxis/chemically induced , Female , Humans , Indoles/therapeutic use , Male , Middle Aged , Nasopharyngeal Carcinoma , Pyrroles/therapeutic use , Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors , Sunitinib , Treatment OutcomeABSTRACT
AIMS: POU class 2 homeobox 1 (POU2F1), also known as octamer-binding transcription factor-1 (OCT-1), is a ubiquitous transcription factor that plays a key role in the regulation of genes related to inflammation and cell cycles. POU2F1 is located on chromosome 1q24, a region with linkage for Type 2 diabetes in Chinese and other populations. We examined the association of POU2F1 genetic variants with Type 2 diabetes in Hong Kong Chinese using two independent cohorts. METHODS: We genotyped five haplotype-tagging single nucleotide polymorphisms at POU2F1 in 1378 clinic-based patients with Type 2 diabetes and 601 control subjects, as well as 707 members from 179 families with diabetes. RESULTS: We found significant associations of rs4657652, rs7532692, rs10918682 and rs3767434 (OR = 1.26-1.59, 0.0003 < P(unadjusted) < 0.035) with Type 2 diabetes in the clinic-based case-control cohorts. Rs3767434 was also associated with Type 2 diabetes (OR = 1.55, P(unadjusted) = 0.013) in the family-based cohort. Meta-analysis revealed similar associations. In addition, the risk G allele of rs10918682 showed increased usage of insulin treatment during a mean follow-up period of 7 years [hazard ratio = 1.50 (1.05-2.14), P = 0.025]. CONCLUSIONS: Using separate cohorts, we observed consistent results showing the contribution of multiple variants at POU2F1 to the risk of Type 2 diabetes.
Subject(s)
Asian People/genetics , Diabetes Mellitus, Type 2/genetics , Genetic Predisposition to Disease , Octamer Transcription Factor-1/genetics , Polymorphism, Single Nucleotide , Adult , Diabetes Mellitus, Type 2/epidemiology , Female , Genetic Linkage/genetics , Genotype , Hong Kong/epidemiology , Humans , Male , Middle Aged , Phylogeny , Risk Factors , Transcription Factors/geneticsSubject(s)
HLA Antigens/genetics , Immunogenetic Phenomena , Severe Acute Respiratory Syndrome/genetics , Severe acute respiratory syndrome-related coronavirus/pathogenicity , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Male , Middle Aged , Severe Acute Respiratory Syndrome/epidemiology , Severe Acute Respiratory Syndrome/immunology , Young AdultABSTRACT
AIMS: To evaluate the current UICC/AJCC Staging System for nasopharyngeal carcinoma and to search for ways of improving the system. MATERIALS AND METHODS: This is a retrospective analysis of 2687 consecutive patients treated in five public centres in Hong Kong during the period 1996-2000. All patients were staged by computed tomography, magnetic resonance imaging, or both. The prognostic significance of the current stage assignment on various aspects of tumour control was evaluated. RESULTS: T-category, N-category and stage-group were all significant prognostic factors for major end points (P < 0.01). However, the distinction of prognosis between Stage I and II was insignificant (5-year cancer-specific survival being 92% vs 95%; P = 0.13). Multivariate analyses (corrected for age and sex) revealed lack of significance between T2a and T1 in hazards of local and distant failures, N3a and N2 in distant failure and subgroups of T1-2N0 in cancer-specific deaths. Corresponding down-staging of T2a to T1, N3a to N2, and subgroup T2N0 to stage I, resulted in more even and orderly increase in the hazard ratio of cancer-specific deaths (from 1 for stage I to 1.98 for II, 3.5 for III, 6.08 for IVA and 8.62 for IVB), better hazard consistency among subgroups of the same stage and more balanced stage distribution. CONCLUSIONS: The current UICC/AJCC Staging System could be further improved by the modifications suggested; validation of the current proposal by external data is urgently awaited.
Subject(s)
Nasopharyngeal Neoplasms/epidemiology , Nasopharyngeal Neoplasms/pathology , Neoplasm Staging , Adolescent , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Female , Hong Kong/epidemiology , Humans , Male , Medical Records , Middle Aged , Nasopharyngeal Neoplasms/mortality , Prognosis , Retrospective Studies , Survival AnalysisABSTRACT
BACKGROUND: Rh isoimmunization and hemolytic disease of the newborn still occur despite the availability of Rh immunoglobulin. For the prenatal investigation of sensitized RhD-negative pregnant women, determination of the zygosity of the RhD-positive father has important implications. The currently available molecular methods for RhD zygosity assessment, in general, are technically demanding and labor-intensive. Therefore, at present, rhesus genotype assessment is most commonly inferred from results of serological tests. The recent elucidation of the genetic structure of the prevalent RHD deletion in Caucasians, as well as the development of real-time PCR, allowed us to explore two new approaches for the molecular determination of RhD zygosity. METHODS: Two methods for RhD zygosity determination were developed. The first was based on the double Amplification Refractory Mutation System (double ARMS). The second was based on multiplex real-time quantitative PCR. For the double ARMS assay, allele-specific primers were designed to directly amplify the most prevalent RHD deletion found in RhD-negative individuals in the Caucasian population. The multiplex real-time quantitative PCR assay, on the other hand, involved coamplification and quantification of RHD-specific sequences in relation to a reference gene, albumin, in a single PCR reaction. A ratio, DeltaCt, based on the threshold cycle, was then determined and reflects the RHD gene dosage. RESULTS: The allele-specific primers of the double ARMS assay reliably amplified the RHD-deleted allele and therefore accurately distinguished homozygous from heterozygous RhD-positive samples. The results were in complete concordance with serological testing. For the multiplex real-time quantitative PCR assay, the DeltaCt values clearly segregated into two distinct populations according to the RHD gene dosage, with mean values of 1.70 (SD, 0.17) and 2.62 (SD, 0.29) for the homozygous and heterozygous samples, respectively (P: <0.001, t-test). The results were in complete concordance with the results of serological testing as well as with the double ARMS assay. CONCLUSION: Double ARMS and real-time quantitative PCR are alternative robust assays for the determination of RhD zygosity.
Subject(s)
Rh-Hr Blood-Group System/genetics , Albumins/genetics , Heterozygote , Homozygote , Humans , Polymerase Chain Reaction/methodsABSTRACT
There is increasing interest in measuring health related quality of life in cancer clinical trials. Most quality of life data are measured repeatedly over a fixed time schedule to capture changes and to reflect relative advantages of study treatments. A multivariate repeated measures model is usually used to analyse this type of data. However, one of the difficulties of this analysis is that quality of life may be affected by the occurrence of some critical events experienced by patients. We may separate a patient's lifetime during study into different 'health states'. The duration of these health states may vary among patients, and may relate to the efficacy of the study treatment. In some cases quality of life data may be missing due to one of the many different types of missing data mechanisms specific for a health state. It is reasonable to assume that the missing data mechanism for a treatment arm is homogeneous within a defined health state, and to control for the potential confounding effect to appropriately assess the impact of treatment on the quality of life. In this paper, we propose a growth curve model conditional on a time-dependent variable of defined health states in order to assess the overall treatment effect while taking into account occurrences of missing data and measurements from irregular visits. A specific contrast can be drawn within the overall model for testing a specific hypothesis without relying on the analysis of subgroups of patients based on a smaller number of repeated measurements. Quality of life data from a recently completed small-cell lung cancer randomized trial are used to illustrate this method.
Subject(s)
Clinical Trials as Topic/methods , Models, Statistical , Neoplasms/psychology , Quality of Life , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Small Cell/drug therapy , Health Status , Humans , Longitudinal Studies , Lung Neoplasms/drug therapy , Neoplasms/drug therapy , Research DesignABSTRACT
PURPOSE: The importance of the timing of thoracic irradiation (TI) in the combined modality therapy of limited-stage small-cell lung cancer (SCLC) was assessed in a randomized trial. METHODS: All 308 eligible patients received cyclophosphamide, doxorubicin, and vincristine (CAV) alternating with etoposide and cisplatin (EP) every 3 weeks for three cycles of each chemotherapy regimen. Patients randomized to early TI received 40 Gy in 15 fractions over 3 weeks to the primary site concurrent with the first cycle of EP (week 3), and late TI patients received the same radiation concurrent with the last cycle of EP (week 15). After completion of all chemotherapy and TI, patients without progressive disease received prophylactic cranial irradiation (25 Gy in 10 fractions over 2 weeks). RESULTS: Although complete remission rates were not significantly different between the two arms, progression-free survival (P = .036) and overall survival (P = .008) were superior in the early TI arm. Patients in the late TI arm had a higher risk of brain metastases (P = .006). CONCLUSION: The early administration of TI in the combined modality therapy of limited-stage SCLC is superior to late or consolidative TI.
Subject(s)
Carcinoma, Small Cell/radiotherapy , Lung Neoplasms/radiotherapy , Aged , Carcinoma, Small Cell/pathology , Combined Modality Therapy , Female , Humans , Lung Neoplasms/pathology , Male , Middle Aged , Neoplasm Staging , Radiotherapy/adverse effects , Radiotherapy/methods , Regression Analysis , Survival Analysis , Time FactorsABSTRACT
Morphometric measurements were performed on pulmonary arteries in 58 patients with systemic sclerosis (20 limited cutaneous and 38 diffuse cutaneous involvement [21 with and 17 without renal crisis]) and age, race, and sex matched autopsy controls. Matched pairs analysis was employed. For arteries of all sizes, the area of the intima and percent luminal occlusion were greater in the limited and diffuse (no renal crisis) groups than in controls, and these differences were statistically significant for large and medium sized vessels. The greatest luminal occlusion was found in limited cutaneous patients, and especially those with clinical evidence of pulmonary arterial hypertension, providing a rationale for the poor response to vasodilator therapy in these patients.
Subject(s)
Pulmonary Artery/pathology , Scleroderma, Systemic/pathology , Constriction, Pathologic/complications , Constriction, Pathologic/epidemiology , Constriction, Pathologic/pathology , Female , Humans , Hypertension/complications , Hypertension/pathology , Male , Middle Aged , Retrospective Studies , Scleroderma, Localized/complications , Scleroderma, Localized/epidemiology , Scleroderma, Localized/pathology , Scleroderma, Systemic/complications , Scleroderma, Systemic/epidemiologyABSTRACT
In four phase II trials of trimetrexate given iv daily for 5 days, we noted marked variability among patients in the development of severe or life-threatening toxic effects. In an effort to define which of 15 patient characteristics were associated with toxic effects of this degree, we have carried out single-factor and multifactor analyses on toxic effects during the first cycle of therapy in 68 patients. The final logistic regression model identified both low pretreatment serum protein levels and metastatic liver disease as significant correlates of severe toxic effects (P = .02 and P = .0005, respectively). While drug dose was an important element of the best logistic model, its statistical significance was only borderline. Trimetrexate is extensively protein bound and is cleared primarily by hepatic metabolism, so it is not unreasonable to believe that alteration in protein binding of the drug or in metabolic capacity of the liver could produce enhanced toxic effects. Although the validity of these predictors should be confirmed, it seems prudent to recommend lower starting doses of trimetrexate for patients with metastatic liver disease and/or low protein levels and dose escalation if toxic effects allow it.
Subject(s)
Antineoplastic Agents/adverse effects , Folic Acid Antagonists/adverse effects , Quinazolines/adverse effects , Antineoplastic Agents/metabolism , Blood Proteins/analysis , Drug Evaluation , Female , Folic Acid Antagonists/metabolism , Humans , Liver Neoplasms/secondary , Male , Protein Binding , Quinazolines/metabolism , TrimetrexateABSTRACT
A long-term retrospective case-control study was performed comparing 119 patients with rheumatoid arthritis treated with cyclophosphamide and 119 matched control patients with rheumatoid arthritis not treated with cyclophosphamide to determine the risk of subsequent malignancy. Thirty-seven malignancies were detected in 29 cyclophosphamide-treated patients, while 16 malignancies were found in 16 control patients (p less than 0.05) during a mean follow-up period of more than 11 years. Urinary bladder cancer (six cyclophosphamide-treated patients, no control patients) and skin cancer (eight cyclophosphamide-treated patients, no control patients) were identified as differing statistically between the groups, and hematologic malignancy (five cyclophosphamide-treated patients, one control patient) showed a similar trend. Survival analysis indicated that the rate of development of malignancy in the cyclophosphamide-treated patients was significantly greater than in the control patients at six years following drug initiation, and that this increased rate persisted even at 13 years (p less than 0.01). Of the many risk factors evaluated, mean total cyclophosphamide dose and duration and tobacco use were significantly increased in patients in whom cancer subsequently developed. These long-term complications must be considered seriously when cyclophosphamide or other cytotoxic drugs are initiated for the treatment of rheumatoid arthritis.