Gender differences in doxorubicin pharmacology for subjects with chemosensitive cancers of young adulthood.

PURPOSE: For many cancers, adolescents and young adults (AYA) have worse outcomes than for children and adults. Many factors may contribute to the AYA survival gap, including differences in biology, therapeutic intent, and adherence to therapy. It has been observed that male AYAs have poorer outcomes than females. The purpose of this work was to test the proposition that gender-related pharmacologic factors may account for a component of the AYA survival gap. PATIENTS AND METHODS: A prospective, multi-institutional pharmacologic study of 79 patients in total with chemosensitive cancers (Ewing sarcoma, osteosarcoma and Hodgkin lymphoma) was conducted, with conventional doxorubicin treatment. Pharmacokinetic data of 13 children, 40 AYAs and 13 adults were valid for analysis. Population pharmacokinetics models were developed for doxorubicin and its metabolite doxorubicinol based on the data created in this study. Consequently, model-based analysis was conducted to investigate the relevant topics. RESULTS: The clearance of doxorubicinol (normalized to body surface area), the main active metabolite of doxorubicin, appears faster in male AYAs than female (p = 0.04, 95% CI 0.1-3.9 L/h). The exposure of doxorubicinol (normalized to dose) is lower in male AYA than female (p = 0.03, 95% CI - 0.005 to - 0.0002 h/L). These might be correlated to the observed difference on nadir neutrophil count between male AYA and female (p = 0.027, 95% CI 0.09-1.4). CONCLUSION: Gender-related differences in doxorubicin pharmacology may account for worse outcomes for male AYAs with chemosensitive cancers compared to females. These findings may reduce the AYA survival gap compared to other age groups.

Limb preservation surgery with extracorporeal irradiation in the management of malignant bone tumor: the oncological outcomes of 101 patients.

BACKGROUND: En bloc resection, extracorporeal irradiation (ECI) and reimplantation have been used selectively at our centers as part of limb preservation surgery of malignant bone tumors since 1996. We report the long-term oncological outcomes. PATIENTS AND METHODS: One hundred one patients were treated with ECI at two Australian centers between 1996 and 2011. A single dose of 50 Gy was delivered to the resected bone segments. The irradiated bones were reimplanted immediately as a biological graft. Patients were treated with chemotherapy as per standard protocol. The three main histological diagnoses were Ewing's sarcoma (35), osteosarcoma (37) and chondrosarcoma (20). There were nine patients with a range of different histologies. RESULTS: There was one local recurrence (2.86%) in Ewing's sarcoma and the 5-year cumulative overall survival was 81.9%. There was no local recurrence in osteosarcoma and five distant recurrences. The 5-year cumulative overall survival was 85.7%. The local recurrence rate was 20% (4 of 20) in chondrosarcoma, and the 5-year cumulative overall survival was 80.8%. Limb preservation was achieved in 97 patients. For the 64 patients with disease in the pelvis or lower limb, 53 (82.3%) could walk without aids at the time of last follow-up. CONCLUSIONS: This large series of ECI shows an excellent long-term local control. It is a good alternative reconstruction method in selected patients. The overall survival is comparable to other published series.

Pulmonary inflammatory myofibroblastic tumor after Hodgkin's lymphoma and application of PET imaging.

Inflammatory myofibroblastic tumor (IMT) is a rare tumor with a particular histological pattern of myofibroblasts and mixed inflammatory infiltrate. IMT has been rarely described in association with malignancy. This case report is of a 16-year-old male who had Hodgkin's disease (stage IVA) and who after chemotherapy and radiotherapy developed IMT, 16 months post completion of therapy. The IMT was in the lung in an area which was previously involved with HD and had undergone radiotherapy. PET imaging with F(18)FDG was used in the initial diagnosis and has been used in follow-up after full surgical resection of the lesion.

Fifteen cases of t(1;19)(q23;p13.3) identified in an Australian series of 122 children and 80 adults with acute lymphoblastic leukemia.

The t(1;19)(q23;p13) has been reported in up to 6% of cytogenetically abnormal cases of acute lymphoblastic leukaemia (ALL), associated with a pre-B-ALL phenotype. In the 5-year period 1995-1999, we detected t(1;19) in 13 children and 2 adults with newly diagnosed ALL. This represented 10% of pediatric and 2.5% of adult diagnostic ALL samples successfully cultured in one center during this time. There were 9 males and 6 females. The mean age at diagnosis for the 13 children was 6.5 years (range 1.5 to 14 years) and the 2 adults were aged 42 and 45 years. The unbalanced t(1;19) occurred in 7 of 13 children (54%), contrary to the reported excess of unbalanced translocations at 75%; both adults had the unbalanced translocation. At diagnosis, the t(1;19) was the sole abnormality in 4 patients (26%), and in the remainder (74%) was part of a complex karyotype, which included i(7q) (2 patients), hyperdiploidy (2 patients) and del(6q) (2 patients). Correlation of karyotype with white cell, blast and platelet counts, cell surface markers, initial response to chemotherapy and short-term outcome showed no difference between the balanced and unbalanced forms of the translocation in children or whether t(1;19) was present as the sole abnormality or part of a complex karyotype.

Multiparameter-fluorescence activated cell sorting analysis of retroviral vector gene transfer into primitive umbilical cord blood cells.

Retroviral vector gene transfer strategies are currently being developed to treat a variety of hematopoietic disorders. To date, genetic modification of human pluripotent hematopoietic stem cells has been inefficient. In the present study we developed reagents and procedures for rapidly screening retroviral vector gene transfer conditions using a multiparameter fluorescence-activated cell sorting (FACS) assay. To identify transduced cells using FACS analysis, we developed a retroviral vector, termed MN, which stably expressed high levels of a truncated version of the low-affinity nerve growth factor receptor (LNGFR). In addition, procedures were developed for enriching CD34+ cells from cryopreserved umbilical cord blood. These cells were transduced with MN and evaluated using multiparameter FACS analysis for expression of CD34, CD38, and LNGFR. Stem cell maintenance was determined by measuring the CD34hi and CD34hiCD38lo/- cells remaining after ex vivo gene transfer. Gene transfer into these cells was measured by evaluating cells expressing high levels of LNGFR. Initial studies with this assay and with in vitro functional assays indicated that retroviral gene transfer following pre-incubation with a variety of cytokines in serum containing conditions resulted in 1) poor maintenance of hematopoietic stem cells and 2) gene transfer predominantly in relatively mature cells. When gene transfer in serum-free conditions was performed, some improvement was observed in the maintenance of cells retaining primitive immunophenotypes with no reduction in the gene transfer efficiency. The MN vector and multiparameter FACS analysis will be useful in efficiently screening ongoing efforts designed to improve stem cell gene transfer.

Activity of high-dose cyclophosphamide in the treatment of childhood malignant gliomas.

Seventeen patients less than or equal to 20 years of age with newly diagnosed (n = 10) or recurrent (n = 7) malignant gliomas (anaplastic astrocytoma and glioblastoma multiforme) were treated with cyclophosphamide in association with hematopoietic cytokines (GM-CSF or G-CSF). Cyclophosphamide was given at a dose of 2 g/m2 daily for 2 days at 4-week intervals. Toxicity consisted of grade IV neutropenia and thrombocytopenia in 95% and 48% of cycles, respectively. There were no cyclophosphamide-related cardiac, pulmonary, or urothelial toxicities observed. Four of 10 patients with newly diagnosed disease demonstrated responses (three complete and one partial responses; one CR was only of 2 months duration). None of the seven patients with recurrent tumors demonstrated a response. We conclude that high-dose cyclophosphamide warrants further evaluation in children with newly diagnosed malignant glioma.

A dose-intensive, cyclophosphamide-based regimen for the treatment of recurrent/progressive or advanced solid tumors of childhood: a report from the Australia and New Zealand Children's Cancer Study Group.

BACKGROUND: Children with solid tumors that progress or recur after conventional multimodality therapies have a very poor prognosis. In a pilot study, vincristine, etoposide, and dose-escalated cyclophosphamide (VETOPEC) was shown to be a promising salvage regimen. Continued accrual of patients and increased duration of follow-up has resulted in substantial experience with VETOPEC. METHODS: Between May 1991 and March 1994, 56 pediatric patients from 6 centers were enrolled in this study; 44 had recurrent or progressive tumors (Group A) and 12 had newly diagnosed, advanced tumors with a very poor prognosis (Group B). The VETOPEC regimen was comprised of vincristine, 0.05 mg/kg, on Days 1 and 14; etoposide, 2.5 mg/kg, on Days 1, 2, and 3; and fractionated, dose-escalated cyclophosphamide on Days 1, 2, and 3. The initial cyclophosphamide dose was 90 mg/kg (2.7 g/m2)/cycle with an escalation of 15 mg/kg/cycle in each subsequent cycle, to a maximum (over 6 cycles) of 165 mg/kg (5.0 g/m2)/cycle. Tumor response was evaluated every two to three cycles and included central review of imaging. RESULTS: The combined and partial response rates for Groups A and B were 66% (25 of 38 patients) and 91% (10 of 11 patients), respectively. In Group A, best evaluable responses and event free (EF) survivors were observed with: brain tumors (7 of 9 patients; 2 EF at 39 and 45 months [mos], respectively), Wilms' tumor (6 of 7 patients; 3 EF at 37-49 mos), and lymphoma (4 of 4 patients; 2 EF at 52 and 59 mos, respectively); in Group B best evaluable responses and EF were observed with: neuroblastoma (5 of 6 patients; 1 disease free at 57 mos) and rhabdomyosarcoma (4 of 4 patients; no survivors). Hematologic toxicity was limiting despite support with myeloid growth factors in 33 patients. Four deaths in Group A and one in Group B were directly associated with this toxicity. Specifically, no cases of drug-related myocardial toxicity or pneumonitis were observed. CONCLUSIONS: This chemotherapy regimen with its intense scheduling produced a high response rate and appreciable survival in patients with a variety of recurrent, progressive, or advanced solid tumors of childhood.

Granulocyte-macrophage colony-stimulating factor in association with high-dose chemotherapy (VETOPEC) for childhood solid tumors: a report from the Australia and New Zealand Children's Cancer Study Group.

PURPOSE: Combination chemotherapy with vincristine, etoposide, and high-dose, escalating cyclophosphamide (VETOPEC) is an effective regimen in pediatric patients with high-risk solid tumors. The toxicity of the regimen is predominantly haematologic. This study addressed the role of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) following each cycle of chemotherapy in decreasing neutropaenia, incidence of fever/ hospitalization, and/or increasing chemotherapy dose-intensity. PATIENTS AND METHODS: Twenty-nine children with recurrent solid tumors were treated with the VETOPEC regimen. Sequential cohorts of patients received no GM-CSF (Group I), or GM-CSF in a dosage of 5 micrograms/kg/day (Group II) or 10 micrograms/kg/day (Group III) on days 4-18 of each chemotherapy cycle. Up to four cycles of chemotherapy were analysed with respect to haematopoietic recovery, clinical parameters, and dose intensity. RESULTS: Neutrophil recovery was significantly more rapid in patients treated with GM-CSF. Time to achieving an absolute neutrophil count (ANC) over 0.5 x 10(9)/L in Groups I, II, and III were 21, 18, and 16 days, respectively (P < 0.0001). Time to achieving an absolute neutrophil count (ANC) over 1.0 x 10(9)/L in Groups I, II, and III were 24, 19, and 17 days, respectively (P < 0.0001). There was no significant difference in the incidence of febrile neutropaenia between the three groups. Febrile neutropaenia occurred following 42, 68, and 62% of chemotherapy cycles in Groups I, II, and III, respectively (P = 0.27). Chemotherapy dose intensity was not different between the three groups. GM-CSF was associated with pericarditis and myalgias in one patient, and transient hypoxia/hypotension in another. CONCLUSION: GM-CSF led to significantly more rapid neutrophil recovery following VETOPEC chemotherapy, but did not lead to any demonstrable clinical benefit, either in reducing febrile events, or in increasing chemotherapy dose intensity.

Monitoring of neoadjuvant therapy response of soft-tissue and musculoskeletal sarcoma using fluorine-18-FDG PET.

UNLABELLED: The purpose of this study was to investigate the potential role of FDG-PET in the monitoring of neoadjuvant therapy of soft-tissue and musculoskeletal sarcomas. METHODS: Nine patients were studied. Neoadjuvant therapy consisted of either chemotherapy or combined radiotherapy and hyperthermia. The FDG-PET studies were obtained, when possible, prior to therapy, 1-3 wk after commencement of therapy, and prior to surgery after completion of neoadjuvant therapy. In two patients, all three studies were completed. The remainder of patients underwent one or two studies at varying timepoints. RESULTS: In tumors treated with combined radiotherapy and hyperthermia, well-defined regions of absent uptake developed within responsive tumors, correlating pathologically with necrosis. Following treatment, a peripheral rim of FDG accumulation was found to correlate pathologically with the formation of a fibrous pseudocapsule. In tumors treated with chemotherapy, FDG accumulation decreased more homogeneously throughout the tumor, in responsive cases. Despite 100% tumor cell kill in some patients, persistent tumor FDG uptake was observed which correlated pathologically with uptake within benign therapy-related fibrous tissue. Significant FDG accumulation was also observed at the site of an uncontaminated incisional biopsy. CONCLUSION: These initial results demonstrate changes in tumor accumulation of FDG during and after neoadjuvant therapy; these changes are dependent on the type of neoadjuvant therapy administered. Prominent FDG accumulation was observed in benign tissues both within and adjacent to the treated tumor.

Successful treatment of childhood pilocytic astrocytomas metastatic to the leptomeninges with high-dose cyclophosphamide.

Leptomeningeal dissemination of childhood pilocytic astrocytoma (PA) is a rare event with little information available regarding therapy. We report here four children with disseminated PA whom we treated with high doses of cyclophosphamide with clinical benefit. The patients were aged 2.5 to 8 years. Three patients presented with PA localized in the posterior fossa, initially treated with surgical resection (n = 3) and radiotherapy (n = 1). Leptomeningeal dissemination occurred at 32, 44, and 8 months from diagnosis, respectively. The fourth patient presented with an optic pathway tumor with leptomeningeal dissemination at diagnosis. At commencement of cyclophosphamide therapy, disease was present in the subarachnoid space (intracranial, n = 2; spinal, n = 4), cerebral ventricles (n = 2), and primary site (n = 3). Histology was identical at diagnosis and recurrence in the two biopsied cases and cerebrospinal fluid was negative in all cases. Treatment was with cyclophosphamide 4-5 g/m2/cycle given every 4 weeks for a total of two cycles (n = 1) and four cycles (n = 3). One patient achieved disease stabilization (duration 27 months at the time of publication) and three patients experienced significant reductions in tumor burden. Subsequent intrathecal therapy was administered to two patients. Two patients developed disease progression at 10 and 9 months from cessation of chemotherapy. The one re-treated patient responded to further, lower dose, cyclophosphamide. This is the first report of the use of high dose cyclophosphamide for disseminated PA. The recurrence of disease in two cases with a further response to lower dose cyclophosphamide has implications for the optimal duration of therapy for these low grade, aggressive tumors.

Treatment of patients with pineoblastoma with high dose cyclophosphamide.

The outcome for patients with pineoblastoma has historically been very poor, with most patients dying of disseminated disease despite irradiation. Furthermore, the low incidence of this tumor has hindered progress toward defining better treatment strategies. Here we report the activity and toxicity of cyclophosphamide administered as a single agent at a dose schedule of 2 g/m2/day for 2 successive days at monthly intervals for a maximum of four courses. Eight patients were evaluated, six newly diagnosed and two recurrent. Amongst the six newly diagnosed patients, there were three patients demonstrating partial responses, and three had stable disease throughout the cyclophosphamide treatment period. All six patients are alive and disease free after further therapy. One patient with recurrent disease demonstrated tumor progression on cyclophosphamide, and the other had stable disease throughout the cyclophosphamide treatment period. Both patients subsequently died of progressive disease. The major toxicity of high dose cyclophosphamide was hematopoietic, with one patient requiring a dose reduction after three courses due to prolonged thrombocytopenia. One patient was also withdrawn from treatment with cyclophosphamide due to impaired pulmonary function. This study demonstrates the activity of high dose cyclophosphamide in the treatment of pineoblastoma and may serve as basis for the design of future studies of this tumor.

Successful treatment of two children with Langerhans' cell histiocytosis with 2'-deoxycoformycin.

PURPOSE: Langerhans' cell histiocytosis (LCH) is problematic illness with a subset of patients experiencing a relapsing or progressive course despite therapy with chemotherapy and/or immunosuppressive agents. Novel therapies are required. 2'-deoxycoformycin (2'-dCF) is an inhibitor of adenosine deaminase (ADA) and is toxic to lymphocytes and monocytes. We hypothesized that 2'-dCF might be effective in treatment of children with LCH, in part because of recent success reported with 2-chlorodeoxyadenosine. In this report we describe our experience using 2'-dCF to treat two patients with refractory LCH. PATIENTS AND METHODS: The patients, aged 5 and 3 years, had received therapy for 4 and 2.5 years, respectively, with vinblastine, corticosteroids, etoposide, methotrexate, 6-mercaptopurine, and, in one case, cyclosporine. While receiving cyclosporine, the first patient developed rapidly enlarging lytic skull lesions accompanied by pain and tenderness. While receiving methotrexate and 6-mercaptopurine, the second patient developed fever, anemia, multiple new bony lesions, and massive abdominal and axillary adenopathy, proven at biopsy to be due to recurrent LCH. Treatment in both cases was with 2'-dCF 4 mg/m2 given by intravenous push weekly for 8 weeks then continuing every 2 weeks for >21 and 16 months, respectively. RESULTS: Both patients responded to 2'-dCF therapy. The first patient's pain resolved following three doses of 2'-dCF, and the skull lesions decreased in size significantly over the following 6 months. After 15 months of therapy he developed asymptomatic radiologic evidence of a possible new lesion in the femur which did not progress over the subsequent 3 months. The second patient experienced improvement at all sites of disease over 8 weeks, with complete resolution of bony lesions over the next 5 months. At 16 months from initiation of 2'-dCF therapy she remains disease-free. Toxicity was limited to asymptomatic grade III-IV lymphopenia and abnormalities of lymphocyte mitogen responses. The patients are asymptomatic and continue biweekly and monthly 2'-dCF therapy, respectively. CONCLUSION: 2'-dCF has shown activity against LCH in these two cases, with minimal toxicity. Further study of this agent in the therapy of LCH is warranted.

Autologous bone marrow transplantation for advanced neuroblastoma using teniposide, doxorubicin, melphalan, cisplatin, and total-body irradiation.

BACKGROUND: Disseminated neuroblastoma after infancy has a dismal prognosis; long-term survival with conventional therapy occurs in approximately 10% of cases. PATIENTS AND METHODS: Between 1985 and 1992, we followed a strategy aimed to achieve remission with an induction combination of intensive chemotherapy, primary resection, and tumor-bed radiotherapy (TBRT). Patients who achieved remission proceeded to myeloablative chemoradiotherapy and unpurged autologous bone marrow transplant (ABMT). Twenty-eight patients older than 1 year presented with stage IV disease during the study period; six died of progressive disease and three died of complications of therapy. Nineteen patients achieved remission, two of whom did not receive ABMT. Seventeen patients proceeded to ABMT. Conditioning was with teniposide 130 mg/m2, doxorubicin 30 mg/m2, melphalan 120 mg/m2, cisplatin 80 mg/m2, and total-body irradiation 12 Gy in six fractions (modified VAMP-TBI). RESULTS: Principal nonhematologic toxicities were mucositis and diarrhea. There were no ABMT-related deaths. Two patients relapsed at 8 and 26 months post-ABMT, respectively. Fifteen patients remain in complete remission (CR) at 24 to 102 months (median, 71) from ABMT and 30 to 114 months (median, 78) from diagnosis. Survival rates of all 28 patients are 61% and 50% at 2 and 5 years, respectively, and the disease-free survival (DFS) of the ABMT group is 94% and 87% at 2 and 5 years, respectively. CONCLUSION: Modified VAMP-TBI appears to be an effective conditioning regimen, with 15 of 17 patients remaining disease-free, with no toxic deaths. This result compares favorably with that of other groups. Larger numbers of patients need to be treated to confirm the efficacy of this therapy.

Dose-intensive cyclophosphamide with etoposide and vincristine for pediatric solid tumors: a phase I/II pilot study by the Australia and New Zealand Childhood Cancer Study Group.

PURPOSE: This pilot study of the Australia and New Zealand Childhood Cancer Study Group investigated the effectiveness and toxicity of a regimen incorporating vincristine (VCR), etoposide, and divided-dose, escalating cyclophosphamide (CPA) (VETOPEC) in 23 patients aged 1 to 20 years with solid tumors. PATIENTS AND METHODS: Seventeen patients (group A) had recurrent or refractory tumors after prior multiagent therapy, and six patients (group B) with adverse prognostic indicators were treated at initial presentation. Treatment cycles were 21 to 28 days and consisted of vincristine (0.05 mg/kg) on days 1 and 14, with etoposide (2.5 mg/kg/d) plus escalating CPA on days 1, 2, and 3. The CPA dosage was escalated from 30 mg/kg/d in cycle no. 1 by 5 mg/kg/d in each cycle to a maximum of 55 mg/kg/d in cycle no. 6. RESULTS: Of 20 patients assessable for tumor response, 19 (95%) responded after two to six cycles of VETOPEC: seven complete responses (CRs); eight very good partial responses (VGPRs); and four partial responses (PRs). In group A, 13 of 14 (93%) assessable patients responded (five CRs, four VGPRs, four PRs), and in group B, five stage IV and one stage III patient achieved two CRs and four VGPRs. The principal toxicity was myelosuppression. Grade IV neutropenia occurred after 98% of cycles, and the incidence of grade IV thrombocytopenia increased from 37% after cycle no. 1 to 91% after cycle no. 6 (P = .002). A total of 115 cycles delivered were followed by 62 febrile admissions (54%), and showed a significant rise with increasing cycles (P = .001). One patient died of septicemia. CONCLUSION: This combination and scheduling produced a high response rate in patients with recurrent, refractory, or advanced solid tumors of childhood. Further studies of this regimen and of strategies to reduce hematologic toxicity are warranted.

The experience of a single Australian paediatric oncology unit. 1000 patients 1964-1987.

OBJECTIVE: To determine the survival for children with malignant disease diagnosed in the period 1964-1987 and treated in a single paediatric oncology unit. DESIGN: Records of patients treated by the Department of Haematology and Oncology at the Prince of Wales Children's Hospital were reviewed to determine the survival of children with cancer according to decade of diagnosis and diagnostic group. PATIENTS: Patients were eligible for the study if referred for treatment at or soon after diagnosis of malignancy. One thousand patients were treated during the study period. There were 363 with acute lymphoblastic leukaemia (ALL), 126 with tumours of the central nervous system (CNS), 86 with acute non-lymphoblastic leukaemia (ANLL), 81 with lymphoma, 79 with neural crest tumours, 69 with renal tumours, 66 with bone sarcomas, 53 with soft tissue sarcomas, and 77 with various other diagnoses. Age range was one day to 20.75 years. INTERVENTIONS: Treatment included surgery, radiotherapy and chemotherapy in a variety of protocols. RESULTS: Ten-year survival for the 1960s, 1970s and 1980s was 15%, 51% and 64% respectively (P < 0.001), excluding tumours of the CNS. From 1985 onwards, actual survival at five years has been 79%. Survival from Wilms' tumour and Hodgkin's disease remained high throughout the study period, and significant improvement in survival occurred with ALL, non-Hodgkin's lymphoma (NHL) and osteogenic sarcoma. Survival remained poor with neuroblastoma and ANLL. CONCLUSIONS: Significant improvement in outcomes for childhood malignancy has been achieved over the last three decades, with five-year survival currently at 79% (excluding tumours of the CNS). Some diagnostic groups have had only small improvements in outcome and require new strategies.

Prevalence of bronchial hyperresponsiveness and asthma in a rural adult population.

The prevalence of bronchial hyperresponsiveness in adult populations is not known. To document its prevalence and distribution and to determine the factors associated with it, a random sample of the adult population of Busselton, Western Australia, was studied. Spirometric function, bronchial responsiveness to histamine, and atopic responses to skin prick tests were measured. Respiratory symptoms were determined by questionnaire. Data were obtained from 916 subjects. Of these, 876 underwent a histamine inhalation test and bronchial hyperresponsiveness to histamine (defined as a dose of histamine provoking a 20% fall in FEV1 equal to or less than 3.9 mumol) was found in 10.5%. Another 40 subjects with poor lung function were tested with a bronchodilator and 12 were found to have bronchial hyperresponsiveness (defined as a greater than 15% increase in FEV1), making the total prevalence of bronchial hyperresponsiveness 11.4%. The prevalence of current asthma, defined as bronchial hyperresponsiveness plus symptoms consistent with asthma in the last 12 months, was 5.9%. The distribution of bronchial hyperresponsiveness in the studied population was continuous. There was a significant association between it and respiratory symptoms, atopy, smoking, and abnormal lung function (p less than 0.001 for all associations). There was no association with age, sex, or recent respiratory tract infection.