Reconocimiento geofísico del deslizamiento de Rosiana (depresión de Tirajana, Gran Canaria)

The landslide of Rosiana is considered the largest slope movement amongst those known in historical times in Gran Canana, Canary Islands. It has been activated at least 4 times in the last century, and in the movement of 1956, when about 3.106 m3 of materials were involved, 250 people had to be evacuated and many buildings were destroyed. The present geological hazard has lead to specific studies of the phenomenon which, once characterised, can be used as a guide for the scientific and technical works that are to be made in this or similar areas. This paper wants to increase the knowledge about the unstable mass of Rosiana by using geophysical techniques based on the method of seismic by refraction. The geophysical measues have been interpreted with the aid of the available geomorphologic data, thus obtaining a first approximation to the geometry of the slope movements

Definition of tolerable soil erosion values

Although the criteria for defining erosion tolerance are well established, the limits generally used are not consistent with natural, economical and technological conditions. Rates greater than soil formation can be accepted only until a minimum of soil depth is reached, provided that they are not associated with environmental hazard or productivity losses. A sequence of equations is presented to calculate erosion tolerance rates through time. The selection of equation parameters permits the definition of erosion tolerance rates in agreement with environmental, social and technical needs. The soil depth change that is related to irreversible soil degradation can be calculated. The definition of soil erosion tolerance according to these equations can be used as a guideline for sustainable land use planning and is compatible with expert systems.

Phase 3 randomized trial on larynx preservation comparing sequential vs alternating chemotherapy and radiotherapy.

BACKGROUND: Both induction chemotherapy followed by irradiation and concurrent chemotherapy and radiotherapy have been reported as valuable alternatives to total laryngectomy in patients with advanced larynx or hypopharynx cancer. We report results of the randomized phase 3 trial 24954 from the European Organization for Research and Treatment of Cancer. METHODS: Patients with resectable advanced squamous cell carcinoma of the larynx (tumor stage T3-T4) or hypopharynx (T2-T4), with regional lymph nodes in the neck staged as N0-N2 and with no metastasis, were randomly assigned to treatment in the sequential (or control) or the alternating (or experimental) arm. In the sequential arm, patients with a 50% or more reduction in primary tumor size after two cycles of cisplatin and 5-fluorouracil received another two cycles, followed by radiotherapy (70 Gy total). In the alternating arm, a total of four cycles of cisplatin and 5-fluorouracil (in weeks 1, 4, 7, and 10) were alternated with radiotherapy with 20 Gy during the three 2-week intervals between chemotherapy cycles (60 Gy total). All nonresponders underwent salvage surgery and postoperative radiotherapy. The Kaplan-Meier method was used to obtain time-to-event data. RESULTS: The 450 patients were randomly assigned to treatment (224 to the sequential arm and 226 to the alternating arm). Median follow-up was 6.5 years. Survival with a functional larynx was similar in sequential and alternating arms (hazard ratio of death and/or event = 0.85, 95% confidence interval = 0.68 to 1.06), as were median overall survival (4.4 and 5.1 years, respectively) and median progression-free interval (3.0 and 3.1 years, respectively). Grade 3 or 4 mucositis occurred in 64 (32%) of the 200 patients in the sequential arm who received radiotherapy and in 47 (21%) of the 220 patients in the alternating arm. Late severe edema and/or fibrosis was observed in 32 (16%) patients in the sequential arm and in 25 (11%) in the alternating arm. CONCLUSIONS: Larynx preservation, progression-free interval, and overall survival were similar in both arms, as were acute and late toxic effects.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial.

BACKGROUND: Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. METHODS: The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. FINDINGS: The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4.0%) events of disabling stroke or death in the stenting group compared with 27 (3.2%) events in the endarterectomy group (hazard ratio [HR] 1.28, 95% CI 0.77-2.11). The incidence of stroke, death, or procedural myocardial infarction was 8.5% in the stenting group compared with 5.2% in the endarterectomy group (72 vs 44 events; HR 1.69, 1.16-2.45, p=0.006). Risks of any stroke (65 vs 35 events; HR 1.92, 1.27-2.89) and all-cause death (19 vs seven events; HR 2.76, 1.16-6.56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. There was one event of cranial nerve palsy in the stenting group compared with 45 in the endarterectomy group. There were also fewer haematomas of any severity in the stenting group than in the endarterectomy group (31 vs 50 events; p=0.0197). INTERPRETATION: Completion of long-term follow-up is needed to establish the efficacy of carotid artery stenting compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for patients suitable for surgery. FUNDING: Medical Research Council, the Stroke Association, Sanofi-Synthélabo, European Union.

Socio-economic benefits of using space technologies to monitor and respond to earthquakes

Earthquakes represent a major hazard for populations around the world, causing frequent loss of life,human suffering and enormous damage to homes, other buildings and infrastructure. The Technology Resources forEarthquake Monitoring and Response (TREMOR) Team of 36 space professionals analysed this problem over thecourse of the International Space University Summer Session Program and published their recommendations in the formof a report. The TREMOR Team proposes a series of space- and ground-based systems to provide improved capabilityto manage earthquakes. The first proposed system is a prototype earthquake early-warning system that improves theexisting knowledge of earthquake precursors and addresses the potential of these phenomena. Thus, the system willat first enable the definitive assessment of whether reliable earthquake early warning is possible through precursormonitoring. Should the answer be affirmative, the system itself would then form the basis of an operational earlywarningsystem. To achieve these goals, the authors propose a multi-variable approach in which the system will combine,integrate and process precursor data from space- and ground-based seismic monitoring systems (already existing andnew proposed systems) and data from a variety of related sources (e.g. historical databases, space weather data, faultmaps). The second proposed system, the prototype earthquake simulation and response system, coordinates the maincomponents of the response phase to reduce the time delays of response operations, increase the level of precisionin the data collected, facilitate communication amongst teams, enhance rescue and aid capabilities and so forth. It isbased in part on an earthquake simulator that will provide pre-event (if early warning is proven feasible) and post-eventdamage assessment and detailed data of the affected areas to corresponding disaster management actors by means of ageographic information system (GIS) interface. This is coupled with proposed mobile satellite communication hubs toprovide links between response teams. Business- and policy-based implementation strategies for these proposals, suchas the establishment of a non-governmental organisation to develop and operate the systems, are included.

RANTES/CCL5 and risk for coronary events: results from the MONICA/KORA Augsburg case-cohort, Athero-Express and CARDIoGRAM studies.

BACKGROUND: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. METHODS AND FINDINGS: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±4.8 years). Cox proportional hazard models adjusting for age, sex, body mass index, metabolic factors and lifestyle factors revealed no significant association between RANTES and incident coronary events (HR [95% CI] for increasing RANTES tertiles 1.0, 1.03 [0.75-1.42] and 1.11 [0.81-1.54]). None of six CCL5 single nucleotide polymorphisms and no common haplotype showed significant associations with coronary events. Also in the CARDIoGRAM study (>22,000 cases, >60,000 controls), none of these CCL5 SNPs was significantly associated with coronary artery disease. In the prospective Athero-Express biobank study, RANTES plaque levels were measured in 606 atherosclerotic lesions from patients who underwent carotid endarterectomy. RANTES content in atherosclerotic plaques was positively associated with macrophage infiltration and inversely associated with plaque calcification. However, there was no significant association between RANTES content in plaques and risk for coronary events (mean follow-up 2.8±0.8 years). CONCLUSIONS: High RANTES plaque levels were associated with an unstable plaque phenotype. However, the absence of associations between (i) RANTES serum levels, (ii) CCL5 genotypes and (iii) RANTES content in carotid plaques and either coronary artery disease or incident coronary events in our cohorts suggests that RANTES may not be a novel coronary risk biomarker. However, the potential relevance of RANTES levels in platelet-poor plasma needs to be investigated in further studies.

n-3 fatty acids and cardiovascular outcomes in patients with dysglycemia.

BACKGROUND: The use of n-3 fatty acids may prevent cardiovascular events in patients with recent myocardial infarction or heart failure. Their effects in patients with (or at risk for) type 2 diabetes mellitus are unknown. METHODS: In this double-blind study with a 2-by-2 factorial design, we randomly assigned 12,536 patients who were at high risk for cardiovascular events and had impaired fasting glucose, impaired glucose tolerance, or diabetes to receive a 1-g capsule containing at least 900 mg (90% or more) of ethyl esters of n-3 fatty acids or placebo daily and to receive either insulin glargine or standard care. The primary outcome was death from cardiovascular causes. The results of the comparison between n-3 fatty acids and placebo are reported here. RESULTS: During a median follow up of 6.2 years, the incidence of the primary outcome was not significantly decreased among patients receiving n-3 fatty acids, as compared with those receiving placebo (574 patients [9.1%] vs. 581 patients [9.3%]; hazard ratio, 0.98; 95% confidence interval [CI], 0.87 to 1.10; P=0.72). The use of n-3 fatty acids also had no significant effect on the rates of major vascular events (1034 patients [16.5%] vs. 1017 patients [16.3%]; hazard ratio, 1.01; 95% CI, 0.93 to 1.10; P=0.81), death from any cause (951 [15.1%] vs. 964 [15.4%]; hazard ratio, 0.98; 95% CI, 0.89 to 1.07; P=0.63), or death from arrhythmia (288 [4.6%] vs. 259 [4.1%]; hazard ratio, 1.10; 95% CI, 0.93 to 1.30; P=0.26). Triglyceride levels were reduced by 14.5 mg per deciliter (0.16 mmol per liter) more among patients receiving n-3 fatty acids than among those receiving placebo (P<0.001), without a significant effect on other lipids. Adverse effects were similar in the two groups. CONCLUSIONS: Daily supplementation with 1 g of n-3 fatty acids did not reduce the rate of cardiovascular events in patients at high risk for cardiovascular events. (Funded by Sanofi; ORIGIN ClinicalTrials.gov number, NCT00069784.).

Cumulative risk factors for adolescent alcohol misuse and its perceived consequences among 16 to 20 year old adolescents in Switzerland.

AIMS: To assess the cumulative impact of environmental and individual factors associated with adolescent alcohol misuse and their correlation with self-reported consequences of drinking. METHOD: Cross-sectional school-based survey of a nationally representative sample of 7548 post-mandatory school students and apprentices aged 16-20 years, Switzerland 2002. Alcohol misuse defined by frequency of alcohol use, episodes of drunkenness and driving while drunk. RESULTS: Fifteen significant risk factors were identified among both boys, and girls. An individual score of cumulated risk factors was created by adding the risk factors. The association between the score and the likelihood of being engaged in alcohol misuse was highly significant and dose-dependent (p<.001). A significant proportion of adolescents report perceived adverse consequences of their alcohol consumption. A linear trend (p<.001) was found between the score of risk factors and the proportion of respondents reporting problems related to drinking such as diminished school performance, physical hazard, relational problems and current risky sexual behavior. CONCLUSION: Risk factors for adolescent alcohol misuse are cumulative and can be synthesized into an individual score correlated with the likeliness of misuse. A further indication of the validity of this score is its linear relationship with self-reported problems related to drinking.

Medical treatments and risk factors for resection surgery in Crohn's disease: results from the Swiss IBD Cohort Study

Background: Surgery has been previously reported to be necessary in up to 80% of Crohn's disease (CD) patients, and up to 65% of patients needed reoperation after 10 years. Prevention of surgery is therefore a particularly important issue for these patients. Treatment options are controversial and data on them are scarce. This study reports medical treatments and main clinical risk factors in CD patients having undergone one or several surgeries. Risks for being free from surgery were also assessed. Methods: Retrospective cohort study, using data from patients included in the Swiss IBD cohort study from November 2006 to July 2011. History of resective surgeries, clinical characteristics and drug regimens were collected through detailed medical records. Univariate and multivariate analyses for clinical and therapeutic factors were performed. Cox regression was made to estimate free-of-surgery risks for different phenotypes and drugs. Results: Out of 1138 CD patients in the cohort, 721 (63.4%) were free of surgery at inclusion; 203 (17.8%) had 1 surgery and 214 (18.8%) >1 surgery. Main risk factors for surgery were disease duration 5-10 years (OR=2.92; p<0.001) and >10 years (OR=10.45; p<0.001), as well as stricturing (OR=8.33; p<0.001) or fistulizing disease (OR=7.34; p<0.001). Risk factors for repeated surgery was disease duration >10 years (OR=2.55; p=0.006) or fistulizing disease (OR=3.79; p<0.001). At inclusion, 107 patients (25.7%) had at least one anti-TNF alpha, 168 (40.3%) at least one immunosuppressive agent, and 41 (9.8%) at least 5-ASA or antibiotics. 64 (15.3%) were not exposed to any medical treatment. Kaplan-Meier curves showed that the risk of being free of surgery was 65% after 10 years, 42% after 20 years and 23% after 40 years. Surgical risks were four resp. five time higher for fistulizing and stricturing phenotypes (Hazard ratio (HR) =4.2; p<0.001; resp. HR=4.7; p<0.001) compared to inflammatory phenotype. Surgical risk was 4 times lower (HR=0.27; p=0.063) in CD patients under anti-TNF alpha compared to those under other or no drugs. Conclusion: The risk of having resective surgery was confirmed to be very high for CD in our cohort. Duration of disease, fistulizing and stricturing disease pattern enhance the risk of surgery. Anti-TNF alpha tends to lower this risk.

Fatal metformin overdose: case report and postmortem biochemistry contribution.

Metformin is an oral antihyperglycemic agent used in the management of type 2 diabetes mellitus. Lactic acidosis from metformin overdose is a rare complication of metformin therapy and occurs infrequently with therapeutic use. Fatal cases, both accidental and intentional, are extremely rare in clinical practice. Metformin is eliminated by the kidneys, and impaired renal function can result in an increased plasma concentration of the drug. In this report, we describe an autopsy case involving a 70-year-old woman suffering from diabetes mellitus and impaired renal function who received metformin treatment. Metformin concentrations in the peripheral blood collected during hospitalization and femoral blood collected during autopsy were 42 and 47.3 µg/ml, respectively. Lactic acidosis (29.10 mmol/l) was objectified during hospitalization. Furthermore, postmortem biochemistry allowed ketoacidosis to be diagnosed (blood β-hydroxybutyrate, 10,500 µmol/l). Death was attributed to lactic acidosis due to metformin intoxication. Increased plasma concentrations of the drug were attributed to severely impaired renal function. The case emphasizes the usefulness of performing exhaustive toxicology and postmortem biochemistry towards the more complete understanding of the pathophysiological mechanisms that may be involved in the death process.

Contribution of in vitro neurotoxicology studies to the elucidation of neurodegenerative processes.

Only a small percentage of neurodegenerative diseases like Alzheimer's disease and Parkinson's disease is directly related to familial forms. The etiology of the most abundant, sporadic forms seems to involve both genetic and environmental factors. Environmental compounds are now extensively studied for their possible contribution to neurodegeneration. Chemicals were found which were able to reproduce symptoms of known neurodegenerative diseases, others may either predispose to the onset of neurodegeneration, or exacerbate distinct pathogenic processes of these diseases. In any case, in vitro studies performed with models presenting various degrees of complexity have shown that many environmental compounds have the potential to cause neurodegeneration, through a variety of pathways similar to those described in neurodegenerative diseases. Since the population is exposed to a huge number of potentially neurotoxic compounds, there is an important need for rapid and efficient procedures for hazard evaluation. Xenobiotics elicit a cascade of reactions that, most of the time, involve numerous interactions between the different brain cell types. A reliable in vitro model for the detection of environmental toxins potentially at risk for neurodegenerative diseases should therefore allow maximal cell-cell interactions and multiparametric endpoints determination. The combined use of in vitro models and new analytical approaches using "omics" technologies should help to map toxicity pathways, and advance our understanding of the possible role of xenobiotics in the etiology of neurodegenerative diseases.

Mortality associated with diabetes mellitus in comparison with history of cardiovascular disease in older women.

BACKGROUND: Women with diabetes mellitus have an increased risk of cardiovascular disease (CVD) mortality and current treatment guidelines consider diabetes to be equivalent to existing CVD, but few data exist about the relative importance of these risk factors for total and cause-specific mortality in older women. METHODS: We studied 9704 women aged ≥65 years enrolled in a prospective cohort study (Study of Osteoporotic Fractures) during a mean follow-up of 13 years and compared all-cause, CVD and coronary heart disease (CHD) mortality among non-diabetic women without and with a prior history of CVD at baseline and diabetic women without and with a prior history of CVD. Diabetes mellitus and prior CVD (history of angina, myocardial infarction or stroke) were defined as self-report of physician diagnoses. Cause of death was adjudicated from death certificates and medical records when available (>95% deaths confirmed). Ascertainment of vital status was 99% complete. Log-rank tests for the rates of death and multivariate Cox hazard models adjusted for age, smoking, physical activity, systolic blood pressure, waist girth and education were used to compare mortality among the four groups with non-diabetic women without CVD as the referent group. Results are reported as adjusted hazard ratios (HR) with 95% confidence intervals (CI). RESULTS: At baseline mean age was 71.7±5.3 years, 7.0% reported diabetes mellitus and 14.5% reported prior CVD. 4257 women died during follow-up, 36.6% were attributed to CVD. The incidence of CVD death per 1000 person-years was 9.9 and 21.6 among non-diabetic women without and with CVD, respectively, and 23.8 and 33.3 among diabetic women without and with CVD, respectively. Compared to nondiabetic women without prior CVD, the risk of CVD mortality was elevated among both non-diabetic women with CVD (HR=1.82, CI: 1.60-2.07, P<0.001) and diabetic women without prior CVD (HR=2.24, CI: 1.87-2.69, P<0.001). CVD mortality was highest among diabetic women with CVD (HR=3.41, CI: 2.61-4.45, P<0.001). Compared to non-diabetic women with CVD, diabetic women without prior CVD had a significantly higher adjusted HR for total and CVD mortality (P<0.001 and P<0.05 respectively). CHD mortality did not differ significantly between non-diabetic women with CVD and diabetic women without prior CVD. CONCLUSION: Older diabetic women without prior CVD have a higher risk of all-cause and CVD mortality and a similar risk of CHD mortality compared to non-diabetic women with pre-existing CVD. For older women, these data support the equivalence of prior CVD and diabetes mellitus in current guidelines for the prevention of CVD.

Development of a control banding tool for nanomaterials

Control banding (CB) can be a useful tool for managing the potential risks of nanomaterials. The here proposed CB, which should be part of an overall risk control strategy, groups materials by hazard and emission potential. The resulting decision matrix proposes control bands adapted to the risk potential levels and helps define an action plan. If this plan is not practical and financially feasible, a full risk assessment is launched. The hazard banding combines key concepts of nanomaterial toxicology: translocation across biological barriers, fibrous nature, solubility, and reactivity. Already existing classifications specific to the nanomaterial can be used "as is." Otherwise, the toxicity of bulk or analogous substances gives an initial hazard band, which is increased if the substance is not easily soluble or if it has a higher reactivity than the substance. The emission potential bands are defined by the nanomaterials' physical form and process characteristics. Quantities, frequencies, and existing control measures are taken into account during the definition of the action plan. Control strategies range from room ventilation to full containment with expert advice. This CB approach, once validated, can be easily embedded in risk management systems. It allows integrating new toxicity data and needs no exposure data. [Authors]

Transcatheter aortic valve implantation in failed bioprosthetic surgical valves.

IMPORTANCE: Owing to a considerable shift toward bioprosthesis implantation rather than mechanical valves, it is expected that patients will increasingly present with degenerated bioprostheses in the next few years. Transcatheter aortic valve-in-valve implantation is a less invasive approach for patients with structural valve deterioration; however, a comprehensive evaluation of survival after the procedure has not yet been performed. OBJECTIVE: To determine the survival of patients after transcatheter valve-in-valve implantation inside failed surgical bioprosthetic valves. DESIGN, SETTING, AND PARTICIPANTS: Correlates for survival were evaluated using a multinational valve-in-valve registry that included 459 patients with degenerated bioprosthetic valves undergoing valve-in-valve implantation between 2007 and May 2013 in 55 centers (mean age, 77.6 [SD, 9.8] years; 56% men; median Society of Thoracic Surgeons mortality prediction score, 9.8% [interquartile range, 7.7%-16%]). Surgical valves were classified as small (≤21 mm; 29.7%), intermediate (>21 and <25 mm; 39.3%), and large (≥25 mm; 31%). Implanted devices included both balloon- and self-expandable valves. MAIN OUTCOMES AND MEASURES: Survival, stroke, and New York Heart Association functional class. RESULTS: Modes of bioprosthesis failure were stenosis (n = 181 [39.4%]), regurgitation (n = 139 [30.3%]), and combined (n = 139 [30.3%]). The stenosis group had a higher percentage of small valves (37% vs 20.9% and 26.6% in the regurgitation and combined groups, respectively; P = .005). Within 1 month following valve-in-valve implantation, 35 (7.6%) patients died, 8 (1.7%) had major stroke, and 313 (92.6%) of surviving patients had good functional status (New York Heart Association class I/II). The overall 1-year Kaplan-Meier survival rate was 83.2% (95% CI, 80.8%-84.7%; 62 death events; 228 survivors). Patients in the stenosis group had worse 1-year survival (76.6%; 95% CI, 68.9%-83.1%; 34 deaths; 86 survivors) in comparison with the regurgitation group (91.2%; 95% CI, 85.7%-96.7%; 10 deaths; 76 survivors) and the combined group (83.9%; 95% CI, 76.8%-91%; 18 deaths; 66 survivors) (P = .01). Similarly, patients with small valves had worse 1-year survival (74.8% [95% CI, 66.2%-83.4%]; 27 deaths; 57 survivors) vs with intermediate-sized valves (81.8%; 95% CI, 75.3%-88.3%; 26 deaths; 92 survivors) and with large valves (93.3%; 95% CI, 85.7%-96.7%; 7 deaths; 73 survivors) (P = .001). Factors associated with mortality within 1 year included having small surgical bioprosthesis (≤21 mm; hazard ratio, 2.04; 95% CI, 1.14-3.67; P = .02) and baseline stenosis (vs regurgitation; hazard ratio, 3.07; 95% CI, 1.33-7.08; P = .008). CONCLUSIONS AND RELEVANCE: In this registry of patients who underwent transcatheter valve-in-valve implantation for degenerated bioprosthetic aortic valves, overall 1-year survival was 83.2%. Survival was lower among patients with small bioprostheses and those with predominant surgical valve stenosis.

Free β-human chorionic gonadotropin, total human chorionic gonadotropin and maternal risk of breast cancer.

BACKGROUND: We investigated whether the free β-human chorionic gonadotropin (free β-hCG) would provide additional information to that provided by total hCG alone and thus be useful in future epidemiological studies relating hCG to maternal breast cancer risk. MATERIALS & METHODS: Cases (n = 159) and controls (n = 286) were a subset of our previous study within the Northern Sweden Maternity Cohort on total hCG during primiparous pregnancy and breast cancer risk. RESULTS: The associations between total hCG (hazard ratio: 0.79; 95% CI: 0.49-1.27), free β-hCG (hazard ratio: 0.85; 95% CI: 0.33-2.18) and maternal risk of breast cancer were very similar in all analyses and mutual adjustment for either one had minor effects on the risk estimates. CONCLUSION: In the absence of a reliable assay on intact hCG, total hCG alone can be used in epidemiological studies investigating hCG and breast cancer risk, as free β-hCG does not appear to provide any additional information.