Lung cancer registries in Denmark, Finland, Norway and Sweden: a comparison and proposal for harmonization

BACKGROUND

Lung cancer is the leading cause of cancer-related death in all Nordic countries which, though similar in demographics and healthcare systems, have noticeable differences in lung cancer survival. Historically, Denmark and Finland have had higher lung cancer incidences and lower survival than Norway and Sweden. All four countries have national cancer registries. Data in these registries are often compared, but their full potential as a source of learning across the Nordic countries is impeded by differences between the registries. In this paper, we describe and compare the Nordic registries on lung cancer-specific data and discuss how a more harmonized registration practice could increase their usefulness as a source for mutual learning and quality improvements.

METHODS

We describe and compare the characteristics of data on lung cancer cases from registries in Denmark, Finland, Norway and Sweden. Moreover, we compare the results from the latest annual reports and specify how data may be acquired from the registries for research.

RESULTS

Denmark has a separate clinical lung cancer registry with more detailed data than the other Nordic countries. Finland and Norway report lung cancer survival as relative survival, whereas Denmark and Sweden report overall survival. The Danish Lung Cancer Registry and the Swedish Cancer Registry do not receive data from the Cause of Death registries in contrast to the Finnish Cancer Registry and the Cancer Registry of Norway.

CONCLUSION

The lung cancer registries in Denmark, Finland, Norway and Sweden have high level of completeness. However, several important differences between the registries may bias comparative analyses.

Assessing how routes to diagnosis vary by the age of patients with cancer: a nationwide register-based cohort study in Denmark

BACKGROUND

Older patients with cancer have poorer prognosis compared to younger patients. Moreover, prognosis is related to how cancer is identified, and where in the healthcare system patients present, i.e. routes to diagnosis (RtD). We investigated whether RtD varied by patients' age.

METHODS

This population-based national cohort study used Danish registry data. Patients were categorized into age groups and eight mutually exclusive RtD. We employed multinomial logistic regressions adjusted for sex, region, diagnosis year, cohabitation, education, income, immigration status and comorbidities. Screened and non-screened patients were analysed separately.

RESULTS

The study included 137,876 patients. Both younger and older patients with cancer were less likely to get diagnosed after a cancer patient pathways referral from primary care physician compared to middle-aged patients. Older patients were more likely to get diagnosed via unplanned admission, death certificate only, and outpatient admission compared to younger patients. The patterns were similar across comorbidity levels.

CONCLUSIONS

RtD varied by age groups, and middle-aged patients were the most likely to get diagnosed after cancer patient pathways with referral from primary care. Emphasis should be put on raising clinicians' awareness of cancer being the underlying cause of symptoms in both younger patients and in older patients.

P1384 Longitudinal strain in basal, midventricular and apical segments in aortic stenosis and mitral regurgitation and the relationship to pulmonary capillary wedge pressure at exercise

Funding Acknowledgements

Supported by the Danish Heart Foundation

Background

Two dimensional speckle tracking provide reproducible regional and global assessment of left ventricular (LV) function. Valvular heart disease imposes both pressure overload (aortic stenosis (AS) and volume overload (mitral regurgitation (MR) on the LV. Despite high prevalence of valvular heart disease, little is known about the relationship between longitudinal strain (LS) measures and exercise hemodynamics in the pressure over loaded LV AS and the volume over loaded LV in MR.

Purpose

To describe the relationship between segmental LS in AS and MR according to normal or increased pulmonary capillary wedge pressure with exercise.

Methods

In a cross-sectional study patients with asymptomatic AS (aortic valve area <1 cm2 and peak velocity >3.5 m/s) and patients with primary MR (effective regurgitant orifice > 0.30 cm2) underwent echocardiography and stress test in semi-supine position with invasive hemodynamic assessment using a Swan-Ganz catheter. Echocardiograms were performed at rest on a Vivid 9 (GE, Horten, Norway) and stored for offline analysis. Semi-automatic software (Echopac version 202, GE) was used for LS analysis and recorded using an 18-segment model of the LV followed by segmentation into basal (BAS), midventricular (MID) and apical (API) segments. Semi-supine stress test was performed with increase in workload every third minute until exhaustion; at maximum exercise, pulmonary capillary wedge pressure was measured (maxPCWP). Patients were grouped according to maxPCWP > 28 mmHg (group 1) or ≤ 28 mmHg (group 2). Results are shown as mean ± SD, student’s t-test was used for continues data and pearsons chi-squared test was used for categorical data.

Results

Thirty-five patients with AS (age 73 ± 7.0 years, 74% men), and in 44 patients with MR (age 64 ± 8.8 years, 77% men) were studied. Patients with AS had a global LS of -18.8 ± 3.3% vs. -21.5 ± 3.3% in MR patients (p = 0.001). Basal, midventricular and apical LS was -14.5%±2.2%, -18.4 ± 2.9% and -26.3 ± 5.5% in AS patients and -18.4 ± 2.6%, -21.9 ± 2.9% and -26.7 ± 5.1% in MR patients (p < 0.001, p < 0.001 and 0.442, respectively). The proportion of AS patients that were in group 1(n = 23) were higher than the proportion of MI patients that were in group 1 (n = 19, 66 % vs 42%, p = 0.046). Patients in group 1 had lower LS in all segments (BAS: -15.7 ± 2.8% vs -17.7 ± 3.1%, MID: -19.3 ± 2.9% vs. -21.6 ± 3.4%, API: -26.0 ± 5.0% vs -27.8 ± 5.4%) but only BAS and MID segments were statistically significant(p = 0.005 and p = 0.002, respectively). In both AS and MR, patients in group 1 had lower segmental LS, but only MID LS in MR patients was statistically significant (-20.9%±2.5% vs -22.7 ± 2.9%, p = 0.030).

Conclusion

In patients with AS or MR PCWP above 28 mmHg with exercise was associated with lower LS in BAS and MID segments. This implies that in both pressure and volume overload resting LV function is depressed when patients have abnormally elevated filling pressure with exercise.

Abstract P1384 Figure. Longitudinal strain

Positron emission tomography within a magnetic field using photomultiplier tubes and lightguides

The spatial resolution of positron emission tomography (PET) improves when positron annihilation takes place in a strong magnetic field. In a magnetic field, the Lorentz force restricts positron range perpendicular to the field. Since positron annihilation occurs closer to its point of origin, the positron annihilation point spread function decreases. This was verified experimentally by measuring the spread function of positron annihilation from a 500 mm 68Ge bead imbedded in tissue-equivalent wax. At 5 T the spread function full width at half maximum (FWHM) and the full width at tenth maximum (FWTM) decrease by a factor of 1.42 and 2.09, respectively. Two NaI(Tl) scintillation crystals that interface to a pair of photomultiplier tubes (PMTS) through long lightguides detect positron annihilation at zero field and 5.0 T. Photomultiplier tubes, inoperable in strong magnetic fields, are functional if lightguides bring the photons produced by scintillators within the field to a minimal magnetic field. These tests also demonstrate techniques necessary for combining magnetic resonance imaging (MRI) and PET into one scanner.

Use of a magnetic field to increase the spatial resolution of positron emission tomography

Detector geometry, spatial sampling, and more fundamentally, positron range and noncollinearity of annihilation photon emission define Positron Emission Tomography (PET) spatial resolution. In this paper, a strong magnetic field is used to constrain positron travel transverse to the field. Measurement of the spread function from a 500 microns diameter 68Ga impregnated resin bead shows a squeezing of the full width at half maximum (FWHM) by a factor of 1.0, 1.22, 1.42, and 2.05, at 0, 4.0, 5.0, and 9.4 Tesla, respectively. The full width at tenth maximum (FWTM) decreases by a factor of 1.0, 1.73, 2.09, and 3.20, at 0, 4.0, 5.0, and 9.0 Tesla, respectively. Acquiring a PET image in a magnetic field should significantly reduce resolution loss due to positron range.

Fire and the Nitrogen Cycle in California Chaparral

Analysis of soils from burned and unburned chaparral indicates that high nitrate concentrations following fire are due to the addition of ammonium and organic nitrogen in the ash. Inhibition of mineralization in unburned chaparral results in low nitrate concentrations. Fluctuations in the amount of soil nitrate in unburned chaparral are the direct result of foliar leaching.