Identifying prevalent cases of breast cancer in the French case-mix databases

OBJECTIVES

Little is known about cancer prevalence due to a lack of systematic recording of cancer patient follow-up data. To estimate the annual hospital prevalence of breast cancer in the general population of the Isère department (1.1 million inhabitants) in the Rhône-Alpes region, the second largest region in France (6 million inhabitants), we used the inpatient case-mix data, available in most European countries, to develop a method of cancer case identification.

METHODS

A selection process was applied to the acute care hospital datasets among women aged 18 years or older, living in the Isère department and treated for breast cancer between 2004 and 2007. The first step in case selection was based on the national anonymous unique patient identifier. The second step consisted of retrieving all hospital stays for each case. The third step was designed to detect inconsistencies in the coding of the primary localization. An algorithm based on ICD-10 code for the hospital admission diagnosis was used to rule out hospitalizations unrelated to breast cancer. Five possible models for estimating prevalence were created combining selection steps with the admission diagnosis algorithm.

RESULTS

Hospital prevalence over the four-year period varied from 6073 breast cancer cases for the simplest model (first selection step without the admission diagnosis algorithm) to 4951 when the first selection step was associated with the breast cancer code as admission diagnosis. The model combining the third selection step with a breast cancer-specific admission reason provided 5275 prevalent cases.

CONCLUSION

The last model seems more appropriate for case-mix-data coding. Selecting admission diagnosis improved specificity. Combining all hospital stays for each patient has improved diagnostic sensitivity.

[Time trends in the geographic variation of thyroid cancer incidence by tumor size from 1983 to 2000 in France]

BACKGROUND

The aim of this investigation was to study geographic time trends of thyroid cancer incidence according to tumor size in France, 1983 to 2000.

METHODS

Incidence data were provided from six French registries over the period 1983-2000 covering seven administrative districts. Five tumor size groups were distinguished: < 10mm, 10-20mm, 20-40mm, > 40mm and unknown size. Papillary cancers diagnosed in women were analyzed according to tumor size in each geographic area. World age standardized rates were calculated and annual percent change rates were estimated for each tumor size group in each geographic area. Loglinear Poisson regression models were used to study geographic discrepancies in time trends incidences.

RESULTS

The six French registries included 2222 papillary thyroid cancers in women between 1983 et 2000. Thyroid cancer incidence was increasing in the six geographic areas. Geographical variations in time trends incidence between registries reflected geographical variations in time trends incidence of small sized tumors (less than 10mm).

CONCLUSION

Wide geographic variations in thyroid cancer incidence were noticed for small size tumors, which may be correlated with geographic variations in medical practices.

Multi-state Markov models in cancer screening evaluation: a brief review and case study

This work presents a brief overview of Markov models in cancer screening evaluation and focuses on two specific models. A three-state model was first proposed to estimate jointly the sensitivity of the screening procedure and the average duration in the preclinical phase, i.e. the period when the cancer is asymptomatic but detectable by screening. A five-state model, incorporating lymph node involvement as a prognostic factor, was later proposed combined with a survival analysis to predict the mortality reduction associated with screening. The strengths and limitations of these two models are illustrated using data from French breast cancer service screening programmes. The three-state model is a useful frame but parameter estimates should be interpreted with caution. They are highly correlated and depend heavily on the parametric assumptions of the model. Our results pointed out a serious limitation to the five-state model, due to implicit assumptions which are not always verified. Although it may still be useful, there is a need for more flexible models. Over-diagnosis is an important issue for both models and induces bias in parameter estimates. It can be addressed by adding a non-progressive state, but this may provide an uncertain estimation of over-diagnosis. When the primary goal is to avoid bias, rather than to estimate over-diagnosis, it may be more appropriate to correct for over-diagnosis assuming different levels in a sensitivity analysis. This would be particularly relevant in a perspective of mortality reduction estimation.

[Prostate cancer management and factors associated with radical prostatectomy in France in 2001]

INTRODUCTION

Prostate cancer was the most common cancer in men in France in 2005, and the second cause of male death from cancer. In this study, we analyzed clinical characteristics of patients with prostate cancer diagnosed in France in 2001 with a focus on therapeutic management of localized prostate cancers.

PATIENTS AND METHODS

A total of 2181 cases of prostate cancer diagnosed in 2001 from 11 French counties covered by a cancer registry were analyzed. A descriptive study of the clinical characteristics of patients was performed. Parameters studied included age, county, TNM stage, PSA value, Gleason score, D'Amico prognostic group, Charlson's comorbidity index and initial treatment modalities. For localized cancers, multivariate logistic regression analysis identified factors associated with radical prostatectomy.

RESULTS

The proportion of localized prostate cancer (T1 or T2) was 86.6 %. The use of invasive curative treatment (radical prostatectomy and radiotherapy) was 58.4 % for localized cancers. Significant differences in therapeutic management were found between counties. Radical prostatectomy was associated with age at diagnosis, D'Amico prognostic group and the presence of comorbidities.

CONCLUSIONS

Most of prostate cancers diagnosed in France in 2001 were clinically localized and were treated by invasive therapy. The consequences of these practices remain to be determined given the limited evolution of many prostate cancers and the frequency of adverse events related to invasive treatments.

Comparison of interval breast cancer rates for two-versus single-view screening mammography: a population-based study

OBJECTIVE

To determine whether the implementation of two-view mammography was followed by a reduction in the rates of interval cancers.

MATERIAL AND METHOD

We analyzed the data concerning women aged 50-69 who attended the breast cancer screening program between January 1, 1994 and December 31, 2006 in Isère, France. We performed Poisson regressions to estimate age-adjusted rate ratios of women being recalled, cancer detection, and interval cancer for two-view compared to single-view mammography.

RESULTS

After adjusting for age, two-view mammography was associated with a higher risk of cancer detection (1.37 [95% CI, 1.16-1.62]) and with a decreased risk of 12-month (0.46 [95% CI, 0.23-0.92]) and 24-month (0.64 [95% CI, 0.46-0.88]) interval cancer.

CONCLUSION

Two-view mammography for first and subsequent screens is associated with lower rates of interval breast cancer. This is at the expense of an increased number of women being recalled for further assessment after subsequent screens.

[Estimating the incidence of colorectal cancer in France from a hospital discharge database, 1999-2003]

BACKGROUND

Cancer incidence in France is monitored by district-level cancer registries, which cover only 15% of the population. Incidence at the national and regional level are estimated from mortality data by extrapolating the ratio between incidence and mortality observed in the districts covered by a cancer registry. Using the incidence/mortality ratio might not be relevant at the district-level (département). This study aims to produce district-level estimations of colorectal cancer incidence, using the ratio between incident cases from cancer registries and surgery admissions for colorectal cancer identified in the national hospital discharge database.

METHODS

This ratio was studied for the period 1999-2003 in the 13 districts covered by a cancer registry. For each sex separately, the number of incident cases was analyzed according to the number of surgery admissions for resection of colorectal cancer using a Poisson model. Age was introduced in the model as a fixed effect and district as a random effect. The model's ability to predict incidence was tested through cross-validation. The model was then extrapolated in order to estimate incidence of colorectal cancer in all French districts.

RESULTS

In the districts covered by a cancer registry, cross-validation showed the model had a good predictive ability, except in men for one district where the difference between predicted and observed incidence reached 10%. Estimated incidence rates, age-standardized on the world population, ranged broadly from 29 to 44 per 100,000 in men and from 17 to 27 per 100,000 in women. Incidence did not show any clear geographical pattern.

CONCLUSION

Among districts covered by a cancer registry, cross-validation showed overall good accuracy of predicted incidence. Inclusion of several admissions per patient was certainly a minor source of error in these estimations. Indeed, our selection only included 2% of multiple admissions, without geographical variations, in 2002 and 2003, years for which patient identifiers were available in the hospital discharge database. Estimated incidence rates presented moderate geographical variations and their prediction intervals should be taken into account.

Fast ternary and quaternary breakup of the 197Au + 197Au system in collisions at 15 MeV/nucleon

A new reaction mechanism of violent reseparation of a heavy nucleus-nucleus system, 197Au + 197Au, into three or four massive fragments in collisions at 15 MeV/nucleon has been observed. After reseparation, the fragments are almost exactly aligned, thus showing a very short time scale of the reseparation process, of about 70-80 fm/c.

[Some interpretation of regional estimates of the incidence of cancer in France over the period 1980--2005]

Francim Network has already provided French national estimations of cancer incidence then regional estimations for Metropolitan France. The present technical note summarizes the underlying hypotheses and the limits of the method and suggests some aspects of interpretation of those regional results in terms of absolute numbers and of standardized rates. Results on "all cancers" illustrate those comments.

[Inframunicipality distribution of lung cancer in the urban area of Grenoble]

BACKGROUND

Mapping a Cancer Atlas for the urban area of Grenoble revealed spatial distribution in the incidence of lung cancer among males at municipality level. Thus, our goal in this work was to use a new finer spatial scale to find out whether or not observed spatial variations might mask intramunicipality spatial variations.

METHODS

The use of a Bayesian smoothing approach allowed us to overcome problems related to the very small inframunicipality scale and to take into account the spatial autocorrelation existing between neighbouring units. The relative risks were adjusted on different socioeconomic variables like the median income per consumption unit.

RESULTS

After smoothing, areas with statistically significant 30 to 40% excess of cases and lack of cases were identified within the urban area of Grenoble. Median income per consumption unit appeared to be the most discriminating variable for characterizing the studied population.

CONCLUSION

The inframunicipality scale enables the study of a health problem as the lung cancer within a context of strong demographic disparities.

Concurrent and adjuvant docetaxel with three dimensional conformal radiation therapy (3-D CRT) for poor-risk localized prostate cancer: A phase II trial

5003

Background: Docetaxel increases survival in hormone refractory prostate cancer. The objective of this trial is to evaluate the feasibility of concomitant weekly docetaxel with 3-D CRT and adjuvant docetaxel in unfavorable localized or locally advanced prostate carcinoma. Methods: Sixteen patients with poor risk localized carcinoma (T1c-2b N0M0) and 34 with locally advanced tumors (T3N0- 1M0) according to the 1997 UICC classification, underwent 3-D CRT (72Gy/36 fractions); docetaxel 20mg/m2 iv was delivered concurrently on weeks 1–2-3–5-6–7; adjuvant docetaxel 60mg/m2 q3w started 4 weeks after the completion of radiotherapy for 3 cycles. The patients had to receive LHRH agonist, 6 months to 3 years, according to the number of poor prognostic factors. Acute toxicity was assessed with the NCI CTC v:2.0. Results: From November 2003 to November 2005, 50 patients were included (438 cycles) from six institutions. Median age was 50 years (48–76), median PSA 17.7 ng/ml (3.4–260) and median follow-up 17 months (9–38). Forty six patients completed the chemoradiation regimen (423 cycles), with full dose of docetaxel, 4 patients did not, due to: 1 grade 4 GI toxicity during the cycle 3, 1 grade 3 dysuria after cycle 6, 1 grade 4 myocardial infarction after cycle 6, 1 grade 4 anal fistula between two cycles of adjuvant docetaxel; these patients were excluded. The percentage of grade 3 acute toxicity was 10.8% (5/46): 1 grade 3 neutropenia, 1 grade 3 rectal bleeding, 2 grades 3 diarrhea, 1 grade 3 dysuria. Grade 2 toxicity (nausea, diarrhea and rectitis) were observed, in a percentage of 26%; no grade 2–3 toxicity occurred as regard hypotension, venous thrombosis, peripheral neuropathy, respiratory morbidity, oedemas. Twelve months after the end of the treatment, 44 patients were in complete remission (clinical and biological) and two patients suffer from distant metastases. Conclusion: The feasibility of this combined chemo-radiation regimen deserves to be followed by a phase III trial.

No significant financial relationships to disclose.

[Role of endovascular surgery in presence of rupture of the thoracic aorta in patients with severe multisystemic post-traumatic surgical lesions]

The endovascular treatment (ET) of traumatic rupture of the thoracic aorta (TRTA) may represent, particularly in patients with severe multisystemic post-traumatic surgical lesions, an alternative approach to traditional surgery. We observed (October 2001- November 2004) 5 male patients (age: range 23-42 years - average 32,4) affected by TRTA (3 isthmic aortic ruptures - 2 distal descending thoracic aorta ruptures), all successfully treated with an endovascular approach. The Glasgow Coma Score (GCS) ranged between 5 and 13. After performing resuscitation manoeuvres, all patients were investigated with total body CT scans in order to evaluate the thoracic aorta and to identify associated visceral lesions. In 4 cases were evident associated visceral lesions (3 cases: bone, abdominal and neurosurgical trauma - 1 case: bone, abdominal, neurosurgical and thoracic trauma). All the procedures were performed in the operative room using DSA (Digital Subtraction Angiography). The mean operating time was 105 minutes (range 80 - 125). We didn't observed early and late complications (follow-up: average 24 months, range 12-36). In conclusion the ET of TRTA represents in 'critical' patients with severe polytrauma an alternative approach to traditional surgery in order to 'stabilizing' the cardiovascular clinical parameters and to treating 'safety' the other associated surgical lesions.

[Influence of a priori parameters on bayesian relative risks estimations. Spatial distribution of bladder cancer in the urban area of Grenoble]

Bayesian estimates of disease relative risks is currently the gold standard in disease mapping when the disease is rare and/or when the geographical area is small. Its use has become quite easy with adhoc software. However, the implicit mechanisms of the choices made by the user must be clearly identified. We were interested here in the consequences of the choice of the hyper a priori parameters. We have compared results obtained using various hyper a priori parameters. The consequences of these choices are illustrated through the example of the incidence of bladder cancer among men in the urban area of Grenoble. We show that the risks can appear weak from a statistical point of view but important from an epidemiologic point of view in the presentation of the results.

A time trend analysis of papillary and follicular cancers as a function of tumour size: a study of data from six cancer registries in France (1983-2000)

The incidence of thyroid cancers, and in particular the papillary forms, has been increasing sharply for many years in Western countries. However, the factors explaining this increase have not been clearly established. Some studies mention the effects of radioactive fallout, particularly after the accident in Chernobyl. Another probable cause is related to progress in medical practice, and particularly in diagnosis. In this article, we describe time trends in the incidence of papillary and follicular cancers, taking into account the size of the tumour at the time of diagnosis. The analysis was carried out on cases from six French cancer registries for the period 1983-2000. Anatomopathological reports concerning 3381 cancer cases were systematically recoded and centralised, following ICDO-3 rules. Over the whole period, the annual percent change of the incidence of papillary cancers was +8.13% and +8.98%, respectively in men and in women. For micropapillary carcinomas (< or = 10 mm), this increase was respectively +12.05% and +12.85%. There is no significant effect of period apart from micropapillary carcinomas in women. However, a birth cohort effect exists for some groups. This effect corresponds to an acceleration in the risk for people born after the 1930s. For the most recent period (1998-2000), half the cases of papillary cancer were micropapillary carcinomas, and for one third of these, the tumour was < or = 5 mm. Our description of a time trend of incidence as a function of tumour size supports the hypothesis of the role of medical practice in a context of high prevalence. Obviously, these findings do not exclude the possible role of other factors.

[Predictive value and sensibility of hospital discharge system (PMSI) compared to cancer registries for thyroïd cancer (1999-2000)]

BACKGROUND

Cancer registries have a complete recording of new cancer cases occurring among residents of a specific geographic area. In France, they cover only 13% of the population. For thyroid cancer, where incidence rate is highly variable according to the district conversely to mortality, national incidence estimates are not accurate. A nationwide database, such as hospital discharge system, could improve this estimate but its positive predictive value and sensibility should be evaluated.

METHODS

The positive predictive value and the sensitivity for thyroid cancer case ascertainment (ICD-10) of the national hospital discharge system in 1999 and 2000 were estimated using the cancer registries database of 10 French districts as gold standard. The linkage of the two databases required transmission of nominative information from the health facilities of the study. From the registries database, a logistic regression analysis was carried out to identify factors related to being missed by the hospital discharge system.

RESULTS

Among the 973 standardized discharge charts selected from the hospital discharge system, 866 were considered as true positive cases, and 107 as false positive. Forty five of the latter group were prevalent cases. The predictive positive value was 89% (95% confidence interval (CI): 87-91%) and did not differ according to the district (p=0,80). According to the cancer registries, 322 thyroid cancer cases diagnosed in 1999 or 2000 were missed by the hospital discharge system. Thus, the sensitivity of this latter system was 73% (70-76%) and varied significantly from 62% to 85% across districts (p<0.001) and according to the type of health facility (p<0.01).

CONCLUSION

Predictive positive value of the French hospital discharge system for ascertainment of thyroid cancer cases is high and stable across districts. Sensitivity is lower and varies significantly according to the type of health facility and across districts, which limits the interest of this database for a national estimate of thyroid cancer incidence rate.

Isospin effects on subthreshold kaon production at intermediate energies

We show that in collisions with neutron-rich heavy ions at energies around the production threshold K0 and K+ yields probe the isospin-dependent part of the nuclear equation of state at high baryon densities. In particular, we suggest the K0/K+ ratio as a promising observable. Results obtained in a covariant relativistic transport approach are presented for Au+Au collisions at 0.8-1.8A GeV. The focus is put on the equation of state influence which goes beyond the collision-cascade picture. The isovector part of the in-medium interaction affects the kaon multiplicities via two mechanisms: (i) a symmetry potential effect, i.e., a larger neutron repulsion in n-rich systems, and (ii) a threshold effect, due to the change in the self-energies of the particles involved in inelastic processes. Genuine relativistic contributions are revealed that could allow one to directly "measure" the Lorentz structure of the effective isovector interaction.