Decreasing incidence of cancer after liver transplantation-A Nordic population-based study over 3 decades

Cancer remains one of the most serious long-term complications after liver transplantation (LT). Data for all adult LT patients between 1982 and 2013 were extracted from the Nordic Liver Transplant Registry. Through linkage with respective national cancer-registry data, we calculated standardized incidence ratios (SIRs) based on country, sex, calendar time, and age-specific incidence rates. Altogether 461 cancers were observed in 424 individuals of the 4246 LT patients during a mean 6.6-year follow-up. The overall SIR was 2.22 (95% confidence interval [CI], 2.02-2.43). SIRs were especially increased for colorectal cancer in recipients with primary sclerosing cholangitis (4.04) and for lung cancer in recipients with alcoholic liver disease (4.96). A decrease in the SIR for cancers occurring within 10 years post-LT was observed from the 1980s: 4.53 (95%CI, 2.47-7.60), the 1990s: 3.17 (95%CI, 2.70-3.71), to the 2000s: 1.76 (95%CI, 1.51-2.05). This was observed across age- and indication-groups. The sequential decrease for the SIR of non-Hodgkin lymphoma was 25.0-12.9-7.53, and for nonmelanoma skin cancer 80.0-29.7-10.4. Cancer risk after LT was found to be decreasing over time, especially for those cancers that are strongly associated with immunosuppression. Whether immunosuppression minimization contributed to this decrease merits further study.

Response to Intravenous Glucose-Tolerance Test and Risk of Cancer: A Long-Term Prospective Cohort Study

Background

Impaired glucose regulation, measured with an oral glucose-tolerance test, has been associated with the risk of cancer. Here, we explored whether the response to an intravenous glucose-tolerance test (IVGTT) is associated with the risk of cancer.

Methods

A cohort of 945 healthy men, aged 40–59 years in 1972–75, was followed for 40 years. An IVGTT was performed at baseline. Blood samples for glucose determinations were drawn immediately before glucose injection and thereafter every 10 min for 1 h. Associations were assessed with incidence rate ratios (IRR) and Cox models.

Findings

Cancer incidence was higher among men with 10-min glucose levels below the median than in men with levels above the median (IRR: 1.5, 95% CI: 1.2–1.9). This association remained significant after adjusting for relevant confounders (HR: 1.6, 95% CI: 1.3–2.1) and when excluding the first 10 years of follow-up to minimize the possibility of reverse causality (HR: 1.5, 95% CI: 1.2–2.0).

Interpretation

Healthy middle-aged males that responded to an intravenous glucose injection with rapid glucose elimination during the first phase had an elevated risk of cancer during 40 years of follow-up. First phase response to a glucose load might be related to cancer development.

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Rapid elimination of plasma glucose during the first phase response was associated with a 60% elevated risk of cancer

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Plasma glucose uptake during the first-phase may depend on the effectiveness of the molecular glucose-sensing apparatus

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Polymorphisms critical for glucose transport into normal cells may also be crucial for transporting glucose into cancer cells

In this study low levels of plasma glucose in the early phase of an intravenous glucose-tolerance test were associated with a 60% elevated risk of cancer. The glucose level in the early phase may depend on the effectiveness of the molecular glucose-sensing apparatus. The transport of glucose into cancer cells, that normally requires a constant supply of high glucose, may be rate limited by polymorphisms that are critical for plasma glucose-sensing in general. Previous research has shown that some key proteins, e.g. GLUT 1 and GLUT 2, are involved as glucose transporters into cancer cells.

Perinatal characteristics and breast cancer risk in daughters: a Scandinavian population-based study

The in utero origins of breast cancer are an increasing focus of research. However, the long time period between exposure and disease diagnosis, and the lack of standardized perinatal data collection makes this research challenging. We assessed perinatal factors, as proxies for in utero exposures, and breast cancer risk using pooled, population-based birth and cancer registry data. Birth registries provided information on perinatal exposures. Cases were females born in Norway, Sweden or Denmark who were subsequently diagnosed with primary, invasive breast cancer (n = 1419). Ten controls for each case were selected from the birth registries matched on country and birth year (n = 14,190). Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using unconditional regression models. Breast cancer risk rose 7% (95% CI 2-13%) with every 500 g (roughly 1 s.d.) increase in birth weight and 7% for every 1 s.d. increase in birth length (95% CI 1-14%). The association with birth length was attenuated after adjustment for birth weight, while the increase in risk with birth weight remained with adjustment for birth length. Ponderal index and small- and large-for-gestational-age status were not better predictors of risk than either weight or length alone. Risk was not associated with maternal education or age, gestational duration, delivery type or birth order, or with several pregnancy complications, including preeclampsia. These data confirm the positive association between birth weight and breast cancer risk. Other pregnancy characteristics, including complications such as preeclampsia, do not appear to be involved in later breast carcinogenesis in young women.

Toxicity in long-term survivors after adriamycin containing chemotherapy of malignant germ-cell tumors

In order to assess overall treatment-induced long-term morbidity after high-dose adriamycin-based chemotherapy +/- radiotherapy, clinically significant toxicity was studied in survivors after treatment of advanced germ-cell cancer who had received adriamycin-containing chemotherapy before cisplatin became available in Norway. Most of the patients were also irradiated. The study comprises 47 patients with advanced germ-cell cancer who survived for at least 5 years after chemotherapy containing adriamycin (VACAM: vincristine, adriamycin, cyclophosphamide, actinomycin-D and medroxyprogesterone acetate) as part of their primary systemic treatment (before 1978) or as maintenance chemotherapy after initial cisplatin-based cytotoxic treatment (after 1978). Thirty-two patients also had radiotherapy. The median follow-up was 12.3 years. Forty-one events of late toxicities were recorded in 25 patients, 37 of these were observed after combined radiotherapy and chemotherapy. The most frequent late side effects were cardiotoxicity, gastrointestinal toxicity and neurological disorders observed in 7, 12 and 8 patients, respectively. Three patients who were irradiated to the cardiac region, died of heart failure. Secondary solid cancer developed in 7 patients after a median follow-up of 10.5 years (relative risk 4.8, 95% confidence interval 1.9 to 9.9). In a historical perspective high-dose adriamycin-containing combination chemotherapy if applied with cyclophosphamide and/or radiotherapy, may occasionally be curative in selected patients with advanced germ cell tumours, but leads to an unacceptable high incidence of severe cardiac, gastrointestinal and neurological late side effects. The present follow-up study highlights that such treatment should be avoided in the curatively intended treatment of cancer patients and emphasizes the need of long-term follow-up studies in surviving cancer patients.

Metabolic risk factors and skin cancer in the Metabolic Syndrome and Cancer Project (Me-Can)

BACKGROUND

Little is known about the associations of metabolic aberrations with malignant melanoma (MM) and nonmelanoma skin cancer (NMSC).

OBJECTIVES

To assess the associations between metabolic factors (both individually and combined) and the risk of skin cancer in the large prospective Metabolic Syndrome and Cancer Project (Me-Can).

METHODS

During a mean follow-up of 12 years of the Me-Can cohort, 1728 (41% women) incident MM, 230 (23% women) fatal MM and 1145 (33% women) NMSC were identified. Most NMSC cases (76%) were squamous cell carcinoma (SCC) (873, 33% women). Hazard ratios (HRs) were estimated by Cox proportional hazards regression for quintiles and standardized z-scores (with a mean of 0 and SD of 1) of body mass index (BMI), blood pressure, glucose, cholesterol, triglycerides and for a combined metabolic syndrome score. Risk estimates were corrected for random error in the measurements.

RESULTS

Blood pressure per unit increase of z-score was associated with an increased risk of incident MM cases in men and women [HR 1·17, 95% confidence interval (CI) 1·04-1·31 and HR 1·18, 95% CI 1·03-1·36, respectively] and fatal MM cases among women (HR 2·39, 95% CI 1·58-3·64). In men, all quintiles for BMI above the reference were associated with a higher risk of incident MM. In women, SCC NMSC risk increased across quintiles for glucose levels (P-trend 0·02) and there was a trend with triglyceride concentration (P-trend 0·09).

CONCLUSION

These findings suggest that mechanisms linked to blood pressure may be involved in the pathogenesis of MM. SCC NMSC in women could be related to glucose and lipid metabolism.

Metabolic syndrome and rare gynecological cancers in the metabolic syndrome and cancer project (Me-Can)

BACKGROUND

Risk factors for rare gynecological cancers are largely unknown. Initial research has indicated that the metabolic syndrome (MetS) or individual components could play a role.

MATERIALS AND METHODS

The Metabolic syndrome and Cancer project cohort includes 288,834 women. During an average follow-up of 11 years, 82 vulvar, 26 vaginal and 43 other rare gynecological cancers were identified. Hazard ratios (HRs) were estimated fitting Cox proportional hazards regression models for tertiles and standardized z-scores [with a mean of 0 and a standard deviation (SD) of 1] of body mass index (BMI), blood pressure, glucose, cholesterol, triglycerides and MetS. Risk estimates were corrected for random error in the measurement of metabolic factors.

RESULTS

The MetS was associated with increased risk of vulvar [HR 1.78, 95% confidence interval (CI) 1.30-2.41) and vaginal cancer (HR 1.87, 95% CI 1.07-3.25). Among separate MetS components, 1 SD increase in BMI was associated with overall risk (HR 1.43, 95% CI 1.23-1.66), vulvar (HR 1.36, 95% CI 1.11-1.69) and vaginal cancer (HR 1.79, 95% CI 1.30-2.46). Blood glucose and triglyceride concentrations were associated with increased risk of vulvar cancer (HR 1.98, 95% CI 1.10-3.58 and HR 2.09, 95% CI 1.39-3.15, respectively).

CONCLUSION

The results from this first prospective study on rare gynecological cancers suggest that the MetS and its individual components may play a role in the development of these tumors.

Familial risks in nervous system tumours: joint Nordic study

Background:

Familial nervous system cancers are rare and limited data on familial aspects are available particularly on site-specific tumours.

Methods:

Data from five Nordic countries were used to analyse familial risks of nervous system tumours. Standardised incidence ratios (SIRs) were calculated for offspring of affected relatives compared with offspring of non-affected relatives.

Results:

The total number of patients with nervous system tumour was 63 307, of whom 32 347 belonged to the offspring generation. Of 851 familial patients (2.6%) in the offspring generation, 42 (4.7%) belonged to the families of a parent and at least two siblings affected. The SIR of brain tumours was 1.7 in offspring of affected parents; it was 2.0 in siblings and 9.4 in families with a parent and sibling affected. For spinal tumours, the SIRs were much higher for offspring of early onset tumours, 14.0 for offspring of affected parents and 22.7 for siblings. The SIRs for peripheral nerve tumours were 16.3 in offspring of affected parents, 27.7 in siblings and 943.9 in multiplex families.

Conclusion:

The results of this population-based study on medically diagnosed tumours show site-, proband- and age-specific risks for familial tumours, with implications for clinical genetic counselling and identification of the underlying genes.

Metabolic Profile (Blood Pressure, Lipids and Body Mass Index) in Relation to Breast Cancer Mortality

Background: Metabolic profile (body mass, blood pressure, lipids) may affect biological mechanisms of importance for breast cancer. In the present study we have studied whether these factors are related to breast cancer mortality.Material and Methods: Within the Norwegian Counties Study, a population-based study (1974-2005), we identified 1364 female invasive breast cancer cases.Results: The 1364 cases had a mean age at diagnosis 57.5 years (range 27.1-79.4 years), mean body mass index (BMI) was 24.0 kg/m2, mean systolic blood pressure was 128.1 mmHg, mean diastolic blood pressure 78.6 mmHg, mean serum cholesterol was 6.17 mmol/L and mean HDL-cholesterol was 1.45 mmol/L. A total of 429 cases died during a mean follow-up of 8.2 years. Those with a BMI ≥30 kg/m2 had a 1.45 (CI, 1.07 to 1.95) higher risk of dying during the follow-up than women with a BMI of 18.5–25 kg/m2. Women in the highest tertile of blood pressure had a 43% increase in mortality compared to women in the lowest tertile of blood pressure (HR=1.43, 95% CI, 1.10 to 1.85). Additionally, women in the highest tertile of total cholesterol had a 29% increase in mortality compared to women in the lowest tertile (HR=1.29, 95% CI, 1.01 to 1.65).Conclusion: Our study supports a relationship between total mortality among breast cancer patients and metabolic profile.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3047.

Conditions in utero and cancer risk

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Association between serum 25(OH)D and death from prostate cancer

Based on observations that for certain cancers, mortality varies according to sun exposure, vitamin D has been proposed to influence on disease progression. This study aims to investigate whether serum levels of 25(OH)D are associated with prognosis in patients with prostate cancer. In total, 160 patients with a serum sample in the JANUS serum bank were included. For 123 patients a pre-treatment serum sample was taken, whereas 37 of the patients had received hormone therapy prior to the blood collection. The serum level of 25(OH)D was classified as low (<50 nmol l(-1)), medium (50-80 nmol l(-1)) or high (>80 nmol l(-1)). A Cox proportional hazard regression model was used to assess the association between serum 25(OH)D and cancer mortality. During follow-up, 61 deaths occurred, of whom 52 died of prostate cancer. The median time of follow-up was 44.0 months (range, 1.2-154.6). Serum 25(OH)D at medium or high levels were significantly related to better prognosis (RR 0.33; 95% CI 0.14-0.77, RR 0.16; 95% CI 0.05-0.43) compared with the low level. Analysis restricted to patients receiving hormone therapy gave a stronger association. The serum level of 25(OH)D may be involved in disease progression and is a potential marker of prognosis in patients with prostate cancer.

17β-estradiol levels during an entire menstrual cycle in response to adult stature and insulin, of possible importance for breast cancer risk. The EBBA-I study

Abstract #4078

Background: The normal breast cells develop into malignant cells as a result of a complex interplay between genetic, environmental, nutritional and hormonal factors. Attained adult stature and insulin levels, risk factors for breast cancer, may also vary in response to the same factors. Thus, we hypothesize that 17β-estradiol, a key factor in the carcinogenesis of the breast, may vary in response to adult height in combination with insulin levels of possible importance of breast cancer risk.&#x2028; Methods: Among 204 healthy women, aged 25-35 years who participated in the Norwegian EBBA-I study, 17β-estradiol concentrations were measured in daily saliva samples throughout one entire menstrual cycle using radioimmunoassay (RIA). Attained height (cm) was measured, and serum concentrations of insulin were determined in fasting blood samples. The associations between adult height, insulin and 17β-estradiol levels throughout a menstrual cycle were studied using multivariate linear regression analyses and linear mixed models for repeated measures. Adjustments for potential confounding factors were performed.&#x2028; Results: A 37.2 % increase in 17β-estradiol levels was observed during the entire menstrual cycle among women with an adult height ≥170 cm (upper tertile) and insulin levels ≥ 90 pmol/L (upper tertile) compared to women with the same attained adult height, and insulin levels &lt; 90pmol/L. The association was even more pronounced when we looked into those women with attained adult height ≥170 cm (upper tertile) and serum insulin ≥ 101 pmol/L (upper quartile) (Fig. 1). Adjustments for potential confounding factors were performed.&#x2028; &#x2028; Conclusion: Our findings support that premenopausal levels of 17β-estradiol vary in response to adult height and insulin levels, suggesting that women who become taller are put at risk for higher estradiol levels throughout the entire menstrual cycle when their insulin levels rise, of possible importance for breast cancer risk.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4078.

Body size and thyroid cancer in two million Norwegian men and women

We investigated relations between measured body mass index (BMI) and stature and thyroid cancer (3046 cases) in a large Norwegian cohort of more than two million individuals. The risk of thyroid cancer, especially of the papillary and follicular types, increased moderately with increasing BMI and height in both sexes.

Risk factors for testicular cancer – differences between pure non-seminoma and mixed seminoma/non-seminoma?

The origin of testicular germ cell cancer (TGCC) is believed to be carcinoma in situ cells developed in utero. Clinically, TGCCs are divided into two major histological groups, seminomas and non-seminomas, where the latter group includes non-seminomatous TGCCs with seminomatous components (mixed S/NS TGCC). Recent studies, however, have suggested that non-seminomas and mixed S/NS TGCCs could have certain differences in aetiology, and in this study the TGCCs were divided into three, rather than the conventional two histological groups. A large case-control study was undertaken on data on all live-born boys registered in the Medical Birth Registry of Norway during the period 1967-1998 (n=961 396). Among these were 1087 TGCC cases registered in the Cancer Registry of Norway until February 2004. We found several risk factors for TGCC, including low parity, low gestational age, epilepsy and retained placenta. Several of the variables studied seemed to be risk factors for specific histological groups, e.g. parity 0 vs. 2 and low gestational age being associated with increased risk of non-seminomas, but not of mixed S/NS TGCC, and low maternal age being associated with increased risk of mixed S/NS TGCC, but not of non-seminomatous TGCC. Therefore, our results might suggest that non-seminomas and mixed S/NS TGCCs have partially different risk factors, whose associations may be obscured by combining these two histological groups. The histological groups were not significantly different, however. Most of our findings on risk factors for TGCC are in agreement with at least some previous studies. An unexplainable exception is low birth weight being associated with reduced risk of TGCC in our study.

Improved short-term survival for advanced ovarian, tubal, and peritoneal cancer patients operated at teaching hospitals

The aim of this study was to study the impact of hospital level and surgical skill on short-term survival of advanced ovarian, tubal, and peritoneal cancer patients in a prospective population-based study. All 198 women with a diagnosis of advanced epithelial invasive ovarian, tubal, and peritoneal cancer in Norway who underwent surgery during 2002 were included in this study. The data were derived from notifications to the Norwegian Cancer Registry and from medical, surgical, and histopathologic records. The hospitals were grouped into teaching and nonteaching hospitals (NTH), and the operating physicians were classified according to specialty (specialist gynecologist, gynecologist, and surgeon). The follow-up period was from 455 to 820 days. The short-term survival at 450 days was 79% for women operated at teaching hospitals (TH) and 62% at NTH (P= 0.02). After simultaneous adjustment for seven prognostic factors and residual disease, the risk of death within 600 days at NTH was unchanged compared to TH, hazard ratio 1.83. The women operated on by specialist compared to general gynecologists had a 20% increased short-term survival (P < 0.0001). TH and specialist gynecologists achieved better short-term survival of patients operated for advanced ovarian, tubal, and peritoneal cancer. Centralization and specialization of ovarian cancer surgery might improve the outcome for this patient group.

Surgery and pre-operative irradiation for locally advanced or recurrent rectal cancer in patients over 75 years of age

OBJECTIVE

Reports of multimodal treatment regimens especially focusing on locally advanced or recurrent rectal cancer in the elderly, aged>75 years, are unavailable. We have tried to identify and evaluate pre- and peri-operative risk factors for morbidity and mortality and outcome after irradiation/surgery regimens in such patients.

PATIENTS AND METHODS

Prospective registration of 86 consecutive patients aged>75 years undergoing elective surgery after irradiation 46-50 Gy for either primary locally advanced rectal cancer (n=51) or recurrent rectal cancer (n=35) from January 1991 to August 2003, 51 men and 35 women, median age 78 years (range 75-85 years) in a national cancer hospital.

RESULTS

Multivisceral resections were needed in 63% of patients and 70% R0 resections were obtained in locally advanced cases and 46% in recurrent ones. Both in-hospital- and 30-day-mortality was 3.5%. Sixty-two postoperative complications occurred in 38 patients, three of them fatal. Both operation times over 5 h and transfusion of more than 3 SAG were prognostic factors regarding infections. Estimated five-year survival in R0 patients was 46%. Estimated five-year survival for patients with nonmetastatic tumours with locally advanced primary cancer was 29% and for locally recurrent rectal cancer 32%. Old males had a higher mortality rate the first year after surgery than females with only 65% relative survival compared to a matched normal population. The estimated five-year local recurrence rates were 24% for R0 resections and 54% for R1 resections (P=0.434 ns) and 24% and 45% for locally advanced and recurrent rectal cancer (P=0.248 ns), respectively.

CONCLUSION

Thorough pre-operative evaluation and preparation and judicious surgery are important for achieving potentially curative treatment with acceptable morbidity in locally advanced and recurrent rectal cancer in patients over 75 years of age. We suggest that these patients should be evaluated and considered for treatment by multidisciplinary teams as younger patients.

Improved short-term survival for advanced ovarian, tubal, and peritoneal cancer patients operated at teaching hospitals

The aim of this study was to study the impact of hospital level and surgical skill on short-term survival of advanced ovarian, tubal, and peritoneal cancer patients in a prospective population-based study. All 198 women with a diagnosis of advanced epithelial invasive ovarian, tubal, and peritoneal cancer in Norway who underwent surgery during 2002 were included in this study. The data were derived from notifications to the Norwegian Cancer Registry and from medical, surgical, and histopathologic records. The hospitals were grouped into teaching and nonteaching hospitals (NTH), and the operating physicians were classified according to specialty (specialist gynecologist, gynecologist, and surgeon). The follow-up period was from 455 to 820 days. The short-term survival at 450 days was 79% for women operated at teaching hospitals (TH) and 62% at NTH (P= 0.02). After simultaneous adjustment for seven prognostic factors and residual disease, the risk of death within 600 days at NTH was unchanged compared to TH, hazard ratio 1.83. The women operated on by specialist compared to general gynecologists had a 20% increased short-term survival (P < 0.0001). TH and specialist gynecologists achieved better short-term survival of patients operated for advanced ovarian, tubal, and peritoneal cancer. Centralization and specialization of ovarian cancer surgery might improve the outcome for this patient group.

Early life events and later risk of colorectal cancer: age-period-cohort modelling in the Nordic countries and Estonia

BACKGROUND

A lowering of colorectal cancer risk for the birth cohorts born around World War II (WWII) has previously been observed in Norway, a country which suffered some 20% caloric restriction during the war. The purpose of the study was to conduct a similar kind of analysis in the other Nordic countries and Estonia, which were also subjected to various degrees of energy restriction during WWII.

METHODS

All new cases of colorectal cancer in the Nordic countries and Estonia diagnosed between 40 and 84 years of age and born between 1874 and 1953, were collected from the national cancer registries. The incidence data were fitted to an age-period-cohort model.

RESULTS

A transient drop in the estimated colorectal cancer incidence rate was observed for the birth cohorts born around WWII in Estonia, together with a tendency of decreased risk in Sweden and Denmark.

CONCLUSION

The previously observed lowering of colorectal cancer risk for persons born during WWII in Norway also prevails in Estonia. Energy restriction is a possible explanation for these findings, since the countries suffered from varying nutritional conditions during the war. Exogenous factors acting during periods early in life may have an impact on later colorectal cancer risk.

Height and body mass index in relation to cancer of the small intestine in two million Norwegian men and women

The present study aimed at exploring the relations between body mass index (BMI, (weight in kilograms)/(height in meters)(2)) and stature and cancer of the small intestine (1162 cases) in a large Norwegian cohort (of two million) with measured height and weight. Elevated BMI in males and increasing height in both sexes were associated with a moderately increased risk of cancer of the small intestine.

Breast and other cancers in 1445 blood relatives of 75 Nordic patients with ataxia telangiectasia

Epidemiological studies have consistently shown elevated rates of breast cancer among female blood relatives of patients with ataxia telangiectasia (AT), a rare autosomal recessive disease. A large proportion of the members of AT families are carriers of AT-causing gene mutations in ATM (Ataxia Telangiectasia Mutated), and it has been hypothesised that these otherwise healthy carriers are predisposed to breast cancer. This is an extended and enlarged follow-up study of cancer incidence in blood relatives of 75 patients with verified AT in 66 Nordic families. Blood relatives were identified through population registry linkages, and the occurrence of cancer was determined from cancer registry files in each country and compared with national incidence rates. The ATM mutation carrier probabilities of relatives were assigned from the combined information on location in family, consanguinity, if any, and supplementary carrier screening in some families. Among the 1445 blood relatives of AT patients, 225 cancers were observed, with 170.4 expected, yielding a standardised incidence ratio (SIR) of 1.3 (95% confidence interval (CI), 1.1-1.4). Invasive breast cancer occurred in 34 female relatives (SIR, 1.7; 95% CI, 1.2-2.4) and was diagnosed in 21 women before the age of 55 years (SIR, 2.9; 95% CI, 1.8-4.5), including seven mothers of probands (SIR, 8.1; 95% CI, 3.3-17). When the group of mothers was excluded, no clear relationship was observed between the allocated mutation carrier probability of each family member and the extent of breast cancer risk. We concluded that the increased risk for female breast cancer seen in 66 Nordic AT families appeared to be restricted to women under the age of 55 years and was due mainly to a very high risk in the group of mothers. The findings of breast cancer risk in mothers, but not other likely mutation carriers, in this and other studies raises questions about the hypothesis of a simple causal relationship with ATM heterozygosity.

Weak associations between sociodemographic factors and breast cancer: possible effects of early detection

Differences in incidence and survival of breast cancer have been observed to vary with regard to sociodemographic factors. This might be related to variation in frequency of doctor consultation and in time of diagnosis, since sociodemographic factors appear to influence the individual's attention to cancer symptoms and susceptibility to participate in screening programmes. This study aimed to examine the variation in breast cancer incidence and case fatality in sociodemographic groups in Norway, and to discuss whether any variation can result from temporal variation in detection time. The study included 589 521 women with information on residential history, childbearing pattern, educational level and occupational physical activity. Analyses were conducted using Poisson and Cox regression models. Although all the associations were weak, breast cancer incidence was associated with residence in urban areas, high age at first childbirth and high level of education. The urban women also tended to have better survival compared with the rural women. Childlessness was associated with high incidence and high case fatality. A high educational level was associated with the lowest case fatality. This study may emphasize the importance of discussing potential effects of early cancer detection. This is particularly important in epidemiological studies revealing weak associations between sociodemographic factors and breast cancer. Mortality rates may be less influenced by problems associated with early detection and, thus, analyses of breast cancer-specific mortality could give additional information.

Effect of hospital caseload on long-term outcome after standardization of rectal cancer surgery at a national level

Background

The purpose of this prospective study was to examine the influence of hospital caseload on long-term outcome following standardization of rectal cancer surgery at a national level.

Methods

Data relating to all 3388 Norwegian patients with rectal cancer treated for cure between November 1993 and December 1999 were recorded in a national database. Treating hospitals were divided into four groups according to their annual caseload: hospitals in group 1 (n = 4) carried out 30 or more procedures, those in group 2 (n = 6) performed 20–29 procedures, group 3 (n = 16) 10–19 procedures and group 4 (n = 28) fewer than ten procedures.

Results

The 5-year local recurrence rates were 9·2, 14·7, 12·5 and 17·5 per cent (P = 0·003) and 5-year overall survival rates were 64·4, 64·0, 60·8 and 57·8 per cent (P = 0·105) respectively in the four hospital caseload groups. An annual hospital caseload of less than ten procedures increased the risk of local recurrence compared with that in hospitals where 30 or more procedures were performed each year (hazard ratio 1·9 (95 per cent confidence interval (c.i.) 1·3 to 2·7); P &lt; 0·001). Overall survival was lower for patients treated at hospitals with an annual caseload of less than ten versus hospitals with 30 or more (hazard ratio 1·2 (95 per cent c.i. 1·0 to 1·5); P = 0·023).

Conclusion

The rate of local recurrence was higher for hospitals with a low annual caseload of less than ten procedures than for hospitals with a high treatment volume of 30 or more. Patients treated in small hospitals also had a shorter long-term survival than those treated in large hospitals.

The association between nutritional conditions during World War II and childhood anthropometric variables in the Nordic countries

BACKGROUND

The purpose of the study was to examine the height and weight in Nordic children during the years around World War II (WWII), and compare them with the nutritional situation during the same period.

METHODS

Information on food consumption and energy intake were obtained from the literature. Anthropometric data were collected from the Nordic capitals and cover the period from 1930 to 1960 for ages 7-13 years.

RESULTS

The greatest energy restriction took place in Norway (20%), followed by Finland (17%), while Sweden and Denmark had a restriction of 4-7% compared to pre-war levels. The most pronounced effect of WWII on height and weight is seen in Norwegian children, while some effect is observed for the youngest children in Finland. Little or no effect is seen in Sweden and Denmark.

CONCLUSION

The Nordic children were affected by WWII in terms of a transient reduction in temporal trends in height and weight, and the magnitude of this decrease was associated with the severity of the energy restriction prevailing in the respective country during the war. These findings warrant further studies of the chronic diseases associated with height and weight for cohorts being in their growth periods during WWII.

Symptoms and referral of women with epithelial ovarian tumors

OBJECTIVE

To study referral to hospital units and the clinical characteristics of women with epithelial ovarian tumors in a prospective, population-based study.

METHODS

Clinical information on all women diagnosed with epithelial invasive (n=486) and borderline ovarian tumors (n=137) in Norway during 2002 was derived from notifications to the Cancer Registry of Norway and medical, surgical and histopathological records.

RESULTS

Sixty-one percent of women with invasive ovarian tumors were initially referred to gynecology units. The 38% of women referred to surgical and medical units were more likely to have symptoms as 'bowel irregularity', 'pain outside the abdominal cavity', 'persisting fatigue' and 'respiratory difficulties'. These women were older, had lower performance status and had a delay in treatment of 20 and 24 days respectively compared to 11 at gynecology units.

CONCLUSION

Greater awareness of the symptoms of ovarian cancer might lead to earlier diagnosis and treatment and thus possibly improve survival.

Trends in Incidence of Brain and Central Nervous System Tumors in Norway, 1970–1999

The aim of this study was to investigate trends in the incidence of childhood and adult brain and central nervous system (CNS) tumors in Norway from 1970 through 1999. In this period, a total of 14,641 patients were diagnosed with a primary benign or malignant neoplasm of the brain and CNS. Age-adjusted incidence rates were reported together with results of loglinear regression and an age-period-cohort model based on the Poisson regression model. In children (<15 years), the proportion of brain and CNS tumors was 28.2% (1,042/3,697) of all new cancer cases compared with 2.8% in adults (13,599/492,237). The overall rate of brain and CNS tumors increased during the study period from 6.49 to 12.02 cases per 100,000 person-years. A trend of leveling off in incidence of most tumor categories during the study period was indicated with a possible continuing increase in the period 1995-1999, especially in the age group 0-4 years and in patients aged 60 years or more. Age and period together provided a satisfactory model in patients being <60 years of age and less completeness of diagnosis was found in males compared with females, possibly due to the distribution in males of more aggressive tumors.

Increased mortality rates in young and middle-aged patients with malignant germ cell tumours

Cisplatin-based chemotherapy of malignant germ cell tumours (MGCT) has been reported to increase the risk of cardiovascular morbidity. A high incidence of second nongerm cell malignancies is well documented in MGCT survivors. The death risk due to these conditions is, however, more unknown in MGCT patients. Standard mortality rates (SMRs) were established in 3378 Norwegian MGCT patients treated from 1962 to 1997 aged ⩽55 years. The patients represented three principal treatment strategies: 1962/1969 (period 1): radiotherapy only; 1970/1979 (period 2): radiotherapy with or without noncisplatin-containing chemotherapy; 1980/1997 (period 3): surgery only or radiotherapy or cisplatin-based chemotherapy. Patients were censored when they reached the age of 60 years. Patients not dying from MGCT displayed significantly increased SMRs for respectively diseases of the circulatory system (SMR: 1.2, 95% confidence interval (CI): 1.0–1.5), benign gastrointestinal disorders (SMR: 2.1, 95% CI: 1.1–3.5) and nongerm cell malignancies (SMR: 2.0, 95% CI: 1.7–2.4). The SMRs for diseases of the circulatory system were similar in the three observation periods, whereas the highest SMR for benign gastrointestinal disorders was observed in patients from period 2. The risk of dying from a nongerm cell malignancy was increased both in periods 2 and 3. In conclusion, although the overall SMR for diseases of the circulatory system is increased in MCGT survivors, the introduction of cisplatin-based chemotherapy into the treatment of MGCT has so far not resulted in increased death rates due to these conditions. Patients with MGCT have a significantly increased relative death risk due to a second nongerm cell cancer, even after the introduction of modern treatment principles with overall reduction of radiotherapy. The increased death risk due to benign gastrointestinal disorders, probably related to radiotherapy, requires future in-depth analysis.

Colorectal cancer survival trends in Norway 1958–1997

The purpose of this study was to examine the pattern of survival for colorectal adenocarcinoma (CRC), and to investigate the prognostic factors for the disease. In the analysis, 50993 cases of CRC aged 40-84 years, diagnosed between 1958 and 1997 in Norway, were included. Esteve's relative survival method was used, together with a time trend analysis, conducted by least-squares linear regression. Cox proportional hazards regression analysis was used to examine cause-specific mortality. Five-year relative CRC survival has increased by an estimated 3% per 5-year diagnostic period. In 1958-1962, relative survival was about 40% for both males and females, and increased to 56 and 60%, respectively, in 1993-1997. Rectal cancer had a higher cause-specific mortality (RR 1.26, 95% CI 1.22-1.30) than proximal colon (reference) and distal colon (RR 0.97, 95% CI 0.93-1.00 cancers), while females had a lower cause-specific mortality than males (RR 0.88, 95% CI 0.86-0.90). The increase in the relative survival rate in Norway is probably due to improved treatments and advanced diagnostics. Norway has a higher CRC survival rate than the EUROCARE average.

Height, body mass index, and prostate cancer: a follow-up of 950000 Norwegian men

The present study explored body mass index (BMI), height, and risk of prostate cancer in a large Norwegian cohort of 950000 men aged 20-74 years, whose height and weight were measured in a standardised way in the period 1963-1999. These were followed for an average of 21 years. The Cox proportional hazard models were used in the analyses. During follow-up, 33 300 histologically verified cases of prostate cancer were registered. The risk of prostate cancer increased by both BMI and height. The magnitude of the increase by BMI was modest, the relative risk (RR) of obese men (BMI>or=30) compared with normal weighted was 1.09 (95% CI: 1.04-1.15). However, the RR at age 50-59 years was 1.58 (95% CI: 1.29-1.94) in men being obese at about age 45 years compared with normal weighted men. The tallest men had an RR of 1.72 (95% CI: 1.46-2.04) compared with the shortest men. The overall effect of BMI on the incidence of prostate cancer was modest. The larger effect found in men aged 50-59 years might partly explain the previous inconsistent findings.

Benefit of population-based screening for phenotypic hemochromatosis in young men

BACKGROUND

Hereditary hemochromatosis (HH) is a common genetic disease leading to accumulation of iron in the body, most notably in the liver. More men than women become clinically ill. The prognosis is excellent if phlebotomy treatment is started before liver cirrhosis develops. Screening has been recommended, but the benefit of population-based screening has never been shown in a randomized clinical trial. In this article, we estimate the benefit of screening young men, using a theoretical model.

METHODS

A phenotypic screening scenario was modelled using a decision tree. Gain of quality-adjusted life-years was used as a measure of benefit, and estimated using Markov processes. Data on the accuracy of the screening tests, the prevalence of HH and the risk of liver cirrhosis were mainly derived from a cross-sectional study on the prevalence and morbidity of HH in 30509 men. Data on the excess mortality of cirrhosis were taken from relevant literature. Sensitivity analysis was done for important variables.

RESULTS

Assuming basal case values for variables, screening a cohort of 1000 men aged 30 years for phenotypic HH would gain about 8 quality-adjusted life-years, compared to awaiting symptomatic disease. Based on actual costs of our cross-sectional study, the screening cost was US$250 per quality-adjusted life-year gained. The prevalence of phenotypic HH, the excess mortality of liver cirrhosis, the quality of life in non-cirrhotic HH patients, and the fractions of patients compliant with treatment were the most important variables in the sensitivity analysis.

CONCLUSION

Incorporating screening for phenotypic HH in health survey programmes for young men may be worthwhile.

Trends in colorectal cancer incidence in Norway by gender and anatomic site: an age-period-cohort analysis

The purpose of this study was to examine the secular trend of colorectal cancer in Norway by gender and subsite. All new cases of cancer in proximal colon, distal colon and rectum diagnosed between 1958 and 1997 in Norway were included in the study, altogether 34 202 and 34 097 cases for men and women, respectively. The incidence data were fitted separately for each gender and subsite to an age-period-cohort model. An increase in incidence of colorectal cancer was seen from 1958 to 1997 for both men and women, although a moderate attenuation of the increase has taken place in the last 15-20 years. This observation is most pronounced for cancer of the distal colon, but is also evident for proximal colonic and rectal cancers. For the distal colon and rectum, the period effect is more important than the cohort effect for both genders, whilst opposite for the proximal colon. The main estimated trend for cohort effects is a steady increase for both men and women, apart from an unexpected drop in incidence among the cohorts born during or shortly after World War II. These findings indicate that different aetiological risk factors may act on cancers of the proximal and distal part of the large bowel and further suggest that exogenous risk factors acting very early in life may play a more important role for colorectal cancer than previously recognized.

Breast cancer incidence in food- vs non-food-producing areas in Norway: possible beneficial effects of World War II

It has been suggested that World War II influenced breast cancer risk among Norwegian women by affecting adolescent growth. Diet changed substantially during the war, and the reduction in energy intake was assumed to be larger in non-food-producing than in food-producing municipalities. In the present study, we have looked at the influence of residential history in areas with and without food production on the incidence of breast cancer in a population-based cohort study consisting of 597,906 women aged between 30 and 64 years. The study included 7311 cases of breast cancer, diagnosed between 1964 and 1992. The risk estimates were calculated using a Poisson regression model. The results suggest that residential history may influence the risk of breast cancer, where the suggested advantageous effect of World War II seems to be larger in non-food-producing than in food-producing areas. Breast cancer incidence was observed to decline for the post-war cohorts, which is discussed in relation to diet.

Birth weight as a predictor of breast cancer: a case-control study in Norway

The hypothesis that birth weight is positively associated with adult risk of breast cancer implies that factors related to intrauterine growth may be important for the development of this malignancy. Using stored birth records from the two main hospitals in Trondheim and Bergen, Norway, we collected information on birth weight, birth length and placenta weight among 373 women who developed breast cancer. From the same archives, we selected as controls 1150 women of identical age as the cases without a history of breast cancer. Information on age at first birth and parity were collected from the Central Person Registry in Norway. Based on conditional logistic regression analysis, breast cancer risk was positively associated with birth weight and with birth length (P for trend=0.02). Birth weights in the highest quartile (3730 g or more) were associated with 40% higher risk (odds ratio, 1.4, 95% confidence interval, 1.1-1.9) of breast cancer compared to birth weights in the lowest quartile (less than 3090 g). For birth length, the odds ratio for women who were 51.5 cm or more (highest quartile) was 1.3 (95% confidence interval, 1.0-1.8) compared to being less than 50 cm (lowest quartile) at birth. Adjustment for age at first birth and parity did not change these estimates. Placenta weight was not associated with breast cancer risk. This study provides strong evidence that intrauterine factors may influence future risk of breast cancer. A common feature of such factors would be their ability to stimulate foetal growth and, simultaneously, to influence intrauterine development of the mammary gland.

Blood pressure levels in treated hypertensive patients in general practice in Norway

The aim of this study was to examine the blood pressure (BP) levels in patients treated for essential hypertension in 1816 patients in general practice in Norway. The study was based on an optical readable questionnaire filled out by the physician including information about systolic (S) and diastolic (D) BP, gender, age, body weight, smoking habits and all pharmaceutical treatment given. Sixty-four per cent of the patients were treated with one antihypertensive drug. Only 22.3% of the women and 30.7% of the men (p < 0.05) had BP < or = 140/90 mmHg. When BP < 160/95 was used as criterion for BP control, the fraction of patients was 50%. The fraction of patients with DBP < or = 80 mmHg was 26% in the whole group of patients. DBP < or = 90 mmHg was achieved in 74% and SBP < or = 140 mmHg in 30% of the patients. The BP control was less in women and in patients above 60 years of age. Patients on combination therapy were no better controlled than those on monotherapy. Based on our results, the proportion of hypertensive patients on drug treatment with insufficient BP control is too high. Efforts should be made to improve the medical treatment of hypertension in general practice in Norway.

Risk factors for male breast cancer--a case-control study from Scandinavia

We report a population-based case-control study on risk factors for male breast cancer. Data on a broad range of previously suggested risk factors were collected in a set of Scandinavian breast cancer cases and matched controls. Incident cases (n = 282) with histologically verified carcinomas of the breast were identified from notification to the cancer registries of Denmark, Norway and Sweden over a 4-year period 1987-1991 and of these cases, 156 men could be approached and responded. Controls were identified through national central population registers and were matched individually for country, sex and year of birth. Controls with a diagnosis of breast cancer were excluded; 468 of 780 controls responded. Data on risk factors were collected by self-administered questionnaires mailed to the cases between land 2 years after diagnosis and to controls during the same period. The findings were compatible with an increased risk associated with family history of breast cancer (odds ratio (OR) = 3.3, 95% confidence interval (CI) 2.0-5.6), obesity 10 years before diagnosis (OR = 2.1, 95% CI 1.0-4.5) for BMI > 30, diabetes (OR = 2.6, 95% CI 1.3-5.3) and the use of digoxin and methyldopa (OR = 2.0 and 2.1, respectively). The association with family history of breast cancer has been repeated in several studies, while the relation to anthropometric measures has been equivocal. We could not substantiate some associations seen in other studies; namely those with high education, fertility, marital status, testicular injury, liver disease and religion. The detailed questions about gynaecomastia indicated that many cases reported signs of breast cancer as a gynaecomastia. This type of misunderstanding may explain the strong association with gynaecomastia seen in other studies. Several patients died before contact. Thus, risk factors related to a more aggressive male breast cancer or related to high risk of dying (e.g. liver cirrhosis, heavy smoking) may have been missed.

Cutaneous malignant melanoma in Norway: variation by region of residence before and after the age 17

OBJECTIVE

The aim of this study was to examine indirectly the importance of sun exposure during childhood and adolescence for the development of cutaneous malignant melanoma (CMM) by using a migration approach.

METHODS

A nested case-control study was carried out based on all inhabitants living in Norway at any time between 1960 and 1980. The cases were all diagnosed between 1960 and 1992 (n = 13,934) and 10 controls were added for each case (n = 130,507). Analyses were conducted on residence history in the southeast, mid-west and northern part of Norway, before and after age 17, also including working condition and educational level.

RESULTS

Birthplace in southeast was found to be twice as hazardous for the risk of CMM compared with birthplace in the north. The region of residence before as well as after age 17 was shown to influence the risk of CMM; the risk pattern in migrants tended to change direction toward the risk in the region to which they move. Associations was found between indoor working condition and CMM, and between high level of education and CMM, which support the hypothesis that pattern of sun exposure in adulthood affects the risk of CMM.

CONCLUSION

The results indicate sun exposure at any age to be of importance for the lifetime risk of CMM.

Premorbid body weight and its relations to primary tumour diameter in breast cancer patients; its dependence on estrogen and progesteron receptor status

Hormonal mechanisms have been offered as an explanation for the higher frequency of large tumours, lymph node metastases and poorer prognosis in obese breast cancer patients than in lean ones. If hormonal mechanisms are important for these relations, they should probably act more strongly in patients with hormonal receptor positive tumours than in those with negative ones. We have examined if the relations between premorbid body weight or Quetelet's index (weight/height2) and tumour diameter are modified by estrogen receptor alpha (ER) and progesteron receptor (PgR) status. The analyses were based on 1,241 women with unilateral disease treated with modified radical mastectomy living in the geografic area of Haukeland Hospital. Their body weight and height have been measured as a mean 12.5 years before presentation of the disease. Body weight and Quetelet's index have been adjusted for age. The relations were studied using linear regression analyses adjusting the effect of body weight with height and mean nuclear area of the tumour cells and adjusting the effect of Quetelet's index for mean nuclear area. The main findings showed that patients with high body weight or Quetelet's index presented more often with PgR positive tumours than lean ones. Quetelet's index was also positively related to ER. These relations were present in patients older than 50 years of age (older). Patients with large tumours (>2.0 cm) had significantly higher body weight and Quetelet's index than those with small ones. These differences were significantly present in older patients and in patients with PgR negative and ER negative-PgR negative tumours. Linear regression analyses confirmed that tumour diameter increases with body weight and Quetelet's index. These relations were present in both lymph node groups and in older patients. Stratification according to hormonal receptor status showed these relations to be significant in patients with ER negative, with PgR negative and those with ER negative-PgR negative tumours only. Taking age and hormonal receptor status into consideration simultaneously, both body weight and Quetelet's index were significantly related to tumour diameter in older patients with hormone receptor negative tumours. In conclusion body size was positively related to hormone receptor status and to diameter of the primary tumour. The relation to tumour diameter was present in older patients with hormone receptor negative tumours. Although hormonal mechanisms able to act on the tumour can not be excluded, mechanisms acting independent of hormonal receptors must be considered. Different mechanisms related to body fat cytokines are discussed.

An epidemiological study of cancer in adult twins born in Norway 1905-1945

We have identified 23 334 individuals (40%) of twins born in Norway 1905-45 where both twins were alive in 1960 without malignant disease. These were linked to the Cancer Registry of Norway. A reduced risk of malignant disease was demonstrated among twins for all tumour sites combined; standardized incidence rate (SIR): 0.90 (95% CI 0.85-0.94) in females and 0.95 (95% Cl 0.90-0.99) in males. In both sexes, we observed a significant reduced incidence of malignant melanomas of the skin. The incidence of colorectal cancer tended to be reduced for both sexes. In females, the incidence of tumours of the central nervous system and lungs were reduced. We consider our findings are real, but cannot explain them.

Cancer in patients with ataxia-telangiectasia and in their relatives in the nordic countries

BACKGROUND

Epidemiologic studies of the families of patients with ataxia-telangiectasia (A-T), a recessive genetic neurologic disorder caused by mutation of the ATM gene, suggest that heterozygous carriers of an ATM mutation are at increased risk of cancer. A population-based study of cancer incidence in A-T families with unbiased selection and tracing of relatives would confirm this hypothesis.

METHODS

We conducted a study in the Nordic countries of 1218 blood relatives of 56 A-T patients from 50 families. The relatives were identified from population registries, and the occurrence of cancer was determined from cancer registry files in each country and compared with national incidence rates. All statistical tests were two-sided.

RESULTS

Among the 56 patients with A-T, we observed six cases of cancer (four leukemias and two non-Hodgkin's lymphomas) compared with 0.16 expected, yielding a standardized incidence ratio (SIR) of 37 (95% confidence interval [CI] = 13 to 80). Among the 1218 relatives, 150 cancers were recorded, with 126 expected (SIR = 1.19; 95% CI = 1.01 to 1.40). Invasive breast cancer occurred in 21 female relatives of A-T patients (SIR = 1.54; 95% CI = 0.95 to 2.36), including five of the 50 mothers (all of whom are obligate ATM mutation carriers) (SIR = 7.1; 95% CI = 2.3 to 17). Relatives who were less likely to be carriers of a mutant ATM allele had no increase or only a modest, statistically nonsignificant increase in the risk of breast cancer. There was no evidence of increased risk for cancer at any other site.

CONCLUSIONS

We confirmed the previously recognized high risk of lymphoma and leukemia in A-T patients. Our data are also consistent with an increased risk of breast cancer among blood relatives of A-T patients. The epidemiologic findings suggest, however, that, even if ATM mutations are responsible for some breast cancer cases, ATM is a relatively weak genetic risk factor for the disease.

Reproductive function in male rats after brief in utero exposure to diethylstilboestrol

Long-term effects of brief in utero exposure to diethylstilboestrol (DES) during a foetal period known to be critical for gonadal development were evaluated. Rats were exposed to DES (100 microg/kg body-weight) from day 17 to 19 of pregnancy. All of the DES-treated pregnant rats (11/11) ate parts or whole of their offspring during the first day after birth (p=0.03). Surviving male offspring were examined on day 63 post-partum. DES induced a reduction in weight of the testis (p=0.06) and ventral prostate (p=0.07), even after this short exposure. DES tended to reduce the number of Sertoli cells (p=0.13). Our findings indicate that even a short in utero exposure of rats to DES during a critical period for gonadal development results in cannibalism and reduced testis and ventral prostate weight.

Characterization of ATM mutations in 41 Nordic families with ataxia telangiectasia

The Ataxia Telangiectasia Mutation (ATM) gene is mutated in the rare recessive syndrome Ataxia Telangiectasia (AT), which is characterized by cerebellar degeneration, immunodeficiency, and cancer predisposition. In this study, 41 AT families from Denmark, Finland, Norway, and Sweden were screened for ATM mutations. The protein truncation test (PTT), fragment length and heteroduplex analyses of large (0.8-1.2 kb) cDNA fragments were used. In total, 67 of 82 (82%) of the disease-causing alleles were characterized. Thirty-seven unique mutations were detected of which 25 have not previously been reported. The mutations had five different consequences for the ATM transcript: mutations affecting splicing (43%); frameshift mutations (32%); nonsense mutations (16%); small in-frame deletions (5%); and one double substitution (3%). In 28 of the probands mutations were found in both alleles, in 11 of the probands only one mutated allele was detected, and no mutations were detected in two Finnish probands. One-third of the probands (13) were homozygous, whereas the majority of the probands (26) were compound heterozygote with at least one identified allele. Ten alleles were found more than once; one Norwegian founder mutation constituted 57% of the Norwegian alleles. Several sequence variants were identified, none of them likely to be disease-causing. Some of them even involved partial skipping of exons, leading to subsequent truncation of the ATM protein.

[Prescription patterns of antihypertensive agents in general practice in 1995]

BACKGROUND

Hypertension represents a risk factor in the development of cardiovascular disease.

MATERIAL AND METHODS

The prescription of antihypertensive drugs and the daily doses used were examined in a questionnaire-based survey among 2,586 drug-treated hypertensive patients who attended a general practitioner for clinical control in November 1995.

RESULTS

The proportion of patients treated with one antihypertensive drug only was 63%. ACE inhibitors, alpha blockers and angiotensin-II antagonists constituted 22.7%, 6.6% and 4.4%, and betablockers, calcium channel blockers and diuretics 21.7%, 23.7% and 16.3% of the prescriptions respectively. Women were more often prescribed diuretics than men, and older individuals more often than younger persons. No striking difference in the prescription of antihypertensive drugs were observed between the five health regions of Norway. There was no reduction in the prescribed daily doses of antihypertensives used in combination therapy compared with monotherapy. In approximately one quarter of the prescriptions there was a positive correlation between the prescribed daily dose and the patient's weight. The number of antihypertensives prescribed did positively correlate with the patient's weight.

INTERPRETATION

This survey shows that antihypertensives without any documented effect on morbidity and mortality were frequently prescribed for hypertension in general practice. Except for the low proportion of diuretic users among elderly patients, our results is in accordance with the Guidelines from the Norwegian Society of General Practitioners.

Trends for invasive squamous cell neoplasia of the skin in Norway

Over the period 1966-1995, based on 11,662 patients, the incidence of squamous cell carcinoma of the skin increased three to four times in Norway mainly as a result of an increased number of localized tumours. In men, cancer of the auricle was the second most common site; in women the incidence was low.

Adverse drug reactions in current antihypertensive therapy: a general practice survey of 2586 patients in Norway

The objective of this study was to determine the frequency and profile of adverse reactions to antihypertensive drugs in an unselected group of drug-treated hypertensive patients. A questionnaire-based survey was carried out among 2586 drug-treated hypertensive patients who attended a general practitioner for clinical control. Adverse drug reactions reported spontaneously, upon general inquiry, upon specific questioning and as evaluated by a physician were used as the main outcome measures. The study shows that the percentage of patients who reported adverse drug reactions spontaneously, upon general inquiry and upon specific questioning were 16%, 24% and 62% respectively. Users of diuretics reported the lowest frequency of adverse reactions, whereas users of beta-blockers reported the highest frequency. In 7% of the patients, the adverse drug reactions were of such a nature that the physicians considered discontinuing the treatment. As a conclusion, the reported frequency of adverse drug reactions in antihypertensive treatment is high, but with significant differences between the various drug groups. Monotherapy is connected with far fewer adverse drug reactions than combination therapy.

Analyzing incidence of testis cancer by means of a frailty model

There are two striking epidemiological features of testicular cancer. First, the incidence has increased strongly over the past few decades. Secondly, the incidence is greatest among younger men, and then declines from a certain age. We have constructed a statistical model to fit these observations. The idea of the model is that a subgroup of men is particularly susceptible to testicular cancer. In statistical terminology this is called a frailty model, since it focuses on varying frailty of the individuals. The frailty, or susceptibility, is considered as being established by birth, and due to a mixture of genetic and environmental effects. The strong increase in incidence over calendar time points to strong environmental effects, which are thought to operate in fetal life, causing damage to the fetus. Based on data from the Norwegian Cancer Registry we fit a frailty model to incidence data collected during 1953-93. The model gives a good fit and we discuss the interpretations of our findings.