Mats Lambe

Cancer survival in Australia, Canada, Denmark, Norway, Sweden, and the UK, 1995–2007 (the International Cancer Benchmarking Partnership): an analysis of population-based cancer registry data

Summary Background Cancer survival is a key measure of the effectiveness of health-care systems. Persistent regional and international differences in survival represent many avoidable deaths. Differences in survival have prompted or guided cancer control strategies. This is the first study in a programme to investigate international survival disparities, with the aim of informing health policy to raise standards and reduce inequalities in survival. Methods Data from population-based cancer registries in 12 jurisdictions in six countries were provided for 2·4 million adults diagnosed with primary colorectal, lung, breast (women), or ovarian cancer during 1995–2007, with follow-up to Dec 31, 2007. Data quality control and analyses were done centrally with a common protocol, overseen by external experts. We estimated 1-year and 5-year relative survival, constructing 252 complete life tables to control for background mortality by age, sex, and calendar year. We report age-specific and age-standardised relative survival at 1 and 5 years, and 5-year survival conditional on survival to the first anniversary of diagnosis. We also examined incidence and mortality trends during 1985–2005. Findings Relative survival improved during 1995–2007 for all four cancers in all jurisdictions. Survival was persistently higher in Australia, Canada, and Sweden, intermediate in Norway, and lower in Denmark, England, Northern Ireland, and Wales, particularly in the first year after diagnosis and for patients aged 65 years and older. International differences narrowed at all ages for breast cancer, from about 9% to 5% at 1 year and from about 14% to 8% at 5 years, but less or not at all for the other cancers. For colorectal cancer, the international range narrowed only for patients aged 65 years and older, by 2–6% at 1 year and by 2–3% at 5 years. Interpretation Up-to-date survival trends show increases but persistent differences between countries. Trends in cancer incidence and mortality are broadly consistent with these trends in survival. Data quality and changes in classification are not likely explanations. The patterns are consistent with later diagnosis or differences in treatment, particularly in Denmark and the UK, and in patients aged 65 years and older. Funding Department of Health, England; and Cancer Research UK.

Transient Increase in the Risk of Breast Cancer after Giving Birth

BACKGROUND The effect of pregnancy on the risk of breast cancer is not clear. We tested the hypothesis that the risk of breast cancer increases transiently after pregnancy but then falls to a level below that of age-matched nulliparous women. METHODS We conducted a case-control study of a nationwide cohort in Sweden, using a computerized record linkage between the Cancer Registry and the Fertility Registry. The study subjects were women born from 1925 through 1960 who were resident citizens of Sweden at the time of the 1960 census. A total of 12,666 patients with breast cancer were compared with 62,121 age-matched control subjects. We used conditional logistic regression to estimate odds ratios for the development of breast cancer at different ages, according to maternal age at first delivery (in uniparous as compared with nulliparous women) and age at second delivery (in biparous as compared with uniparous women). RESULTS Uniparous women were at higher risk of breast cancer than nulliparous women for up to 15 years after childbirth and at lower risk thereafter. The excess risk was most pronounced among women who were older at the time of their first delivery (odds ratio 5 years after delivery among women 35 years old at first delivery, 1.26; 95 percent confidence interval, 1.10 to 1.44). Women who had two pregnancies had a less striking increase in risk. CONCLUSIONS Pregnancy has a dual effect on the risk of breast cancer: it transiently increases the risk after childbirth but reduces the risk in later years. In women with two pregnancies, the short-term adverse effect is masked by the long-term protection imparted by the first pregnancy. A plausible biologic interpretation is that pregnancy increases the short-term risk of breast cancer by stimulating the growth of cells that have undergone the early stages of malignant transformation but that it confers long-term protection by inducing the differentiation of normal mammary stem cells that have the potential for neoplastic change.

Parity, age at first childbirth, and risk of ovarian cancer

Increasing parity is associated with a reduction in the risk of ovarian cancer, but it is not clear whether this association applies to different histopathological types and to borderline tumours. Moreover, the temporal relations are poorly understood, and the possible role of age at first birth remains unequivocal. We have investigated these issues in a case-control study nested in a nationwide cohort of women born between 1925 and 1960 in Sweden. During follow-up until 1984, 3486 invasive ovarian cancers (2992 epithelial, 330 stromal, 149 germ-cell, 15 not classifiable) and 510 tumours of borderline malignant potential were diagnosed. 5 individually age-matched controls (total 19,980) were selected for each case woman. After simultaneous adjustment for parity and age at first birth, increasing parity was associated with a pronounced consistent decrease in relative risk of all invasive cancers (odds ratio for each additional birth 0.81 [95% Cl 0.77-0.85]), epithelial cancer (0.81 [0.77-0.86]), stromal cancer (0.84 [0.72-0.98]), and germ-cell cancer (0.71 [0.48-1.05]), but a less consistent decrease for borderline tumours (0.92 [0.81-1.04]). The risk of ovarian cancer decreased by about 10% for each 5-year increment in age at first childbirth (odds ratios 0.89 [0.84-0.94] epithelial cancer, 0.92 [0.77-1.10] stromal cancer, 0.92 [0.65-1.32] germ-cell cancer, 0.93 [0.80-1.09] borderline tumours). Because our findings cannot be readily explained by theories involving incessant ovulation or high serum concentrations of gonadotropins, new aetiological hypotheses are needed. Pregnancy-dependent clearance from the ovaries of cells that have undergone malignant transformation could explain the reproductive risk factors for ovarian cancer.

Parity, age at first and last birth, and risk of breast cancer: A population-based study in Sweden

SummaryAssociations between parity and the risk of breast cancer, and the relative importance of age at first and age at last birth on breast cancer risk, were estimated in a case-control study nested in a nation-wide cohort of Swedish women born between 1925 and 1960. A total of 12,782 women with breast cancer and five times as many individually age-matched controls, aged less than 60 years with concomitant fertility information, were included in the analysis. Increasing parity was associated with a pronounced decrease in the risk of breast cancer with each additional birth conferring a 10 percent risk reduction (odds ratio 0.90 [95% CI 0.88–0.91]). In an analysis limited to women with two or more parities, and after adjustment for the effects of ages at interim births, the risk of breast cancer increased by about 13 percent for each five-year increment in age at first birth (odds ratio 1.13 [1.08–1.19]). For every five year-increase in age at last birth there was a small risk increase of marginal statistical significance (odds ratio 1.05 [1.01–1.09]).The present findings contradict recent claims that age at last birth has a stronger effect than age at first birth on breast cancer risk. The dominance of age at first birth as risk modulator is likely to reflect the protection afforded by the terminal differentiation of breast cells induced by a first pregnancy.

Mortality After Appendectomy in Sweden, 1987–1996

ObjectiveTo study mortality after appendectomy. Summary Background DataThe management of patients with suspected appendicitis remains controversial, with advocates of early surgery as well as of expectant management. Mortality is not known. MethodsThe authors conducted a complete follow-up of deaths within 30 days after all appendectomies in Sweden (population 8.9 million) during the years 1987 to 1996 (n = 117,424) by register linkage. The case fatality rate (CFR) and the standardized mortality ratio (SMR) were analyzed by discharge diagnosis. ResultsThe CFR was 2.44 per 1,000 appendectomies. It was strongly related to age (0.31 per 1,000 appendectomies at 0–9 years of age, decreasing to 0.07 at 20–29 years, and reaching 164 among nonagenarians) and diagnosis at surgery (0.8 per 1,000 appendectomies after nonperforated appendicitis, 5.1 after perforated appendicitis, 1.9 after appendectomies for nonsurgical abdominal pain, and 10.0 for those with other diagnoses). The SMR showed a sevenfold excess rate of deaths after appendectomy compared with the general population. The relation to age was less marked (SMR of 44.4 at 0–9 years, decreasing to 2.4 in patients aged 20–29 years. and reaching 8.1 in nonagenarians). The SMR was doubled after perforation compared with nonperforated appendicitis (6.5 and 3.5, respectively). Nonsurgical abdominal pain and other diagnoses were associated with a high excess rate of deaths (9.1 and 14.9, respectively). The most common causes of deaths were appendicitis, ischemic heart diseases and tumors, followed by gastrointestinal diseases. ConclusionsThe CFR after appendectomy is high in elderly patients. The excess rate of death for patients with nonperforated appendicitis and nonsurgical abdominal pain suggests that the deaths may partly be caused by the surgical trauma. Increased diagnostic efforts rather than urgent appendectomy are therefore warranted among frail patients with an equivocal diagnosis of appendicitis.

Excellent school performance at age 16 and risk of adult bipolar disorder: national cohort study

BACKGROUND Anecdotal and biographical reports suggest that bipolar disorder may be associated with high IQ or creativity, but evidence for any such connection is weak. AIMS To investigate possible associations between scholastic achievement and later bipolar disorder, using prospective data, in a whole-population cohort study. METHOD Using individual school grades from all individuals finishing compulsory schooling in Sweden between 1988 and 1997, we tested associations between scholastic achievement at age 15-16 and hospital admission for psychosis between ages 17 and 31, adjusting for potential confounders. RESULTS Individuals with excellent school performance had a nearly fourfold increased risk of later bipolar disorder compared with those with average grades (hazard ratio HR = 3.79, 95% CI 2.11-6.82). This association appeared to be confined to males. Students with the poorest grades were also at moderately increased risk of bipolar disorder (HR = 1.86, 95% CI 1.06-3.28). CONCLUSIONS These findings provide support for the hypothesis that exceptional intellectual ability is associated with bipolar disorder.

A Comprehensive Analysis of Human Gene Expression Profiles Identifies Stromal Immunoglobulin κ C as a Compatible Prognostic Marker in Human Solid Tumors

Purpose: Although the central role of the immune system for tumor prognosis is generally accepted, a single robust marker is not yet available. Experimental Design: On the basis of receiver operating characteristic analyses, robust markers were identified from a 60-gene B cell–derived metagene and analyzed in gene expression profiles of 1,810 breast cancer; 1,056 non–small cell lung carcinoma (NSCLC); 513 colorectal; and 426 ovarian cancer patients. Protein and RNA levels were examined in paraffin-embedded tissue of 330 breast cancer patients. The cell types were identified with immunohistochemical costaining and confocal fluorescence microscopy. Results: We identified immunoglobulin κ C (IGKC) which as a single marker is similarly predictive and prognostic as the entire B-cell metagene. IGKC was consistently associated with metastasis-free survival across different molecular subtypes in node-negative breast cancer (n = 965) and predicted response to anthracycline-based neoadjuvant chemotherapy (n = 845; P < 0.001). In addition, IGKC gene expression was prognostic in NSCLC and colorectal cancer. No association was observed in ovarian cancer. IGKC protein expression was significantly associated with survival in paraffin-embedded tissues of 330 breast cancer patients. Tumor-infiltrating plasma cells were identified as the source of IGKC expression. Conclusion: Our findings provide IGKC as a novel diagnostic marker for risk stratification in human cancer and support concepts to exploit the humoral immune response for anticancer therapy. It could be validated in several independent cohorts and carried out similarly well in RNA from fresh frozen as well as from paraffin tissue and on protein level by immunostaining. Clin Cancer Res; 18(9); 2695–703. ©2012 AACR.

Review of 103 Swedish Healthcare Quality Registries

In the past two decades, an increasing number of nationwide, Swedish Healthcare Quality Registries (QRs) focusing on specific disorders have been initiated, mostly by physicians. Here, we describe the purpose, organization, variables, coverage and completeness of 103 Swedish QRs.

Sociodemographic predictors of non-attendance at invitational mammography screening: a population-based register study (Sweden)

Objective: To investigate the role of sociodemographic factors in predicting mammography uptake in an outreach screening program. Methods: Linkage of data from a regional population-based mammography program with four Swedish nationwide registers: the Population and Housing Census of 1990, the Fertility Register, the Cancer Register, and the Cause of Death Register. We computed odds ratios (OR) and 95% confidence intervals (CI) for non-attendance by sociodemographic factors. Non-attendance was defined as failure to attend in response to the two most recent invitations. Results: Multivariate analyses among 4198 non-attenders and 38,972 attenders revealed that both childless and high-parity women were more likely to be non-attenders (OR = 1.8, 95% CI: 1.6–2.0 and OR = 2.2, 95% CI: 1.8–2.7, respectively). Women living without a partner were less likely to attend (OR = 1.7, 95% CI: 1.5–1.9), as were non-employed women (OR = 2.1, 95% CI: 1.9–2.3). Those renting an apartment were more likely to be non-attenders compared with home-owners (OR = 1.8, 95% CI: 1.6–2.0), and immigrants from non-Nordic countries were more than twice as likely to be non-attenders compared with Swedish-born women (OR = 2.4, 95% CI: 2.0–2.8). Conclusions: There are identifiable subgroups in which mammography utilization can be increased. Special attention should be paid to women who have never attended, childless women, and non-Nordic immigrants.

Absolute and Relative Risk of Cardiovascular Disease in Men With Prostate Cancer: Results From the Population-Based PCBaSe Sweden.

PURPOSE Cardiovascular disease (CVD) is a potential adverse effect of endocrine treatment (ET) for prostate cancer (PC). We investigated absolute and relative CVD risk in 76,600 patients with PC undergoing ET, curative treatment, or surveillance. METHODS PCBaSe Sweden is based on the National Prostate Cancer Register, which covers more than 96% of PC cases. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) of ischemic heart disease (IHD), acute myocardial infarction (MI), arrhythmia, heart failure, and stroke were calculated to compare observed and expected (using total Swedish population) numbers of CVD, taking into account age, calendar time, and previous CVD. RESULTS Between 1997 and 2007, 30,642 patients with PC received primary ET, 26,432 curative treatment, and 19,527 surveillance. SIRs for CVD were elevated in all men with the highest for those undergoing ET, independent of circulatory disease history (SIR MI for men without circulatory disease history: 1.40 [95% CI, 1.31 to 1.49], 1.15 [95% CI, 1.01 to 1.31], and 1.20 [95% CI, 1.11 to 1.30] for men undergoing ET, curative treatment, and surveillance, respectively). Absolute risk differences (ARD) showed that two (arrhythmia) to eight (IHD) extra cases of CVD would occur per 1,000 person-years. SMRs showed similar patterns, with ARD of zero (arrhythmia) to three (IHD) per 1,000 person-years. CONCLUSION Increased relative risks of nonfatal and fatal CVD were found among all men with PC, especially those treated with ET. Because ET is currently the only effective treatment for metastatic disease and the ARDs were rather small, our findings indicate that CVD risk should be considered when prescribing ET but should not constitute a contraindication when the expected gain is tangible.