Insulin-like growth factor-1 (IGF1) genotype predicts breast volume after pregnancy and hormonal contraception and is associated with circulating IGF-1 levels: implications for risk of early-onset breast cancer in young women from hereditary breast cancer families

BRCA1/2 mutations predispose to early-onset breast cancer, especially after oral contraceptive (OC) use and pregnancy. However, the majority of breast cancers might be due to more prevalent low-penetrance genes, which may also modify the risk in BRCA mutation carriers. The absence of the IGF1 19-repeat allele has been associated with high insulin-like growth factor-1 (IGF-1) levels during OC use. High IGF-1 levels are linked to early-onset breast cancer and larger breast volumes in the general population. The goal of this study was to elucidate the relationships between IGF1 genotype, early-onset breast cancer, breast volume, circulating IGF-1 levels and OC use in a prospective cohort of 258 healthy women ⩽40 years old from high-risk breast cancer families. All women completed a questionnaire including information on reproductive factors and OC use. We measured the height, weight, breast volumes and plasma IGF-1 levels. IGF-1 levels were similar among parous and nulliparous women not using OCs. In all, 13% had no IGF1 19-repeat allele. There was an interaction between IGF1 genotype and OC use on IGF-1 levels (P=0.026) in nulliparous women and another interaction between IGF1 genotype and parity on breast volume (P=0.01). Absence of the 19-repeat allele was associated with high IGF-1 levels in nulliparous OC users and with larger breast volumes in parous women and OC users. Incident breast cancers were also more common in women without the 19-repeat allele (log rank P=0.002). Our results suggest that lack of the IGF1 19-repeat allele modifies IGF-1 levels, breast volume and possibly early-onset breast cancer risk after hormone exposure in young high-risk women.

Dental pulp capping: effect of Emdogain Gel on experimentally exposed human pulps

AIM

To investigate the effect of Emdogain Gel (Biora AB, Malmo, Sweden), consisting of a enamel matrix derivative (EMD) in a propylene glycol alginate (PGA) vehicle, on experimentally exposed human pulps and to register postoperative symptoms.

METHODOLOGY

Nine pairs of contralateral premolars scheduled for extraction on orthodontic indications were included. Following a superficial pulp amputation performed with a small (016) diamond bur, either EMDgel or a mix of calcium hydroxide and sterile saline was placed at random in contact with the pulp wound. The subjects made records of symptoms and were also interviewed about pain/discomfort by a blinded examiner. After 12 weeks the teeth were extracted, prepared and subjected to light microscopic examination in which the inflammation and newly formed hard tissue in the pulp were analysed. Immunohistochemistry was performed using affinity-purified rabbit anti-EMD polyclonal antibodies.

RESULTS

Postoperative symptoms were less frequent in the EMDgel-treated than in the calcium hydroxide-treated teeth, especially during the first six weeks. In the EMDgel-treated teeth, new tissue partly filled the space initially occupied by the gel and hard tissue was formed alongside the exposed dentine surfaces and in patches in the adjacent pulp tissue. EMD was detected in the areas where new hard tissue had been formed. The wound area of the EMDgel-treated teeth exhibited inflammation in the majority of the teeth whereas less inflammation was seen in the calcium hydroxide-treated teeth where the hard tissue was formed as a bridge.

CONCLUSIONS

In the EMDgel-treated teeth, postoperative symptoms were less frequent and the amount and pattern of hard tissue formation were markedly different than in the teeth treated with calcium hydroxide. However, the operative procedure and the formulation with EMD in a PGA vehicle do not seem to be effective for the formation of a hard tissue barrier.

Tumour necrosis factor blockers do not increase overall tumour risk in patients with rheumatoid arthritis, but may be associated with an increased risk of lymphomas

OBJECTIVE

To determine whether TNF blockers increase tumour risk in patients with RA.

MATERIALS AND METHODS

The South Swedish Arthritis Treatment Group register (SSATG) comprises over 90% of anti-TNF treated patients with RA in the area. 757 patients treated with etanercept or infliximab included between 1 February 1999 and 31 December 2002 were identified. 800 patients with conventional antirheumatic treatment in a community based cohort served as a comparison cohort. Tumours and deaths were identified in the cancer registry and population census registers. Patients were followed up from initiation of anti-TNF treatment or 1 July 1997 for the comparison group, until death or 31 December 2002.

RESULTS

In the anti-TNF group, 16 tumours (5 lymphomas) were identified in 1603 person-years at risk, and in the comparison group 69 tumours (2 lymphomas) in 3948 person-years. Standardised incidence ratios (SIRs) for total tumour relative risk for the anti-TNF group and the comparison group were 1.1 (95% confidence interval (CI) 0.6 to 1.8) and 1.4 (95% CI 1.1 to 1.8), respectively. The lymphoma relative risk (RR) was 11.5 (95% CI 3.7 to 26.9) and 1.3 (95% CI 0.2 to 4.5), respectively The total tumour RR excluding lymphoma was 0.79 (95% CI 0.4 to 1.42) and 1.39 (95% CI 1.08 to 1.76), respectively. Proportional hazard analysis for lymphomas yielded RR 4.9 (95% CI 0.9 to 26.2) in anti-TNF treated versus untreated patients.

CONCLUSION

Community based patients with RA treated conventionally had an increased overall tumour risk compared with the background population. A possible additional increased risk for lymphoma associated with TNF blockers was based on few cases and needs confirmation.

Birth weight is associated with postmenopausal breast cancer risk in Swedish women

There is some evidence that birth weight is associated with breast cancer. Whether this association differs between premenopausal and postmenopausal ages is still unclear. The results from this study suggest that higher birth weight is a risk factor for postmenopausal breast cancer (OR 1.06, CI 1.00–1.12, per 100 g), independent of selected early-life and adult factors.

Familial risk of tumors associated with hereditary non-polyposis colorectal cancer: a Swedish population-based study

BACKGROUND

Familial clustering, which may be due to inherited predisposition, is seen in several common cancer types. The aim of this study was to assess the familial risk of tumors that are associated with hereditary non-polyposis colorectal cancer (HNPCC), a familial cancer syndrome that confers an increased risk of several cancer types, and is associated with a low age at onset.

METHODS

The National Swedish Cancer Registry and population registers were utilized to identify all tumors among the offspring of individuals who had developed any of the diagnoses included in the Amsterdam II criteria for HNPCC. In all, 204,358 offspring of 102,814 individuals with cancer of the colorectum, endometrium, upper urinary tract or small intestine were identified.

RESULTS

Significantly increased risks for several tumor types were demonstrated. If the parent was below age 50 at diagnosis, the offspring Standard Incidence Ratios (SIRs) were 3.6 for colon cancer, 3.8 for rectal cancer, 2.8 for gastric cancer, and 2.3 for ovarian cancer. Offspring who had both a parent and a sibling with HNPCC-associated cancer showed even higher SIRs for cancer of the colorectum, endometrium, ovary, and urinary tract. The highest values were observed in the subgroup whose parent had developed multiple primary tumors; SIR 34.0 for colon cancer, 17.9 for rectal cancer, 21.8 for endometrial cancer, and 5.8 for ovarian cancer.

CONCLUSIONS

The study demonstrates that there is an increased risk for several tumor types among individuals whose parents developed HNPCC-associated tumors, where a young age at diagnosis and development of multiple tumors in the parents lead to the highest SIRs.

Breast-feeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Several studies have reported that the risk of breast cancer decreases with increasing duration of breast-feeding. Whether breast-feeding is associated with a reduced risk of hereditary breast cancer in women who carry deleterious BRCA1 and BRCA2 mutations is currently unknown.

METHODS

We conducted a case-control study of women with deleterious mutations in either the BRCA1 or the BRCA2 gene. Study participants, drawn from an international cohort, were matched on the basis of BRCA mutation (BRCA1 [n = 685] or BRCA2 [n = 280]), year of birth (+/-2 years), and country of residence. The study involved 965 case subjects diagnosed with breast cancer and 965 control subjects who had no history of breast or ovarian cancer. Information on pregnancies and breast-feeding practices was derived from a questionnaire administered to the women during the course of genetic counseling. Conditional logistic regression analyses were used to estimate odds ratios (ORs) for the risk of breast cancer. All statistical tests were two-sided.

RESULTS

Among women with BRCA1 mutations, the mean total duration of breast-feeding was statistically significantly shorter for case subjects than for control subjects (6.0 versus 8.7 months, respectively; mean difference = 2.7 months, 95% confidence interval [CI] = 1.4 to 4.0; P<.001). The total duration of breast-feeding was associated with a reduced risk of breast cancer (for each month of breast-feeding, OR = 0.98, 95% CI = 0.97 to 0.99; P(trend)<.001). Women with BRCA1 mutations who breast-fed for more than 1 year were less likely to have breast cancer than those who never breast-fed (OR = 0.55, 95% CI = 0.38 to 0.80; P =.001), although no such association was seen for BRCA2 (OR = 0.95, 95% CI = 0.56 to 1.59; P =.83).

CONCLUSIONS

Women with deleterious BRCA1 mutations who breast-fed for a cumulative total of more than 1 year had a statistically significantly reduced risk of breast cancer.

Melanoma and nonmelanoma skin cancer in patients with multiple tumours--evidence for new syndromes in a population-based study

BACKGROUND

The hypotheses that Swedish patients with four or more primary tumours [including at least one cutaneous malignant melanoma (CMM)] harbour an increased number of CDKN2A (formerly p16) germline mutations, and that this group of patients show a predisposition to other tumours, e.g. nonmelanoma skin cancer (NMSC), were studied descriptively. So far the mutation 113insArg explains all CDKN2A-associated CMM in ethnic Swedes.

OBJECTIVES

All patients with four or more primary tumours, of which at least one was a CMM, from the Southern Swedish Regional Tumour Registry, between 1958 and 1999, were included in this study.

METHODS

Forty-four patients were found and subdivided into three groups according to having multiple CMM (group A) or single CMM +/- NMSC (groups B and C). Screening for the presence of the Swedish founder mutation 113insArg in blood or in tissue blocks was performed.

RESULTS

Patients in group A were younger at the time of the first CMM diagnosis than patients in group B and group C. The 113insArg mutation was found in four of 44 patients (9%), three with multiple CMM. In group C (n = 14) no founder mutation was evident, while in group B (n = 15) one mutation carrier was found. Nonmutation carriers with multiple CMM (group A) also had a predilection for meningiomas and neurinomas (four patients) or multiple NMSC (three patients). In group B CMM were especially associated with adenocarcinomas but in group C CMM were associated with multiple NMSC.

CONCLUSION

The association between meningiomas and neurinomas (no acoustic neurinoma was seen) might indicate a new syndrome. Patients in groups B and C may harbour unknown genetic defects, which could interact with different environmental risk factors.

No relations between breast cancer risk and fatty acids of erythrocyte membranes in postmenopausal women of the Malmö Diet Cancer cohort (Sweden)

OBJECTIVE

To examine the fatty acid composition of erythrocyte membranes, in relation to obesity indexes and breast cancer risk.

DESIGN

A nested case-control study.

SETTING

The Malmö Diet Cancer cohort, Sweden.

SUBJECTS

Among women 50 y or older at baseline (n=12 803), incident breast cancer cases (n=237) were matched to controls (n=673) on age and screening date.

METHODS

A diet history method, a structured questionnaire, anthropometrics and blood samples provided data. Analysis included partial correlation coefficients between dietary fatty acids (DFA) and fatty acids of erythrocyte membranes (EFA), and Spearman's rank order correlations between EFA and four obesity indexes. Conditional logistic regression examined breast cancer risks related to EFA.

RESULTS

DFA and EFA from fish and milk, and DFA and EFA linoleic acid, show significant positive associations. Relations are negative between indexes of obesity and "milk" EFA, but positive between indexes of obesity and indexes of delta9- and delta6-desaturase enzyme activity. No significant relations were observed between EFA and breast cancer risk.

CONCLUSIONS

Similar to other studies, dietary fish and milk fatty acids, and linoleic acid, are related to the corresponding EFA. Breast cancer risk was not significantly related to EFA in this study. However, the findings suggest positive relations between body mass index, body fat per cent and indexes of desaturase activity, and negative relations between central obesity and milk EFA.

SPONSORSHIP

The Swedish Cancer Society, the Swedish Medical Research Council, the European Commission, the Swedish Dairy Association and the City of Malmö.

Intakes of plant foods, fibre and fat and risk of breast cancer--a prospective study in the Malmö Diet and Cancer cohort

The objective of this study was to investigate prospectively the associations between intakes of plant foods, fibre and relative fat and risk of breast cancer in a subsample of 11 726 postmenopausal women in the Malmö Diet and Cancer cohort. Data were obtained by an interview-based diet history method, a structured questionnaire, anthropometrical measurements and national and regional cancer registries. During 89 602 person-years of follow-up, 342 incident cases were documented. Cox regression analysis examined breast cancer risks adjusted for potential confounders. High fibre intakes were associated with a lower risk of postmenopausal breast cancer, incidence rate ratio=0.58, 95% CI: 0.40, 0.84, for the highest quintile of fibre intake compared to the lowest quintile. The combination high fibre–low fat had the lowest risk when examining the effect in each cell of cross-classified tertiles of fibre and fat intakes. An interaction (P=0.049) was found between fibre- and fat-tertiles. There was no significant association between breast cancer risk and intakes of any of the plant food subgroups. These findings support the hypothesis that a dietary pattern characterised by high fibre and low fat intakes is associated with a lower risk of postmenopausal breast cancer.

One in 10 ovarian cancer patients carry germ line BRCA1 or BRCA2 mutations

At least 10% of all ovarian cancers are estimated to have a hereditary background. Hereditary breast-ovarian cancer (HBOC) due to mutations in the BRCA genes is a major cause of hereditary ovarian cancer, although its frequency and relationship to age and family history in unselected series of ovarian cancers is not completely known. We report here the results of a full mutational screening analysis for germ line BRCA1 and BRCA2 mutations in 161 patients with invasive epithelial ovarian carcinomas. Age at diagnosis ranged from 22 to 82 years (mean 59 years). Deleterious (frame-shift, nonsense and missense) mutations were detected in 13/161 (8%) of the patients and affected BRCA1 in 12 cases and BRCA2 in one case. Four additional missense variants (one in BRCA1 and three in BRCA2) with a possible association with an increased risk ovarian cancer were revealed, resulting in a total frequency of BRCA gene alterations of 17/161 (11%). The 13 patients with deleterious mutations had a mean age of 57 years (range 41-76 years) and only three of these patients were below 50 years of age. A family history of at least one breast cancer and/or ovarian cancer was reported in all but 1 of the patients with BRCA mutations compared with only 24% of patients without mutations. Our findings in this prospective study confirm approximately 1 in 10 patients with ovarian cancer carry a germ line BRCA gene mutation associated with HBOC, and also indicate that a large number of these patients are over 50 years of age at diagnosis.

Maintenance therapy with budesonide and formoterol in chronicobstructive pulmonary disease

Lung function in chronic obstructive pulmonary disease (COPD) can be improved acutely by oral corticosteroids and bronchodilators. Whether clinical improvement can be maintained by subsequent inhaled therapy is unknown. COPD patients (n=1,022, mean prebronchodilator forced expiratory volume in one second (FEV1) 36% predicted) initially received formoterol (9 microg b.i.d.) and oral prednisolone (30 mg o.d.) for 2 weeks. After this time, patients were randomised to b.i.d. inhaled budesonide/formoterol 320/9 microg, budesonide 400 microg, formoterol 9 microg or placebo for 12 months. Postmedication FEV1 improved by 0.21 L and health-related quality of life using the St George's Respiratory Questionnaire (SGRQ) by 4.5 units after run-in. Fewer patients receiving budesonide/formoterol withdrew from the study than those receiving budesonide, formoterol or placebo. Budesonide/formoterol patients had a prolonged time to first exacerbation (254 versus 96 days) and maintained higher FEV1 (99% versus 87% of baseline), both primary variables versus placebo. They had fewer exacerbations (1.38 versus 1.80 exacerbations per patient per year), had higher prebronchodilator peak expiratory flow, and showed clinically relevant improvements in SGRQ versus placebo (-7.5 units). Budesonide/formoterol was more effective than either monocomponent in both primary variables. Budesonide/formoterol in a single inhaler (Symbicort) maintains the benefit of treatment optimisation, stabilising lung function and delaying exacerbations more effectively than either component drug alone or placebo.

Are smoking-associated cancers prevented or postponed in women using hormone replacement therapy?

OBJECTIVE

[corrected] To investigate the relationship between hormone replacement therapy (HRT), smoking, and cancer incidence.

METHODS

Baseline interviews were conducted from 1990 to 1992 in a population-based cohort of 29,508 Swedish women aged 25-65 years with no history of cancer. Cancer incidence in the cohort was assessed through December 31, 1999, with the Swedish Cancer Registry, the Population Census Registry, and the Cause of Death Registry.

RESULTS

When follow-up ended, the cohort included 226,611 person-years. A total of 1145 malignancies were diagnosed (observed), and 1166.6 were expected (standardized incidence ratio 0.98; 95% confidence interval [CI] 0.93, 1.04). Women who had experienced a natural menopause and had ever used HRT had no increased incidence of cancer overall (standardized incidence ratio 1.03; 95% CI 0.88, 1.19). Long-term HRT users who smoked had a decreased incidence of smoking-related cancers, such as the oral cavity, pharynx, hypopharynx, larynx, esophagus, lung, cervix, and bladder (standardized incidence ratio 0.24; 95% CI 0.08, 0.76). The effect was seen regardless of the type of HRT (progestin versus non-progestin-containing preparations) used and number of cigarettes smoked. The protective role of HRT for colon cancer was evident among both smokers and nonsmokers. An increased incidence of endometrial cancer was seen only for nonsmokers who used HRT.

CONCLUSION

Our data indicate that HRT use protects women against smoking-associated cancers. This effect occurs regardless of the type of HRT and the amount of smoking.

Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies

Germline mutations in BRCA1 and BRCA2 confer high risks of breast and ovarian cancer, but the average magnitude of these risks is uncertain and may depend on the context. Estimates based on multiple-case families may be enriched for mutations of higher risk and/or other familial risk factors, whereas risk estimates from studies based on cases unselected for family history have been imprecise. We pooled pedigree data from 22 studies involving 8,139 index case patients unselected for family history with female (86%) or male (2%) breast cancer or epithelial ovarian cancer (12%), 500 of whom had been found to carry a germline mutation in BRCA1 or BRCA2. Breast and ovarian cancer incidence rates for mutation carriers were estimated using a modified segregation analysis, based on the occurrence of these cancers in the relatives of mutation-carrying index case patients. The average cumulative risks in BRCA1-mutation carriers by age 70 years were 65% (95% confidence interval 44%-78%) for breast cancer and 39% (18%-54%) for ovarian cancer. The corresponding estimates for BRCA2 were 45% (31%-56%) and 11% (2.4%-19%). Relative risks of breast cancer declined significantly with age for BRCA1-mutation carriers (P trend.0012) but not for BRCA2-mutation carriers. Risks in carriers were higher when based on index breast cancer cases diagnosed at <35 years of age. We found some evidence for a reduction in risk in women from earlier birth cohorts and for variation in risk by mutation position for both genes. The pattern of cancer risks was similar to those found in multiple-case families, but their absolute magnitudes were lower, particularly for BRCA2. The variation in risk by age at diagnosis of index case is consistent with the effects of other genes modifying cancer risk in carriers.

Relation between the rate of tumour cell proliferation and latency time in radiation associated breast cancer

BACKGROUND

Patients with possible radiation induced cancer could be used to study if the rate of tumour cell proliferation is related to latency time. Such a finding could help researcher to find time periods when other initiating risk factors operate.

METHODS

Seventeen women with breast cancer, with a prior history of radiation treatment towards the parts or the whole breast, exclusive of the primary treatment of a breast cancer were identified. Most women had received treatment for benign disorders as hemangiomas, shoulder pain or skin infections. Three patients had been treated with mantle radiation for Hodgkin's disease prior to developing breast cancer. DNA analysis were performed, on remaining tumour tissue after hormone receptor analysis had been done, measuring the fraction of tumour cells in S-phase. Latency time (time between diagnosis and previous radiation treatment) was calculated and related to the S-phase fraction.

RESULTS

A significant inverse relationship between latency time and S-phase was found (p < 0.0025), indicating that tumours with a high S-phase had a short latency time and vice versa. Among the possible radiation induced tumours, median S-phase was 14%, comparable with a median latency time of 22 years. Very high S-phase values were associated with short latency times (eg a S-phase of 35% would be compatible with a latency time of 7 years).

CONCLUSION

Our preliminary results indicate that S-phase is related to latency time and that the median latency time maybe as long as 22 years. Our data may also explain why breast cancer is rare before 30 years of age and if patients are diagnosed at early ages, tumours often show high S-phase values and bad prognostic signs. We postulate that these results from radiation induced breast cancer may be used to extrapolate possible latency times in patients with non radiation induced breast tumours in order to isolate possible time periods for research after other initiating events.

Defective mismatch-repair in patients with multiple primary tumours including colorectal cancer

Individuals with an inherited predisposition to cancer development are at an increased risk of developing multiple tumours. Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common hereditary cancer syndromes and is estimated to account for approximately 2% of colorectal cancers. However, HNPCC individuals are at an increased risk of developing other tumour types such as cancers of the endometrium, urothelium and small intestine. We have utilised a population-based regional cancer registry to identify all patients with double primary colorectal cancers and at least one additional malignancy and characterised the tumour spectrum in this patient group. We subsequently selected those 47 individuals who had developed at least four malignancies, including two colorectal cancers, for studies of the tumour characteristics associated with HNPCC. In total, these individuals developed 209 tumours, 156 of which were successfully retrieved. Microsatellite instability (MSI), a phenomenon caused by defective mismatch-repair (MMR), was identified in 63/154 (41%) evaluable tumours with a MSI-high pattern in 59 and a MSI-low pattern in four tumours. All tumours were immunohistochemically stained for the MMR proteins MLH1 and MSH2, with loss of expression in 55/63 (87%) MSI tumours and in 2/89 (2%) microsatellite stable (MSS) tumours. This loss affected MLH1 in 24 tumours and MSH2 in 33 tumours. A concordant loss of expression for the same MMR protein in several tumours from the same individual, a pattern that strongly suggests an underlying germline MMR gene mutation, was found in 17/45 (38%) patients and affected MLH1 in 8 patients and MSH2 in 9 patients. We conclude that the development of multiple primary tumours, including synchronous or metachronous colorectal cancers, is associated with an increased frequency of MSI and loss of immunohistochemical expression of MLH1 and MSH2.

Efficacy and safety of budesonide/formoterol in the management of chronic obstructive pulmonary disease

The efficacy and safety of budesonide/formoterol in a single inhaler compared with placebo, budesonide and formoterol were evaluated in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). In a 12-month, randomised, double-blind, placebo-controlled, parallel-group study in 812 adults (mean age 64 yrs, mean forced expiratory volume in one second (FEV1) 36% predicted normal), patients received two inhalations twice daily of either budesonide/formoterol (Symbicort) 160/4.5 microg (delivered dose), budesonide 200 microg (metered dose), formoterol 4.5 microg or placebo. Severe exacerbations and FEV1 (primary variables), peak expiratory flow (PEF), COPD symptoms, health-related quality of life (HRQL), mild exacerbations, use of reliever beta2-agonist and safety variables were recorded. Budesonide/formoterol reduced the mean number of severe exacerbations per patient per year by 24% versus placebo and 23% versus formoterol. FEV1 increased by 15% versus placebo and 9% versus budesonide. Morning PEF improved significantly on day 1 versus placebo and budesonide; after 1 week, morning PEF was improved versus placebo, budesonide and formoterol. Improvements in morning and evening PEF versus comparators were maintained over 12 months. Budesonide/formoterol decreased all symptom scores and use of reliever beta2-agonists significantly versus placebo and budesonide, and improved HRQL versus placebo. All treatments were well tolerated. These results suggest a role for budesonide/formoterol in the long-term management of moderate-to-severe chronic obstructive pulmonary disease.

A cohort study of reproductive factors and family history of breast cancer in southern Sweden

BACKGROUND

Studies have been contradictory regarding the hypothesis that reproductive risk factors of breast cancer as parity and age at first full-term pregnancy (AFFP) operate differently in women with and without a family history of breast cancer.

METHODS

The overall tumour incidence and breast cancer incidence related to fertility factors were followed in a population based cohort of 29,508 women aged 25-65 when interviewed between 1990 and 1992 in south Sweden. At the end of the follow up in December 1999, the cohort constituted 226,611 person years. The risk of breast cancer in relation to reproductive factors were studied in women with at least one first degree relative with breast cancer and compared with women without a family history.

FINDINGS

A total of 1145 malignant tumours were seen and 1166.6 were expected (SIR = 0.98, 95% CI = 0.93-1.04). Slightly more breast cancer cases were seen 434 than expected 387.69 (SIR = 1.12, 95% CI = 1.02-1.23). A family history of breast cancer among a first degree relative was present in 1615 women . Forty-five breast cancers were seen among these women while 24.27 was expectecd (SIR = 1.85, 95% CI = 1.35-2.48). Nulliparous women with a family history of breast cancer had a higher risk of breast cancer, SIR = 1.76, 95% CI = 0.64-3.82, compared with nulliparous women without a family history, SIR = 1.13, 95% CI = 0.99-1.29. Similarly women with parity 1-2 with a family history had a higher SIR = 1.81, 95% CI = 1.16-2.69 compared with women without a family history having 1-2 children, SIR = 1.13, 95% CI = 0.99-1.29. In women with > or = 3 children those with a family history continued to have a high SIR = 1.98, 95% CI = 1.11-3.27 compared with women without a family history SIR = 0.90, 95% CI = 0.73-1.09. An early full-term pregnancy was protective in both groups. A higher risk than nulliparous women were seen after age 25 in the family history group and after age 30 in the sporadic cancer group.

INTERPRETATION

Women with a first degree family history of breast cancer do not experience the sameprotection from a high number of pregnancies as women without a family history. However, an early first full-term pregnancy seems to offer a substantial protection in the family history group if undertaken before age 20. This suggest that reproductive factors tend to operate differently in the two groups of women.

Clinical and histopathological features of malignant melanoma in germline CDKN2A mutation families

Primary cutaneous malignant melanomas (CMMs) from 26 individuals belonging to nine families with an identified mutation were clinically and histopathologically compared with 78 matched CMM controls and with a population-based series of CMMs ( = 667). All tumours were histopathologically re-examined. CDKN2A-associated cases were significantly less invasive compared with the matched controls, with an adjusted odds ratio (adjOR) of 2.9 and a 95% confidence interval (CI) of 1.0-8.1 ( = 0.04). According to the odds ratio (OR) values, CDKN2A-associated cases seemed to have tumours more often located on the head and neck (adjOR 2.9, 95% CI 0.6-13.7), with less inflammation (adjOR 0.7, 95% CI 0.3-1.8) and regression (adjOR 0.6, 95% CI 0.2-1.8) but more frequent histological ulceration (adjOR 1.9, 95% CI 0.6-5.8). In comparison with the population-based material, CDKN2A-associated cases were significantly younger at diagnosis (crude OR 3.5, 95% CI 1.6-7.5, divided at 50 years) and had less regressive reaction in their tumours (crude OR 0.35, 95% CI 0.2-0.8). No significant differences were seen for tumour thickness between the different groups. On multivariate analysis, the overall survival was significantly worse for thicker tumours and older age ( = 0.04 for both). To our knowledge this is the first description of the histopathological features of CMMs from families with mutations in the CDKN2A gene.

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Male gynecomastia and risk for malignant tumours--a cohort study

BACKGROUND

Men with gynecomastia may suffer from absolute or relative estrogen excess and their risk of different malignancies may be increased. We tested whether men with gynecomastia were at greater risk of developing cancer.

METHODS

A cohort was formed of all the men having a histopathological diagnosis of gynecomastia at the Department of Pathology, University of Lund, following an operation for either uni- or bilateral breast enlargement between 1970-1979. All possible causes of gynecomastia were accepted, such as endogenous or exogenous hormonal exposure as well as cases of unknown etiology. Prior to diagnosis of gynecomastia eight men had a diagnosis of prostate carcinoma, two men a diagnosis of unilateral breast cancer and one had Hodgkin's disease. These patients were included in the analyses. The final cohort of 446 men was matched to the Swedish Cancer Registry, Death Registry and General Population Registry.

RESULTS

At the end of the follow up in December 1999, the cohort constituted 8375.2 person years of follow-up time. A total of 68 malignancies versus 66.07 expected were observed; SIR = 1.03 (95% CI 0.80-1.30). A significantly increased risk for testicular cancer; SIR = 5.82 (95% CI 1.20-17.00) and squamous cell carcinoma of the skin; SIR = 3.21 (95% CI 1.71-5.48) were noted. The increased risk appeared after 2 years of follow-up. A non-significantly increased risk for esophageal cancer was also seen while no new cases of male breast cancer were observed. However, in the prospective cohort, diagnostic operations for gynecomastia may substantially have reduced this risk

CONCLUSIONS

There is a significant increased risk of testicular cancer and squamous cell carcinoma of the skin in men who have been operated on for gynecomastia.

Malignancies during follow-up in an epidemiologically defined systemic lupus erythematosus inception cohort in southern Sweden

The objective of this study was to identify all malignancies in an inception cohort of SLE patients in southern Sweden and compare with the observed frequencies and spectrum of malignancies in the general population. All adult incidence cases of SLE in a defined population during the period 1981-1996 were retrieved from a prospective database and the cases were followed to endpoint or through 1998. The SLE cohort registry was aggregated with the National Cancer Registry to identify all malignancies by date, type and outcome. Standardized morbidity rates (SMR) were calculated based on the sex- and age-matched general population of the region. Sixteen malignancies occurred in 13 patients out of a total of 116 SLE patients observed for 1086 patient-years. The SMR for all cancers detected was 2.24 (confidence interval 0.6-5.7) for males and 1.02 (confidence interval 0.4-2.1) for females and thus indicative of no general increase in malignancies. However, the SMR for non-Hodgkin lymphoma was 11.63 (confidence interval 1.4-42.0), for pulmonary cancer 5.55 (confidence interval 0.7-20.1) and prostatic cancer 6.41 (confidence interval 1.3-18.7) all significantly increased. The increase in prostatic carcinoma disappeared when only cases occurring after a latency period of 3y after SLE diagnosis were included. In this comprehensive inception cohort of SLE no increase in relative risk of malignancy overall was found, but the frequencies of non-Hodgkin lymphoma and pulmonary cancer were increased, possibly also the frequency of prostatic carcinoma.

A hypothesis about tumour development and the clinical features of hereditary breast cancers

A unifying hypothesis is presented about tumour biology in hereditary breast cancer in relation to the epithelial origin and the degree of differentiation of the normal epithelium at the time of tumour initiation. By using different breast cancer syndromes as examples, it is possible to, at least partly, predict the tumour biology, clinical presentation and therapeutic response.

Potentials and pitfalls using high affinity radioligands in PET and SPET determinations on regional drug induced D2 receptor occupancy--a simulation study based on experimental data

The D2 dopamine receptor density ranges from 0.2 to 40 nM among human brain regions. For high density regions radioligands like [(11)C]raclopride provide accurate and reliable estimates of the receptor density. In research on neuropsychiatric disorders there is, however, a growing need for quantitative approaches that accurately measure D2 dopamine receptor occupancy induced by drugs or endogenous dopamine in regions with low receptor density. The new high affinity radioligands [(11)C]FLB 457 and [(123)I]epidepride have been shown to provide a signal for extrasriatal D2 dopamine receptor populations in the human brain in vivo. Initial observations indicate, however, that the time required to reach equilibrium is dependent on receptor density. Ratio analyses may thus not be readily used for comparisons among different brain regions. The aim of the present simulation study was to examine commonly used approaches for calculation of drug induced D2 dopamine receptor occupancy among regions with widely different receptor density. The input functions and the rate constants of [(11)C]FLB 457 and the reference ligand [(11)C]raclopride were first used in a simulation estimating the effect of receptor density on equilibrium time. In a second step we examined how errors produced by inaccurate determination of the binding potential parameter propagate to calculations of drug induced receptor occupancy. The simulations showed a marked effect of receptor density on equilibrium time for [(11)C]FLB 457, but not for [(11)C]raclopride. For [(11)C]FLB 457, a receptor density above about 7 nM caused the time of equilibrium to fall beyond time of data acquisition (1 h). The use of preequilibrium data caused the peak equilibrium and the end time ratio approaches but not the simplified reference tissue model (SRTM) approach to underestimate the binding potential and thus also the drug occupancy calculated for high-density regions. The study supports the use of ratio and SRTM analyses in extrastriatal low-density receptor regions for which the high affinity ligand [(11)C]FLB 457 was developed. However, in high-density regions such as the human striatum simple ratio approaches cannot be validly applied, whereas the SRTM approach has higher potential to provide valid estimates. Interestingly, the results suggest that published data on a proposed extrastriatal selectivity for the antipsychotic drugs clozapine and olanzapine may be due to erroneous estimations of the binding potential when using ratio approaches.

Prognostic factors in invasive cutaneous malignant melanoma: a population-based study and review

A population-based study from Sweden identified 711 patients with cutaneous malignant melanoma diagnosed in 1965, 1975, 1985 and 1989. Prognostic factors were evaluated and a review of the literature was performed. On univariate analysis, thick tumours (> 0.8 mm) (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.6-2.1), increasing Clark level (OR 1.8, 95% CI 1.6-2.0), ulceration (OR 1.8, 95% CI 1.6-2.0), nodular melanoma (OR 1.5, 95% CI 1.3-1.6) and increasing age (continuous variable, P < 0.0001) were associated with a shorter survival. Location on extremities (OR 0.8, 95% CI 0.7-0.9), inflammation (OR 0.8, 95% CI 0.7-0.9) and female gender (OR 0.8, 95% CI 0.8-0.9) were associated with improved survival. On multivariate analysis, thick tumours (> 0.8 mm) (OR 1.5, 95% CI 1.2-1.7) and ulceration (OR 1.4, 95% CI 1.2-1.6) were independently related to a poor prognosis, while location on extremities (OR 0.8, 95% CI 0.7-0.9), inflammation (OR 0.8, 95% CI 0.7-0.9) and female gender (OR 0.8, 95% CI 0.8-1.0) were associated with improved survival. No difference in mean tumour thickness was seen over time, but there was a significant increase in the percentage of thin melanomas (< 0.8 mm) in 1985 (P = 0.01) and 1989 (P = 0.002) compared with 1965. The incidence of melanomas with inflammation increased significantly (P = 0.04), as did age at diagnosis (P = 0.005).