Risk of oesophageal cancer by histology among patients hospitalised for gastroduodenal ulcers

OBJECTIVE

The mechanism behind the epidemiologically evident inverse relation between Helicobacter pylori seropositivity and risk of oesophageal adenocarcinoma (OAC) remains obscure. Severe corpus gastritis is unlikely to be in the causal pathway. With the hypothesis of a uniformly low risk, the associations of OAC with duodenal ulcer and gastric ulcer were explored, both linked to H pylori infection but with different patterns of bacterial colonisation and intragastric acidity. Possible associations of oesophageal squamous cell carcinoma (OSCC) with these ulcer types were also addressed.

DESIGN AND PATIENTS

Retrospective cohorts of 61,548 and 81,379 unoperated patients with duodenal ulcer and gastric ulcer, respectively, recorded in the Swedish Inpatient Register since 1965, were followed from the first hospitalisation until the date of any cancer, death, emigration, definitive surgery, or 31 December 2003. Standardised incidence ratios (SIRs), with 95% CIs, expressed relative risk of oesophageal cancer, compared with the Swedish population matched for age, sex and calendar period.

RESULTS

Contrary to expectation, patients with duodenal ulcer had a significant 70% excess risk of OAC (SIR 1.7, 95% CI 1.1 to 2.5). Gastric ulcer was unrelated to OAC (SIR 1.1, 95% CI 0.6 to 1.7). Although duodenal ulcer was non-significantly associated with a small excess of OSCC (SIR 1.3, 95% CI 0.96 to 1.8), gastric ulcer was linked to 80% increased risk (SIR 1.8, 95% CI 1.4 to 2.3).

CONCLUSION

The inverse association between H pylori and OAC does not pertain to all infections. The pattern of gastric colonisation and/or impact on acidity may be important. With the reservation for the possibility of confounding, this study also provides some support for the importance of intragastric environment in the aetiology of OSCC.

Recovery after minor traffic injuries: a randomized controlled trial

OBJECTIVES

To assess the efficacy of an acute multidisciplinary group intervention on self-perceived recovery following minor traffic-related musculoskeletal injuries.

DESIGN

Open, randomized controlled trial.

SETTING

A large inner-city hospital.

PARTICIPANTS

127 patients (> or = 15 y) with traffic-related acute minor musculoskeletal injuries and predicted to be at risk for delayed recovery were randomized into an intervention group (n = 65) or a control group (n = 62).

INTERVENTION

Four 1 1/2-h sessions in open groups with the aim of providing information about injuries in general, calling attention to the importance of self-care and promoting physical activity. In addition, both groups received standard medical care by regular staff.

OUTCOME MEASURES

The main outcome measure was self-reported recovery at 12 mo. Secondary outcome measures were ratings of functional health status (SF-36, SMFA), pain and mental distress on visual analog scales, and self-reported duration of sick leave.

RESULTS

At 12 mo, there was a 21.9 percentage point difference: 52.4% of the patients in the intervention group and 30.5% in the control group reported self-perceived recovery (95% confidence interval for the difference 5%-38%; p = 0.03). There were no statistically significant differences between the groups regarding the secondary outcome measures.

CONCLUSION

A simple group intervention may accelerate the self-perceived recovery in selected patients. As we did not find evidence of improvements in the secondary outcome measures, the clinical significance of the treatment benefit remains to be defined.

The risk of pancreatic cancer in patients with gastric or duodenal ulcer disease

Although Helicobacter pylori (H. pylori) seropositivity is linked to an excess risk of pancreatic cancer, the biologic mechanism is unknown. Gastric ulcer is primarily associated with corpus colonization of H. pylori, atrophic gastritis and formation of N-nitrosamines. Duodenal ulcer is a marker of antral colonization, hyperacidity and uninhibited secretin release. We estimated relative risks for pancreatic cancer among patients with gastric or duodenal ulcer, based on a register-based retrospective cohort study with 88,338 patients hospitalized for gastric ulcer and 70,516 patients for duodenal ulcer recorded in the Swedish Inpatient Register between 1965 and 2003. Following operation, the 14,887 patients who underwent gastric resection and 8,205 with vagotomy were analyzed separately. Multiple record-linkages allowed complete follow-up and identification of all incident cases of pancreatic cancer until December 31, 2003. Standardized incidence ratios (SIRs) estimated relative risks. During years 3-38 of follow-up, we observed a 20% excess risk (95% confidence interval [CI] 10-40%) for pancreatic cancer among unoperated gastric ulcer patients. The excess increased to 50% (95% CI 10-110%) 15 years after first hospitalization (p for trend = 0.03). SIR was 2.1 (95% CI 1.4-3.1) 20 years after gastric resection. Unoperated duodenal ulcer was not associated with pancreatic cancer risk, nor was vagotomy. Our results lend indirect support to the nitrosamine hypothesis, but not to the hyperacidity hypothesis in the etiology of pancreatic cancer.

Risk factors for Barrett's oesophagus: a population-based approach

OBJECTIVE

Given its often subclinical course, Barrett's oesophagus (BO) hardly lends itself to epidemiologically stringent evaluations. The objective of this study was to investigate risk factors for incident BO diagnosed in a defined population in southeast Sweden while paying particular attention to epidemiological aspects of the study design.

MATERIAL AND METHODS

Consecutive patients (aged 18-79 years) who were endoscoped with new indications at units exclusively responsible for all gastroscopies in defined catchment area populations were invited to take part in the study. Biopsies were taken above and immediately below the gastro-oesophageal junction, and exposure information was collected through self-administered questionnaires. Endoscopy-room-based cross-sectional data from 604 patients were supplemented with exposure data from 160 population controls. Associations, expressed as odds ratios (ORs), were modelled by means of multivariable logistic regression.

RESULTS

In the comparison with population controls, reflux symptoms and smoking indicated a 10.7- and 3.3-fold risk, respectively, for BO (95% confidence interval (CI) 3.5-33.4 and 1.1-9.9, respectively). Body mass was unrelated to risk. In the cross-sectional analysis among endoscopy-room patients, reflux symptoms were associated with an OR of 2.0 (95% CI 0.8-5.0). This association was, however, modified by the subjunctional presence of Helicobacter pylori; although the infection was not in itself significantly connected with risk, a combination of reflux symptoms and H. pylori infection was linked to an almost 5-fold risk (95% CI 1.4-16.5) as compared with the absence of both factors. The BO prevalence increased by 5% per year of age (95% CI 1-9%).

CONCLUSIONS

Reflux is the predominant risk factor for BO, and proximal gastric colonization of H. pylori seems to amplify this risk.

A long-term follow-up study on the natural course of oral leukoplakia in a Swedish population-based sample

AIM

To assess the natural course of screening-detected oral leukoplakia (OL) among non-consulting individuals.

METHODS

A cohort of 555 individuals with OL, confirmed in 1973-1974 during a population-based survey, were followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 104 drawn from the 297 surviving cohort members who still were living in the area in 1993-1995 was invited to a re-examination. Sixty-seven of them attended.

RESULTS

At the time of re-examination OL had disappeared in 29 (43%) individuals. There was a statistically significant association between cessation of/no smoking habits in 1993-1995 and the disappearance of OL. Never/previous daily smokers were thus over-represented among individuals whose OL had disappeared compared to those with persisting OL [n = 23 (82%) vs. n = 18 (47%), P < 0.01]. Eighteen (78%) of the twenty three non-smokers with disappearing OL had quit after the initial examination. One man and two women developed oral cancer during follow-up while 0.7 and 0.07, respectively, were expected.

CONCLUSION

Smoking cessation was associated with an increased disappearance of OL. Hence, at least one-fourth had lesions that could be classified as tobacco-related. Small observed and expected numbers prohibited firm conclusions about a possible excess risk of developing oral cancer.

A population-based binational register for monitoring long-term outcome and possible disease concordance among blood donors and recipients

BACKGROUND AND OBJECTIVES

Even with appropriate donor deferrals and advanced screening tests, the risk of disease transmission through blood transfusion cannot be completely disregarded. Efficient monitoring of possible disease transmission between blood donors and recipients should be an important component of a comprehensive haemovigilance system.

MATERIALS AND METHODS

We assembled the Scandinavian Donations and Transfusions (SCANDAT) database, with data on virtually all blood donors and recipients who have been registered at least once in any of the computerized local blood bank databases in Sweden and Denmark since the start of computerized registration in 1966. The records of these individuals, with their entire computerized donation and/or transfusion histories and all donor-component-recipient connections, were linked to nationwide population and health registers to attain essentially complete follow-up for up to 36 years regarding reproduction, hospital morbidity, cancer, and death.

RESULTS

After data cleaning, the database contained 1,134,290 blood donors who contributed 15,091,280 records of donations and 1,311,079 recipients who received 11,693,844 transfusions. The data quality in the existing data sources was satisfactory. From the data obtained from local blood banks, 4.6%, 1.6%, and 6.4% of the person, donation, and transfusion records, respectively, had to be discarded after review of the legitimacy of recorded values, and comparisons with independent, external databases.

CONCLUSION

It is possible to use existing computerized data, collected in routine health care, in haemovigilance systems for monitoring long-term outcome and disease concordance in blood donors and transfusion recipients.

Recovered? Association between self-perceived recovery and the SF-36 after minor musculoskeletal injuries

OBJECTIVE

Recovery after minor musculoskeletal injuries is often disproportionately protracted. Our aim was to relate Short Form-36 (SF-36), to self-perceived recovery assessed with the question" Do you feel recovered". We hypothesized that restitution of physical factors would be reported at least as often as improvement of symptoms or impairments and that social and mental factors would dominate over physical as determinants for recovery. We followed 318 patients with minor traffic-related injuries for up to 6 months.

RESULTS

For all SF-36 subscores more than 60% of the recovered patients had returned to their pre-injury levels. The subscores with the highest proportions (> 80%) were all mainly reflecting disability. For no subscore, however, was the proportion 100%. Normalizations in the SF-36 subscores for "Bodily Pain" (BP) (Odds Ratio, OR = 7.2), "Role limitations due to physical function" (OR = 5.3) were associated with self-perceived recovery.

CONCLUSION

Abolition of pain appears to be paramount for the self-perceived recovery, but it is neither a sufficient nor a necessary prerequisite. Contrary to our expectation, physical aspects of functional health status were more strongly associated with recovery than were emotional or social aspects.

Risk factors for long-term pain after hernia surgery

OBJECTIVE

To estimate the prevalence of residual pain 2 to 3 years after hernia surgery, to identify factors associated with its occurrence, and to assess the consequences for the patient.

SUMMARY BACKGROUND DATA

Iatrogenic chronic pain is a neglected problem that may totally annul the benefits from hernia repair.

METHODS

From the population-based Swedish Hernia Register 3000 patients aged 15 to 85 years were sampled from the 9280 patients registered as having undergone a primary groin hernia operation in the year 2000. Of these, the 2853 patients still alive in 2003 were requested to fill in a postal questionnaire.

RESULTS

After 2 reminders, 2456 patients (86%), 2299 men and 157 women responded. In response to a question about "worst perceived pain last week," 758 patients (31%) reported pain to some extent. In 144 cases (6%), the pain interfered with daily activities. Age below median, a high level of pain before the operation, and occurrence of any postoperative complication were found to significantly and independently predict long-term pain in multivariate logistic analysis when "worst pain last week" was used as outcome variable. The same variables, along with a repair technique using anterior approach, were found to predict long-term pain with "pain right now" as outcome variable.

CONCLUSION

Pain that is at least partly disabling appears to occur more often than recurrences. The prevalence of long-term pain can be reduced by preventing postoperative complications. The impact of repair technique on the risk of long-term pain shown in our study should be further assessed in randomized controlled trials.

Antibiotic treatment and risk of gastric cancer

BACKGROUND/AIMS

Helicobacter pylori infection is undoubtedly an important risk factor for gastric cancer. It remains unclear however whether antibiotic treatment may prevent gastric cancer development. Our aim was to assess long term gastric cancer risks in historic cohorts of patients presumed to have been heavily exposed to antibiotics.

SUBJECTS

Using the Swedish Inpatient Register, we identified 501 757 individuals discharged with any one of 10 selected infectious disease diagnoses between 1970 and 2003.

METHODS

We counted person time and non-cardia gastric cancer occurrences through linkage to virtually complete population and health care registers. Standardised incidence ratios (SIRs) were calculated for comparisons with cancer incidence rates of the general population in Sweden.

RESULTS

No reduction in gastric cancer risk was observed in the infectious disease cohort in total (SIR 1.08 (95% confidence intervals 1.00-1.17) or for any of the presumed antibiotic regimens. There were no clear trends towards decreasing risk with time of follow up, but the risk tended to fall with increasing age at first hospitalisation for the infection (p<0.04).

CONCLUSIONS

Our results do not confirm earlier observational findings of a reduced risk of gastric cancer following exposure to heavy antibiotic treatment among hip replacement patients. Suboptimal drug regimens, inadequate timing of H pylori eradication, or insufficient follow up time may possibly explain the lack of association in this setting. Although our findings do not rule out the cancer preventive potential of H pylori eradication, they emphasise that detection of such an effect, if any, may require considerable efforts.

Perinatal Risk Factors for Cancer of the Esophagus and Gastric Cardia: A Nested Case-Control Study

BACKGROUND

We have previously hypothesized that preterm birth or impaired fetal growth may cause esophageal adenocarcinomas through gastroesophageal reflux early in life. In this study, we aimed to test if there is an association between gestational duration and birth weight on the one hand, and risk of esophageal and cardia adenocarcinoma on the other.

METHODS

We conducted a nested case-control study of 67 cases of esophageal adenocarcinoma and 93 cases of cardia adenocarcinoma, whereas 50 cases of squamous cell carcinoma were studied for comparison. Birth records of cases were traced. Three matched controls per case were randomly selected. Perinatal data were extracted from birth records.

RESULTS

Long gestational duration was associated with a decreased risk of cardia adenocarcinoma (P(trend) = 0.001) and a nonsignificant decreased risk of esophageal adenocarcinoma (P = 0.07), whereas no such association was found for esophageal squamous cell carcinoma (P = 0.96). Birth weight was not associated with risk of any of the studied cancers. Compared with lower maternal age (</=24 years) at giving birth, maternal age of 25 to 29 years were associated with a decreased risk of esophageal adenocarcinoma and squamous cell carcinoma (odds ratio, 0.4; 95% confidence interval, 0.2-0.9 and odds ratio, 0.3; 95% confidence interval, 0.1-0.8, respectively).

CONCLUSIONS

Numerical constraints hamper inference, but our results are somewhat consistent with the idea that future risk of esophageal and cardia cancer may in part be determined already perinatally or in infancy and give some limited support to the hypothesis that timing of birth influences risk.

Elevated anal squamous cell carcinoma risk associated with benign inflammatory anal lesions

BACKGROUND

The association between benign anal lesions and anal cancer is still unclear. Few data from large cohort studies are available.

METHODS

We conducted a register based retrospective cohort study including 45,186 patients hospitalised for inflammatory anal lesions (anal fissures, fistulas, and perianal abscesses) as well as 79,808 haemorrhoid patients, from 1965 to 2002. Multiple record linkages identified all incident anal (squamous cell carcinoma only) and colorectal cancers through to 2002. Relative risk was estimated by standardised incidence ratio (SIR), the ratio of observed number of cases divided by that expected in the age, sex, and calendar year-matched general Swedish population.

RESULTS

There was a distinct incidence peak in the first three years of follow up among patients with inflammatory lesions. SIR then levelled off at around 3 and remained at this level throughout follow up (SIR during years 3-37 of follow up was 3.3 (95% confidence interval 1.8-5.7)). A similar initial incidence peak was observed among haemorrhoid patients but was confined to the first year; SIR was 2.8 in the second year, and then it decreased further and was close to unity in the following years (SIR during years 3-37 was 1.3 (95% confidence interval 0.7-2.1)). Among inflammatory lesion and haemorrhoid patients, a significantly increased risk of colorectal cancer was observed only in the first year after hospitalisation.

CONCLUSIONS

Inflammatory benign anal lesions are associated with a significantly increased long term risk of anal cancer. In contrast, haemorrhoids appear not to be a risk factor for this malignancy.

On the natural course of oral lichen lesions in a Swedish population-based sample

OBJECTIVES

The aim was to assess the natural course of oral lichen lesions (OLL) among unselected, non-consulting individuals.

SUBJECTS AND METHODS

A cohort of 327 subjects with OLL, confirmed in 1973-1974 during a population-based survey in two Swedish municipalities, was followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 80 drawn from the 194 surviving subjects who still resided in the area in 1993-1995 was invited for interview and oral re-examination.

RESULTS

At the end of follow-up, one case of oral cancer was detected, while 0.4 were expected. The overall mortality among subjects with OLL was not significantly different from that in the 15,817 OLL-free subjects who participated in the initial population based survey in 1973-1974. The lesion had disappeared in 14 (39%) of 36 re-examined subjects with white OLLs in 1973-1974, and four (11%) had transformed into red types. In the corresponding group of 19 with red forms initially, five (26%) had become lesion free and four (21%) had switched to white types. Although the cohort size does not permit firm conclusions regarding oral cancer risk, the natural course over up to 30 years appears to be benign in the great majority.

Obesity and risk for chronic renal failure

Few large-scale epidemiologic studies have quantified the possible link between obesity and chronic renal failure (CRF). This study analyzed anthropometric data from a nationwide, population-based, case-control study of incident, moderately severe CRF. Eligible as cases were all native Swedes who were aged 18 to 74 yr and had CRF and whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women) during the study period. A total of 926 case patients and 998 control subjects, randomly drawn from the study base, were enrolled. Face-to-face interviews, supplemented with self-administered questionnaires, provided information about anthropometric measures and other lifestyle factors. Logistic regression models with adjustments for several co-factors estimated the relative risk for CRF in relation to body mass index (BMI). Overweight (BMI>or=25 kg/m2) at age 20 was associated with a significant three-fold excess risk for CRF, relative to BMI<25. Obesity (BMI>or=30) among men and morbid obesity (BMI>or=35) among women anytime during lifetime was linked to three- to four-fold increases in risk. The strongest association was with diabetic nephropathy, but two- to three-fold risk elevations were observed for all major subtypes of CRF. Analyses that were confined to strata without hypertension or diabetes revealed a three-fold increased risk among patients who were overweight at age 20, whereas the two-fold observed risk elevation among those who had a highest lifetime BMI of >35 was statistically nonsignificant. Obesity seems to be an important-and potentially preventable-risk factor for CRF. Although hypertension and type 2 diabetes are important mediators, additional pathways also may exist.

The XPD 751Gln allele is associated with an increased risk for esophageal adenocarcinoma: a population-based case-control study in Sweden

Mechanisms behind the strong associations of esophageal adenocarcinoma risk with gastroesophageal reflux (GOR) and body mass remain to be defined. In a nationwide population-based case-control study, we examined associations of polymorphisms in the DNA repair genes XPD, XPC, XRCC1 and XRCC3 with risk of esophageal adenocarcinoma, squamous-cell carcinoma (SCC) and gastric cardia adenocarcinoma, and paid special attention to possible interactions with symptomatic reflux or body mass. We collected blood samples from 96, 81 and 126 interviewed incident cases of esophageal adenocarcinoma, esophageal SCC and gastric cardia adenocarcinoma, respectively, and 472 randomly selected controls, frequency-matched with regard to age and sex. DNA was extracted and polymorphisms in XPD codon 751 (Lys-->Gln), codon 312 (Asp-->Asn), C insertion in intron 10 of XPD, XPC codon 939 (Lys-->Gln), XRCC1 codon 399 (Arg-->Gln) and XRCC3 codon 241 (Thr-->Met) were examined using PCR-RFLP. Odds ratios (ORs) derived from multivariate logistic regression with adjustments for potential confounding factors estimated relative risks. XPD codon 751 Lys/Gln and Gln/Gln genotypes, compared with Lys/Lys genotype, were both associated with a more than doubled risk for esophageal adenocarcinoma (OR=2.4; 95% CI=1.4-4.4; OR=2.7, 95% CI=1.3-5.9). The combined effects of these genotypes and symptomatic GOR or body mass showed borderline significant deviation from additivity. Excess risks for esophageal SCC were also noted for XPD 751Gln variant genotypes. Other studied variants were not found to be related to the three tumors. Our study suggests that XPD 751Gln allele is a potential genetic marker for susceptibility to esophageal adenocarcinoma.

Meat intake and risk of stomach and esophageal adenocarcinoma within the European Prospective Investigation Into Cancer and Nutrition (EPIC)

BACKGROUND

Dietary factors are thought to have an important role in gastric and esophageal carcinogenesis, but evidence from cohort studies for such a role is lacking. We examined the risks of gastric cancer and esophageal adenocarcinoma associated with meat consumption within the European Prospective Investigation Into Cancer and Nutrition (EPIC) cohort.

METHODS

A total of 521,457 men and women aged 35-70 years in 10 European countries participated in the EPIC cohort. Dietary and lifestyle information was collected at recruitment. Cox proportional hazard models were used to examine associations between meat intake and risks of cardia and gastric non-cardia cancers and esophageal adenocarcinoma. Data from a calibration substudy were used to correct hazard ratios (HRs) and 95% confidence intervals (CIs) for diet measurement errors. In a nested case-control study, we examined interactions between Helicobacter pylori infection status (i.e., plasma H. pylori antibodies) and meat intakes. All statistical tests were two-sided.

RESULTS

During a mean follow-up of 6.5 years, 330 gastric adenocarcinoma and 65 esophageal adenocarcinomas were diagnosed. Gastric non-cardia cancer risk was statistically significantly associated with intakes of total meat (calibrated HR per 100-g/day increase = 3.52; 95% CI = 1.96 to 6.34), red meat (calibrated HR per 50-g/day increase = 1.73; 95% CI = 1.03 to 2.88), and processed meat (calibrated HR per 50-g/day increase = 2.45; 95% CI = 1.43 to 4.21). The association between the risk of gastric non-cardia cancer and total meat intake was especially large in H. pylori-infected subjects (odds ratio per 100-g/day increase = 5.32; 95% CI = 2.10 to 13.4). Intakes of total, red, or processed meat were not associated with the risk of gastric cardia cancer. A positive but non-statistically significant association was observed between esophageal adenocarcinoma cancer risk and total and processed meat intake in the calibrated model. In this study population, the absolute risk of development of gastric adenocarcinoma within 10 years for a study subject aged 60 years was 0.26% for the lowest quartile of total meat intake and 0.33% for the highest quartile of total meat intake.

CONCLUSION

Total, red, and processed meat intakes were associated with an increased risk of gastric non-cardia cancer, especially in H. pylori antibody-positive subjects, but not with cardia gastric cancer.

Airborne occupational exposures and risk of oesophageal and cardia adenocarcinoma

BACKGROUND

The reasons for the increasing incidence of and strong male predominance in patients with oesophageal and cardia adenocarcinoma remain unclear. The authors hypothesised that airborne occupational exposures in male dominated industries might contribute.

METHODS

In a nationwide Swedish population based case control study, 189 and 262 cases of oesophageal and cardia adenocarcinoma respectively, 167 cases of oesophageal squamous cell carcinoma, and 820 frequency matched controls underwent personal interviews. Based on each study participant's lifetime occupational history the authors assessed cumulative airborne occupational exposure for 10 agents, analysed individually and combined, by a deterministic additive model including probability, frequency, and intensity. Furthermore, occupations and industries of longest duration were analysed. Relative risks were estimated by odds ratios (OR), with 95% confidence intervals (CI), using conditional logistic regression, adjusted for potential confounders.

RESULTS

Tendencies of positive associations were found between high exposure to pesticides and risk of oesophageal (OR 2.3 (95% CI 0.9 to 5.7)) and cardia adenocarcinoma (OR 2.1 (95% CI 1.0 to 4.6)). Among workers highly exposed to particular agents, a tendency of an increased risk of oesophageal squamous cell carcinoma was found. There was a twofold increased risk of oesophageal squamous cell carcinoma among concrete and construction workers (OR 2.2 (95% CI 1.1 to 4.2)) and a nearly fourfold increased risk of cardia adenocarcinoma among workers within the motor vehicle industry (OR 3.9 (95% CI 1.5 to 10.4)). An increased risk of oesophageal squamous cell carcinoma (OR 3.9 (95% CI 1.2 to 12.5)), and a tendency of an increased risk of cardia adenocarcinoma (OR 2.8 (95% CI 0.9 to 8.5)), were identified among hotel and restaurant workers.

CONCLUSIONS

Specific airborne occupational exposures do not seem to be of major importance in the aetiology of oesophageal or cardia adenocarcinoma and are unlikely to contribute to the increasing incidence or the male predominance.

A long-term follow-up study on the natural course of snus-induced lesions among Swedish snus users

Snus-induced lesions (SILs) are mucosal changes that are regularly seen in users of moist snuff (snus). Their role in oral carcinogenesis remains undefined. Our aim was to assess the natural course of SILs over several decades. A cohort of 1,115 individuals with SILs, confirmed in 1973-1974 during a population-based survey was followed for 27-29 years through multiple record linkages with virtually complete population- and health registers. A sample (n = 267) of the cohort members were invited for reexamination after 19-22 years. Register-based follow-up through January 2002 revealed a total of 3 incident cases of oral cancer (standardized incidence ratio of 2.3, 95% CI 0.5-6.7), none of which occurred at the site of the original SIL. There was a strong association noted between the degree of SIL and current snus consumption. The SILs had disappeared in all 62 individuals who had permanently quit using snus. In no case did we observe an important clinical change for the worse among individuals who had decreased their use or continued unabatedly. While the incidence of oral cancer in this cohort of individuals with SILs tended to be higher than expected, we conclude that cancers rarely occur at the site of lesions observed in the distant past.

Obstetric risk factors for symptomatic prolapse: a population-based approach

OBJECTIVE

The purpose of this study was to identify obstetric risk factors for symptomatic prolapse.

STUDY DESIGN

This was a population-based case-control study of prolapse prevalence.

RESULTS

Four hundred fifty-four women with self-reported symptomatic pelvic organ prolapse who were identified among 5489 women who participated in a population survey (cases) and 405 control subjects without symptoms were selected randomly from the same survey. All cases and control subjects received a mailed questionnaire with 72 questions about factors that were suspected to be linked to risk and that included obstetric history. The response rate was 76%. Among parous women, the odds for symptomatic pelvic organ prolapse increased with number of childbirths and were 3.3-fold higher among mothers of 4 than among mothers of 1. Indices of excessive stretching and tearing during labor (vaginal lacerations or episiotomies) were associated with increased risk for symptomatic pelvic organ prolapse. Instrumental delivery with forceps or vacuum did not seem to increase the risk of symptomatic pelvic organ prolapse, nor did length of delivery or maternal age at time for delivery. Abdominal deliveries appeared to be protective; the age- and parity-adjusted odds ratio of symptomatic pelvic organ prolapse after > or =1 abdominal deliveries was 0.5 (95% CI, 0.3-0.9), relative to women who had had only vaginal deliveries. A positive association with child birth weight in unadjusted analyses disappeared after adjustments for attained age and parity of the mother.

CONCLUSION

Excessive stretching and tearing and multiple deliveries seem to be the main predisposing obstetric factors for symptomatic pelvic organ prolapse. Abdominal delivery emerged as a comparably strong protective factor.

A nationwide epidemiologic study of breast cancer incidence following breast reduction surgery in a large cohort of Swedish women

While it has been demonstrated that prophylactic mastectomy reduces breast cancer incidence among women at high risk, many women often consider this disfiguring surgery unacceptable. One alternative approach may be breast reduction surgery. In order to evaluate the long-term incidence of breast cancer following surgical removal of breast tissue, we have extended by 9 years the follow-up period of our earlier retrospective cohort study of Swedish women electing cosmetic breast reduction surgery (n=30,444) between 1965 and 1993, yielding an average of nearly 16 years of follow-up. Cancer incidence through 2002 was ascertained via the Swedish Cancer Registry. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated comparing women who underwent breast reduction surgery with women in the general Swedish population. Breast cancer was observed in 443 women versus 624 expected for a statistically significant reduced SIR of 0.71 (95% CI=0.65-0.78). Analyses by age at surgery, time since surgery or calendar year of surgery revealed similar reductions in risk. Our study of over 30,000 women with long-term follow-up offers further evidence that women undergoing breast reduction surgery have reduced breast cancer risk. As the evidence from large-scale cohort studies accumulates, direct testing of this reduction in risk through clinical trials should be considered.

Elevated hip fracture risk in type 1 diabetic patients: a population-based cohort study in Sweden

OBJECTIVE

Patients with type 1 diabetes often have low bone mineral density, but epidemiological data on fracture risk are sparse and imprecise, particularly for men.

RESEARCH DESIGN AND METHODS

In the Swedish Inpatient Register, we identified a population-based cohort of 24,605 patients (12,551 men and 12,054 women) who were hospitalized for diabetes before age 31 years during 1975 through 1998. Follow-up for hip fracture was accomplished through cross-linkage in the Inpatient Register until the end of 1998. Censoring information was obtained from the registers of Death and Migration. Using the Kaplan-Meier method, we calculated the cumulative probability of getting a hip fracture. Standardized hospitalization ratios and their 95% CIs estimated relative risks with the age-, sex-, and calendar period-matched Swedish general population as reference.

RESULTS

In total, 70 and 51 first hip fractures were ascertained in men and women, respectively, corresponding to a cumulative probability (both sexes) of 65.8/1,000 until age 65 years. Markedly elevated risks were observed in both men and women (standardized hospitalization ratios = 7.6 [95% CI 5.9-9.6] and 9.8 [7.3-12.9], respectively), increasing with follow-up time. Ophthalmic, nephropathic, neurological, and cardiovascular complications were indicators of particularly high risks.

CONCLUSIONS

Both male and female type 1 diabetic patients are at increased risk for hip fracture. Although optimal preventive measures still need to be defined, the co-occurrence with other diabetes complications suggests that tighter metabolic control might reduce the risk.

The Natural History of Chronic Renal Failure: Results From an Unselected, Population-Based, Inception Cohort in Sweden

BACKGROUND

Mortality rates in patients with chronic renal failure (CRF) are high both before and after start of renal replacement therapy (RRT). However, few studies of mortality and progression have been performed in an unselected CRF population.

METHODS

We followed up a population-based inception cohort of 920 men and women aged 18 to 74 years who had CRF (serum creatinine level > 3.4 mg/dL [>300 micromol/L] for men and >2.8 mg/dL [>250 micromol/L] for women) for 55 to 79 months. Relationships between the outcomes (death and start of RRT) and independent variables under study (age, sex, primary renal disease, body mass index [BMI], and glomerular filtration rate [GFR] at entry) were explored by using Cox regression models.

RESULTS

Seven hundred thirty-nine patients (80%) started RRT during the follow-up period. As expected, GFR at entry was clearly linked to the incidence of RRT (P < 0.0001). Age was related inversely to incidence of RRT (adjusted relative risk for patients > or =65 years relative to patients <45 years, 0.72; 95% confidence interval, 0.57 to 0.90). Men progressed to RRT more often than women (adjusted relative risk, 1.59; 95% confidence interval, 1.35 to 1.88). BMI was unrelated to RRT incidence. By the end of follow-up, 389 patients with CRF (42%) had died, 89 of them (10%) before the start of RRT. The most common primary cause of death was cardiovascular disease (37.5%). Characteristics significantly related to a greater mortality rate included older age, diagnoses of diabetic nephropathy and nephrosclerosis, and low BMI.

CONCLUSION

Preuremic characteristics (age, sex, primary renal diagnosis, BMI, and GFR) are predictive of prognosis in unselected patients with CRF.

Incidence of cancer among patients with atopic dermatitis

OBJECTIVE

To assess the risk of skin cancer and other cancers among patients with atopic dermatitis.

DESIGN

Register-based retrospective cohort study.

SETTING

Sweden. Patients A total of 15 666 hospitalized patients identified in the national Inpatient Register as having discharge diagnoses of atopic dermatitis between January 1, 1965, and December 31, 1999. Interventions The National Swedish Cancer Register coded malignant neoplasms during the entire period of study. Follow-up time was calculated from the date of entry in the cohort until the occurrence of a first cancer diagnosis, emigration, death, or the end of the observation period, whichever occurred first.

MAIN OUTCOME MEASURES

Follow-up by means of record linkages to several nationwide registers, among them the National Swedish Cancer Register. Standardized incidence ratios (SIRs) (the ratios of numbers of observed patients with cancer to expected numbers of incident cases of cancer) estimated the risk of developing cancer relative to the risks in the age-, sex-, and calendar year- matched general Swedish population.

RESULTS

After excluding the first year of follow-up, the risk of developing any cancer was increased by 13% (95% confidence interval [CI] of SIR, 1.01-1.25, based on 311 observed patients with cancer). Excess risks were observed for cancers of the esophagus (SIR, 3.5; 95% CI, 1.3-7.7; 6 patients), pancreas (SIR, 1.9; 95% CI, 1.0-3.4; 11 patients), brain (SIR, 1.6; 95% CI, 1.1-2.4; 27 patients), and lung (SIR, 2.0; 95% CI, 1.3-2.8; 31 patients) and for lymphoma (SIR, 2.0; 95% CI, 1.4-2.9; 29 patients). There was a nonsignificant 50% excess risk for nonmelanoma skin cancer (SIR, 1.5; 95% CI, 0.8-2.6; 12 patients), seemingly confined to men and to the first 10 years of follow-up. Malignant melanoma did not occur more often than expected.

CONCLUSIONS

The observed risk elevations, all of borderline statistical significance, should be interpreted cautiously. We could not control for possible confounding by cases of cancer caused by smoking, and the combination of multiple significance testing and few observed patients may have generated chance findings.

Helicobacter pylori eradication has the potential to prevent gastric cancer: a state-of-the-art critique

Helicobacter pylori infection continues to play a key role in gastric diseases. Colonization of the gastric mucosa with the bacterium invariably results in the development of chronic gastritis and subsets of patients have a progression of the chronic gastritis to either ulcer or cancer. Epidemiological evidence indicates that the proportion of all gastric cancers attributable to H. pylori infection, and hence potentially preventable upon elimination of this risk factor, is somewhere in the range of 60% to 90%. This portends significant benefit in terms of morbidity and mortality, not least in populations with high prevalence of H. pylori infection coupled with high incidence of gastric cancer. The effect of prophylactic H. pylori eradication on gastric cancer incidence in humans remains unknown, however. Results from randomized trials are eagerly awaited, but availability of strong conclusive results may take many years. A growing number of studies show considerable variation in risk for gastric cancer development, depending on H. pylori strain type and the genetic predisposition of the host. There is also a remote possibility that elimination of the infection may have adverse health implications (e.g., antibiotic resistance), and therefore "simple" risk stratification and targeted chemoprevention is required. Based on "in depth" evidence presented at this workshop, the majority of the scientific task force favored a search-and-treat strategy in first-degree relatives of gastric cancer patients and an overwhelming majority felt that a more general screen-and-treat strategy should be focused in the first instance on a population with a high incidence of H. pylori-associated diseases.

Prevalence of precancerous and other metaplasia in the distal oesophagus and gastro-oesophageal junction

OBJECTIVE

The epidemiology of Barrett's oesophagus (BO) is characterized by divergent results. The aim of this study was to estimate the prevalence of BO and intestinal metaplasia (IM) at the gastro-oesophageal junction (GOJ) in a population-based series of patients referred for first-time gastroscopy.

MATERIAL AND METHODS

Consecutive patients who underwent endoscopy for the first time at endoscopy units exclusively serving defined catchment areas were invited to take part in the study. Biopsies were taken immediately below the GOJ and from the distal oesophagus, and clinical data were recorded.

RESULTS

A total of 769 patients (mean age 53 years, 43% M) were examined. Overall IM prevalence was 14%. BO was noted in 4%. Overall, the prevalence of IM increased by 8% (95% CI 6-10%) per year of age. BO patients were predominately women (69%). Presence of cardia-type mucosa in the cardia increased with age from 25% among the youngest to 59% among the oldest patients. Pancreatic acinar metaplasia (PAM) was found in 18%.

CONCLUSIONS

While BO is not common among Swedish gastroscopy patients, IM and PAM are found in every 7th and 6th patient, respectively. Age-dependent increments in prevalence suggest that not only BO and IM, but also cardia-type mucosa are acquired and/or progressive lesions.