Pneumonia diagnosis in childhood and incidence of leukaemia, lymphoma and brain cancer:a Danish nationwide cohort study

ObjectivesThere is an ongoing debate on the possible association between infections in early childhood and subsequent cancer risk, but it remains unclear if a hospital admission for infection is associated with risk of childhood cancer diagnosis. We examined if a hospital-based diagnosis of pneumonia was a clinical marker of the three most common childhood cancers.DesignPopulation-based cohort study.SettingDenmark, hospital diagnoses, 1994–2013.MethodsUsing national health registries, we compared the observed incidence of leukaemia, lymphoma and brain cancer among 83 935 children with a hospital-based pneumonia diagnosis with that expected among children in the general population. We calculated absolute cancer risks and standardised incidence ratios (SIRs) as a measure of relative risk.ResultsThe cancer SIRs were substantially increased during the first 6 months of follow-up; lymphoid leukaemia: 6.2 (95% CI 3.5 to 10.3); myeloid leukaemia: 14.8 (95% CI 6.0 to 30.6); Hodgkin’s lymphoma: 60.8 (95% CI 26.2 to 120), non-Hodgkin’s lymphoma: 15.9 (95% CI 5.2 to 37.2) and brain cancer: 4.4 (95% CI 1.9 to 8.7). The 6-month absolute risks of leukaemia, lymphoma and brain cancer were all low, reaching 0.05% when combined. An increased risk persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the 5-year absolute cancer risk was 0.14%.ConclusionsThe short-term incidence of leukaemia, lymphoma and brain cancer was higher than expected and persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the absolute cancer risk was low.</jats:sec

Associations between adjustment disorder and hospital-based infections in the Danish population.

OBJECTIVE:There is some evidence that posttraumatic stress disorder (PTSD) is associated with increased risk of infections, and it is unknown whether adjustment disorder is as well. We assessed the association between adjustment disorder and subsequent infections, and assessed additive interaction with sex. METHODS:The study population included a nationwide cohort of all Danish-born residents of Denmark diagnosed with adjustment disorder between 1995 and 2011, and an age- and sex-matched general population comparison cohort. We compared rates of infections requiring inpatient or outpatient hospitalization in the two cohorts. We fit Cox proportional hazards models to compute adjusted hazard ratios (aHR) for the associations between adjustment disorder and 32 types of infections, and calculated interaction contrasts to assess interaction between adjustment disorder and sex. RESULTS:Adjustment disorder was associated with increased rates of infections overall (n&nbsp;=&nbsp;19,838 infections, aHR&nbsp;=&nbsp;1.8, 95% confidence interval&nbsp;=&nbsp;1.8. 1.9), and increased rates of each individual infection type (aHRs for 30 infections ranged from 1.5 to 2.3), adjusting for baseline psychiatric and somatic comorbidities and marital status. For many infection types (e.g., skin infections, pneumonia), interaction contrasts indicated rate differences were greater among men than women, while for two (urinary tract infections and sexually transmitted infections), rate differences were greater for women. CONCLUSIONS:These findings are consistent with studies examining the relationship between psychological stress and infections, and between PTSD and infections. They may be explained by a combination of the triggering of unhealthy behaviors as well as immune responses to stress

Pericarditis as a Marker of Occult Cancer and a Prognostic Factor for Cancer Mortality.

BACKGROUND: Pericarditis may be a serious complication of malignancy. Its significance as a first symptom of occult cancer and as a prognostic factor for cancer survival is unknown. METHODS: Using Danish medical databases, we conducted a nationwide cohort study of all patients with a first-time diagnosis of pericarditis during 1994 to 2013. We excluded patients with previous cancer and followed up the remaining patients for subsequent cancer diagnosis until November 30, 2013. We calculated risks and standardized incidence ratios of cancer for patients with pericarditis compared with the general population. We assessed whether pericarditis predicts cancer survival by the Kaplan-Meier method and Cox regression using a matched comparison cohort of cancer patients without pericarditis. RESULTS: Among 13 759 patients with acute pericarditis, 1550 subsequently were diagnosed with cancer during follow-up. The overall cancer standardized incidence ratio was 1.5 (95% confidence interval [CI], 1.4-1.5), driven predominantly by increased rates of lung, kidney, and bladder cancer, lymphoma, leukemia, and unspecified metastatic cancer. The <3-month cancer risk among patients with pericarditis was 2.7%, and the standardized incidence ratio was 12.4 (95% CI, 11.2-13.7). The 3- to <12-month standardized incidence ratio of cancer was 1.5 (95% CI, 1.2-1.7), subsequently decreasing to 1.1 (95% CI, 1.0-1.2). Three-month survival after the cancer diagnosis was 80% and 86% among those with and without pericarditis, respectively, and the hazard ratio was 1.5 (95% CI, 1.3-1.8). One-year survival was 65% and 70%, respectively, corresponding to a 3- to <12-month hazard ratio of 1.3 (95% CI, 1.1-1.5). CONCLUSIONS: Pericarditis may be a marker of occult cancer and augurs increased mortality after a cancer diagnosis

Posttraumatic stress disorder and cancer risk: a nationwide cohort study

The association between stress and cancer incidence has been studied for more than seven decades. Despite plausible biological mechanisms and evidence from laboratory studies, findings from clinical research are conflicting. The objective of this study was to examine the association between PTSD and various cancer outcomes. This nation-wide cohort study included all Danish-born residents of Denmark from 1995 to 2011. The exposure was PTSD diagnoses (n = 4131). The main outcomes were cancer diagnoses including: (1) all malignant neoplasms; (2) hematologic malignancies; (3) immune-related cancers; (4) smoking- and alcohol-related cancers; (5) cancers at all other sites. Standardized incidence ratios (SIR) were calculated. Null associations were found between PTSD and nearly all cancer diagnoses examined, both overall [SIR for all cancers = 1.0, 95 % confidence interval (CI) = 0.88, 1.2] and in analyses stratified by gender, age, substance abuse history and time since PTSD diagnosis. This study is the most comprehensive examination to date of PTSD as a predictor of many cancer types. Our data show no evidence of an association between PTSD and cancer in this nationwide cohort