Stress and cancer: Nordic pieces to the complex puzzle

Sense of coherence and risk of breast cancer

Sense of coherence (SoC) is the origin of health according to Antonovsky. The link between SoC and risk of cancer has however rarely been assessed. We performed a cohort study of 46,436 women from the Karolinska Mammography Project for Risk Prediction of Breast Cancer (Karma). Participants answered a SoC-13 questionnaire at recruitment to Karma and were subsequently followed up for incident breast cancer. Multivariate Cox models were used to assess the hazard ratios (HRs) of breast cancer in relation to SoC. We identified 771 incident cases of breast cancer during follow-up (median time: 5.2 years). No association was found between SoC, either as a categorical (strong vs. weak SoC, HR: 1.08, 95% CI: 0.90–1.29) or continuous (HR: 1.08; 95% CI: 1.00–1.17 per standard deviation increase of SoC) variable, and risk of breast cancer. In summary, we found little evidence to support an association between SoC and risk of breast cancer.

Psychological distress is associated with cancer-specific mortality among patients with cervical cancer

Emerging evidence suggests a role of psychological factors in the progression of different cancer types. However, it is unclear whether psychological distress around the time of diagnosis of invasive cervical cancer places patients at a higher risk of cancer-specific mortality, independently of tumor characteristics and treatment modalities. We conducted a nationwide cohort study, including 4,245 patients with newly diagnosed cervical cancer during 2002-2011 in Sweden. Psychological distress was indicated by a clinical diagnosis of depression, anxiety, or stress reaction and adjustment disorders, or the experience of a stressful life event, including death or severe illness of a family member, divorce, or between jobs, from one year before cancer diagnosis and onwards. We calculated the hazard ratios (HRs) of cancer-specific mortality among the patients exposed to psychological distress, compared to unexposed patients, controlling for socioeconomic characteristics and other known prognostic indicators such as tumor and treatment characteristics. We found that patients exposed to psychological distress had an increased risk of cancer-specific mortality (HR 1.33, 95% CI 1.14 to 1.54). The association was primarily driven by distress experienced within one year before or after diagnosis (HR 1.30, 95% CI 1.11 to 1.52), but not thereafter (HR 1.12, 95% CI 0.84 to 1.49). In summary, our study shows that psychiatric disorders and stressful life events around cancer diagnosis are associated with increased cancer-specific mortality among patients with cervical cancer, independent of tumor characteristics and treatment modality.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.