Cancer mortality and morbidity among patients with schizophrenia: A hospital-based cohort study, 1992-2020

OBJECTIVE

Due to the inconsistency of the evidence about the cancer risk among patients with schizophrenia, the aim of this study was to analyse cancer mortality and morbidity in patients with schizophrenia treated in a single centre in Lithuania during the study period of 1992-2020.

MATERIALS AND METHODS

A retrospective cohort study was conducted in Vilnius Republican Psychiatric Hospital, the biggest specialised psychiatric hospital in Lithuania, with approximately 5000 hospital admissions annually. The patients' cohort was established by identifying all patients with the diagnosis of schizophrenia (ICD-10 code F20) in the hospital database from 1 January 1992 until 31 December 2017. The cancer cases and cancer deaths in the cohort were identified in the Lithuanian Cancer Register through linkage procedures. The analysis of risk was based on a comparison of observed and expected numbers of cancers and deaths. Expected number of cancer cases were calculated by multiplication of the exact person-years under observation in the cohort by sex, calendar year and a 5-year age-group-specific national incidence and mortality rate. All statistical analyses were carried out using STATA 15 statistical software.

RESULTS

During the follow-up, out of 8553 patients, 673 cases of cancer were diagnosed in both sexes. Statistically significantly lower risk for overall cancer incidence was observed in men (SIR 0.74, 95% CI 0.66-0.83), but not in women (SIR 1.07, 95% CI 0.97-1.18). Statistically significant lower overall cancer mortality risk was observed in men (SMR 0.82, 95% CI 0.70-0.96), while in the women's group, risk of cancer deaths was significantly higher compared to the general population (SMR 1.28, 95% CI 1.11-1.48). We observed lower risk for pancreatic cancer (SIR 0.36, 95% CI 0.14-0.96), non-melanoma skin cancer (SIR 0.54, 95% CI 0.33-0.88) and prostate cancer (SIR 0.69, 95% CI 0.55-0.87) in men and higher risk for malignant neoplasm of liver (SIR 2.58, 95% CI 1.53-4.36) and skin melanoma (SIR 2.03, 95% CI 1.12-3.66) in men and for breast cancer (SIR 1.38, 95% CI 1.14-1.66) and corpus uteri cancer (SIR 1.56, 95% CI 1.18-2.07) in women.

CONCLUSIONS

The current results of our study indicate lower risk of overall cancer incidence and mortality in male patients with schizophrenia, while female patients had a higher mortality risk, alongside variations in the risk of different cancer types. This information is important not only for patients, but for healthcare specialists to develop effective disease-specific preventive interventions and programmes.

Lithuanian cohort of Chernobyl cleanup workers: Cancer incidence follow-up 1986-2012

BACKGROUND

Cancer risks following radiation exposure in adulthood after Chernobyl are less studied compared to those after exposure in childhood. We aimed to evaluate cancer risk in the Lithuanian cohort of Chernobyl cleanup workers 26 years after their exposure in Chernobyl.

METHODS

Study population (6707 men) was followed for cancer incidence upon return from Chernobyl till the end of 2012 by linkage procedure with the Lithuanian Cancer Registry and for migration and death - with Central Population Registry. The site-specific cancer risk in the cohort was estimated by calculating the standardised incidence ratio (SIR) with 95 % confidence interval (CI).

RESULTS

A total of 596 cancer cases was observed in the cohort, against 584 expected (SIR 1.02; 95 % CI 0.94, 1.11). Only incidence of mouth and pharynx cancers was increased compared to the expected (SIR 1.41; 95 % CI 1.07, 1.86). Nevertheless, an increased risk of thyroid cancer was observed among cleanup workers who were younger than 30 years when entering the Chernobyl zone (SIR 2.90; 95 % CI 1.09, 7.72), whose radiation dose was above 100 milisievert (mSv) (SIR 3.13; 95 % CI 1.30, 7.52) and who had shorter duration of stay (SIR 2.30; 95 % CI 1.03, 5.13).

CONCLUSIONS

Our findings are consistent with those observed in other cohorts of workers, namely, the increased risk of cancer sites related to behavioural factors. The increased risk of thyroid cancer among cleanup workers who were younger than 30 years when entering Chernobyl and whose radiation dose was above 100 mSv cannot exclude the association with the radiation exposure in Chernobyl.

Increased Mortality Risk in People with Type 2 Diabetes Mellitus in Lithuania

This retrospective cohort study aimed to analyze overall and cause-specific mortality risk in people with type 2 diabetes mellitus (T2DM) in Lithuania. Information on the diagnosis of T2DM and glucose-lowering medication was obtained from the National Health Insurance Fund database, causes of death–from death certificates. Sex, age, and calendar period-standardized mortality ratios (SMRs) were calculated. In addition, 89,512 patients were followed-up between 2010 and 2017, contributing to the observation period of 592,321 person-years. Overall mortality risk was increased for both sexes (overall SMR = 1.35, 95% confidence interval (CI) 1.34–1.37). Greatest mortality risk was in the age group of 40–49 years at diabetes diagnosis (SMR = 1.68, 95% CI 1.60–1.76) and among those who had died before the age of 50 (SMR = 22.04, 95% CI 18.82–25.81). Patients treated with insulin only had the highest SMR (2.43, 95% CI 2.32–2.55). Mortality risk increased with increasing diabetes duration and was higher in women in all these groups. The highest cause-specific SMRs were infection-related causes (SMR = 1.44), particularly septicemia (SMR = 1.78), diseases of the circulatory system (SMR = 1.42), especially ischemic heart (SMR = 1.46) and cerebrovascular diseases (SMR = 1.38), as well as diseases of the digestive system (SMR = 1.35). Cancer mortality risk was elevated for women (SMR = 1.13), but not for men (SMR = 0.93). In conclusion, people with T2DM had an excess mortality risk, which was higher in women compared to men, younger people, in those who were diagnosed with T2DM at a younger age, had longer diabetes duration, and who required treatment with insulin.

A Cohort Study of Antihyperglycemic Medication Exposure and Gastric Cancer Risk

We assessed gastric cancer risk in type 2 diabetes mellitus patients. Gastric cancer patients with diabetes between 2001–2012 were identified. Four groups were analysed: combination therapy with metformin users; insulin and other medication users; metformin and insulin users; and sulfonylurea users. Standardised incidence ratios (SIRs) for gastric cancers as a ratio of the observed number of cancer cases in people with diabetes to the expected number of cancer cases in the underlying general population were calculated. A total of 99,992 patients with diabetes were analysed and 337 gastric cancer cases in patients with diabetes were observed when compared to the expected number of 400.54 gastric cancer cases, according to the cancer rates of the general population (SIR 0.84, 95% confidence interval (CI): 0.76–0.94). Lower risk of gastric cancer was found both in male and female patients with diabetes, however, risk among females was insignificantly lower. Higher gastric cancer risk was found in the group of diabetic patients treated with sulfonylureas (SIR 1.31, 95% CI: 1.04–1.65) and significantly lower risk than expected from the general population was found in the group of metformin users (SIR 0.75, 95% CI: 0.66–0.86). Type 2 diabetes mellitus was not associated with increased risk of gastric cancer. Metformin might decrease the risk of gastric cancer in patients with diabetes, while sulfonylureas may increase gastric cancer risk.

Suicide risk among colorectal cancer patients in Lithuania

PURPOSE

We aimed to estimate suicide risk among colorectal cancer patients in the country showing the highest suicide rates among developed countries.

METHODS

Patients with colorectal cancer diagnosed between 1998 and 2012 were identified from the Lithuanian Cancer Registry. Standardised mortality ratios (SMRs) for suicide were calculated for patients diagnosed with cancer in Lithuania, relative to suicide rates in the general population.

RESULTS

Twenty thousand seven hundred sixty-five primary colorectal cancer cases diagnosed between 1998 and 2012 were extracted from the database. Among 19,409 first primary colorectal cancer patients, we identified 67 suicides and the expected number of suicides calculated from general population was 41.4 in this cohort, resulting in an SMR of 1.62 for both sexes (95% CI, 1.27-2.06). A higher suicide risk was found for women (SMR 2.15; 95% CI 1.35-3.41), than for men (SMR 1.48; 95% CI 1.12-1.96). The suicide risk was almost twice higher in patients 60 and older, with highest increase in the oldest patients (SMR 2.12, 95% CI 1.01-4.46). The risk of suicide was not significantly elevated in colorectal cancer patients with localised tumours, but there was a fourfold increase in risk in patients with stage IV tumours. Compared with the general population, the risk of suicide among colorectal cancer patients was four times higher during the first 3 months after diagnosis and decreased thereafter.

CONCLUSIONS

The patients with colorectal cancer have a higher rate of suicide compared with the general Lithuanian population. Sex, age, advanced rectal cancer and distant spread of disease were the main predictors of suicide among colorectal cancer patients.

Education predicts cervical cancer survival: a Lithuanian cohort study

Background

: We examined inequalities in cervical cancer survival in Lithuania by education and place of residence. : The study is based on the linked dataset that includes all records of the 2001 population Census, all records from Lithuanian Cancer Registry (cancer incidence) and all death and emigration records from Statistics Lithuania for the period between 6 April 2001 and 31 December 2009. The study group includes cervical cancers registered in the Cancer Registry from 1 January 2002 to 31 December 2006. Analysis was restricted to women who were 25-64 years old at the Census date (in total 1 866 cases). : During the study period there were 671 deaths corresponding to an overall 5-year survival proportion 64.13% (95% CI 61.86-66.31). Place of residence and education of cervical cancer patients had strong impact on survival; 5-year survival was higher in women living in urban areas than in rural (68.61 and 55.93%) and survival decreased with decreasing education: from 79.77% in highest education group to 64.85 and 50.48% in groups with secondary and lower than secondary education. The effect of place of residence declined when stage of disease was included in the model and became not significant in final model with education adjustment. The effect of education declined after inclusion of stage and other variables, however, remained significant. : We found that women with higher education experienced higher survival following a cervical cancer diagnosis, and stage of disease at the time of diagnosis explains only the part of observed differences.

Parity and Risk of Thyroid Cancer: a Population-Based Study in Lithuania

An association between parity and thyroid cancer risk has been investigated in a number of independent studies but yielded contradictory findings. The aim of this study was to explore the association between parity and thyroid cancer risk. The population-based cohort study in Lithuanian was conducted. The study dataset based on the linkages between all records from the 2001 population census, all cancer incidence records from the Lithuanian Cancer Registry, and all death and emigration records from Statistics Lithuania for the period between 6 April 2001 and 31 December 2009. Cox's proportional hazards regression models were used to estimate the hazard ratios (HRs) for parity, age at first birth, number of children, place of residence, education, and age at census. The cohort of 868,105 women was followed for 8.6 years, and 1775 thyroid cancer cases were diagnosed during the study period. The significantly higher thyroid cancer risk was observed among parous women (HR = 1.45, 95% CI: 1.20, 1.75) and in women with 1, 2, and 3 children, after adjusting for the possible confounding effects of relevant demographic variables. The findings of this study are consistent with the hypothesis that parity might be associated with the risk of thyroid cancer in women.