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.

Value of combined serum CEA, CA72-4, and CA19-9 marker detection in diagnosis of colorectal cancer

BACKGROUND

The aim of this study was to examine whether the combination of serum tumor markers (carcinoembryonic antigen [CEA], carbohydrate antigen [CA]72-4, CA19-9) improves sensitivity and accuracy in the diagnosis of colorectal cancer and precancerous lesion tubular adenoma.

METHODS

An automatic electrochemiluminescence immunoassay with matched kits (ECLIA) was performed on a Roche Cobas e411 analyzer to determine the levels of serum CEA, CA72-4, and CA19-9 in 35 patients with early colorectal cancer, 87 patients with tubular adenoma, and 58 healthy people undergoing colonoscopy after positive fecal immunochemical test (FIT) in a colorectal cancer screening program 2021 January to April. The values of these three tumor markers in the diagnosis of colorectal cancer and tubular adenoma were analyzed.

RESULTS

180 patients (92 female and 88 male) were included into the study. We compared serum CEA, CA72-4 and CA19-9 markers among 3 groups: healthy people (mean age 64,0 ±8,6), patients with tubular adenoma (mean age 62,7 ± 6,4) and colorectal cancer (mean age 59,2 ±6,2). The levels of serum CEA, CA72-4, and CA19-9 were higher in the colorectal cancer group than in the tubular adenoma group and healthy subjects, and these differences were significant (p < 0.05). The combination of CEA, CA72-4, and CA19-9 had a higher diagnostic value for colorectal cancer compared to single markers, and the positive detection rate was 54.3%. The diagnostic power when using all three markers was the best, and applied for colorectal cancer and tubular adenoma.

CONCLUSIONS

The combination of CA72-4, CEA, and CA19-9 markers increases the sensitivity and accuracy in the diagnosis of colorectal cancer and can thus be considered an important tool for early colorectal diagnosis.

Psychological distress 35 years after the Chornobyl accident in the Lithuanian clean-up workers

The adverse effects on the health of the Chornobyl nuclear power plant accident clean-up workers have been reported previously. However, there is a lack of studies on the mental health of Chornobyl clean-up workers. The current study explored psychological distress in a sample of Lithuanian clean-up workers 35 years after the accident. In total, 107 Lithuanian Chornobyl clean-up workers (M_age = 62.5) and 107 controls were included in the study. The Hospital Anxiety and Depression Scale (HAD) was used for the assessment of anxiety and depression. The depression symptoms were significantly higher in the clean-up workers compared to the control group. The prevalence of severe depression symptoms was 23.4% and 4.7% in the Chornobyl clean-up workers and control groups, respectively. The risk for severe depression was associated with Chornobyl clean-up work (adjusted OR = 5.9). No differences in the anxiety symptoms were found between clean-up workers and controls. The study revealed the deteriorated mental health of the Lithuanian Chornobyl clean-up workers 35 years after the disaster - in particular, high levels of depression. Psychosocial support programmes for clean-up workers should be provided to mitigate the adverse effects of the disaster.

Efficacy of focal high-dose-rate brachytherapy in the treatment of patients diagnosed with low or favourable: intermediate-risk prostate cancer-a protocol for a randomised controlled trial

INTRODUCTION

Prostate cancer (PCa) is men's second most predominant cancer worldwide. Because the prostate-specific antigen test is used in diagnostics, PCa is more often diagnosed in the early stages, making radical treatment of the disease possible. However, it is estimated that over a million men worldwide suffer from radical treatment-related complications. Thus, focal treatment has been proposed as a solution, which aims to destroy the predominant lesson that determines the progression of the disease. The main objective of our study is to compare the quality of life and efficacy of patients diagnosed with PCa before and after the treatment with focal high-dose-rate brachytherapy and to compare results with focal low-dose-rate brachytherapy and active surveillance.

METHODS AND ANALYSIS

150 patients diagnosed with low-risk or favourable intermediate-risk PCa who meet the inclusion criteria will be enrolled in the study. Patients are going to be randomly assigned to the study groups: focal high-dose-rate brachytherapy (group 1), focal low-dose-rate brachytherapy (group 2) and active surveillance (group 3). The study's primary outcomes are quality of life after the procedure and time without biochemical disease recurrence. The secondary outcomes are early and late genitourinary and gastrointestinal reactions after the focal high-dose and low-dose-rate brachytherapies and evaluation of the importance and significance of in vivo dosimetry used for high-dose-rate brachytherapy.

ETHICS AND DISSEMINATION

Bioethics committee approval was obtained before this study. The trial results will be published in peer-reviewed journals and at conferences.

TRIAL REGISTRATION NUMBER

Vilnius regional bioethics committee; approval ID 2022/6-1438-911.

Incidence, Mortality, and Survival Trends in Cancer of the Gallbladder and Extrahepatic Bile Ducts in Lithuania

Background and Objectives: Gallbladder cancer is a rare type of cancer, with aggressive clinical behavior. Limited treatment options provide poor survival prognosis. We aimed to investigate the incidence, mortality trends, and survival of gallbladder and extrahepatic bile duct cancer in Lithuania between 1998 and 2017. Materials and Methods: The study was based on the Lithuanian Cancer Registry database. The study included all cases of cancer of the gallbladder and extrahepatic bile ducts reported to the Registry in the period 1998–2017. Age-specific and age-standardized incidence rates were calculated. In addition, 95% confidence intervals for APC (Annual Percent Change) were calculated. Changes were considered statistically significant if p was <0.05. Relative survival estimates were calculated using period analysis according to the Ederer II method. Results: Age-standardized rates for gallbladder cancer and extrahepatic bile duct cancer among females decreased from 3.91 to 1.93 cases per 100.000 individuals between 1998 and 2017, and from 2.32 to 1.59 cases per 100.000 individuals between 1998 and 2017 among males. The highest incidence rates were found in the 85+ group with 27.5/100,000 individuals in females and 26.8/100,000 individuals in males. The 1-year as well as 5-year relative survival rates of both genders were 34.29% (95% CI 32.12–36.48) and 16.29% (95% CI 14.40–18.27), respectively. Conclusions: Incidence and mortality from gallbladder and extrahepatic bile duct cancer decreased in both sexes in Lithuania. Incidence and mortality rates were higher in females than in males. Relative 1-year and 5-year survival rates showed a steady increase during the study period among males and females.

Incidence, mortality and survival trends of penile cancer in Lithuania 1998-2017

Background and objectives

The aim of this study was to analyse trends in penile cancer incidence, mortality, and relative survival in Lithuania during the period of 1998-2017.

Materials and methods

The study was based on all cases of penile cancer reported to the Lithuanian Cancer Registry between 1998 and 2017. Age-specific rates standardized rates were calculated, using the direct method (World standard population). The Joinpoint regression model was used to provide estimated average annual percentage change (AAPC). One-year and five-year relative survival estimates were calculated using period analysis. Relative survival was calculated as the ratio of the observed survival of cancer patients and the expected survival of the underlying general population.

Results

During the study period, the age-standardized incidence rate of penile cancer varied between 0.72 and 1.64 per 100 000, with AAPC 0.9% (95% CI -0.8-2.7). The mortality rate of penile cancer in Lithuania during this period varied from 0.18 to 0.69 per 100 000, with AAPC of -2.6% (95% CI -5.3-0.3). Relative one-year survival of patients, diagnosed with penile cancer improved over the time from 75.84% in period 1998-2001 to 89.33% in period 2014-2017. Relative five-year survival rate of patients, diagnosed with penile cancer changed from 55.44% in period 1998-2001 to 72.90% in period 2014-2017.

Conclusions

The incidence rates of penile cancer showed an increasing trend, while mortality rates were decreasing in Lithuania during 1998-2017. One-year and five-year relative survival increased, however, it does not reach the highest scores of Northern European countries.

Trends in Pancreatic Cancer Incidence and Mortality in Lithuania, 1998-2015

BACKGROUND

Pancreatic cancer is one of the deadliest cancers worldwide, and its incidence is increasing. The aim of this study was to examine the time trends in the incidence and mortality rates of pancreatic cancer for the period of 1998-2015 for the first time in Lithuania by sex, age, subsite, and stage.

METHODS

This study was based on all cases (deaths) of pancreatic cancer diagnosed between 1998 and 2015. Age-standardized incidence (mortality) rates and group-specific rates were calculated for each sex using the direct method (European Standard). TNM classification-based information reported to the cancer registry was grouped into three categories: (1) localized cancer: T1-3/N0/M0; (2) cancer with regional metastasis: any 1-3/N+/M0; (3) advanced cancer: any T/any N/M+. Joinpoint regression was used to provide annual percentage changes (APCs) and to detect points in time where statistically significant changes in the trends occurred.

RESULTS

Overall, 8514 pancreatic cancer cases (4364 in men and 3150 in women) were diagnosed and 7684 persons died from cancer of the pancreas. Pancreatic cancer incidence rates were considerably lower for women than for men, with a female:male ratio of 1:2. Incidence rates changed during the study period from 14.2 in 1998 to 15.0/100,000 in the year 2015 in men, and from 6.7 to 9.8/100,000 in women. Incidence rates over the study period were stable for men (APC = 0.1%) and increasing for women by 1.1% per year. Similarly, mortality rates increased in women by 0.9% per year, and were stable in men. During the study period, incidence and mortality rates of pancreatic cancer were close. For the entire study period, rates increased significantly in the 50-74 years age group; only cancer of the head of pancreas showed a decline by 0.9%, while tail and not-specified pancreatic cancer incidence increased by 11.4% and 4.51%, respectively.

CONCLUSIONS

The increasing pancreatic cancer incidence trend in the Lithuanian population may be related to the prevalence of its main risk factors (smoking, obesity, physical inactivity, diet, and diabetes).

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.

Risk of Endometrial Cancer in Women with Diabetes: A Population-Based Retrospective Cohort Study

The aim of this study was to examine the association between type 2 diabetes (T2DM), use of glucose-lowering medications and endometrial cancer (EC) risk.

METHODS

The risk of EC incidence among women with T2DM in Lithuania was assessed using a retrospective cohort study design. Female patients who were registered with T2DM between 1 January 2000 and 31 December 2012 were identified in the National Health Insurance Fund database. EC cases (ICD-10 code C54) were identified from the Lithuanian Cancer Registry. Standardized incidence ratios (SIRs) were calculated by dividing the observed numbers of EC among patients with T2DM by the expected number of EC, calculated using national rates.

RESULTS

A total of 77,708 diabetic women were included in the analysis, and 995 cases of EC were identified. A significantly increased EC risk in diabetic women was found as compared to the general population (SIR = 1.69, 95% CI 1.59-1.80). The greatest EC risk was found among younger patients at T2DM diagnosis, and the risk declined gradually with increasing age but persisted in being significantly increased among all age groups. The risk for EC increased with increasing duration of diabetes, and the highest EC risk was observed more than 10 years after T2DM diagnosis. A significantly higher EC risk than expected from the general population was found in all patient groups by glucose-lowering medication combinations. The lowest EC risk was observed in diabetic women who were users of "oral only" (without metformin) (SIR = 1.42, 95% CI 1.10-1.83) and "metformin only" (SIR = 1.69, 95% CI 1.49-1.92) medications. A two times greater EC risk was observed among the remaining glucose-lowering medication categories. In contrast, use of insulin only was not related to a higher EC incidence risk (SIR = 0.45, 95% CI 0.23-0.86); however, the risk estimation was based on nine cases.

CONCLUSIONS

Our study shows a significantly increased EC risk in diabetic women as compared to the general population. In this study, a significantly higher EC risk was found in all patient groups by glucose-lowering medication combinations, except for insulin only users.

Retrospective cohort study of androgen deprivation therapy and the risk of diabetes in men with prostate cancer in Lithuania

OBJECTIVES

To examine the risk of type 2 diabetes in patients with prostate cancer and its association with androgen deprivation therapy (ADT).

DESIGN AND PARTICIPANTS

We performed a retrospective cohort study of patients diagnosed with prostate cancer in the Lithuanian male population between 1 January 2003 and 31 December 2012 who were identified through the Lithuanian Cancer registry. All prostate cancer cases were linked to the National Health Insurance Fund database to obtain information regarding the diagnosis of diabetes mellitus and information on prescriptions of antiandrogens and gonadotropin-releasing hormone (GnRH) agonists. Patients with prostate cancer were followed up until the diagnosis of type 2 diabetes, or 31 December 2017, or date of death, whichever came first. Cox proportional hazard models were used to estimate the risk of type 2 diabetes in patients with prostate cancer with or without ADT exposure.

RESULTS

27 580 men were diagnosed with prostate cancer, out of whom 14 502 (52.6%) did not receive ADT and 13 078 (47.4%) were treated with ADT. The incidence of type 2 diabetes for all patients with prostate cancer was 7.4/1000 person-years, for men on GnRH agonists 9.0/1000 person-years and 5.8/1000 person-years for men on antiandrogens. There was an increased risk of developing type 2 diabetes comparing ADT users and non-users (HR=1.49, 95% CI 1.34 to 1.66).

CONCLUSION

This study showed an increased risk of diabetes in patients with prostate cancer treated with ADT in comparison to ADT-free patient cohort. GnRH agonist users showed higher susceptibility, while the group on antiandrogen monotherapy showed no such increase.

Positive effect of metformin treatment in colorectal cancer patients with type 2 diabetes: national cohort study

We aimed to estimate colorectal cancer risk in patients with type 2 diabetes mellitus (T2DM) using metformin. Patients with colorectal cancer and diabetes from 2000 to 2012 were identified form Lithuanian Cancer Registry and the National Health Insurance Fund database. Standardized incidence ratios (SIRs) for colorectal cancers as a ratio of observed number of cancer cases in people with diabetes to the expected number of cancer cases in the underlying general population was calculated. We analysed 111 109 patients with diabetes. Overall, 1213 colorectal cancers were observed versus 954.91 expected within a period of observation entailing an SIR of 1.27 [95% confidence interval (CI): 1.20-1.34]. Significantly higher risk of colorectal cancer was found both in male and female patients with diabetes in all age groups. Higher risk was found for both colon and rectum cancers 1.36 (95% CI: 1.27-1.46) and 1.11 (95% CI: 1.01-1.22), respectively. There were no differences in risk over time since initial diabetes diagnosis. Never-users of metformin had twice higher risk of colorectal cancer compared to general population (SIR: 2.14, 95% CI: 1.95-2.35). Among metformin users, risk was lover (SIR: 1.47, 95% CI: 1.36-1.58) and colorectal cancer risk decreased with increasing cumulative dose of metformin (P < 0.001). Patients with T2DM had increased risk of colorectal cancer compared with the general Lithuanian population. Decreasing colorectal cancer risk with increasing cumulative dose of metformin indicates that metformin may be a protective agent for colorectal cancer development.

Trends in Incidence and Mortality of Primary Liver Cancer in Lithuania 1998-2015

Background: Recently, reports have suggested that rates of liver cancer have increased during the last decades in developed countries; increasing hepatocellular carcinoma and cholangiocarcinoma rates were reported. The aim of this study was to examine time trends in incidence and mortality rates of liver cancer for the period of 1998-2015 in Lithuania by sex, age, and histology. Methods: We examined the incidence of liver cancer from 1998 to 2015 using data from the Lithuanian Cancer Registry. Age-standardized incidence rates were calculated by sex, age, and histology. Trends were analyzed using the Joinpoint Regression Program to estimate the annual percent change. Results: A total of 3086 primary liver cancer cases were diagnosed, and 2923 patients died from liver cancer. The total number of liver cancer cases changed from 132 in 1998 to 239 in 2015. Liver cancer incidence rates changed during the study period from 5.02/100,000 in 1998 to 10.54/100,000 in 2015 in men and from 2.43/100,000 in 1998 to 6.25/100,000 in 2015 in women. Annual percentage changes (APCs) in the age-standardized rates over this period were 4.5% for incidence and 3.6% for mortality. Hepatocellular cancer incidence rates were stable from 1998 to 2005 (APC -5.9, p = 0.1) and later increased by 6.7% per year (p < 0.001). Intrahepatic ductal carcinoma incidence increased by 8.9% per year throughout the study period. The rise in incidence was observed in all age groups; however, in age groups < 50 and between 70 and 79 years, observed changes were not statistically significant. For mortality, the significant point of trend change was detected in 2001, where after stable mortality, rates started to increase by 2.4% per year. Conclusions: Primary liver cancer incidence and mortality increased in both sexes in Lithuania. The rise om incidence was observed in both sexes and main histology groups. The increasing incidence trend may be related to the prevalence of main risk factors (alcohol consumption, hepatitis B and C infections. and diabetes).

Reduced risk of prostate cancer in a cohort of Lithuanian diabetes mellitus patients

BACKGROUND

During the past decade, a huge interest was devoted to the type-2 diabetes mellitus and their associations with prostate cancer development.

OBJECTIVES

The aim of this study was to determine whether type 2 diabetes mellitus and treatment with metformin is associated with prostate cancer risk.

MATERIALS AND METHODS

The cohort was composed of diabetic male patients identified in the National Health Insurance Fund database during 2000-2016 and cancer cases in national Cancer Registry. We calculated standardized incidence ratios (SIR) for prostate cancers as a ratio of observed number of cancer case in people with diagnosis of diabetes to the expected number of cancer cases in the underlying general population.

RESULTS

2754 prostate cancers were observed versus 3111.26 expected within the period of observation entailing an SIR of 0.89 (95% CI: 0.85-0.92). Significantly lower risk of prostate cancer was found in diabetes patients in all age groups, also was in metformin-users and never-users' groups, with higher risk reduction in metformin-users (SIR 0.71, 95% CI: 0.68-0.75) than in diabetes patients never-users (SIR 0.88, 95% CI: 0.80-0.96).

CONCLUSION

In this large population-based study, we found a significantly decreased risk of prostate cancer among men with diabetes and metformin-users.

Increased kidney cancer risk in diabetes mellitus patients: a population-based cohort study in Lithuania

BACKGROUND

Diabetes is associated with increased risk of various cancers but its association with kidney cancer is unclear. The objective of this study was to evaluate the association between T2DM with or without metformin use and the risk of kidney cancer in a population-based national cohort in Lithuania.

METHODS

The cohort was composed of diabetic patients identified in the NHIF database during 2000-2012. Cancer cases were identified by record linkage with the national Cancer Registry. Standardized incidence ratios (SIRs) for kidney cancer as a ratio of observed number of cancer cases in diabetic patients to the expected number of cancer cases in the underlying general population were calculated.

RESULTS

T2DM patients (11,592) between 2000 and 2012 were identified. Overall, 598 cases of primary kidney cancer were identified versus 393.95 expected yielding an overall SIR of 1.52 (95% CI: 1.40-1.64). Significantly higher risk was found in males and females. Significantly higher risk of kidney cancer was also found in both metformin users and never-users' groups (SIRs 1.45, 95% CI: 1.33-1.60 and 1.78 95% CI: 1.50-2.12, respectively).

CONCLUSIONS

The patients with T2DM have higher risk for kidney cancer compared with the general Lithuanian population.

The impact of metformin on survival in patients with melanoma-national cohort study

PURPOSE

The primary study outcome was melanoma-specific mortality in patients with type 2 diabetes mellitus (T2DM) using metformin.

METHODS

Data regarding patients were provided by the Lithuanian Cancer Registry and were linked with National Health Insurance Fund in accordance with unique personal identification numbers during the period of thirteen years.

RESULTS

About 2817 patients met eligibility criteria and were included in the retrospective cohort study. About 163 patients had pre-existing T2DM and 103 of them were treated with metformin. In the multivariable analysis, there was significant risk difference in melanoma-specific survival between diabetic, metformin-using patients, and nondiabetic patients (P=0.02) in favor of metformin users.

CONCLUSION

Melanoma patients with T2DM treated with metformin had lower risk of melanoma-specific mortality; however, prospective controlled studies are mandatory to confirm this finding.

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.

Cohort Study of Antihyperglycemic Medication and Pancreatic Cancer Patients Survival

Background: We assessed the association between the use of metformin and other antihyperglycemic medications on overall survival in diabetic patients with pancreatic cancer. Methods: Patients with pancreatic cancer and diabetes between 2000 and 2015 were identified from the Lithuanian Cancer Registry and the National Health Insurance Fund database. Cohort members were classified into six groups according to type 2 diabetes mellitus treatment: sulfonylurea monotherapy; metformin monotherapy; insulin monotherapy; metformin and sulfonylurea combination; metformin and other antihyperglycemic medications; all other combinations of oral antihyperglycemic medications. Survival was calculated from the date of cancer diagnosis to the date of death or the end of follow-up (31 December 2018). Results: Study group included 454 diabetic patients with pancreatic cancer. We found no statistically significant differences in overall survival between patients by glucose-lowering therapy. However, highest mortality risk was observed in patients on insulin monotherapy, and better survival was observed in the groups of patients using antihyperglycemic medication combinations, metformin alone, and metformin in combination with sulfonylurea. Analysis by cumulative dose of metformin showed significantly lower mortality risk in the highest cumulative dose category (HR 0.76, 95% CI 0.58–0.99). Conclusions: Our study showed that metformin might have a survival benefit for pancreatic cancer patients, suggesting a potentially available option for the treatment.

Preexisting diabetes, metformin use and long-term survival in patients with prostate cancer

OBJECTIVE

To assess prostate cancer-specific and overall survival in prostate cancer patients with or without preexisting type 2 diabetes mellitus (T2DM) with regards to metformin use.

METHODS

Patients diagnosed with prostate cancer in the Lithuanian population between 2001 and 2005 were identified through the Lithuanian Cancer Registry and followed until 2016, date of death, loss to follow-up or whichever came first. Information regarding the diagnosis of T2DM and antihyperglycemic medications were obtained from the National Health Insurance Fund database. Prostate cancer-specific and overall survival outcomes were analysed using univariate and multivariate Cox proportional hazard models.

RESULTS

Out of 6689 men included, 254 (3.8%) had preexisting T2DM. There were 4807 deaths during follow-up, including 2084 from prostate cancer. No differences were found in prostate cancer-specific survival between men with or without T2DM. The risk of overall mortality was higher (HR = 1.24, 95% CI = 1.07-1.43) in diabetic men. Univariate analysis showed cancer stage at diagnosis and age to be significant predictors of survival. After adjustment for age and stage at diagnosis, there was no difference in prostate-specific survival between non-diabetic patients compared to metformin users or metformin non-users. However, overall survival was lower in T2DM patients, with a higher mortality risk for metformin non-users (HR = 1.63, 95% CI = 1.27-2.10). Prostate cancer-specific mortality risk was insignificantly lower in diabetic men on metformin (HR = 0.74, 95% CI = 0.54-1.02).

CONCLUSION

There was no difference in long-term prostate cancer-specific survival in patients with or without T2DM. Overall survival was lower in T2DM patients not treated with metformin.

Malignant mesothelioma of the tunica vaginalis testis: a rare case and review of literature

Background

Malignant mesothelioma of the tunica vaginalis is a rare tumour which comprises less than 1% of all mesotheliomas.

Case presentation

69-years old patient with painful hard mass and hydrocele in the right scrotum to whom a right hydrocelectomy was performed. Any history of scrotal trauma or exposure to asbestos was not present. Excisional biopsy revealed a multinodular tumour with focal areas of necrosis and infiltrative growth. According to morphological and immunohistochemical findings, diagnosis of malignant biphasic mesothelioma of the tunica vaginalis testis was made. Two months after hydrocelectomy, right inguinal orchidectomy was performed. Post-surgical whole body CT scan revealed paraaortic and pararenal lymphadenopathy, likely to be metastatic. Adjuvant treatment with 6 cycles of cisplatin and pemetrexed was applied. After 3 cycles of chemotherapy, CT scan showed progression and the treatment was changed to gemcitabine 1 month after.

Conclusions

Although malignant mesothelioma of the tunica vaginalis is a rare malignancy, it poses a diagnostic challenge which can mimic common inguinal or scrotal diseases such as hydrocele. Despite aggressive surgical procedures or adjuvant therapies, the prognosis remains poor.

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.

Increased Risk of Site-Specific Cancer in People with Type 2 Diabetes: A National Cohort Study

A retrospective cohort design was used with the objective to evaluate cancer risk among people with type 2 diabetes mellitus (T2DM) in Lithuania. The cohort was established by identifying all patients with the first diagnosis of T2DM in the National Health Insurance Fund database during 2000-2012. Cancer cases were identified by record linkage with the Lithuanian Cancer Registry. Standardized incidence ratios (SIRs) were calculated. Of the 127,290 people that were included, 5959 cases of cancer in men and 6661 cancer cases in women with T2DM were observed. A statistically significant increase in risk for all cancer sites was observed in women, SIR 1.16 (95% CI 1.14-1.19), but not in men, SIR 1.00 (95% CI 0.98-1.03). Among males, a significant increase of liver (SIR 2.11, 95% CI 1.79-2.49]), pancreas (SIR 1.77, 95% CI 1.57-1.99), kidney (SIR 1.46 95% CI 1.31-1.62), thyroid (SIR 1.83, 95% CI 1.32-2.54), colorectal (SIR 1.23, 95% CI 1.14-1.31]), skin melanoma (SIR 1.40, 95% CI 1.11-1.76), and non-melanoma skin (SIR 1.14, 95% CI 1.05-1.23) cancer was observed. For females with T2DM, a significant increase in risk of cancer of the liver (SIR 1.45, 95% CI 1.17-1.79), pancreas (SIR 1.74, 95% CI 1.56-1.93), kidney (SIR = 1.43, 95% CI 1.28-1.60), thyroid (SIR = 1.40, 95% CI 1.22-1.62), breast (SIR = 1.24, 95% CI 1.17-1.31), and corpus uteri (SIR 2.07, 95% CI 1.93-2.21) was observed. In conclusion, people with T2DM in Lithuania had an increased risk of site-specific cancer.

Changing Incidence and Stage Distribution of Prostate Cancer in a Lithuanian Population-Evidence from National PSA-Based Screening Program

Background: The aim of this study was to examine the impact of screening introduction on prostate cancer incidence changes, and changes in stage distribution in Lithuania between 1998–2016. Methods: Age-standardized incidence as well as stage-specific incidence rates were calculated. Joinpoint regression was used to estimate the annual percentage change in the incidence changes by determined stage: Localized, advanced, distant and unknown. Results: Over the study period, a total number of 48,815 new prostate cancer cases was identified. Age-standardized incidence rose from 51.9 per 100,000 in 1998 to 279.3 per 100,000 in 2007 (by 20.3% per year) and then decreased thereafter by 3.8% annually. Highest incidence rates after introduction of prostate specific antigene (PSA)-based screening was found for localized disease, followed by advanced. Incidence of localized disease rose by 38.2% per year until 2007 reaching the highest rate of 284.6 per 100,000, with a subsequent decrease of 5.5% every year thereafter. Advanced stage of disease experienced rise till 2007, and continuous decrease by 11.1% every year thereafter. Incidence of disease with distant metastasis was lowest, and rose till 2003, thereafter incidence significantly decreased by 8.1% every year. Conclusions: To our knowledge, this is the first report of stage migration effect in Lithuania, following the introduction of nationwide PSA-based screening. Prostate cancer screening substantially increased the overall incidence and incidence of localized cancer.

Skin Melanoma and Subsequent Risk of Prostate Cancer: A Lithuanian Cancer Registry Study

Emerging data indicates that melanoma may be linked to prostate cancer. We evaluated if the incidence of melanoma was associated with subsequent risk of prostate cancer (PC). We extracted data from the Lithuanian cancer registry from 1993 to 2012. We calculated the standardized incidence ratios (SIRs) for PC as a ratio of observed number of cancer cases in people with previous melanoma diagnosis to the expected number of cancer cases in the underlying general population. Therein, 95% confidence intervals for the SIRs were estimated assuming the number of observed cancer cases follows the Poisson distribution. Overall, 65 PCs were observed versus 52.5 expected (SIR 1.24; 95% CI: 0.97–1.58) within a period of 24 years. A significantly increased risk of PC was found in patients with melanoma diagnosis over 70 years (SIR 1.62; 95% CI: 1.11–2.39) and in two periods of diagnosis (SIRs 1.76 and 1.62 in 1993–1997 and 2009–2012, respectively). A significantly increased risk was also found five to nine years after melanoma diagnosis (SIR 1.58; 95% CI: 1.05–2.38). Further studies are needed to evaluate the relationship between melanoma and subsequent risk of prostate cancer.

Prostate cancer incidence and mortality in the Baltic states, Belarus, the Russian Federation and Ukraine

BACKGROUND

Prostate cancer incidence varies internationally largely attributable to differences in prostate-specific antigen (PSA) use. The aim of this study was to provide the most recent detailed international epidemiological comparison of prostate cancer incidence and mortality in six north-eastern European countries (Belarus, Estonia, Latvia, Lithuania, the Russian Federation and Ukraine).

METHODS

The number of incident prostate cancer cases was obtained from the countries national cancer registries. Prostate cancer mortality and corresponding population data were extracted from the WHO Mortality Database. Age-specific and age-standardised incidence and mortality rates were calculated (European Standard). The joinpoint regression model was used to provide an average annual percentage change and to detect points in time where significant changes in trends occurred. The observation period was between 13 (Ukraine) and 48 (Estonia) years regarding incidence and around 30 years regarding mortality.

RESULTS

The comparison of prostate cancer incidence in six European countries showed almost sixfold differences in the age-adjusted rates in most recent years with highest incidence rates in Lithuania and Estonia. Through the observation period, overall a continuous rise was seen in incidence in all countries and a continuous rise in mortality, with a stabilisation in Estonia and a decrease in Lithuania in recent years. Data limitations included a descriptive design using ecological data.

CONCLUSIONS

A widespread use of PSA testing seems to be responsible for the changes in the epidemiology of the disease in north-eastern European countries. Substantial variation in the incidence of prostate cancer in the Baltic states suggests the possibility that PSA performance and utilisation spread have had a major influence on observed incidence trends, with a lack of effect on prostate cancer mortality.

A cohort study of antihyperglycemic medication exposure and survival in patients with gastric cancer

Objective: We aimed to estimate survival in gastric cancer patients with type 2 diabetes mellitus (T2DM) using different antihyperglycemic medication.

Methods: Patients with gastric cancer and diabetes between 2003-2013 were identified form The Lithuanian Cancer Registry and The National Health Insurance Fund database. Cohort members were classified into five groups: four groups of T2DM patients according to treatment: metformin users; metformin and other medication users; sulphonylurea users; insulin and other medication users; and non-diabetic group. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate gastric cancer-specific survival and overall survival.

Results: 8423 patients met eligibility criteria. Survival analysis showed no differences in gastric cancer-specific survival between non-diabetic and diabetic patient groups. Better survival was observed in the groups of patients using antihyperglycemic medication combinations with metformin, metformin alone or insulin. Lowest survival was observed in diabetic patients who were sulphonylurea users. Survival analysis comparing overall survival between non-diabetic and diabetic patients (p = 0.89) showed no evidence of survival difference between groups and survival differences between antihyperglycemic medication user groups were of borderline significance (p = 0.052).

Conclusions: Antihyperglycemic medication use was not associated with a significant effect on survival in patients with gastric cancer and T2DM.

A Population-Based Analysis of Incidence, Mortality, and Survival in Testicular Cancer Patients in Lithuania

Background and objectives: The aim of this study was to analyze trends in testicular cancer incidence, mortality, and survival in Lithuania during the period 1998–2013. Materials and Methods: The study was based on all cases of testicular cancer reported to the Lithuanian Cancer Registry between 1998 and 2013. Age group-specific rates and standardized rates were calculated using the direct method (European standard population). The Joinpoint regression model was used to provide the annual percentage change (APC). Five-year relative survival estimates were calculated using period analysis. Relative survival was calculated as the ratio of the observed survival of cancer patients and the expected survival of the underlying general population. Results: During the study period, the age-standardized incidence rate of testicular cancer increased from 1.97 to 3.45 per 100,000, with APC of 2.97% (95% CI 0.9 to 5.1). Incidence rate of seminomas changed from 0.71 to 1.54 per 100,000, with APC of 2.61% (95% CI −0.4 to 5.7), and the incidence rate of non-seminomas increased from 0.84 to 1.83 per 100,000, with APC of 4.16% (95% CI 1.6 to 6.8). The mortality rate of testicular cancer in Lithuania during this period declined from 0.78 to 0.51 per 100,000, with APC of −2.91% (95% CI −5.5 to −0.3). Relative five-year survival ratio for the period 2009–2013 was 89.39% (95% CI 82.2 to 94.4). In our study, the overall five-year relative survival increased slightly (10.1%) from 2004–2008 to 2009–2013 (from 79.3% to 89.4%). Conclusions: A moderate increase of testicular cancer incidence has been observed in Lithuania between the years 1998 and 2013, while the mortality rate decreased. The five-year relative survival increased according to different period estimates; however, the results could have been higher if a multidisciplinary approach to diagnostics and management in the concerned centers had been implemented in Lithuania as in other countries.

Trends in Breast Cancer Incidence and Stage Distribution Before and During the Introduction of the Mammography Screening Program in Lithuania

Background:

The aim of this study was to analyze the incidence trends of localized and advanced breast cancer (BC) before and during the implementation of the mammography screening program (MSP) in Lithuania.

Methods:

The study period was divided into 2 intervals: the prescreening period (1998-2005) and implementation period (2006-2012). Analysis was performed for 3 age-groups: 0 to 49 years, 50 to 69 (target population), and older than 70.

Results:

In all age-groups, the incidence of localized BC has shown a steady increase, while the incidence of advanced stage BC has decreased. In the target population, during the study period, the stage I BC incidence increased statistically significantly by 10.3% per year (from 3.3 per 100 000 in 1998 to 12.2 per 100 000 in 2012). The increase in localized BC was faster in the period before the implementation of the MSP than during the implementation in 2006 to 2012 (10.3% and 5.7%). A slightly statistically significant decrease was observed for advanced BC during the study period (−1.1% per year), while during the implementation of the MSP, significant changes were not seen.

Conclusions:

The results of our study indicate that the implementation of the MSP in Lithuania did not significantly influence trends of localized and advanced BC. Changes observed during the study period, including the prescreening and screening introduction periods, may reflect the general trends in the awareness of BC and improvements in diagnostics.

Reduced risk of prostate cancer in a cohort of Lithuanian diabetes mellitus patients

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Background: An inverse association has been shown between diabetes and prostate cancer risk. The aim of this study was to determine whether type 2 diabetes mellitus (T2DM) and metformin is associated with prostate cancer risk. Methods: A retrospective cohort design was used to examine the relationship between diabetes and prostate cancer risk. The cohort was composed of male patients identified with diagnosis of T2DM in the National Health Insurance Fund database during 2000–2016. Cancer cases were identified by record linkage with the Lithuanian Cancer Registry which is a nationwide population-based cancer registry that contains personal and demographic information, as well as information on diagnosis of all people diagnosed with cancer in Lithuania since 1978. We calculated standardized incidence ratios (SIRs) for prostate cancers as a ratio of observed number of cancer case in people with diabetes diagnosis to the expected number of cancer cases in the underlying general population. Results: Overall, 68,449 males were diagnosed with diabetes in Lithuania between 2000 and 2016 were included in final cohort. 2,754 prostate cancers were observed versus 3,111.26 expected within a period of observation entailing an SIR of 0.89 (95% CI: 0.85–0.92). Significantly lower risk of prostate cancer was found in diabetic patients in all age groups, there were no differences in prostate cancer risk by time since diabetes diagnosis. Significantly lower risk of prostate cancer also was found in both metformin users and never-users groups, with higher risk reduction in metformin users (SIR 0.71, 95% CI: 0.68–0.75) than in T2DM patients never-users (SIR 0.88, 95% CI: 0.80–0.96). Conclusions: In the large population-based study we found significantly decreased risk of prostate cancer among men with T2DM. Our study suggests that metformin use in patients with T2DM may be associated with reduced risk of developing prostate cancer.

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.

Breast Cancer Screening Program in Lithuania: Interval Cancers and Program Sensitivity After 7 Years of Mammography Screening

OBJECTIVE

Analysis of interval cancers is critical in determining the sensitivity of screening and represents an objective measure of the quality of mammography screening program (MSP).

METHODS

Period analyzed: from 2006 to 2012. The rate of screen-detected, interval cancers and program sensitivity were measured. A comparison of screen-detected and interval cancers was performed.

RESULTS

During the period of the study, 429 473 women were screened and 1297 were found to have cancer. The overall screen-detected cancer rate was 30.2 per 10 000 women screened. Four hundred thirty-one case of interval cancers have occurred during the period of the study. The interval cancer ratio (ICR) was 0.25. Overall sensitivity of MSP amounted to 75.1%. Slightly lower sensitivity was found among the youngest age-group, especially for those with lobular cancers. Interval cancers were bigger in size, more often with metastases in lymph nodes, than screen-detected cancers, but these differences were not statistically significant.

CONCLUSIONS

Overall program sensitivity in Lithuania is about 75%, ICR is 0.25, and these parameters are comparable to other European countries.

Improved perioperative care is associated with improved long-term survival in colorectal cancer

PURPOSE

To compare perioperative colorectal cancer care and survival in patient cohorts operated in 2005 and in 2010 in Lithuania.

METHODS

Comparative observational cohort study was performed. The study was conducted in the three Lithuanian cancer hospitals. Patients, who underwent curative surgery for colorectal cancer in 2005 and 2010, were included. Demographic characteristics, distribution of the tumors, preoperative diagnostics and staging, surgical treatment, the quality of pathological examination, morbidity, and mortality were analyzed. One- and 5-year overall survival data were compared between the groups.

RESULTS

Colorectal cancer diagnostics and treatment improved from 2005 to 2010 significantly. The disease was identified as stage III-IV for 45 vs. 48% of the patients; however, computed tomography staging scan was performed only for 5.9 vs. 17.8% in 2005 and 2010, respectively. Laparoscopic operations were performed 1.5 vs. 10.5% and abdominoperineal resections-42.7 vs. 31.7% in 2005 and 2010, respectively. The number of harvested lymph nodes was mentioned in 55.8 vs. 97.7% of the cases, whereas more than 12 lymph nodes were examined in 18 vs. 66.6% of cases after histological examination. The overall 5-year survival was 52.1 vs. 63.1% (p < 0.0001), while the 5-year survival of the patients with stage IV of disease was 4.2 vs. 17.8% in 2005 and 2010, respectively.

CONCLUSION

Preoperative investigation, surgical treatment, pathological examination, and postoperative course are associated with improved overall survival in colorectal cancer patients, undergoing curative surgery in the resource-limited settings.

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.

Trends in Cervical Cancer Incidence and Mortality in Bulgaria, Estonia, Latvia, Lithuania and Romania

Objective

The burden of cervical cancer varies considerably in the European Union. In this paper, we describe trends in incidence of and mortality from this cancer in the five most affected member states.

Methods

Data on number of deaths from uterine cancers and the size of the female population of Estonia, Latvia, Lithuania, Bulgaria and Romania were extracted from the WHO mortality database. Mortality rates were corrected for inaccuracies in the death certification of not otherwise specified uterine cancer. Incidence data were obtained from the national cancer registries. Joinpoint regression was used to study the annual variation of corrected and standardized incidence and mortality rates. Changes by birth cohort were assessed for specific age groups and subsequently synthesized by computing standardized cohort incidence/mortality ratios.

Results

Joinpoint regression revealed rising trends of incidence (in Lithuania, Bulgaria and Romania) and of mortality (in Latvia, Lithuania, Bulgaria and Romania). In Estonia, rates were rather stable. Women born between 1940 and 1960 were at continuously increasing risk of both incidence of and mortality from cervical cancer.

Conclusions

Rising trends of cervical cancer in the most affected EU member states reveal a worrying pattern that warrants urgent introduction of effective preventive actions as described in the European guidelines.

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.