Income-based disparities in the risk of distant-stage cervical cancer and 5-year mortality after the introduction of a National Cancer Screening Program in Korea

Nomogram model for predicting the long-term prognosis of cervical cancer patients: a population-based study in Mato Grosso, Brazil

BACKGROUND

Cervical cancer (CC) is the third most common cancer among women worldwide and the second most prevalent neoplasm in Mato Grosso, Brazil, in 2020. This study aimed to analyze overall survival (OS), identify prognostic factors, and develop a nomogram to predict the long-term prognosis of CC patients using population-based data from Mato Grosso, Brazil.

METHODS

Integrated data from the Mortality Information System (SIM) and the Population-Based Cancer Registry (RCBP) were used for patients diagnosed with CC between 2001 and 2018. Group differences were analyzed using the Log-rank test, and survival analysis was performed using the Kaplan-Meier method. Univariable and multivariable Cox regression models were applied to identify predictors of OS. A nomogram was developed to predict OS at 1, 3, 5, and 10 years. The accuracy of the model was assessed using the C-index, receiver operating characteristic (ROC) curve, and calibration plots.

RESULTS

The median follow-up time was 12 years (range: 6.28 - 17.1). The OS rates at 1, 3, 5, and 10 years were 95.4%, 91.3%, 89.9%, and 88.3%, respectively. Age, histological type, and disease stage were identified as independent prognostic factors for OS. The C-index for OS was 0.869, and the areas under the ROC curve for 1, 3, 5, and 10 years were 0.910, 0.897, 0.895, and 0.884, respectively, indicating good discrimination. The nomogram demonstrated good agreement with the observed survival rates.

CONCLUSION

The developed nomogram predicts OS for CC patients at 1, 3, 5, and 10 years, showing good concordance with the observed survival rates and serving as a useful tool for guiding personalized interventions. Notably, disease staging and histopathological type were the most significant prognostic factors for OS.

Disparities in Cancer Incidence across Income Levels in South Korea

BACKGROUND

Recent nationwide studies of disparities in cancer incidence by income are scarce in Korea. This study investigated such disparities in cancer incidence and the stage at cancer diagnosis across income groups in Korea.

METHODS

This study utilized data from a national cancer database, specifically focusing on cases recorded in the year 2018. Income levels were categorized into quintiles according to the insurance premium paid in addition to the Medicaid benefit. The slope index of inequality (SII) and relative index of inequality (RII) were used to measure absolute and relative differences in cancer incidence by income. A multivariable logistic regression was performed to estimate the risk of a distant stage at cancer diagnosis.

RESULTS

The total number of cases of incident cancer was 223,371 (men: 116,320, women: 107,051) with shares of the total of 29.5% (5Q), 20.4% (4Q), 16.0% (3Q), 13.5% (2Q), 15.6% (1Q), and 5% (Medicaid). The most common cancer type was thyroid cancer, followed by gastric and colorectal cancers. The age-standardized incidence rate for all cancers was lowest in the highest income group, but the SII was not statistically significant (SII: -35.7), and the RII was -0.07. Colorectal and cervical cancers had lower incidence rates for higher income groups, while thyroid and prostate cancers had higher incidence rates for higher income groups. The odds ratio for a distant stage at diagnosis for all cancers increased for lower income groups relative to 5Q.

CONCLUSIONS

Disparities in cancer incidence in a Korean population differed by cancer type, and lower income was a significant predictor of a distant stage at diagnosis for cancers overall. These results emphasize the need for further study of the underlying causes of disparities in cancer incidence and the stage at diagnosis, as well as the need for interventions to mitigate these disparities.

Menopausal hormone therapy and risk of dementia: health insurance database in South Korea-based retrospective cohort study

Introduction

Menopausal hormone therapy (MHT) is used to alleviate the symptoms associated with menopause, despite the lack of recommendations for MHT in preventing dementia. Recent nationwide studies have explored the association between MHT and dementia risk, but the findings remain limited. This study aims to investigate the association between MHT and the incidence of Alzheimer's disease (AD) and non-AD dementia using national population data from Korea.

Methods

We conducted a retrospective study using data from the National Health Insurance Service in Korea between January 1, 2002, and December 31, 2019. Women over 40 years were eligible for this study and classified into the MHT or non-MHT groups. The MHT group consisted of women who used Tibolone (TIB), combined estrogen plus progestin by the manufacturer (CEPM), estrogen, combined estrogen plus progestin by a physician (CEPP), and transdermal estrogen during menopause. We compared the risk of dementia between the MHT and non-MHT groups.

Results

The study included 1,399,256 patients, of whom 387,477 were in the MHT group, and 1,011,779 were in the non-MHT group. The median duration of MHT was 23 months (range: 10-55 months). After adjusting for available confounders, we found that different types of MHT had varying effects on the occurrence of dementia. TIB (HR 1.041, 95% confidence interval (CI) 1.01-1.072) and oral estrogen alone (HR 1.081, 95% CI 1.03-1.134) were associated with a higher risk of AD dementia. In contrast, there was no difference in the risk of AD dementia by CEPM (HR 0.975, 95% CI 0.93-1.019), CEPP (HR 1.131, 95% CI 0.997-1.283), and transdermal estrogen (HR 0.989, 95% CI 0.757-1.292) use. The use of TIB, CEPM, and oral estrogen alone increased the risk of non-AD dementia (HR 1.335, 95% CI 1.303-1.368; HR 1.25, 95% CI 1.21-1.292; and HR 1.128, 95% CI 1.079-1.179; respectively), but there was no risk of non-AD dementia in the other MHT groups (CEPP and topical estrogen).

Conclusion

Our findings indicate that MHT has varying effects on the incidence of AD and non-AD dementia. Specifically, TIB, CEPM, and oral estrogen alone increase the risk of non-AD dementia, while transdermal estrogen is not associated with dementia risk. It is essential to consider the type of MHT used when assessing the risk of dementia in women.

Individual and joint effect of socioeconomic status and lifestyle factors on cancer in Korea

BACKGROUND

There is limited evidence on the individual and joint effect of socioeconomic status (SES) and unhealthy lifestyle on cancer. Therefore, this study aimed to examine the effects of these factors on cancer incidence and mortality.

METHODS

In this population-based cohort study, income was used as the proxy of SES. A combined unhealthy lifestyle score was obtained using data on smoking, alcohol consumption, physical activity, and body mass index. Hazard ratios were estimated using a Cox proportional hazards model.

RESULTS

The study included data on 8,353,169 participants (median follow-up period, 17 years). Although the association between low income and cancer incidence varied depending on cancer type, low income consistently increased the risk of cancer-related death with a social gradient. Unhealthy behaviors increased the risk of cancer incidence and mortality, except for thyroid and breast cancer in women and prostate cancer in men. Compared with the wealthiest and healthiest individuals, the poorest and unhealthiest men and women showed 2.1-fold (2.05-2.14) and 1.36-fold (1.31-1.41) higher risk of cancer-related death, respectively. The joint effect was most robust for lung, liver, head, and neck cancers in men and liver and cervical cancers in women; further, the effect was stronger with cancer-specific mortality than with incidence.

CONCLUSION

In conclusion, income and combined healthy lifestyle behaviors have individual and joint effects on cancer incidence and mortality. The effect varies by cancer type and sex.