The Insignificant Correlation between Androgen Deprivation Therapy and Incidence of Dementia Using an Extension Survival Cox Hazard Model and Propensity-Score Matching Analysis in a Retrospective, Population-Based Prostate Cancer Registry.

This study aims to evaluate the effect of androgen-deprivation therapy (ADT) on the incidence of dementia, after considering the time-dependent survival in patients with prostate cancer (PC) using a Korean population-based cancer registry database. After excluding patients with cerebrovascular disease and dementia before or within the 3-month-ADT and those with surgical castration, 9880 (19.3%) patients were matched into ADT and non-ADT groups using propensity-score matching (PSM) among 51,206 patients registered between 2006 and 2013. To define the significant relationship between ADT duration and the incidence of dementia, the extension Cox proportional hazard model was used with p-values < 0.05 regarded as statistically significant. The mean age and survival time were 67.3 years and 4.33 (standard deviation [SD] 2.16) years, respectively. A total of 2945 (9.3%) patients developed dementia during the study period, including Parkinson's (11.0%), Alzheimer's (42.6%), vascular (18.2%), and other types of dementia (28.2%). Despite PSM, the PC-treatment subtypes, survival rate, and incidence of dementia significantly differed between the ADT and non-ADT groups (p < 0.05), whereas the rate of each dementia subtype did not significantly differ (p = 0.069). A multivariate analysis for dementia incidence showed no significance of ADT type or use duration among patients with PC (p > 0.05), whereas old age, obesity, regional SEER stage, a history of cerebrovascular disease, and a high Charlson Comorbidity Index were significant factors for dementia (p < 0.05). Insignificant correlation was observed between ADT and the incidence of dementia based on the extension survival model with PSM among patients with PC.

Validation of Cancer Diagnosis Based on the National Health Insurance Service Database versus the National Cancer Registry Database in Korea.

PURPOSE: This study aimed to assess the feasibility of operational definitions of cancer patients in conducting cancer-related studies using the claims data from the National Health Insurance Service (NHIS). MATERIALS AND METHODS: Cancer incidence data were obtained from the Korean Central Cancer Registry, the NHIS primary diagnosis, and from the rare and intractable disease (RID) registration program. RESULTS: The operational definition with higher sensitivity for cancer patient verification was different by cancer type. Using primary diagnosis, the lowest sensitivity was found in colorectal cancer (91.5%; 95% confidence interval [CI], 91.7 to 92.0) and the highest sensitivity was found in breast cancer (97.9%; 95% CI, 97.8 to 98.0). With RID, sensitivity was the lowest in liver cancer (91.9%; 95% CI, 91.7 to 92.0) and highest in breast cancer (98.1%; 95% CI, 98.0 to 98.2). In terms of the difference in the date of diagnosis in the cancer registration data, > 80% of the patients showed a < 31-day difference from the RID definition. CONCLUSION: Based on the NHIS data, the operational definition of cancer incidence is more accurate when using the RID registration program claims compared to using the primary diagnosis despite the relatively lower concordance by cancer type requires additional definitions such as treatment.

Brachytherapy utilization rate and effect on survival in cervical cancer patients in Korea.

OBJECTIVE: External beam radiation therapy (EBRT) with concurrent chemotherapy followed by intracavitary brachytherapy is the standard treatment in locally advanced cervical cancer. This study examined the brachytherapy utilization rate and evaluated the effect of brachytherapy on survival in cervical cancer patients in Korea. METHODS: In this study, data from the Korea Central Cancer Registry and Korean National Health Insurance Service and data on mortality from Statistics Korea were linked and used. Patients with other cancers, distant metastasis at diagnosis, or unknown stage or who underwent hysterectomy were excluded. A total of 12,721 cervical cancer patients were analyzed in this study. RESULTS: The brachytherapy utilization rate (%) was calculated as the proportion of patients who received brachytherapy among those who received curative EBRT. The brachytherapy utilization rate decreased from 84% in 2005 to 78% in 2013 (p<0.001). Brachytherapy utilization rates varied by region, ranging from 72% to 100% except for in Jeju Island, where the rate was 56%. The brachytherapy utilization rate was lower in patients older than 80 years; patients with localized disease, non-squamous cell carcinoma, or Charlson comorbidity index 3 or more; patients diagnosed after 2010; patients from certain regions; patients receiving medical aid; and patients who underwent gynecologic procedures. Multivariable Cox regression analysis showed that brachytherapy when added to curative EBRT was independently associated with better cancer-specific survival (CSS) and overall survival (OS) than curative EBRT only. CONCLUSION: The brachytherapy utilization rate decreased from 2005 to 2013 and varied by region in Korea. Brachytherapy use is independently associated with significantly higher CSS and OS in cervical cancer.