Spatial patterns in prostate Cancer-specific mortality in Pennsylvania using Pennsylvania Cancer registry data, 2004-2014

Spatial-temporal Bayesian accelerated failure time models for survival endpoints with applications to prostate cancer registry data

Prostate cancer is the most common cancer after non-melanoma skin cancer and the second leading cause of cancer deaths in US men. Its incidence and mortality rates vary substantially across geographical regions and over time, with large disparities by race, geographic regions (i.e., Appalachia), among others. The widely used Cox proportional hazards model is usually not applicable in such scenarios owing to the violation of the proportional hazards assumption. In this paper, we fit Bayesian accelerated failure time models for the analysis of prostate cancer survival and take dependent spatial structures and temporal information into account by incorporating random effects with multivariate conditional autoregressive priors. In particular, we relax the proportional hazards assumption, consider flexible frailty structures in space and time, and also explore strategies for handling the temporal variable. The parameter estimation and inference are based on a Monte Carlo Markov chain technique under a Bayesian framework. The deviance information criterion is used to check goodness of fit and to select the best candidate model. Extensive simulations are performed to examine and compare the performances of models in different contexts. Finally, we illustrate our approach by using the 2004-2014 Pennsylvania Prostate Cancer Registry data to explore spatial-temporal heterogeneity in overall survival and identify significant risk factors.

Ambient air exposures to arsenic and cadmium and overall and prostate cancer-specific survival among prostate cancer cases in Pennsylvania, 2004 to 2014

BACKGROUND

Exposures to arsenic (As) and cadmium (Cd) have been associated with higher prostate cancer (PC) mortality; however, these associations have been inconsistent. The authors investigated whether higher ambient air concentrations of As and Cd are associated with lower overall and PC-specific survival among PC cases in Pennsylvania.

METHODS

Incident PC cases of patients, aged 40 years or older, with a clinical diagnosis and nonmetastatic disease were identified in the 2004 to 2014 Pennsylvania Cancer Registry. Demographic, clinical, and pathologic information were extracted from the Pennsylvania Cancer Registry. The 3- and 5-year average and cumulative air concentrations of As and Cd were extracted from the Environmental Protection Agency's Toxics Release Inventory database. Spatial-temporal hierarchical accelerated failure time models were used to examine the associations between air concentrations of As and Cd and overall and PC-specific survival for the total population and stratified by geographical region defined by rurality and Appalachia status, after adjusting for confounders.

RESULTS

There were 78,914 PC cases included. Increasing 3- and 5-year average and cumulative air concentrations of As and Cd were significantly associated with lower overall and PC-specific survival among cases, after adjusting for confounders, for the total population, and stratified by geographical region for most of the estimates.

CONCLUSIONS

Data suggest that increasing ambient air exposures to As and Cd may play a role in overall and PC-specific mortality risk among PC cases. Exposures to As and Cd are modifiable and may provide insight into potential strategies to improve PC health outcomes.

LAY SUMMARY

Arsenic and cadmium exposures linked to increased prostate cancer deaths remain unclear. We investigated whether air levels of arsenic and cadmium reported to be released from industries decrease overall and prostate cancer-specific survival among prostate cancer cases identified in the 2004 to 2014 Pennsylvania Cancer Registry. Among the 78,914 prostate cancer cases, increasing air levels of arsenic and cadmium are found to be associated with lower overall and prostate cancer-specific survival for the total population and within rural and urban Appalachia and urban non-Appalachia counties in Pennsylvania. Reducing exposures to arsenic and cadmium have the potential to decrease prostate cancer deaths.

Spatio-temporal mapping of breast and prostate cancers in South Iran from 2014 to 2017

Background

The most common gender-specific malignancies are cancers of the breast and the prostate. In developing countries, cancer screening of all at risk is impractical because of healthcare resource limitations. Thus, determining high-risk areas might be an important first screening step. This study explores incidence patterns of potential high-risk clusters of breast and prostate cancers in southern Iran.

Methods

This cross-sectional study was conducted in the province of Kerman, South Iran. Patient data were aggregated at the county and district levels calculating the incidence rate per 100,000 people both for cancers of the breast and the prostate. We used the natural-break classification with five classes to produce descriptive maps. A spatial clustering analysis (Anselin Local Moran’s I) was used to identify potential clusters and outliers in the pattern of these cancers from 2014 to 2017.

Results

There were 1350 breast cancer patients (including, 42 male cases) and 478 prostate cancer patients in the province of Kerman, Iran during the study period. After 45 years of age, the number of men with diagnosed prostate cancer increased similarly to that of breast cancer for women after 25 years of age. The age-standardised incidence rate of breast cancer for women showed an increase from 29.93 to 32.27 cases per 100,000 people and that of prostate cancer from 13.93 to 15.47 cases per 100,000 during 2014–2017. Cluster analysis at the county level identified high-high clusters of breast cancer in the north-western part of the province for all years studied, but the analysis at the district level showed high-high clusters for only two of the years. With regard to prostate cancer, cluster analysis at the county and district levels identified high-high clusters in this area of the province for two of the study years.

Conclusions

North-western Kerman had a significantly higher incidence rate of both breast and prostate cancer than the average, which should help in designing tailored screening and surveillance systems. Furthermore, this study generates new hypotheses regarding the potential relationship between increased incidence of cancers in certain geographical areas and environmental risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07674-8.