Pancreatic cancer mortality in South Africa: A case-control study

BACKGROUND

There are variations in the numbers of pancreatic cancer deaths reported annually in South Africa (SA). Since pancreatic cancer deaths in SA from 1997 to 2016, the number of cases has hugely increased, and reached 23 581 in both sexes. Sex differences are likely to contribute to the variations in the strength of associations between the risk factors and pancreatic cancer mortality.

OBJECTIVE

To identify factors associated with an increased risk of pancreatic cancer mortality in SA.

METHODS

A matched case-control study with 1:1 matching was conducted using data collected by Statistics SA from 1997 to 2016. Controls were randomly selected to be as similar as possible to the cases, and matched by age, sex and year of death. Conditional logistic regression was used to identify factors associated with pancreatic cancer mortality.

RESULTS

This case-control study comprised a final selection of 23 581 cases (12 171 males and 11 410 females) and 23 581 controls (12 171 males and 11 410 females). A significantly increased risk of pancreatic cancer mortality was observed among males who were managers (odds ratio (OR) 2.99; 95% confidence interval (CI) 1.36 - 6.60; p=0.006) and craft and related trade workers (OR 1.89; 95% CI 1.14 - 3.14; p=0.013). Elevated risks of pancreatic cancer mortality were also found among females who were managers (OR 6.13; 95% CI 1.32 - 28.52; p=0.021), professionals (OR 2.12; 95% CI 1.24 - 3.63; p=0.006), clerical support workers (OR 3.78; 95% CI 1.79 - 7.98; p=0.001) and elementary occupation workers (OR 1.41; 95% CI 0.99 - 2.00; p=0.059). Smoking was significantly associated with pancreatic cancer mortality in females (OR 1.36; 95% CI 1.02 - 1.82; p=0.039). Working in several occupations was associated with an increased risk of pancreatic cancer mortality in males (OR 1.31; 95% CI 1.01 - 1.71; p=0.045) and females (OR 1.66; 95% CI 1.30 - 2.12; p<0.001).

CONCLUSION

Smoking and certain occupations increased the risk of pancreatic cancer mortality. Further research is needed to evaluate the associations between other extrinsic and intrinsic factors and pancreatic cancer mortality.

RETRACTED

BACKGROUND

Upon the addition of the numbers corresponding to various cancer anatomical locations in the report published by Statistics South Africa (StatsSA), the absolute number and proportion of deaths due to all cancers increased from 36 726 (8.0%) in 2013 to 40 460 (8.5%) in 2015. These high figures suggest that malignant neoplasms were in fact the second-most frequent cause of death in South Africa (SA) in 2013, and moved to the first rank in 2015.

OBJECTIVES

To support the initiative aimed at reducing cancer mortality in SA. To this purpose, we assessed trends in cancer mortality rates among males and females in SA from 1997 to 2016 to better understand the increasing threat of cancer mortality in SA.

METHODS

The general mortality data for the period 1997 - 2016, as captured from death certificates in SA, was retrieved from StatsSA. Agestandardised mortality rates (ASMR) for each year were computed using the world standard population structure proposed by Segi as the reference population. The adjusted rates were reported per 100 000 population per year. The years of potential productive life lost (YPPLL) due to cancer deaths were calculated for each age group and gender.

RESULTS

There were 681  689 total cancer deaths from 1997 to 2016, with 51.1% males and 48.9% females. Males had higher mortality rates than females. The ASMR ranged from 105.0 to 129.2 and 67.9 to 88.3 per 100 000 population per year among males and females, respectively. In 2004, the cancer mortality rate increased significantly among males (129.2 per 100 000 population), which was 1.5 times higher than in females (88.3 per 100 000 population). Among males, cancer of the lung had the highest YPPLL (394 779.3), followed by oesophageal (253 989.4) and liver (207 911.0). The YPPLL for cancer of the cervix (647 855.5) ranked first, followed by breast (483 863.6) and lung (146 304.6) in females.

CONCLUSION

Cancer mortality rates have increased since 1997, regardless of gender. Overall, there was a decline in YPPLL for cancer in the young population, while it increased in the adult population. A significant reduction in cancer deaths could be achieved by broadly applying effective interventions.

Cancer mortality distribution in South Africa, 1997-2016

Introduction

The mortality data in South Africa (SA) have not been widely used to estimate the patterns of deaths attributed to cancer over a spectrum of relevant subgroups. There is no research in SA providing patterns and atlases of cancer deaths in age and sex groups per district per year. This study presents age-sex-specific geographical patterns of cancer mortality at the district level in SA and their temporal evolutions from 1997 to 2016.

Methods

Individual mortality level data provided by Statistics South Africa were grouped by three age groups (0-14, 15-64, and 65+), sex (male and female), and aggregated at each of the 52 districts. The proportionate mortality ratios (PMRs) for cancer were calculated per 100 residents. The atlases showing the distribution of cancer mortality were plotted using ArcGIS. Spatial analyses were conducted through Moran's I test.

Results

There was an increase in PMRs for cancer in the age groups 15-64 and 65+ years from 2006 to 2016. Ranges were 2.83 (95% CI: 2.77-2.89) -4.16 (95% CI: 4.08-4.24) among men aged 15-64 years and 2.99 (95% CI: 2.93-3.06) -5.19 (95% CI: 5.09-5.28) among women in this age group. The PMRs in men and women aged 65+ years were 2.47 (95% CI: 2.42-2.53) -4.06 (95% CI: 3.98-4.14), and 2.33 (95% CI: 2.27-2.38) -4.19 (95% CI: 4.11-4.28). There were considerable geographical variations and similarities in the patterns of cancer mortality. For the age group 15-64 years, the ranges were 1.18 (95% CI: 0.78-1.71) -8.71 (95% CI: 7.18-10.47), p < 0.0001 in men and 1.35 (95% CI: 0.92-1.92) -10.83 (95% CI: 8.84-13.14), p < 0.0001 in women in 2016. There were higher PMRs among women in the Western Cape, Northern Cape, North West, and Gauteng compared to other areas. Similar patterns were also observed among men in these provinces, except in North West and Gauteng.

Conclusion

The identification of geographical and temporal distributions of cancer mortality provided evidence of periods and districts with similar and divergent patterns. This will contribute to understanding the past, present, future trends and formulating interventions at a local level.