Gender differences in colorectal cancer during the past 20 years in Taiwan

Statistical methods for measuring trends in colorectal cancer incidence in registries: A systematic review

Background

Monitoring cancer trends in a population is essential for tracking the disease’s burden, allocating resources, and informing public health policies. This review describes variations in commonly employed methods to estimate colorectal cancer (CRC) incidence trends.

Methods

We performed a systematic literature search in four databases to identify population-based studies reporting CRC incidence trends, published between January 2010 and May 2020. We extracted and described data on methods to estimate trends and assess model validity, and the software used.

Results

This review included 145 articles based on studies conducted in five continents. The majority (93%) presented visual summaries of trends combined with absolute, relative, or annual change estimates. Fourteen (10%) articles exclusively calculated the relative change in incidence over a given time interval, presented as the percentage of change in rates. Joinpoint regression analysis was the most commonly used method for assessing incidence trends (n= 65, 45%), providing estimates of the annual percentage change (APC) in rates. Nineteen (13%) studies performed Poisson regression and 18 (12%) linear regression analysis. Age-period-cohort modeling- a type of generalized linear models- was conducted in 18 (12%) studies. Thirty-nine (37%) of the studies modeling incidence trends (n=104, 72%) indicated the method used to evaluate model fitness. The joinpoint program (52%) was the statistical software most commonly used.

Conclusion

This review identified variation in the calculation of CRC incidence trends and inadequate reporting of model fit statistics. Our findings highlight the need for increasing clarity and transparency in reporting methods to facilitate interpretation, reproduction, and comparison with findings from previous studies.

A systematic review of methods to estimate colorectal cancer incidence using population-based cancer registries

Background

Epidemiological studies of incidence play an essential role in quantifying disease burden, resource planning, and informing public health policies. A variety of measures for estimating cancer incidence have been used. Appropriate reporting of incidence calculations is essential to enable clear interpretation. This review uses colorectal cancer (CRC) as an exemplar to summarize and describe variation in commonly employed incidence measures and evaluate the quality of reporting incidence methods.

Methods

We searched four databases for CRC incidence studies published between January 2010 and May 2020. Two independent reviewers screened all titles and abstracts. Eligible studies were population-based cancer registry studies evaluating CRC incidence. We extracted data on study characteristics and author-defined criteria for assessing the quality of reporting incidence. We used descriptive statistics to summarize the information.

Results

This review retrieved 165 relevant articles. The age-standardized incidence rate (ASR) (80%) was the most commonly reported incidence measure, and the 2000 U.S. standard population the most commonly used reference population (39%). Slightly more than half (54%) of the studies reported CRC incidence stratified by anatomical site. The quality of reporting incidence methods was suboptimal. Of all included studies: 45 (27%) failed to report the classification system used to define CRC; 63 (38%) did not report CRC codes; and only 20 (12%) documented excluding certain CRC cases from the numerator. Concerning the denominator estimation: 61% of studies failed to state the source of population data; 24 (15%) indicated census years; 10 (6%) reported the method used to estimate yearly population counts; and only 5 (3%) explicitly explained the population size estimation procedure to calculate the overall average incidence rate. Thirty-three (20%) studies reported the confidence interval for incidence, and only 7 (4%) documented methods for dealing with missing data.

Conclusion

This review identified variations in incidence calculation and inadequate reporting of methods. We outlined recommendations to optimize incidence estimation and reporting practices. There is a need to establish clear guidelines for incidence reporting to facilitate assessment of the validity and interpretation of reported incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01632-7.

The Risks for Ovarian, Endometrial, Breast, Colorectal, and Other Cancers in Women With Newly Diagnosed Endometriosis or Adenomyosis: A Population-Based Study

OBJECTIVE

Recent studies report a link between endometriosis and ovarian cancer (OC). Using a population-based cohort study to confirm the association between endometriosis and cancer is desirable. We thus examined the magnitude of the risks of OC, endometrial cancer (EC), breast cancer, colorectal cancer (CRC), and other cancers in women with newly diagnosed endometriosis or adenomyosis (internal endometriosis).

METHODS/MATERIALS

Women older than 20 years with claims data between 2003 and 2005 were identified from the Longitudinal Health Insurance Dataset containing 1 million individuals randomly sampled from the National Health Insurance Research Database. Those with preexisting malignancies, hysterectomy, or oophorectomy were excluded. The endometriosis cohort (n = 2266, including 768 cases of pure adenomyosis) and comparison cohort (n = 9064), formed by 1:4 matching, were followed up until incidence cancer, dropout, or December 31, 2008. Outcome measures included cancer incidence and adjusted hazard ratio by Cox model adjusted for age group, comorbidities, and endometriosis medication use.

RESULTS

With 9842 person-years of follow-up in endometriosis cohort and 36,274 person-years of follow-up in comparison cohort, there were increased risks of all cancers (adjusted hazard ratio, 1.8; 95% confidence interval, 1.4-2.4), OC (4.56, 1.72-12.11), and EC (4.05, 1.20-13.66). The ovarian endometriosis group was associated with increased risk of subsequent OC (4.37, 1.07-17.83). The adenomyosis group was strongly associated with both OC (5.50, 1.95-15.50) and EC (5.13, 1.36-19.40). Increased risk of subsequent CRC was observed in women with adenomyosis with coexistent endometriosis at other sites (13.04, 2.21-77.04). However, no statistically significant increased risk of breast or other cancers was observed.

CONCLUSIONS

Having limitations such as lacking of parity information which may affect the magnitude of risk estimates, this study demonstrates that ovarian endometriosis has a 4-fold increased risk of OC. Adenomyosis may associate with a 4- to 5-fold increased risk of OC and EC, and unexpectedly, a 13-fold increased risk of CRC.

Population-based cohort study on the risk of malignancy in East Asian children with juvenile idiopathic arthritis

BACKGROUND

To investigate the association and magnitude of risk between JIA, its associated treatment and cancer development in Taiwanese children.

METHODS

Nationwide population-based 1:4 age- and gender-matched retrospective cohort study was designed using the National Health Insurance Research Database of Taiwan. A cohort of 2,892 children <16 years old with JIA was formed as well as a non-JIA cohort of 11,568 in year 2003 to 2005. They were followed up till a diagnosis of malignancy or up to 8 years until 2010. Relative risk (RR), incidence rate ratio (IRR), and adjusted hazard ratio (aHR) of developing malignancy were calculated.

RESULTS

The female to male ratio was 0.79:1. There were 3 cases of incident cancer in the "MTX use, biologics-naïve" group, only 1 in the anti-TNF biologics-containing group and 29 in the "both MTX- and biologics-naïve" group, in comparison, there were 50 cases of cancer in the non-JIA comparator group. During a 16114.16 patient-years follow-up, the RR and IRR for developing a malignancy in both methotrexate- and anti-tumor necrosis factor (TNF) biologics-naïve JIA children were 2.75 (95% confidence interval, 1.75 - 4.32) and 3.21 (2.01 - 5.05), respectively. For leukemia, the IRR was 7.38 (2.50 - 22.75); lymphoma, 8.30 (1.23 - 69.79); and soft tissue sarcoma, 11.07 (0.84 - 326.4). The IRR of other cancers was 2.08 (1.11 - 3.71). The aHR on cancer risk was 3.14 (1.98 - 4.98) in methotrexate- and biologics-naïve group. There were no statistically significant increased risk in JIA patients treated with methotrexate and/or anti-TNF biologics.

CONCLUSIONS

Compared with children without JIA, children with JIA have 3-fold increase of risk on malignancy in East Asia. Seemingly neither methotrexate nor anti-TNF biologics increases the risk further.

Sex disparities in the association of lung adenocarcinoma with colorectal cancer

BACKGROUND

Most cancers share common risk factors. It might provide evidence of shared risk factors with cancers by investigating cross-country and cross-township comparisons.

METHODS

The data were obtained from International Association of Cancer Registries/World Health Organization and the National Cancer Registration Program of Taiwan. Age standardized incidence rates were calculated among gastric cancer, colorectal cancer and lung adenocarcinoma in 19 countries from 1995 to 1998. The Pearson correlations were also compared among 3 types of cancers for both sexes.

RESULTS

The incidence rates of gastric and colorectal cancer throughout different countries show male dominance with a male-to-female sex ratio of around 2 and 1.5, respectively. Significant cross-country correlations in colorectal cancer (r=0.918, p<0.001), gastric cancer (r=0.985, p<0.001) and lung adenocarcinoma (r=0.685, p=0.001) were observed between men and women. There was a significant international correlation between colorectal cancer and lung adenocarcinoma in men (r=0.526, p=0.021), but not in women. In cross-township comparisons of Taiwan, there were significant correlations in colorectal cancer (r=0.451, p<0.001), gastric cancer (r=0.486, p<0.001), and lung adenocarcinoma (r=0.217, p<0.001) between men and women. There were links of lung adenocarcinoma and gastric cancer (r=0.122, p=0.024) and colorectal cancer (r=0.128, p=0.018) in women, and lung adenocarcinoma and colorectal cancer in men (r=0.276, p<0.001).

CONCLUSIONS

There were associations between lung adenocarcinoma and colorectal cancer between and in both sexes in Taiwan, but not in cross-country comparisons. The results suggest that some factor, like genes, may be important as determinants for the association between lung adenocarcinoma and colorectal cancer.