Dataset Information

Meta-analysis of associations between telomere length and colorectal cancer survival from observational studies.

ABSTRACT:

Background

Telomere length (TL) has been reported to be associated with the risk and survival of several cancers. But it is unclear for the prognostic role of TL in colorectal cancer (CRC).

Materials and methods

Relevant citations were searched and identified using several major online databases through April 2017 which investigated associations between TL and CRC prognosis. We combined summary estimates using hazard ratios (HRs) with 95% confidence interval (CI), which were pooled using a random-effects model. Overall survival (OS) was set as the primary outcome of interest.

Results

There are 8 cohort studies encompassing 1622 patients included in the meta-analysis. Pooled estimate indicated that long TL was not significantly associated with patient OS (HR 1.26, 95% CI, 0.76 to 2.08). When we conducted subgroup analyses based on baseline charcteristics, we found that long TL (versus short TL) was significantly associated with poor OS in studies conducted in Europe (n = 4, HR 2.73, 95% CI, 1.65 to 4.52, I² = 0), using Southern blot to measure TL (n = 3, HR 2.93, 95% CI, 1.69 to 5.10, I² = 0) and patients' age more than 60 years (n = 3, HR 2.65, 95% CI, 1.22 to 5.76, I² = 0). We found no significant associations between TL and patient disease-free, recurrence-free or progression-free survival (HR 1.19, 95% CI, 0.45 to 3.15).

Conclusions

Current evidence did not provide solid indication that long TL is significantly associated with improved or poor survival for patients with CRC. Further large sample size prospective cohort studies are warranted to determine the true relationship for specific patients.

SUBMITTER: Wang W

PROVIDER: S-EPMC5617524 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Publications

Meta-analysis of associations between telomere length and colorectal cancer survival from observational studies.

Wang Wei W Zheng Lei L Zhou Ning N Li Na N Bulibu Gilisihan G Xu Chunlei C Zhang Yi Y Tang Yong Y

Oncotarget 20170807 37

<h4>Background</h4>Telomere length (TL) has been reported to be associated with the risk and survival of several cancers. But it is unclear for the prognostic role of TL in colorectal cancer (CRC).<h4>Materials and methods</h4>Relevant citations were searched and identified using several major online databases through April 2017 which investigated associations between TL and CRC prognosis. We combined summary estimates using hazard ratios (HRs) with 95% confidence interval (CI), which were poole ...[more]

PMID: 28977964

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Project description:BackgroundEpidemiological evidence suggests that use of aspirin after the diagnosis of colorectal cancer can lengthen survival. However, the supporting data vary between studies, and this hypothesis remains controversial. We conducted a meta-analysis to provide a quantitative assessment of the association between use of aspirin after diagnosis of colorectal cancer and patient survival.MethodsWe searched the Medline and Embase databases up to April 2014 to identify studies related to aspirin use after diagnosis and all-cause mortality or colorectal cancer-specific mortality. Summary effect estimates with 95% confidence intervals (CIs) were derived using a fixed or random effects model, depending on the heterogeneity between the included studies.ResultsSeven epidemiologic studies that consisted of six cohort studies and one nested case-control study were included in this meta-analysis. The hazard ratio (HR) of the association between aspirin use after colorectal cancer diagnosis and overall mortality, which was reported in five studies, was 0.74 (95% CI, 0.62-0.89) using a random model (heterogeneity test P=0.003, I(2)=75.3%), and for colorectal cancer-specific mortality (four studies), it was 0.75 (95% CI, 0.51-1.10) using a random model (heterogeneity test P=0.001, I(2)=84.1%). In addition, we analysed postdiagnosis aspirin use according to whether aspirin was also used before diagnosis. The HR for the overall mortality of patients who did not use aspirin before diagnosis, which was reported in four studies, was 0.84 (95% CI, 0.70-1.00), and for colorectal cancer-specific mortality (three studies), it was 0.79 (95% CI, 0.61-1.02). For those who did use aspirin before diagnosis, the HR for overall mortality (four studies) was 0.88 (95% CI, 0.83-0.93), and for colorectal cancer-specific mortality (three studies), it was 0.80 (95% CI, 0.59-1.09). Subgroup analysis showed that use of aspirin after diagnosis was associated with longer overall survival among patients with the variant PIK3CA gene but not for those with wild-type PIK3CA.ConclusionsBased on current evidence, the use of aspirin after diagnosis does not reduce colorectal cancer-specific mortality, but it does reduce all-cause mortality for colorectal cancer patients.

Project description:BackgroundTelomeres are essential for chromosomal integrity and stability. Shortened telomere length (TL) has been associated with risk of cancers and aging-related diseases. Several studies have explored associations between TL and cancer prognosis, but the results are conflicting.MethodsProspective studies on the relationship between TL and cancer survival were identified by a search of PubMed up to May 25, 2015. There were no restrictions on the cancer type or DNA source. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Meta-analysis approaches were conducted to determine pooled relative risks and 95% confidence intervals.ResultsThirty-three articles containing forty-five independent studies were ultimately involved in our meta-analysis, of which twenty-seven were about overall cancer survival and eighteen were about cancer progression. Short TL was associated with increased cancer mortality risk (RR = 1.30, 95%CI: 1.06-1.59) and poor cancer progression (RR = 1.44, 95%CI: 1.10-1.88), both with high levels of heterogeneity (I2 = 83.5%, P = 0.012for overall survival and I2 = 75.4%, P = 0.008 for progression). TL was an independent predictor of overall cancer survival and progression in chronic lymphocytic leukemia. Besides, short telomeres were also associated with increased colorectal cancer mortality and decreased overall survival of esophageal cancer, but not in other cancers. Cancer progression was associated with TL in Asian and America populations and short TL predicted poor cancer survival in older populations. Compared with tumor tissue cells, TL in blood lymphocyte cells was better for prediction. In addition, the associations remained significant when restricted to studies with adjustments for age, with larger sample sizes, measuring TL using southern blotting or estimating risk effects by hazard ratios.ConclusionShort TL demonstrated a significant association with poor cancer survival, suggesting the potential prognostic significance of TL. Additional large well-designed studies are needed to confirm our findings.

Dataset Information

Meta-analysis of associations between telomere length and colorectal cancer survival from observational studies.

Background

Materials and methods

Results

Conclusions

Publications

Meta-analysis of associations between telomere length and colorectal cancer survival from observational studies.

Similar Datasets

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