Years of Life Lost for Older Patients After Colorectal Cancer Diagnosis

Epidemiology of Cancer in Older Adults: A Systematic Review

PURPOSE OF REVIEW

What are the prevalence, incidence and mortality rates of cancer among individuals aged 60 or older on a national, regional, and global scale? What factors affect differences in cancer survival between older and younger adults?

RECENT FINDINGS

The epidemiological literature on cancer in older adults, particularly in low- and middle-income countries (LMICs) and that focusing on the oldest adults, is expanding. These studies consistently show increasing global cancer incidence rates in older populations. Recent research also highlights a widening survival gap between middle-aged and older adults, with the stage at diagnosis being the primary driver. More research is needed to describe the cancer burden in older adults, especially focusing on the oldest population and LMICs, to better understand global healthcare challenges. Additionally, further exploring patient-related, clinical, and tumour-related factors which drive age-related survival differences could improve cancer outcomes in older adults.

Vesicle-associated membrane protein 8 knockdown exerts anti-proliferative, pro-apoptotic, anti-autophagic, and pro-ferroptotic effects on colorectal cancer cells by inhibition of the JAK/STAT3 pathway

Vesicle-associated membrane protein 8 (VAMP8), a soluble n-ethylmaleimide-sensitive factor receptor protein, acts as an oncogenic gene in the progression of several malignancies. Nevertheless, the roles and mechanisms of VAMP8 in colorectal cancer (CRC) progression remain unknown. The expression and prognostic significance of VAMP8 in CRC samples were analyzed through bioinformatics analyses. Cell proliferation was detected using CCK-8 and EdU incorporation assays and apoptosis was evaluated via flow cytometry. Western blot analysis was conducted to examine the protein expression. Ferroptosis was evaluated by measurement of iron metabolism, lipid peroxidation, and glutathione (GSH) content. VAMP8 was increased in CRC samples relative to normal samples on the basis of GEPIA and HPA databases. CRC patients with high level of VAMP8 had a worse overall survival. VAMP8 depletion led to a suppression of proliferation and promotion of apoptosis in CRC cells. Additionally, VAMP8 knockdown suppressed beclin1 expression and LC3-II/LC3-I ratio, elevated p62 expression, increased Fe2+, labile iron pool, lipid reactive oxygen species, and malondialdehyde levels, and repressed GSH content and glutathione peroxidase activity. Moreover, VAMP8 knockdown inhibited the activation of janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway in CRC cells. Mechanistically, activation of the JAK/STAT3 pathway by JAK1 or JAK2 overexpression attenuated VAMP8 silencing-mediated anti-proliferative, pro-apoptotic, anti-autophagic, and pro-ferroptotic effects on CRC cells. In conclusion, VAMP8 knockdown affects the proliferation, apoptosis, autophagy, and ferroptosis by the JAK/STAT3 pathway in CRC cells.

Comparison of non-operative versus operative management of resectable colorectal cancer in elderly patients: study protocol for a systematic review

BACKGROUND

In the 2021 Statistics Canada census, 18.5% of the Canadian population were senior (65 years and older), among those 1.7 million (4.5%) were aged 80 years and older. Colorectal cancer (CRC) is the third most common cancer in both men and women, with its highest incidence rate in septu- and octogenarians. As clinicians encounter a growing number of very elderly patients (80 years and older) with resectable colorectal cancer, justifying major surgery in a comorbid population with limited life expectancy is difficult. Therefore, this study aims to systemically review the available literature to compare non-operative management to surgical resection with respect to overall survival and quality of life.

METHOD

We designed and registered a study protocol for a systematic review. We will include all patients above the age of 80 with resectable colorectal cancer. We will search MEDLINE, EMBASE, and the Cochrane Database of Controlled Trials from January 2000 onwards. We will include randomized, non-randomized controlled trials and observational studies comparing non-operative versus operative management of resectable colorectal cancer in elderly patients. The primary outcomes will be overall survival and mortality. Secondary outcomes will include quality of life, and health services/ resources utilization (e.g., treatments, change of level of care…). Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The study methodological quality (or bias) will be appraised using the ROB-2 and ROBIN-I tools. If feasible, we will conduct random effects meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., study design and methodological quality).

DISCUSSION

This systematic review will synthesize the existing data on the management of colorectal cancer in the very elderly patients, and identify the gap in the literature for potential future research. More specifically, we aim to streamline non-operative outcome data on resectable colorectal cancers to aid clinicians' decision-making with respect to survival outcomes and quality of life. The results of this study will be of interest to multiple audiences including patients, their families, caregivers, healthcare professionals, and policy makers. Results will be published in a peer-reviewed journal.

ELFN1-AS1 accelerates the proliferation and migration of colorectal cancer via regulation of miR-4644/TRIM44 axis

Faced with the increasing colorectal cancer (CRC) cases, the interrogation of pivotal molecules in CRC appears to be vitally important. Long non-coding RNAs (lncRNAs) are well-known regulators of gene expression at transcriptional, post-transcriptional or epigenetic level, among which the competing endogenous RNA (ceRNA) network is a common way that lncRNAs exert their properties. The current study aimed to provide a new insight into improving the outcomes of CRC patients. Our study detected that ELFN1-AS1 expression was elevated in CRC tissues and cells, and ELFN1-AS1 upregulation was correlated with poor prognosis of CRC sufferers. Besides, it was viewed that ELFN1-AS1 knockdown impeded the proliferation and migration abilities as well as activated the apoptosis ability of CRC cells. In subsequence, mechanism assays also displayed that ELFN1-AS1 targeted miR-4644 to augment TRIM44 level. Finally, rescue experiments confirmed that TRIM44 took part in the ELFN1-AS1-medatied promotional influences on CRC cells proliferation and migration. In conclusion, ELFN1-AS1 exerted pro-proliferation, anti-apoptosis and pro-migration functions on CRC cells by acting as a sponge of miR-4644 to increase TRIM44 expression at mRNA and protein level, providing an additional molecule responsible for the carcinogenesis and progression for CRC.

LIN28B/IRS1 axis is targeted by miR-30a-5p and promotes tumor growth in colorectal cancer

Insulin receptor substrate 1 (IRS1) is a potential oncogene that has been implicated in several malignant tumors. However, the regulatory mechanism of IRS1 remains to be investigated. The aim of our current study is to unveil the mechanism by which IRS1 exerts functions in tumorigenesis of colorectal cancer (CRC). The expression level of IRS1 was found to be higher in CRC cells in comparison with the normal cell. To determine the role of IRS1 in regulating CRC cellular processes, loss-of-function assays were designed and carried out in two CRC cell lines. Both in vitro and in vivo functional assays indicated that silencing of IRS1 suppressed CRC cell survival. Based on bioinformatics prediction and mechanism experiments, IRS1 was identified as a downstream target of miR-30a-5p. Furthermore, RNA-binding protein lin-28 homolog B (LIN28B) was determined to be a stabilizer of IRS1 messenger RNA. More importantly, LIN28B also acted as a target of miR-30a-5p.Through rescue assays, we proved that LIN28B-stablized IRS1 mediated miR-30a-5p-mediated CRC cell growth. In conclusion, this study revealed that LIN28B and LIN28B-stablized IRS1 promoted CRC cell growth by cooperating with miR-30a-5p.

The incidence, associated factors, and predictive nomogram for early death in stage IV colorectal cancer

PURPOSE

The purpose of the present study was to investigate the incidence and associated factors for early death in stage IV colorectal cancer (CRC) and to construct the predictive nomogram.

METHODS

Patients with stage IV CRC, who had been diagnosed between 2010 and 2014 in the Surveillance, Epidemiology, and End Results datasets, were eligible for this retrospective cohort study. The univariable and multivariable logistic regression models were conducted to determine the associated factors for early death (survival time ≤ 3 months). The predictive nomogram was constructed and the internal validation was performed.

RESULTS

Ten thousand two hundred sixty-three out of 36,461 (28.1%) eligible patients resulted in all causes of early death (25.8% for cancer-specific early death and 2.3% for non-cancer early death). Advanced age, marital status, right colon, poor differentiation, higher N stage, and bone metastasis were positively associated with all causes of early death, cancer-specific early death, and non-cancer early death, while higher T stage, positive carcinoembryonic antigen, and distant metastases (bone, lung, liver, and brain) were only positively associated with all causes of early death and cancer-specific early death. The calibration curve for all causes of early death, cancer-specific early death, and non-cancer early death showed the prediction curve closely approximated at the 45° line and the areas under the curve were 75.7% (95% CI, 74.9-76.4%), 75.9% (95% CI, 75.1-76.6%), and 76.9% (95% CI, 76.3-77.6%), respectively.

CONCLUSIONS

The nomogram was calibrated to predict all causes of early death development, cancer-specific early death development, and non-cancer early death development. These findings can be utilized in early screening and to tailor targeted treatment regimens for stage IV CRC patients.