Colorectal cancer screening in elderly patients: when should be more useful?

The increasing prevalence of cancer in the elderly: An investigation of epidemiological trends

Cancer poses a significant health threat to the elderly, accounting for a substantial proportion of cancer patients aged 65 and above. As life expectancy continues to rise and the population ages, the incidence of cancer in the elderly is expected to increase further. Age is a major risk factor for the majority of common cancers, with the incidence and prevalence rising as individuals grow older. Factors such as chemoprevention and environmental carcinogen elimination may influence the process of carcinogenesis. Studies reveal that the incidence and mortality rates of various cancers in the elderly and extremely old individuals are on the rise worldwide, with most types peaking around the age of 75 to 90, followed by a sharp decline. Birth cohort and period effects also play a complex role in the connection between aging and cancer risk. Clinical trials often exclude older individuals, limiting our understanding of cancer treatments' effects on this particular age group. More research is needed to focus on the unique requirements of older adults with cancer.

Should we screen for colorectal cancer in people aged 75 and over? A systematic review - collaborative work of the French geriatric oncology society (SOFOG) and the French federation of digestive oncology (FFCD)

BACKGROUND

We have done a systematic literature review about CRC Screening over 75 years old in order to update knowledge and make recommendations.

METHODS

PUBMED database was searched in October 2021 for articles published on CRC screening in the elderly, and generated 249 articles. Further searches were made to find articles on the acceptability, efficacy, and harms of screening in this population, together with the state of international guidelines.

RESULTS

Most benefit-risk data on CRC screening in the over 75 s derived from simulation studies. Most guidelines recommend stopping cancer screening at the age of 75. In private health systems, extension of screening up to 80-85 years is, based on the life expectancy and the history of screening. Screening remains effective in populations without comorbidity given their better life-expectancy. Serious adverse events of colonoscopy increase with age and can outweigh the benefit of screening. The great majority of reviews concluded that screening between 75 and 85 years must be decided case by case.

CONCLUSION

The current literature does not allow Evidence-Based Medicine propositions for mass screening above 75 years old. As some subjects over 75 years may benefit from CRC screening, we discussed ways to introduce CRC screening in France in the 75-80 age group. IRB: An institutional review board composed of members of the 2 learned societies (SOFOG and FFCD) defined the issues of interest, followed the evolution of the work and reviewed and validated the report.

Oxaliplatin plus fluoropyrimidines as adjuvant therapy for colon cancer in older patients: A subgroup analysis from the TOSCA trial

BACKGROUND

Previous studies on oxaliplatin and fluoropyrimidines as adjuvant therapy in older patients with stage III colon cancer (CC) produced conflicting results.

PATIENTS AND METHODS

We assessed the impact of age on time to tumour recurrence (TTR), disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) in 2360 patients with stage III CC (1667 aged <70 years and 693 ≥ 70 years) randomised to receive 3 or 6 months of FOLFOX or CAPOX within the frame of the phase III, TOSCA study.

RESULTS

Older patients compared with younger ones presented more frequently an Eastern Cooperative Oncology Group performance status equal to 1 (10.5% vs 3.3%, p < 0.001), a greater number of right-sided tumours (40.9% vs 26.6%, p < 0.001), and were at higher clinical risk (37.2% vs 33.2%, p = 0.062). The treatments were almost identical in the two cohorts (p = 0.965). We found a greater proportion of dose reductions (46.7% vs 41.4%, p = 0.018), treatment interruptions (26.1% vs 19.3%, p < 0.001) and a higher proportion of recurrences (24.2% vs 20.3%, p = 0.033) in the older patients. The multivariable analysis of the TTR did not indicate a statistically significant effect of age (hazard ratio [HR]: 1.19; 95% confidence interval [CI]: 0.98-1.44; p = 0.082). The HR comparing older with younger patients was 1.34 (95% CI: 1.12-1.59; p = 0.001) for DFS, 1.58 (95% CI: 1.26-1.99; p < 0.001) for OS, and 1.28 (95% CI: 0.96-1.70; p = 0.089) for CSS.

CONCLUSIONS

Worse prognostic factors and reduced treatment compliance have a negative impact on the efficacy of oxaliplatin-based adjuvant therapy in older patients.

Identification of Key Genes in Colorectal Cancer Regulated by miR-34a

Background

The aim of this study was to screen the molecular targets of miR-34a in colorectal cancer (CRC) and construct the regulatory network, to gain more insights to the pathogenesis of CRC.

Material/Methods

The microarray data of CRC samples and normal samples (GSE4988), as well as CRC samples transformed with miR-34a and non-transfected CRC samples (GSE7754), were downloaded from the Gene Expression Omnibus (GEO) database. The differently expressed genes (DEGs) were identified via the LIMMA package in R language. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to identify significant Gene Ontology (GO) terms and pathways in DEGs. The targets of miR-34a were obtained via the miRWalk database, and then the overlaps between them were selected out to construct the regulatory network of miR-34a in CRC using the Cytoscape software.

Results

A total of 392 DEGs were identified in CRC samples compared with normal samples, including 239 upregulated genes and 153 downregulated ones. These DEGs were enriched in 75 GO terms and one Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. At the same time, 332 DEGs (188 upregulated and 144 downregulated) were screened out between miR-34a transformed CRC and miR-34a non-transfected CRC samples and they were enriched in 20 GO terms and eight KEGG pathways. Six overlapped genes were identified in two DEGs groups. There were 1,668 targets of miR-34a obtained via the miRWalk database, among which 21 were identified differently expressed in miR-34a transformed CRC samples compared with miR-34a non-transfected CRC samples. Two regulatory networks of miR-34a in CRC within these two groups of overlapped genes were constructed respectively.

Conclusions

Pathways related to cell cycle, DNA replication, oocyte meiosis, and pyrimidine metabolism might play critical roles in the progression of CRC. Several genes such as SERPINE1, KLF4, SEMA4B, PPARG, CDC45, and KIAA0101 might be the targets of miR-34a and the potential therapeutic targets of CRC.

Impact of age on the efficacy of newer adjuvant therapies in patients with stage II/III colon cancer: findings from the ACCENT database

PURPOSE

Prior studies have suggested that patients with stage II/III colon cancer receive similar benefit from intravenous (IV) fluoropyrimidine adjuvant therapy regardless of age. Combination regimens and oral fluorouracil (FU) therapy are now standard. We examined the impact of age on colon cancer recurrence and mortality after adjuvant therapy with these newer options.

PATIENTS AND METHODS

We analyzed 11,953 patients age < 70 and 2,575 age ≥ 70 years from seven adjuvant therapy trials comparing IV FU with oral fluoropyrimidines (capecitabine, uracil, or tegafur) or combinations of fluoropyrimidines with oxaliplatin or irinotecan in stage II/III colon cancer. End points were disease-free survival (DFS), overall survival (OS), and time to recurrence (TTR).

RESULTS

In three studies comparing oxaliplatin-based chemotherapy with IV FU, statistically significant interactions were not observed between treatment arm and age (P interaction = .09 for DFS, .05 for OS, and .36 for TTR), although the stratified point estimates suggested limited benefit from the addition of oxaliplatin in elderly patients (DFS hazard ratio [HR], 0.94; 95% CI, 0.78 to 1.13; OS HR, 1.04; 95% CI, 0.85 to 1.27). No significant interactions by age were detected with oral fluoropyrimidine therapy compared with IV FU; noninferiority was supported in both age populations.

CONCLUSION

Patients age ≥ 70 years seemed to experience reduced benefit from adding oxaliplatin to fluoropyrimidines in the adjuvant setting, although statistically, there was not a significant effect modification by age, whereas oral fluoropyrimidines retained their efficacy.

Treatment of resistant human colon cancer xenografts by a fluoxetine-doxorubicin combination enhances therapeutic responses comparable to an aggressive bevacizumab regimen

Pre-clinical studies of multidrug resistance (MDR) usually address severe resistance, yet moderate MDR is already clinically-impeding. The purpose of this study was to characterize moderate drug resistance in human colon cancer, and it's modulation by fluoxetine. In vitro fluoxetine enhanced doxorubicin's cytotoxicity (10-fold), increased doxorubicin's intracellular accumulation (32%) and decreased efflux of intracellular doxorubicin (70%). In vivo, mild treatment with a doxorubicin-fluoxetine combination slowed-down tumor progression significantly (p<0.001 vs. doxorubicin alone), comparable to aggressive treatment with bevacizumab. Collectively, our results suggest that combinations of fluoxetine with chemotherapeutic drugs (P-glycoprotein substrates) are worthy of further pursuit for moderate MDR in the clinic.