Chemotherapy treatments for metastatic colorectal cancer: is evidence-based medicine in practice?

Biweekly cetuximab in combination with capecitabine and oxaliplatin (XELOX) or irinotecan (XELIRI) in the first-line and second-line treatment of patients with RAS wild-type metastatic colorectal cancer

Background

Oral capecitabine in combination with intravenous oxaliplatin (XELOX) or irinotecan (XELIRI) are acceptable substitutions to fully intravenous regimens. Biweekly (as opposed to weekly) cetuximab is more convenient when combined with biweekly chemotherapy. Here, we report the tolerability and efficacy of biweekly cetuximab in combination with biweekly XELOX or XELIRI in patients with RAS wild-type metastatic colorectal cancer (RAS-WT mCRC).

Methods

Clinical data of consecutive patients with mCRC who received biweekly cetuximab (500 mg/m²) in combination with XELOX or XELIRI between January 2009 and May 2019 in the first- or second-line settings was extracted. Dosage of XEL (Capecitabine/XELODA) was 1,000 mg/m² twice daily for 9 days, plus on day 1 oxaliplatin 85 mg/m² or irinotecan 180 mg/m². Treatment dose reduction and delay for ≥7 days was analysed as surrogates for toxicity. Extended RAS testing was performed in the context of this study for patients who received treatment based on limited KRAS-WT genotype.

Results

Sixty one patients with RAS-WT mCRC fulfilled the eligibility criteria. XELOX was administered to 26 (42.6%) and XELIRI to 35 (57.4%) of patients. For all patients in the first-line setting, the objective response rate (ORR), median progression free survival (PFS) and median overall survival (OS) were 54%, 8 months and 25 months, respectively. The corresponding outcomes for the subgroup of patients who received first-line XELOX were 68%, 10 months and not reached, respectively. For all patients in the second-line setting, the ORR, PFS and OS were 50%, 7 months and 20 months, respectively. Chemotherapy components dose reduction and delays were observed in 18 (29.5%) and 25 (41%) patients, respectively. The corresponding frequencies for cetuximab were 3 (5%) and 31 (50.8%).

Conclusion

Biweekly cetuximab in combination with XELOX or XELIRI is tolerable and effective. The addition of cetuximab to capecitabine and oxaliplatin is associated with favourable outcome.

Polymeric nanocarriers: A promising tool for early diagnosis and efficient treatment of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most prevalent type of cancer for incidence and second for mortality worldwide. Late diagnosis and inconvenient and expensive current diagnostic tools largely contribute to the progress of the disease. The use of chemotherapy in the management of CRC significantly reduces tumor growth, metastasis, and morbidity rates. However, poor solubility, low cellular uptake, nonspecific distribution, multiple drug resistance and unwanted adverse effects are still among the major drawbacks of chemotherapy that limit its clinical significance in the treatment of CRC. Owing to their remarkable advantages over conventional therapies, the use of nanotechnology-based delivery systems especially polymeric nanocarriers (PNCs) has revolutionized many fields including disease diagnosis and drug delivery.

AIM OF REVIEW

In this review, we shed the light on the current status of using PNCs in the diagnosis and treatment of CRC with a special focus on targeting strategies, surface modifications and safety concerns for different types of PNCs in colonic cancer delivery.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review explores the current progress on the use of PNCs in the diagnosis and treatment of CRC with a special focus on the role of PNCs in improvement of cellular uptake, drug targeting and co-delivery of chemotherapeutic agents. Possible toxicity and biocompatibility issues related to the use of PNCs and imitations and future recommendation for the use of those smart carriers in the diagnosis and treatment of CRC are also discussed.

Optimal Allocation of Chemotherapy Schemes for Metastatic Colon Cancer in Colombia

OBJECTIVES

This study aims to determine the optimal proportion for different chemotherapy schemes in patients with metastatic colorectal cancer who have undergone surgical resection in Colombia.

METHODS

A linear programming model was used to quantify the optimal proportion of the chemotherapy schemes that maximize quality-adjusted life-years (QALYs). The model was evaluated in 6 different scenarios using parametric and dynamic optimization with different budget restriction constraints. The results were compared to the current mixture of schemes used in our country.

RESULTS

The results show that 63%, 37%, and 0.8% of the population should receive the FOLFOXIRI scheme (fluorouracil + leucovorin + oxaliplatin + irinotecan), FOLFIRI (irinotecan + leucovorin + fluorouracil), and FOLFIRI plus cetuximab, respectively. With these proportions, 8734 QALYs and universal coverage of the population are obtained. In an optimistic scenario (high QALYs, low costs, and budget of $40 million), the entire population should receive the FOLFIRI scheme. A pessimistic scenario (low QALYs, high costs, and budget of $15 million) would benefit only 46% of the population with the fluorouracil plus leucovorin scheme. In the other 3 scenarios with higher budget constraints, 52%, 69%, and 86% of the population should receive FOLFIRI, respectively. Dynamic optimization revealed that FOLFIRI and FOLFOX (oxaliplatin + leucovorin + fluorouracil) schemes are more likely to generate higher QALYs with lower costs and a limited budget.

CONCLUSIONS

The current use of chemotherapy schemes is not optimal. An increasing proportion of FOLFIRI, FOLFOX, and FOLFOXIRI should be used more often as schemes to treat metastatic colorectal cancer in Colombia.

Comparison of irinotecan and oxaliplatin as the first-line therapies for metastatic colorectal cancer: a meta-analysis

BACKGROUND

Irinotecan (IRI) and oxaliplatin (Ox) are standard therapeutic agents of the first-line treatments for metastatic colorectal cancer (mCRC). Previous meta-analyses of randomized controlled trials (RCTs) showed that treatment with Ox-based compared with IRI-based regimens was associated with better overall survival (OS). However, these reports did not include trials of molecular targeting agents and did not take methods for the administration of concomitant drugs, such as bolus or continuous infusion of 5-fluorouracil, into account. A systematic literature review was performed to compare the efficacy and toxicity profiles between IRI- and Ox-based regimens as the first-line treatments for mCRC.

METHODS

This meta-analysis used data from the Cochrane Central Register of Controlled Trials, PubMed, and SCOPUS. The primary endpoint was OS, and the secondary endpoints were progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs).

RESULTS

Nineteen trials involving 4571 patients were included in the analysis. No statistically significant difference was observed between the two groups in terms of OS, PFS, and ORR. There was no significant heterogeneity. Regarding ≥ grade 3 AEs, IRI-based regimens were associated with a high incidence of leukopenia, febrile neutropenia, and diarrhea. Moreover, there was a high incidence of thrombocytopenia and peripheral sensory neuropathy in patients who received Ox-based regimens. In a subgroup analysis, IRI combined with bevacizumab was correlated with a better PFS (HR = 0.90, 95% CI = 0.82-0.98, P = 0.02), but not with OS (pooled HR = 0.91, 95% CI = 0.80-1.03, P = 0.15).

CONCLUSION

Although the safety profiles of IRI- and Ox-based regimens varied, their efficacy did not significantly differ. The combination of anti-VEGF antibody and IRI was associated with better PFS compared with anti-VEGF antibody and Ox. Both regimens could be used as the first-line treatments for mCRC with consideration of the patients' condition or toxicity profiles.

Targeting siRNA in colorectal cancer therapy: Nanotechnology comes into view

Colorectal cancer (CRC) is known as one of the most important causes of death and mortality worldwide. Although several efforts have been made for finding new therapies, no achievements have been made in this area. Multidrug resistance (MDR) mechanisms are one of the key factors that could lead to the failure of chemotherapy. Moreover, it has been shown that various chemotherapy drugs are associated with several side effects. Hence, it seems that finding new drugs or new therapeutic platforms is required. Among different therapeutic approaches, utilization of nanoparticles (NPs) for targeting a variety of molecules such as siRNAs are associated with good results for the treatment of CRC. Targeting siRNA-mediated NPs could turn off the effects of oncogenes and MDR-related genes. In the current study, we summarized various siRNAs targeted by NPs which could be used for the treatment of CRC. Moreover, we highlighted other routes such as liposome for targeting siRNAs in CRC therapy.

Dietary glycine decreases both tumor volume and vascularization in a combined colorectal liver metastasis and chemotherapy model

Rationale: Chemotherapy (CTx) with FOLFOX is indicated prior to resection of liver metastases; however, its effect is limited due to chemoresistance and its toxicity prevents from aggressive surgery needed in some cases. Hepatoprotective glycine has been shown to have anti-tumorigenic properties in various cancers. Thus, this study was designed to evaluate the effects of glycine combined with FOLFOX on colorectal liver metastases (CRLM).

Methods: The effect of glycine combined with 5-fluorouracil and oxaliplatin was investigated in vitro on colorectal cancer (CC531). Further, Wag/Rij rats with CRLM were treated with 5% dietary glycine ± FOLFOX. µCT liver scan, anti-Ki67, and anti-CD31 were compared.

Results: Glycine alone and combined with CTx has no effect on both CC531 viability in vitro and tumor proliferation in vivo; however, glycine significantly decreased tumor volume to about 42-35% of controls in vivo (p<0.05) with a 60% decreased tumor microvascular density (MVD) (p=0.004). Further glycine doesn't counteract anti-tumor properties of CTx.

Conclusions: This study nicely demonstrates that glycine inhibits the growth of CRLM and does not decrease CTx effectiveness. Underlying mechanisms most likely include a decreased tumor MVD. Clinical trials are warranted to implement non-toxic hepatoprotective glycine in novel anti-cancer strategies in humans.

Impact of diabetes comorbidity on the efficacy and safety of FOLFOX first-line chemotherapy among patients with metastatic colorectal cancer: a pooled analysis of two phase-III studies

BACKGROUND

The current analysis aims to provide an evaluation of the impact of diabetes mellitus (DM) on the efficacy and safety of first-line FOLFOX chemotherapy for patients with metastatic colorectal cancer (mCRC).

METHODS

This is a pooled analysis of the comparator arms of two clinical trials (NCT00272051; NCT00305188) which evaluated first-line FOLFOX chemotherapy for patients with mCRC. The overall survival and progression-free survival according to patient subsets (non-diabetic and diabetic patients) were assessed through Kaplan-Meier analysis and log-rank testing. Propensity score matching was additionally conducted to account for heterogeneity in baseline characteristics of different subsets of patients.

RESULTS

A total of 756 patients were enrolled in the current analysis; of which 64 patients have pre-existing DM while 692 patients were non-diabetic. Through Kaplan-Meier analysis, no evidence for overall or progression-free survival difference was found among the two patient subsets (P = 0.501; P = 0.960, respectively). Moreover, metformin treatment does not affect overall or progression-free survival among diabetic patients (P = 0.598; P = 0.748, respectively). Repetition of overall and progression-free survival assessment following propensity score matching does not reveal any differences. Comparing diabetic to non-diabetic patients, there were no differences between the two groups in terms of acute oxaliplatin-induced neurological symptoms including cold-induced dysthesia (P = 0.600), laryngeal dysthesia (P = 0.707), jaw pain (P = 0.743) or muscle pain (P = 0.506). Moreover, no difference was seen between the two groups in terms of the incidence of long-term oxaliplatin-induced paresthesia (P = 0.107), highest grade of paresthesia (P = 0.498) or rates of recovery from paresthesia (P = 0.268). Diabetic patients have, however, a shorter time to develop oxaliplatin-induced paresthesia (P = 0.024).

CONCLUSION

DM does not seem to affect overall or progression-free survival of mCRC patients treated with first-line FOLFOX chemotherapy. Moreover, DM does not influence the incidence or severity of oxaliplatin-induced paresthesia in those patients while it might lead to a shorter time to develop oxaliplatin-induced paresthesia compared to non-diabetic patients.

Chrysin Attenuates Cell Viability of Human Colorectal Cancer Cells through Autophagy Induction Unlike 5-Fluorouracil/Oxaliplatin

Chemotherapeutic 5-fluorouracil (5-FU) combined with oxaliplatin is often used as the standard treatment for colorectal cancer (CRC). The disturbing side effects and drug resistance commonly observed in chemotherapy motivate us to develop alternative optimal therapeutic options for CRC treatment. Chrysin, a natural and biologically active flavonoid abundant in propolis, is reported to have antitumor effects on a few CRCs. However, whether and how chrysin achieves similar effectiveness to the 5-FU combination is not clear. In this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), western blotting, fluorescence microscopy, and reactive oxygen species (ROS) production were assayed. We found that chrysin exhibited similar inhibition of cell viability as the 5-FU combination in a panel of human CRC cells. Furthermore, the results showed that chrysin significantly increased the levels of LC3-II, an autophagy-related marker, in CRC cells, which was not observed with the 5-FU combination. More importantly, blockage of autophagy induction restored chrysin-attenuated CRC cell viability. Further mechanistic analysis revealed that chrysin, not the 5-FU combination, induced ROS generation, and in turn, inhibited the phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR). Collectively, these results imply that chrysin may be a potential replacement for the 5-FU and oxaliplatin combination to achieve antitumor activity through autophagy for CRC treatment in the future.

Evaluation of the performance of elastomeric pumps in practice: are we under-delivering on chemotherapy treatments?

BACKGROUND AND AIMS

Elastomeric pumps are widely used to facilitate ambulatory chemotherapy, and studies have shown that they are safe and well received by patients. Despite these advantages, their end of infusion time can fluctuate significantly. The aim of this research was to observe the performance of these pumps in real practice and to evaluate patients' satisfaction.

METHODS

This was a two-phase study conducted at three cancer units over 6 months. Phase-1 was an observational study recording the status of pumps at the scheduled disconnection time and noting remaining volume of infusion. Phase-2 was a survey of patients and their perception/satisfaction. Ethical approval was granted.

RESULTS

A total of 92 cases were observed covering 50 cases disconnected at hospital and 42 disconnected at home. The infusion in 40% of hospital disconnection cases was slow, with patients arriving at hospital with unfinished pumps; 58% of these had an estimated remaining volume which exceeded 10 mL with 35% exceeded 20 mL. In 73% of these cases, and regardless of the remaining volume, the patient was disconnected and the pump was discarded.

CONCLUSIONS

The performance of pumps varied, which affected nurse workload and patients' waiting-times. A smart system is an option to monitor the performance of pumps and to predict their accuracy.

Targeted nanoparticles for colorectal cancer

Colorectal cancer (CRC) is highly prevalent worldwide, and despite notable progress in treatment still leads to significant morbidity and mortality. The use of nanoparticles as a drug delivery system has become one of the most promising strategies for cancer therapy. Targeted nanoparticles could take advantage of differentially expressed molecules on the surface of tumor cells, providing effective release of cytotoxic drugs. Several efforts have recently reported the use of diverse molecules as ligands on the surface of nanoparticles to interact with the tumor cells, enabling the effective delivery of antitumor agents. Here, we present recent advances in targeted nanoparticles against CRC and discuss the promising use of ligands and cellular targets in potential strategies for the treatment of CRCs.