Network Meta-analysis of First-Line Systemic Treatment for Patients With Metastatic Colorectal Cancer

Synergistic effects of Aurora A and AKT inhibitors combined with radiation in colon cancer cells

PURPOSE

This study aimed to investigate the synergistic effects of combining Aurora A and AKT inhibitors with radiation therapy on colon cancer cells and to elucidate the underlying mechanisms.

METHODS

Human colon cancer cell lines HCT-15 and HCT-116 were treated with Alisertib (Aurora A inhibitor), MK2206 (AKT inhibitor), and radiation alone or in combination. Cell viability, cell cycle distribution, apoptosis, and DNA damage were analyzed using MTT assays, flow cytometry, Western blotting, and immunofluorescence staining, respectively.

RESULTS

The combination of Alisertib and MK2206 with radiation significantly suppressed cell proliferation, induced pronounced G2/M phase arrest, and enhanced apoptosis compared to single-agent treatments. Western blot and immunofluorescence analyses revealed elevated γ-H2AX levels, indicating increased DNA double-strand breaks.

CONCLUSION

The integration of Aurora A and AKT inhibitors with radiation therapy synergistically enhances anticancer effects by amplifying DNA damage, disrupting mitotic progression, and inducing apoptosis. This combination represents a promising strategy for overcoming treatment resistance in colon cancer.

Evaluating the efficacy of PARP inhibitor in ARID1A-deficient colorectal cancer: A ex vivo study

ARID1A mutations are a common occurrence in colorectal cancer (CRC) cells, but clinical therapeutic options targeting this anomaly remain unavailable. The loss of ARID1A functionality compromises DNA damage repair processes, potentially causing cancer cells to rely more heavily on PARP-dependent DNA repair pathways to preserve genomic integrity, thereby making them susceptible to PARP inhibitor (PARPi) therapy. To evaluate the suitability of PARPi treatment for CRC patients with ARID1A sufficiency (ARID1A+) and ARID1A deficiency (ARID1A-), our study enrolled 80 patients who had undergone surgical treatment for primary CRC. Surgical specimens underwent immunohistochemical examination to assess ARID1A protein expression. The study explored correlations between ARID1A expression loss and clinicopathological characteristics. Moreover, primary CRC cells were isolated through enzymatic digestion and validated using the colorectal carcinoma marker CK20. Subsequently, PARPi sensitivity was investigated in untreated ARID1A+ and ARID1A- CRC patients using an ATP-tumor chemosensitivity assay (ATP-TCA). Additionally, we confirmed the efficacy of PARPi in these primary CRC cells through clone formation and assessed its impact on cell cycle dynamics, apoptosis, and DNA damage repair signaling pathways using immunofluorescence and flow cytometry. The results demonstrated that the ARID1A- group displayed greater sensitivity to PARPi compared to the ARID1A+ group. PARPi treatment led to increased tumor cell death in the ARID1A- group. Mechanistically, ARID1A deficiency resulted in cell cycle abnormalities, particularly G2/M phase arrest, which was further exacerbated by PARPi treatment. Furthermore, PARPi treatment significantly increased the number of RAD51 foci in ARID1A- cell lines. In conclusion, our study highlights the potential of PARPi as an effective therapeutic option for ARID1A- CRC patients.

Second-line systemic treatment for metastatic colorectal cancer: A systematic review and Bayesian network meta-analysis based on RCT

BACKGROUND

The optimal second-line systemic treatment for metastatic colorectal cancer (mCRC) is inconclusive.

METHODS

We searched PubMed, Web of Science, EMBASE, and Cochrane Library for RCTs comparing second-line systemic treatments for mCRC from the inception of each database up to February 3, 2024. Markov Chain Monte Carlo (MCMC) technique was used in this network meta-analysis (NMA) to generate the direct and indirect comparison results among multiple treatments in progression-free survival (PFS), overall response rate (ORR), overall survival (OS), complete response (CR), partial response (PR), grade 3 and above adverse events (Grade ≥ 3AE), and any adverse events (Any AE). The surface under the cumulative ranking curve (SUCRA) was adopted to evaluate the probability of each treatment being the optimum intervention. Subgroup analyses were performed based on the RAS gene status.

RESULTS

A total of 47 randomized controlled trials were included, involving 16,925 patients and 44 second-line systemic treatments. In improving OS, FOLFOX + Bevacizumab + Erlotinib exhibited significant superiority (SUCRA:92.7%). In improving PFS, Irinotecan + CMAB009 (SUCRA:86.4%) had advantages over other treatments. FOLFIRI + Trebananib (SUCRA:88.1%) had a significant advantage in improving ORR. Among multiple second-line treatments, the SUCRA values of FOLFOX + Bevacizumab in PFS, OS, ORR, and PR were 83.4%, 74.0%, 81.1%, and 86.1%, respectively, and the safety was not significantly different from other interventions. Subgroup analyses showed that FOLFIRI + Bevacizumab + panitumumab ranked among the top in survival outcomes in the RAS-mutant population (OS SUCRA: 87.9%; PFS SUCRA: 70.2%); whereas in the RAS-wild-type population, FOLFIRI + Bevacizumab significantly improved survival outcomes (OS SUCRA: 73.2%; PFS SUCRA: 65.1%).

CONCLUSION

For most people, FOLFOX + Bevacizumab may be the best second-line systemic treatment regimen for mCRC. For RAS-mutant populations, FOLFIRI + Bevacizumab + Panitumumab is recommended. However, the therapeutic effect may be affected by the patient's physiological state, and clinicians should apply it based on actual conditions.

AURKA inhibition shows promise as a therapeutic strategy for ARID1A-mutant colorectal cancer

PURPOSE

Mutations in ARID1A frequently occur in colorectal cancer (CRC) cells. However, there are currently no clinical treatment options specifically addressing this aberration. The preliminary in vitro experiments revealed a synthetic lethal interaction between ARID1A and Aurora kinase A (AURKA) in colorectal cancer (CRC) cells.

METHODS

We collected samples from 80 CRC patients and evaluated the efficacy of AURKA inhibitor (AURKAi) using the ATP-tumor chemosensitivity assay (ATP-TCA) on untreated ARID1A-proficient (ARID1A +) and ARID1A-deficient (ARID1A-) CRC patient samples. In addition, we validated this result by a clonogenic assay. Additionally, we examined the effects of AURKA inhibitors on cell cycle progression and apoptosis in ARID1A + and ARID1A- CRC patient samples using flow cytometry.

RESULTS

The results showed that AURKAi selectively inhibited the growth of ARID1A- CRC cells. Furthermore, AURKA inhibitors significantly increased G2/M arrest and induced apoptosis in ARID1A- cells.

CONCLUSION

We believe that AURKAi hold promise as potential therapeutics for ARID1A mutation colorectal cancer patients.

Safety of first-line systemic therapy in patients with metastatic colorectal cancer: a network meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the safety of first-line systemic therapy for metastatic colorectal cancer through network meta-analysis.

METHODS

The literature from PubMed, Embase, Web of Science, and Cochrane Library databases was searched from the inception of the databases to August 15, 2023, and strict inclusion and exclusion criteria were applied to screen studies. The Cochrane Bias Risk Assessment Tool (RoB 2.0) was used to evaluate the quality of the included literature. Network meta-analysis was conducted using Stata 15.0 and R4.3.1 software to compare the incidence of adverse events (AEs) among different treatment regimens.

RESULTS

A total of 53 randomized controlled trials, involving 17,351 patients with metastatic colorectal cancer (mCRC), were ultimately included, encompassing 29 different therapeutic approaches. According to SUCRA rankings, the CAPOX regimen is most likely to rank first in terms of safety, while the FOLFOXIRI + panitumumab regimen is most likely to rank last. In terms of specific AEs, the CAPOX regimen, whether used alone or in combination with targeted drugs (bevacizumab and cetuximab), is associated with a reduced risk of neutropenia and febrile neutropenia, as well as an increased risk of thrombocytopenia and diarrhea. The FOLFOX regimen, with or without bevacizumab, is linked to an increased risk of neutropenia and peripheral sensory neuropathy. The FOLFIRI/CAPIRI + bevacizumab regimen is associated with a reduced risk of peripheral sensory neuropathy. S-1 and S-1 + oxaliplatin are well-tolerated in terms of gastrointestinal reactions. The FOLFOXIRI regimen, whether used alone or in combination with targeted drugs, is associated with various AEs.

CONCLUSION

In summary, the CAPOX regimen may be the safest option among the first-line systemic treatment regimens for mCRC patients, while the FOLFOXIRI + panitumumab regimen may be associated with a higher incidence of grade 3 or higher AEs.

Cost-Effectiveness Analysis of Monoclonal Antibodies Associated With Chemotherapy in First-Line Treatment of Metastatic Colorectal Cancer

OBJECTIVES

This study aimed to evaluate the cost-effectiveness of anti-epidermal growth factor receptor (cetuximab and panitumumab) or anti-vascular endothelial growth factor (bevacizumab) monoclonal antibodies associated with conventional chemotherapy (CT) (fluorouracil and leucovorin with irinotecan) as a first-line treatment for unresectable metastatic colorectal cancer.

METHODS

A partitioned survival analysis model was adopted to simulate direct health costs and benefits comparing therapeutic options in a 10 years' time horizon. Model data were extracted from the literature and costs were obtained from Brazilian official government databases. The analysis considered the perspective of the Brazilian Public Health System; costs were measured in local currency (BRL) and benefits in quality-adjusted life-years (QALY). A 5% discount rate was applied to costs and benefits. Alternative willingness-to-pay scenarios, varying from 3 to 5 times the cost-effectiveness threshold established in Brazil, were estimated. The results were presented incremental cost-effectiveness ratio (ICER), and both deterministic and probabilistic sensitivity analyses were performed.

RESULTS

The most cost-effective choice would be the association of CT with panitumumab, with an ICER of $58 330.15/QALY compared with isolated CT. The second-best option was CT with bevacizumab and panitumumab, with an ICER of $71 195.40/QALY compared with panitumumab alone. Although having higher costs, the second-best option was the most effective. Both strategies were cost-effective in part of the Monte Carlo iterations, considering the 3× threshold.

CONCLUSIONS

The therapeutic option CT + panitumumab + bevacizumab represents the most significant effectiveness gain in our study. It is the second-lowest cost-effectiveness, and this option includes monoclonal antibodies association for patients with and without KRAS mutation.

Selective vulnerability of ARID1A deficient colon cancer cells to combined radiation and ATR-inhibitor therapy

ARID1A is frequently mutated in colorectal cancer (CRC) cells. Loss of ARID1A function compromises DNA damage repair and increases the reliance of tumor cells on ATR-dependent DNA repair pathways. Here, we investigated the effect of ionizing radiation (IR), in combination with ATR inhibitors (ATRi) in CRC cell lines with proficient and deficient ARID1A. The concept of selective vulnerability of ARID1A deficient CRC cells to ATRi was further tested in an ex vivo system by using the ATP-tumor chemosensitivity assay (ATP-TCA) in cells from untreated CRC patients, with and without ARID1A expression. We found selective sensitization upon ATRi treatment as well as after combined treatment with IR (P<0.001), especially in ARID1A deficient CRC cells (P <0.01). Knock-down of ARID1B further increased the selective radiosensitivity effect of ATRi in ARID1A negative cells (P<0.01). Mechanistically, ATRi abrogates the G2 checkpoint (P<0.01) and homologous recombination repair (P<0.01) in ARID1A deficient cells. Most importantly, ex-vivo experiments showed that ATRi had the highest radiosensitizing effect in ARID1A negative cells from CRC patients. Collectively, our results generate pre-clinical and clinical mechanistic rationale for assessing ARID1A defects as a biomarker for ATR inhibitor response as a single agent, or in a synthetic lethal approach in combination with IR.