Patient demographics and management landscape of metastatic colorectal cancer in the third-line setting: Real-world data in an australian population

Chemotherapy re-use versus anti-angiogenic monotherapy as the third-line treatment of patients with metastatic colorectal cancer: a real-world cohort study

BACKGROUND

There are various recommendations for third-line treatment in mCRC, however, there is no consensus on who is more suitable for particular strategy. Chemotherapy re-use in third-line setting is a common option in clinical practice. This study aimed to investigate the efficacy of third-line chemotherapy re-use by the comparison with that of anti-angiogenic monotherapy, and further find the population more suitable for third-line chemotherapy.

METHODS

Using electronic medical records of patients with mCRC, a retrospective cohort study was conducted. A total of 143 patients receiving chemotherapy and 40 patients receiving anti-angiogenic monotherapy in third-line setting as control group were retrospectively collected. Baseline characteristics were analyzed using the χ² test or the Fisher's exact test. ROC curve and surv_cutpoint function of 'survminer' package in R software were used to calculate the cut-off value. Survival curves were plotted with the Kaplan-Meier method and were compared using the log-rank test. The Cox proportional hazard regression model was used to analyze the potential risk factors.

RESULTS

A total of 143 patients receiving chemotherapy and 40 patients receiving anti-angiogenic monotherapy in third-line setting were retrospectively collected. Chemotherapy rechallenge was recorded in 93 patients (93/143, 65.0%), and the remaining patients chose new chemotherapeutic drugs that had not been previously used, including irinotecan-based (22/50), oxaliplatin-based (9/50), raltitrexed (9/50), gemcitabine (5/50) and other agents (5/50). The ORR and DCR of third-line chemotherapy reached 8.8%, 61.3%, respectively (anti-angiogenic monotherapy group: ORR 2.6%, DCR 47.4%). The mPFS and mOS of patients receiving chemotherapy were 4.9 and 12.0 m, respectively (anti-angiogenic monotherapy group: mPFS 2.7 m, mOS 5.2 m). Subgroup analyses found that patients with RAS/RAF mutation, longer PFS (greater than 10.6 m) in front-line treatment or larger tumor burden had better prognosis with third-line chemotherapy rather than anti-angiogenic monotherapy.

CONCLUSIONS

Third-line chemotherapy re-use was effective in mCRC. Those with more aggressive characteristics (RAS/RAF mutant, larger tumor burden) or better efficacy of previous chemotherapy (longer PFS) were more appropriate for third-line chemotherapy, rather than anti-angiogenic monotherapy.

Third-line treatment patterns and clinical outcomes for metastatic colorectal cancer: a retrospective real-world study

Background

There are multiple recommendations on the third-line therapy of metastatic colorectal cancer (mCRC); however, no consensus has been reached.

Objectives

This study aimed to explore the patient demographics and the real-world third-line treatment landscape of mCRC.

Design

A retrospective real-world cohort study.

Methods

Electronic medical records of mCRC patients from Tianjin Medical University Cancer Institute and Hospital between 2013 and 2020 were collected. Upon descriptive, comparative, and survival analyses, a retrospective study was conducted to describe demographics and clinical outcomes of mCRC patients receiving third-line treatment.

Results

Among 218 mCRC patients receiving third-line therapy, 65.5% received chemotherapy combined with or without targeted drugs, followed by anti-angiogenic monotherapy (18.4%), anti-epidermal growth factor receptor drugs (6.9%) and immunotherapy (6.4%). The overall response rate and disease control rate reached 10.2% and 59.2%, respectively; and median progression-free survival (PFS) and overall survival were 4.0 m and 10.7 m, respectively. After Cox multivariate analysis, we found that therapeutic regime was an independent prognostic factor. Compared to patients receiving anti-angiogenic monotherapy, those receiving chemotherapy combined with or without targeted drugs exhibited better prognosis. For patients whose PFS were longer in the front-line treatment, the PFS of third-line therapy was also relatively longer (p = 0.023). Multiple types of therapies (>3, p = 0.002) or multiple drugs (>5, p = 0.024) in the whole-course management of mCRC are indicators of longer survival.

Conclusion

Chemotherapy combined with or without targeted therapy remained dominated third-line choice and showed favorable efficacy compared with anti-angiogenic monotherapy. With the application of more types and quantities of effective drugs, patients would achieve better survival.

Colorectal cancer databases and registries in Australia: what data is available?

BACKGROUND

There are multiple data sources relating to colorectal cancer (CRC) nationwide. Prospective clinical cancer databases, population-based registries and linked administrative data are powerful tools in clinical outcomes research and provide real-world perspective on cancer treatments. This study aims to review the different Australian data sources for CRC from the perspective of conducting comparative research studies using a PICO (patient, intervention, comparison, outcome) framework.

METHODS

Data dictionaries from the different data sources were evaluated for the types of exposure and outcome variables contained to highlight their differing research utility.

RESULTS

State or territory-based cancer registries contain limited histology, cancer staging and treatment detail. They enable investigation of population-level patterns in overall survival (OS) of cancer patients with different demographics. Prospective clinical cancer databases contain more detail, especially surgical. Their strength is in auditing short-term surgical outcomes. They vary in the amount of data collected for other cancer treatments and completion of follow up data. Linked administrative databases have broad population coverage but less surgical detail. They provide population-level data on treatment patterns, short-term outcome measures and OS, as well as long-term surgical outcomes such as identifying patients who did not undergo stoma reversal. These databases cannot assess disease-free survival.

CONCLUSION

Of the various CRC data sources within Australia, linked administrative databases have the potential to provide the widest population coverage combined with the broadest range of exposures and outcomes, and arguably the most research utility.