Impact on survival without chemotherapy of local treatments of lung metastasis of colorectal cancers: Analysis on REPULCO cohort

BACKGROUND

The impact of local management of pulmonary metastases on the disease course of patients with metastatic colorectal cancer is poorly assessed.

METHODS

REPULCO database was a retrospective cohort on 18 years that included all patients treated for lung metastases from colorectal cancer who received local and/or systemic treatments.

AIMS

Primary objective was overall survival, secondary were progression-free survival and survival without chemotherapy.

RESULTS

Three hundred and fifteen patients were analyzed, 157 with only systemic treatments, 78 with only local treatments, and 80 with local and systemic treatments. Overall survival at 5 years was 26.9% (IC95%: [17.7-36.9]) for systemic treatments only, 61.0% (IC95%: [40.8-76.1]) for local treatments only, and 77.8% (IC95%: [60.1-88.3]) for local and systemic treatments. Progression-free survival at 2 years was 4.8% (IC95%: [2.1-9.2]) for systemic treatment only, 28.3% (IC95%: [17.7-39.9]) for local treatments only, and 21.8% (IC95%: [13.1-31.9]) for local and systemic treatments. Median survival without chemotherapy was 2.99 months (IC95%: [2.33-3.68]) for systemic treatments, 33.97 months (IC95%: [19.06-NA]) for local treatments, and 12.85 months (IC95%: [8.18-21.06]) for local and systemic treatments.

CONCLUSION

Local treatments of lung metastasis led to prolonged survival and allowed long periods of time without chemotherapy in this cohort.

Triplet chemotherapy plus cetuximab as first-line treatment in extended RAS wild-type metastatic colorectal cancer patients

BACKGROUND

Triplet chemotherapy plus cetuximab showed promising results in phase II trials in unsystematically selected RAS population. We evaluated FOLFIRINOX+cetuximab efficacy as first-line treatment in extended RAS wild-type metastatic colorectal cancer (mCRC) patients.

METHODS

We retrospectively analyzed patients treated with FOLFIRINOX+cetuximab, using data from clinical trials and real-life practice. Extended mutation analysis was performed when RAS/BRAF status was unavailable. The primary endpoint was progression-free survival (PFS).

RESULTS

Seventy patients (61.4 % male, median age 58.7 years) were analyzed. Eighty percent had left-sided mCRC and 97.1 % had liver metastases. Median PFS and overall survival (OS) were 13.3 and 48.5 months, respectively. The objective response rate was 85.7 %, with 20 % complete response. Primary tumor location did not affect OS and PFS. BRAF wild-type patients (n = 65) had longer PFS (13.3 vs. 6.0 months; p = 0.005) and OS (50.1 vs. 21.2 months; p = 0.007) than BRAF mutated patients (n = 5, including four BRAFV600E). Median OS was significantly longer in resected patients (n = 39, 55.1 vs. 30.7 months; p = 0.030). Main toxicities were diarrhea (31.4 %) and neutropenia (21.4 %).

CONCLUSION

FOLFIRINOX+cetuximab provides good PFS, high response rate and prolonged disease control in initially unresectable extended RAS wild-type mCRC. This combination is particularly interesting for selected patients with liver-limited disease eligible to secondary resection.

Ramucirumab plus FOLFIRI as second-line treatment for patients with RAS wild-type metastatic colorectal cancer previously treated with anti-EGFR antibody: JACCRO CC-16

BACKGROUND

Chemotherapy in combination with anti-epidermal growth factor receptor (EGFR) antibody is considered a first-line treatment regimen for RAS wild-type and left-sided metastatic colorectal cancer (mCRC), whereas second-line treatment regimens have not yet been established. Few studies have prospectively evaluated second-line treatment with anti-vascular endothelial growth factor antibody after first-line anti-EGFR antibody therapy for RAS wild-type mCRC.

PATIENTS AND METHODS

This non-randomized phase II trial investigated the clinical outcomes of second-line ramucirumab (RAM) plus fluorouracil, levofolinate, and irinotecan (FOLFIRI) after first-line anti-EGFR antibody in combination with doublet or triplet regimen in patients with RAS wild-type mCRC. The primary endpoint was the 6-month progression-free survival (PFS) rate. The secondary endpoints were PFS, overall survival (OS), objective response rate (ORR), rate of early tumor shrinkage (ETS), and safety. We hypothesized a threshold 6-month PFS rate of 30% and an expected 6-month PFS rate of 45%. Treatment was considered effective if the lower limit of the 90% confidence interval (CI) of the 6-month PFS rate was >0.30.

RESULTS

Ninety-two patients were enrolled in the study. The primary tumor was located on the left side in 86 (95.6%) patients. Twenty (22.0%) patients had received triplet plus cetuximab as previous therapy. Six-month PFS rate was 58.2% (90% CI 49.3% to 66.2%) with a median PFS of 7.0 months (95% CI 5.7-7.6 months). Median OS was 23.6 months (95% CI 16.5-26.3 months). The ORR and ETS rate were 10.7% and 16.9%, respectively, in 83 patients with measurable lesions. The 6-month PFS rate was comparable between patients previously treated with doublet and triplet regimens; however, median PFS was longer for the doublet regimen (7.4 versus 6.4 months, P = 0.036).

CONCLUSIONS

Our study demonstrated prospectively that RAM plus FOLFIRI is an effective second-line treatment after anti-EGFR antibody-containing first-line therapy in RAS wild-type and left-sided mCRC. Furthermore, the results were similar for patients who were previously treated with triplet regimen.

New developments in targeted therapy for metastatic colorectal cancer

Colorectal cancer (CRC) is the second most lethal cancer worldwide and the prognosis of metastatic CRC (mCRC) remains poor. Recent advancements in translational research have led to the identification of several new therapeutic targets and improved the treatment outcome of patients with tumours harbouring BRAF V600E mutation, (HER2) ErBB2 alterations, NTRK gene fusions and KRAS(G12C) mutation. Improved understanding towards the mechanism of resistance to targeted therapy such as anti-epidermal growth factor receptor antibodies and the evolving role of therapeutic monitoring with circulating tumour DNA (ctDNA) has enabled the longitudinal tracking of clonal evolution during treatment and the individualization of subsequent treatments. To broaden the community-based implementation of precision oncology in directing targeted therapies for patients with gastrointestinal cancers including mCRC, the feasibility of 'Master Protocols' that utilizes ctDNA-based genotyping platforms is currently being evaluated. Such protocols encompass both observational and interventional clinical trials of novel targeted therapies conducted within a large clinical trial network. In this review, we will discuss the latest developments in targeted therapies, and therapeutic strategies for overcoming acquired drug resistance in patients with mCRC.

Current concepts of anti-EGFR targeting in metastatic colorectal cancer

Anti-EGFR targeting is one of the key strategies in the treatment of metastatic colorectal cancer (mCRC). For almost two decades oncologists have struggled to implement EGFR antibodies in the mCRC continuum of care. Both sidedness and RAS mutational status rank high among the predictive factors for the clinical efficacy of EGFR inhibitors. A prospective phase III trial has recently confirmed that anti-EGFR targeting confers an overall survival benefit only in left sided RAS-wildtype tumors when given in first line. It is a matter of discussion if more clinical benefit can be reached by considering putative primary resistance mechanisms (e.g., HER2, BRAF, PIK3CA, etc.) at this early stage of treatment. The value of this procedure in daily routine clinical utility has not yet been clearly delineated. Re-exposure to EGFR antibodies becomes increasingly crucial in the disease journey of mCRC. Yet re- induction or re-challenge strategies have been problematic as they relied on mathematical models that described the timely decay of EGFR antibody resistant clones. The advent of liquid biopsy and the implementation of more accurate next-generation sequencing (NGS) based high throughput methods allows for tracing of EGFR resistant clones in real time. These displays the spatiotemporal heterogeneity of metastatic disease compared to the former standard radiographic assessment and re-biopsy. These techniques may move EGFR inhibition in mCRC into the area of precision medicine in order to apply EGFR antibodies with the increase or decrease of EGFR resistant clones. This review critically discusses established concepts of tackling the EGFR pathway in mCRC and provides insight into the growing field of liquid biopsy guided personalized approaches of EGFR inhibition in mCRC.