Skin Toxicity as Predictor of Survival in Refractory Patients with RAS Wild-Type Metastatic Colorectal Cancer Treated with Cetuximab and Avelumab (CAVE) as Rechallenge Strategy

The role of anti-EGFR rechallenge in metastatic colorectal cancer, from available data to future developments: A systematic review

Despite recent molecular and immunological advancements, prognosis of metastatic colorectal cancer (mCRC) patients remains poor. In this context, several retrospective and phase II studies suggested that after failure of an upfront anti-EGFR based regimen, a subset of patients can still benefit from further anti-EGFR blockade. Several translational studies involving circulating tumor DNA (ctDNA) analysis demonstrated that cancer clones harboring mutations driving anti-EGFR resistance, which can arise under anti-EGFR agents selective pressure, often decay after anti-EGFR discontinuation potentially restoring sensitivity to this therapeutic strategy. Accordingly, several retrospective analyses and a recent prospective trial demonstrated that ctDNA RAS and BRAF wild-type mCRC patients are those benefitting the most from anti-EGFR rechallenge. Indeed, in molecularly selected patients, anti-EGFR rechallenge strategy achieved up to 30 % response rate, with a progression free survival longer than 4 months and an overall survival longer than 1 year, which favorably compared with other standard therapeutic options available for heavily pretreated patients. Anti-EGFR is also well tolerated with no unexpected toxicities compared to the upfront setting. However, several open questions remain to be addressed towards a broader applicability of anti-EGFR strategy in the everyday clinical practice such as the identification of the best rechallenge regimen, the right placement in mCRC therapeutic algorithm, the best ctDNA screening panel. In our systematic review, we revised available data from clinical trials assessing anti-EGFR rechallenge activity in chemo-refractory mCRC patients, discussing as well potential future scenarios and development to implement this therapeutic approach. Particularly, we discussed the role of ctDNA as a safe, timely and comprehensive tool to refine patient's selection and the therapeutic index of anti-EGFR rechallenge.

Regorafenib therapy as a third-line treatment for metastatic colorectal cancer: A single center long term experience

This study examined the effects of regorafenib (Reg) on progression-free survival (PFS), overall survival (OS), and adverse events (AEs) in metastatic colorectal cancer (mCRC) patients who underwent targeted treatment and chemotherapy. Reg was administered as a third-line treatment to 84 patients who had undergone 2 rounds of chemotherapy and targeted therapy and subsequently experienced progression. Treatment was initiated with a daily dose of 80 or 120 mg, based on the patient's ability to tolerate the medication, which was increased to 160 mg/day. The median PFS with Reg was 4 ± 0.2 months, while the median OS was 9 ± 1.2 months. When compared to patients who started Reg treatment at 80 mg, patients starting at 160 mg had longer median PFS and OS (PFS:6 ± 2.1 months vs 4 ± 0.2 months; P = .05; OS:13 ± 0.7 months vs 6 ± 1.3 months; P = .069). Patients with right-sided colon cancer who received Reg as third-line therapy had a significantly longer mPFS than those with left-sided colon cancer (8 months ± 4 vs 4 months ± 0.3, P = .039). Patients with KRAS mutations had a prolonged mPFS than those with panRAS-wild type (6 ± 1.6 months vs 4 ± 0.3 months, P = .06). The mPFS contribution in the BRAF mutant subgroup with poor prognosis is promising, as it is similar to that of patients without BRAF mutations (4 months ± 0.8 × 4 months ± 0.5, P = .74). The most common AEs reported were elevated liver enzyme levels and dermatological toxicities.

Skin Toxicity as a Predictor of Survival in Metastatic Colorectal Cancer Patients Treated with Anti-EGFR: Fact or Fallacy?

The primary treatment for metastatic colorectal cancer (mCRC) consists of targeted therapy and chemotherapy to improve survival. A molecular target drug with an anti-epidermal growth factor receptor (EGFR) antagonist is recommended when the RAS and BRAF genes are normal. About 50–70% of patients using anti-EGFR antagonists will experience skin reactions. Some studies have shown that severe skin reactions caused by anti-EGFR antagonists may be linked to overall survival (OS) and progression-free survival (PFS), but the results are still uncertain. These data of mCRC patients who underwent anti-EGFR therapy between October 2017 and October 2018 were analyzed retrospectively. A total of 111 patients were included in this study. The survival results showed that gender, age, body mass index, primary tumor site, and recurrence did not significantly affect OS and PFS. However, the first-line anti-EGFR inhibitor treatment was significantly associated with OS (p < 0.001) and PFS (p < 0.001). There was no significant difference in the incidence of acne between males and females in grades 1 and 2, while males have a greater risk in grades 3 and 4 than females (20.3 vs. 4.8%; p-value = 0.041). Skin toxicity was not a predictor of anti-EGFR treatment response in this investigation.

Rechallenge with anti-EGFR therapy to extend the continuum of care in patients with metastatic colorectal cancer

In patients with RAS wild-type metastatic colorectal cancer (mCRC), an anti-epidermal growth factor receptor (EGFR) monoclonal antibody plus chemotherapy is a standard option for treatment in the first-line setting. Patients who progress while on treatment with anti-EGFR-based therapy can be resistant to further anti-EGFR treatment, but evidence suggests that the anti-EGFR-resistant clones decay, thereby opening the potential for rechallenge or reintroduction in later lines of treatment. Results from recent clinical studies have shown that some patients with mCRC who are rechallenged with anti-EGFR monoclonal antibodies exhibit durable responses. While other therapies have demonstrated improved overall survival in chemorefractory mCRC over the past decade, rechallenge with anti-EGFR monoclonal antibodies in later lines of treatment represents a new option that deserves further investigation in clinical trials. In this review, we summarize the molecular rationale for rechallenge or reintroduction in patients with mCRC who have progressed on earlier-line anti-EGFR treatment and examine the current evidence for using liquid biopsy as a method for selecting rechallenge as a therapeutic option. We also provide an overview of published trials and trials in progress in this field, and outline the potential role of rechallenge in the current clinical setting.

Clinical management of metastatic colorectal cancer in the era of precision medicine

Colorectal cancer (CRC) represents approximately 10% of all cancers and is the second most common cause of cancer deaths. Initial clinical presentation as metastatic CRC (mCRC) occurs in approximately 20% of patients. Moreover, up to 50% of patients with localized disease eventually develop metastases. Appropriate clinical management of these patients is still a challenging medical issue. Major efforts have been made to unveil the molecular landscape of mCRC. This has resulted in the identification of several druggable tumor molecular targets with the aim of developing personalized treatments for each patient. This review summarizes the improvements in the clinical management of patients with mCRC in the emerging era of precision medicine. In fact, molecular stratification, on which the current treatment algorithm for mCRC is based, although it does not completely represent the complexity of this disease, has been the first significant step toward clinically informative genetic profiling for implementing more effective therapeutic approaches. This has resulted in a clinically relevant increase in mCRC disease control and patient survival. The next steps in the clinical management of mCRC will be to integrate the comprehensive knowledge of tumor gene alterations, of tumor and microenvironment gene and protein expression profiling, of host immune competence as well as the application of the resulting dynamic changes to a precision medicine-based continuum of care for each patient. This approach could result in the identification of individual prognostic and predictive parameters, which could help the clinician in choosing the most appropriate therapeutic program(s) throughout the entire disease journey for each patient with mCRC. CA Cancer J Clin. 2022;72:000-000.