Use and impact of intermittent versus continuous systemic treatment strategies in metastatic colorectal cancer in routine practice

Oxaliplatin retreatment in metastatic colorectal cancer: Systematic review and future research opportunities

BACKGROUND

Oxaliplatin represents a main component of cytotoxic treatment regimens in colorectal cancer (CRC). Given its efficacy, oxaliplatin is frequently re-administered in the context of the continuum of care in metastatic CRC (mCRC). However, efficacy and tolerability of this therapeutic strategy has not been comprehensively assessed.

METHODS

We performed a systematic review of the literature on September 19th 2020, according to PRISMA criteria 2009. The research was performed on PubMed, ASCO Meeting Library, ESMO library and ClinicalTrials.gov for citations or ongoing trials.

RESULTS

64 records were retrieved and 13 included in the systematic review: 8 full-text articles, 4 abstracts and 1 ongoing clinical trial. According to readministration timing, studies were classified as rechallenge/reintroduction (n = 8) or stop & go/intermittent therapeutic strategies (n = 4). The studies presented wide heterogeneity in terms of efficacy (Response Rate 6-31%; Disease Control Rate 39-79%; median Progression-Free Survival 3.1-7 months). Those patients who received retreatment after prior adjuvant oxaliplatin or exploiting a stop-&-go strategy appeared to achieve better outcomes. However, no formal comparisons on treatment outcomes were feasible. The most frequent grade 3 or higher adverse events were hematologic toxicities (5-27%), peripheral neuropathy (5-14%) and hypersensitivity reactions (5-20%).

CONCLUSIONS

Retreatment with oxaliplatin for mCRC is practiced based on scarce and heterogeneous data indicating efficacy and manageable toxicity. The best strategy to exploit this approach remains to be defined, and the most promising research avenue to improve therapeutic index of oxaliplatin is represented by selection of responder patients whose tumors harbor molecular defects in the DNA damage repair pathway.

Continuum of care strategy in metastatic colorectal cancer: a review

Treatment of human metastatic colorectal cancer (mCRC) has changed remarkably in the past two decades. The use of novel therapies and more complex treatment strategies have contributed to progressively increase the median life expectancy of patients up to approximately 30 months. Although traditional cytotoxic chemotherapy and newer targeted therapy are now available for use in treating patients with mCRC, the optimal treatment strategy remains unknown. In recent years, there has been a treatment paradigm shift for mCRC patients with the emergence of the concept of ‘continuum of care’ as the optimal palliative therapy strategy. It is based on the concept whereby patients are exposed throughout the course of their disease to different active drugs; the therapy is personalized according to the need for rapid response, the burden of disease and molecular subtype status, such as RAS, BRAF, MMR and HER2. Drugs are often reintroduced if they demonstrated activity in a previous line of therapy, and most importantly, maintenance chemotherapy and/or intermittent therapy are considered. This review details available data for the use of the continuum of care strategy in mCRC, in which the strategy has provided significant clinical benefit in clinical studies. As our understanding advances, optimal treatment strategy for the patients with mCRC should still be individualized.