Clinical Modes of EGFR Tyrosine Kinase Inhibitor Failure and Subsequent Management in Advanced Non-Small Cell Lung Cancer

Management of oligometastatic and oligoprogressive epidermal growth factor receptor mutated non-small cell lung cancer patients: state of the art of a combined approach

Recently, the development of targeted therapy approaches such as those based on tyrosine kinase inhibitor (TKI) greatly improved the clinical outcomes of patients affected by oncogene addicted advanced non-small cell lung cancer (NSCLC). Similarly, the improvement of radiation therapy techniques has permitted to deliver high radiation doses to a limited number of metastatic target lesions (oligopersistent or oligoprogressive), with limited high-dose normal tissue exposure that leads to low severe toxicity rates. The aim of this narrative review was to provide an overview of the currently established definition of oligometastatic and oligoprogressive disease, to define first line and subsequent lines targeted therapies and the role of consolidative non-invasive local ablative treatments (LATs) in these settings. The potential benefit of local treatment (LT) such as radiotherapy (RT) or surgery might be represented by an overall reduction of switching to subsequent systemic treatments lowering the risk of further systemic dissemination. Further randomized clinical trials will clarify the role of LT and their correct timing in relation to systemic targeted therapies.

Pseudoprogression and hyperprogression in lung cancer: a comprehensive review of literature

PURPOSE

Immune checkpoint inhibitors are associated with clinical benefit in lung cancer. However, response patterns to immunotherapy, including pseudoprogression and hyperprogression, are difficult to diagnose, and their mechanisms remain unclear. This review aimed to describe two response patterns observed in lung cancer, namely pseudoprogression and hyperprogression, including their epidemiology, diagnostic characteristics, and plausible mechanisms.

METHODS

We performed a comprehensive literature search in the PubMed database, using keywords "pseudoprogression", "hyperprogression", and "lung cancer", among others. The literature was examined for pseudoprogression and hyperprogression characteristics and plausible mechanisms.

RESULTS

Pseudoprogression manifests in multiple forms; however, the immune system-related response criteria and biopsy data are helpful to make accurate diagnosis. Serological biomarkers, such as neutrophil-to-lymphocyte ratio (NLR) and circulating tumor DNA (ctDNA), might help distinguish pseudoprogression from true progression. The incidence of hyperprogression ranges within 5-19.2%, depending on definition. The unique response pattern of rapid progression is observed not only with immunotherapy, but also with other treatment regimens. Molecular mutations and amplifications may result in hyperprogression; however, the exact mechanism remains unclear.

CONCLUSION

Atypical response patterns, such as pseudoprogression and hyperprogression, are increasingly common in clinical practice. Immune-related response criteria can help diagnose pseudoprogression. Molecular mechanisms of hyperprogression remain unclear. Biomarkers for pseudoprogression and hyperprogression are required.