Local treatment of lung cancer beyond conventional concepts

Abstract

Surgical resection is a standard of care for a localized lung cancer, often leading to cure of the disease. In whom surgery deemed impossible, new radiotherapies such as SBRT, IMRT, particle beam are applied as a n option. However, in patients with lymph node metastasis, even if lymph node dissection is performed, recurrence is common. This means that lung cancer that looks regional often extends systemically with invisible micrometastases. Therefore, platinum-based postoperative adjuvant chemotherapy is indicated for these patients, with a minimal benefit. Application of new systemic therapy such as molecular targeted drugs or immune checkpoint inhibitors is being investigated. Meanwhile, the significance of local treatment in the situation where patients have a limited number of metastases (oligometastasis) is also attracting attention. When there is one or a few brain or adrenal metastasis at diagnosis, resection of the primary tumor and local therapy to the brain/adrenal metastasis is widely performed, especially when lymph node metastasis is absent. Also in the case of recurrent diseases, resection of metastatic lesions may be performed especially when all other lesions are controlled by amolecular targeted drug. In kidney cancer, it has been shown that resection of the primary tumor leads to survival extension even if there are systemic metastases at the time of diagnosis. It is not clear whether such a concept can be applicable to lung cancer or not. It may be necessary to verify it as a new possibility. In such a situation, it may be possible to regard the resection of the primary tumor as a large biopsy. This big sample should aid molecular and immunological profiling of the tumor leading to rational treatment strategies. In this presentation, I would like to consider the significance of local treatment of lung cancer in the context of having distant metastasis, that is, the role of local treatment beyond conventional concepts.