Tumor spread through air spaces (STAS): a call for more evidence

We would like to thank Dr. Chen and his colleagues for their interest and positive comments concerning our work (1). The tumor spread through air spaces (STAS), which has been defined as tumor cells (single cells, micropapillary clusters, or solid nests) within air spaces in the surrounding lung parenchyma beyond the edges of the main tumor, was first introduced in the 2015 World Health Organization (WHO) classification for lung cancer and formally proposed as a new invasive pattern of adenocarcinoma (ADC) (2). After that, STAS attracted tremendous interest and has been studied more intensely (3).