How do you approach the treatment for locally advanced gastric adenosquamous carcinoma following D2 resection?   

As you suggested, there is a paucity of prospective data for gastric adenosquamous carcinomas (ASC). Some retrospective works (see Sci Rep 7, 4597 (2017)) have suggested higher T-stage, more nodal involvement, and worse prognosis, when compared to traditional adenocarcinomas. Whether or no...

Prospective data will not be available.  In the absence of better clinical or molecular guidance, I will treat such patients same way I treat adenocarcinomas.