想多了，这种瘤（不是癌）恶性度不高，得几年时间才能长到现在这个尺寸。好好读点书，别胡思乱想

Small GISTs may cause no symptoms, and they may grow so slowly that they have no serious effects. People with larger GISTs usually seek medical attention when they vomit blood or pass blood in their stool due to rapid bleeding from the tumor.

https://www.mayoclinic.org/diseases-conditions/gastrointestinal-stromal-tumors/cdc-20387715