What happened, in summary

A 68-year-old man had previously received perioperative FLOT chemotherapy, distal gastrectomy, and lymph-node dissection for locally advanced gastric adenocarcinoma. At the time of stomach surgery, his left adrenal gland had also been removed because imaging suggested metastasis, but pathology showed that adrenal lesion was benign.

Two years later, he developed fatigue, an 8-kg unintentional weight loss, low blood pressure, and skin darkening. CT found a new mass in his remaining right adrenal gland. Hormone testing confirmed adrenal insufficiency, and biopsy showed that the adrenal mass was metastatic gastric adenocarcinoma. The recurrent tumor was HER2-negative and PD-L1-negative. He started hydrocortisone replacement, which rapidly improved his symptoms and weight.

He then received 6 cycles of FOLFIRI chemotherapy. Imaging showed the adrenal metastasis was stable and no additional metastatic sites were found, so the adrenal lesion was treated with stereotactic body radiotherapy. More than 17 months after the biopsy-confirmed metastatic relapse, he was clinically well on glucocorticoid replacement. Follow-up imaging and laboratory testing showed no signs of active malignant disease elsewhere, although a residual right adrenal lesion remained. At that point, he remained clinically well with stable residual metastatic disease.