NCCN BL-D says that for node-positive disease one can consider  (adjuvant) chemotherapy with a colorectal regimen in urachal carcinoma. However, the nodes were negative in this case. There is, therefore, no literature or guideline support for the use of capecitabine. Urachal cancer is quite rare and I did not find studies supporting adjuvant treatment for node-negative patients, much less with capecitabine. Postoperatively, there is no data to support chemotherapy in the adjuvant setting and it remains a treatment for unresectable and/or metastatic disease.

Dearbhaile C. Collins et al, National Incidence, Management and Survival of Urachal Carcinoma. Rare Tumors. 2016 Sep 5; 8(3): 6257.