What would happen if someone with advanced colon cancer had a hysterectomy if the cancer was not known about?

elderly lady 78 with prolapse had hysterectomy through key hole surgery was very ill after had peritinitus had to have emergency op to wash out stomach have a drain put in stomach and also a colostomy, 3 months later died from rectal cancer which was mive all the time was in the hospital having blood test and scans complaining of a need to go to the toilet a symptom of rectal cancer told only 15 days before she died that it was cancer and nothing could be done