A 65 year old white male in previously good health sta to notice blood in his urine. He develops pain with urination. He also thinks that the stream of his urine is weakened. He goes to his family doctor because of his symptoms. Laboratory findings show an anemia. His urinalysis is positive for red cells, white cells and gram negative rods are seen. A cystogram is done and shows a tumor. A transurethral biopsy is done and confirms a malignant bladder tumor. Which of the following is true of this patient's tumor?