A 58-year-old man with a history of recurrent urinary tract infections undergoes a CT abdomen and pelvis for evaluation of hydronephrosis. The radiologist notes that the patient has received 4 similar CT scans over the past 2 years for similar indications. The cumulative effective dose from these 4 scans is estimated at 48 mSv. The patient asks about the cancer risk from this cumulative radiation exposure. What is the most accurate statement regarding his risk?