- Since our participants are childhood cancer survivors and they can be medically fragile and we are interested in providing all eligible participants with NRT to enhance their ability to quit smoking, we added a cautionary conditions list to the recruitment screening form. Those with severe arrhythmias, myocardial infarction, unstable angina, cerebrovascular incident, blood vessel disease, phaeochromocytoma, diabetes, hyperthyroidism, abnormal kidney or liver function, or history of gastritis or peptic ulcers, or who smoke less than 5 cigarettes per day will not receive NRT.