a way of treating a medical condition that involves a period of waiting and watching for further symptoms (= signs of disease) to develop, rather than immediate treatment such as surgery or chemotherapy

More men with low-risk prostate cancer are now opting for watchful waiting rather than undergoing surgery. 现在，越来越多患有低风险前列腺癌的男性选择接受观察等待治疗，而不是手术。