This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Screening, Subject name: Social & Preventive Medicine
[{'content': 'If rapidly progressive cancers are missed by a screening test, which type of bias will occur? \nSelect and explain. \nA. Lead-time bias, B. Length bias, C. Selection bias, D. Surveillance bias', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Length time bias is a form of selection bias Fast-growing tumours generally have a shoer asymptomatic phase than slower-growing tumours. Thus, there is a shoer period of time during which the cancer is present in the body. As a result, if the same number of slow-growing and fast-growing tumours appear in a year, the screening test detects more slow-growers than fast-growers. If the slow-growing tumours are less likely to be fatal than the fast growers, the people whose cancer is detected by screening do better Ref : Park 23rd edition Pgno : 74', 'role': 'assistant'}]