The level of α-type fetoprotein in one-third of patients with cancer of the liver will not rise, so this form of testing must be accompanied by an ultrasound examination.
這種方式的缺點是「敏感度」不高，大約有三分之一的肝癌患者，其甲種胎兒蛋白濃度並不會升高，故尚須配合超音波檢查。