美国前总统拜登罹患前列腺癌并已扩散至骨骼，缘何这种肿瘤早筛不易

Group 1 - The survival time of prostate cancer patients is closely related to the clinical stage of malignancy at diagnosis [1][2] - Prostate cancer is the second most common malignancy and the fifth leading cause of cancer death among men globally, with significant prevalence in Europe and the United States [1] - The incidence and mortality rates of prostate cancer in China account for 8.2% and 13.6% of the global figures, respectively, indicating a growing public health issue [2] Group 2 - Early detection and timely surgical treatment can lead to complete cure of prostate cancer, emphasizing the importance of early diagnosis [2][3] - The overall prognosis for prostate cancer patients in China is poor, with only 30% of initial cases being clinically localized, compared to higher survival rates in developed countries [2] - The 5-year survival rate for localized prostate cancer in the U.S. is nearly 100%, while it drops to 30% for metastatic cases [2] Group 3 - There is a significant challenge in prostate cancer screening due to insufficient awareness among government, healthcare providers, and the public [3] - The lack of standardized screening protocols and low public awareness hinder effective early diagnosis and treatment of prostate cancer in China [3] - The recommendation for routine PSA testing for men over 50 is not widely implemented, leading to late-stage diagnoses [3]