美国总统每年都体检，为什么没查出拜登的前列腺癌？

Core Viewpoint - The article discusses the recent diagnosis of prostate cancer in former US President Joe Biden, highlighting the implications of prostate cancer screening policies in the US and the importance of early detection [3][4][9]. Group 1: Biden's Diagnosis - Joe Biden was diagnosed with aggressive prostate cancer that has metastasized to his bones, with a Gleason score of 9 and stage 4 classification, indicating late-stage cancer [3][4]. - Biden's case raises questions about the effectiveness of routine health screenings, particularly the PSA test, which has been used for prostate cancer screening since 1991 [3][9]. Group 2: Prostate Cancer Screening Guidelines - The American Cancer Society recommends that men discuss the potential benefits and risks of prostate cancer screening with their doctors, starting at age 50 for average-risk individuals and at age 45 for high-risk groups [9][10]. - PSA levels are used to detect prostate cancer, but elevated levels can also result from benign conditions, complicating the diagnosis [11][13]. Group 3: Screening Recommendations and Risks - The article outlines that men with a PSA level of 2.5 ng/mL or higher should be re-evaluated annually, while those with lower levels should be checked every two years [14]. - The potential negative effects of widespread PSA screening include false positives, overdiagnosis, and overtreatment, which can lead to unnecessary anxiety and complications [16][17][18]. Group 4: Prostate Cancer Statistics in China - In 2022, approximately 134,200 new cases of prostate cancer were reported in China, making it the sixth most common male malignancy, with 47,500 deaths [27]. - The incidence and mortality rates of prostate cancer in urban areas of China have been rising, indicating a growing public health concern [27]. Group 5: Treatment Options - Treatment for advanced prostate cancer, such as Biden's case, typically involves androgen deprivation therapy (ADT), which aims to reduce testosterone levels to slow cancer growth [28]. - Despite advancements in treatment, prognosis is influenced by various factors, including the extent of the disease at diagnosis, with early detection significantly improving survival rates [28].