marker_id,date,year_approx,cancer_type,uspstf_grade,prior_grade,change_summary,expected_direction_on_mortality,source_url,notes
U1,2015-02,2015,Lung,B,new,"First USPSTF recommendation for annual low-dose CT screening for high-risk adults age 55-80 with 30+ pack-year smoking history. Medicare coverage followed.",Increase then decrease — more diagnoses short-term; reduced mortality long-term for eligible population,https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening,"Prior to 2015 no formal USPSTF recommendation existed for lung cancer screening."
U2,2018-05,2018,Prostate,C,D,"Reversed 2012 grade D recommendation. New guidance: offer PSA-based screening to men aged 55-69 years after shared decision-making. Grade D had effectively ended PSA screening at many practices.",Increase — more diagnoses → more treatment → treatment-related mortality; also catching later-stage cancers that were missed during D era,https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/prostate-cancer-screening,"2012 grade D was highly controversial and largely responsible for dramatic drop in prostate cancer diagnoses 2012-2017. 2018 reversal is the most clearly visible USPSTF signal in this dataset."
U3,2021-05,2021,Colorectal,B,B (age 50+),"Lowered recommended start age for colorectal cancer screening from 50 to 45. Expanded eligible population by approximately 22 million adults.",Decrease long-term — earlier detection expected to reduce mortality. Short-term: coincides with post-lockdown catch-up screening.,https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening,"Timing coincides with post-COVID screening rebound. The 2020 lockdown caused colonoscopy volumes to drop ~80%; this guideline change helped drive catch-up."
U4,2021-03,2021,Lung,B,B (age 55+ / 30 pack-years),"Lowered screening age from 55 to 50 and reduced pack-year threshold from 30 to 20 pack-years. Estimate: nearly doubled the eligible screening population.",Decrease long-term — earlier detection. Short-term increase in diagnoses and some treatment-related mortality.,https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening,"Updated from 2015 recommendation. The expansion was partly driven by evidence that the previous criteria missed many women and minority smokers."
U5,2024-05,2024,Breast,B,B (biennial age 50-74),"Changed from biennial mammography for women 50-74 to annual mammography starting at age 40. Significant expansion driven by rising incidence in younger women and evidence of mortality benefit from earlier/more frequent screening.",Decrease long-term. No mortality effect visible in data until 2026 at earliest — guideline is beyond the 2023 endpoint of the type-level dataset.,https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/breast-cancer-screening,"Finalized May 2024. Highly anticipated update. The shift to annual screening from age 40 represents the most significant change to breast cancer screening guidance in over a decade."