Investigator
Division Of Cancer Epidemiology And Genetics
Absolute lung cancer risk increases among individuals with >15 quit‐years: Analyses to inform the update of the American Cancer Society lung cancer screening guidelines
AbstractBackgroundThis report quantifies counteracting effects of quit‐years and concomitant aging on lung cancer risk, especially on exceeding 15 quit‐years, when the US Preventive Services Task Force (USPSTF) recommends curtailing lung‐cancer screening.MethodsCox models were fitted to estimate absolute lung cancer risk among Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) and National Lung Screening Trial (NLST) participants who ever smoked. Absolute lung cancer risk and gainable years of life from screening for individuals aged 50 to 80 in the US‐representative National Health Interview Survey (NHIS) 2015–2018 who ever smoked were projected. Relaxing USPSTF recommendations to 20/25/30 quit‐years versus augmenting USPSTF criteria with individuals whose estimated gain in life expectancy from screening exceeded 16.2 days according to the Life Years From Screening‐CT (LYFS‐CT) prediction model was compared.ResultsAbsolute lung cancer risk increased by 8.7%/year (95% CI, 7.7%–9.7%; p < .001) as individuals aged beyond 15 quit‐years in the PLCO, with similar results in NHIS and NLST. For example, mean 5‐year lung cancer risk for those aged 65 years with 15 quit‐years = 1.47% (95% CI, 1.35%–1.59%) versus 1.76% (95% CI, 1.62%–1.90%) for those aged 70 years with 20 quit‐years in the PLCO. Removing the quit‐year criterion would make 4.9 million more people eligible and increase the proportion of preventable lung cancer deaths prevented (sensitivity) from 63.7% to 74.2%. Alternatively, augmentation using LYFS‐CT would make 1.7 million more people eligible while increasing the lung cancer death sensitivity to 74.0%.ConclusionsBecause of aging, absolute lung cancer risk increases beyond 15 quit‐years, which does not support exemption from screening or curtailing screening once it has been initiated. Compared with relaxing the USPSTF quit‐year criterion, augmentation using LYFS‐CT could prevent most of the deaths at substantially superior efficiency, while also preventing deaths among individuals who currently smoke with low intensity or long duration.
Impact of screening on cervical cancer incidence: A population‐based case–control study in the United States
Cervical cancer is widely preventable through screening, but little is known about the duration of protection offered by a negative screen in North America. A case–control study was conducted with records from population‐based registries in New Mexico. Cases were women diagnosed with cervical cancer in 2006–2016, obtained from the Tumor Registry. Five controls per case from the New Mexico HPV Pap Registry were matched to cases by sex, age and place of residence. Dates and results of all cervical screening and diagnostic tests since 2006 were identified from the pap registry. We estimated the odds ratio of nonlocalized (Stage II+) and localized (Stage I) cervical cancer associated with attending screening in the 3 years prior to case‐diagnosis compared to women not screened in 5 years. Of 876 cases, 527 were aged 25–64 years with ≥3 years of potential screening data. Only 38% of cases and 61% of controls attended screening in a 3‐year period. Women screened in the 3 years prior to diagnosis had 83% lower risk of nonlocalized cancer (odds ratio [OR] = 0.17, 95% CI: 0.12–0.24) and 48% lower odds of localized cancer (OR = 0.52, 95% CI: 0.38–0.72), compared to women not screened in the 5 years prior to diagnosis. Women remained at low risk of nonlocalized cancer for 3.5–5 years after a negative screen compared to women with no negative screens in the 5 years prior to diagnosis. Routine cervical screening is effective at preventing localized and nonlocalized cervical cancers; 3 yearly screening prevents 83% of nonlocalized cancers, with no additional benefit of more frequent screening. Increasing screening coverage remains essential to further reduce cervical cancer incidence.
Absolute risks of cervical precancer among women who fulfill exiting guidelines based on HPV and cytology cotesting
US guidelines recommend that most women older than 65 years cease cervical screening after two consecutive negative cotests (concurrent HPV and cytology tests) in the previous 10 years, with one in the last 5 years. However, this recommendation was based on expert opinion and modeling rather than empirical data on cancer risk. We therefore estimated the 5‐year risks of cervical precancer (cervical intraepithelial neoplasia grade 3 or adenocarcinomain situ[CIN3]) after one, two and three negative cotests among 346,760 women aged 55–64 years undergoing routine cotesting at Kaiser Permanente Northern California (2003–2015). Women with a history of excisional treatment or CIN2+ were excluded. No woman with one or more negative cotests was diagnosed with cancer during follow‐up. Five‐year risks of CIN3 after one, two, and three consecutive negative cotests were 0.034% (95% CI: 0.023%–0.046%), 0.041% (95% CI: 0.007%–0.076%) and 0.016% (95% CI: 0.000%–0.052%), respectively (ptrend< 0.001). These risks did not appreciably differ by a positive cotest result prior to the one, two or three negative cotest(s). Since CIN3 risks after one or more negative cotests were significantly below a proposed 0.12% CIN3+ risk threshold for a 5‐year screening interval, a longer screening interval in these women is justified. However, the choice of how many negative cotests provide sufficient safety against invasive cancer over a woman's remaining life represents a value judgment based on the harmsversusbenefits of continued screening. Ideally, this guideline should be informed by longer‐term follow‐up given that exiting is a long‐term decision.
Non-speculum sampling approaches for cervical screening in older women: randomised controlled trial
BackgroundCervical cancer disproportionately affects women ≥65 years, especially those not screened regularly. Speculum use is a key barrier.AimTo assess if offering non-speculum clinician-taken sampling and self-sampling increases uptake for lapsed attenders aged 50–64 years.Design and settingPragmatic randomised control trial conducted at 10 general practices in East London, UK.MethodParticipants were 784 women aged 50–64 years, last screened 6–15 years before randomisation. Intervention participants received a letter offering the choice of non-speculum clinician- or self-sampling. Control participants received usual care. The main outcome measure was uptake within 4 months.ResultsScreening uptake 4 months after randomisation was significantly higher in the intervention arm: 20.4% (n = 80/393) versus 4.9% in the control arm (n = 19/391, absolute difference 15.5%, 95% confidence interval [CI] = 11.0% to 20.0%, P<0.001). This was maintained at 12 months: intervention 30.5% (n = 120/393) versus control 13.6% (n = 53/391) (absolute difference 17.0%, 95% CI = 11.3% to 22.7%, P<0.001). Conventional screening attendance within 12 months was very similar for both intervention 12.7% (n = 50/393) and control 13.6% (n = 53/391) arms. Ethnic differences were seen in screening modality preference. More White women opted for self-sampling (50.7%, n = 38/75), whereas most Asian and Black women and those from other ethnic backgrounds opted for conventional screening.ConclusionOffering non-speculum clinician-taken sampling and self-sampling substantially increases uptake in older lapsed attendee women. Non-speculum clinician sampling appeals to women who dislike the speculum but still prefer a clinician to take their sample. Providing a choice of screening modality may be important for optimising cervical screening uptake.
PhD
University College London · Epidemiology and Public Health