Journal of the National Cancer Institute. Monographs最新文献

Cancer care delivery research trials conducted within the National Cancer Institute (NCI) Community Oncology Research Program (NCORP) routinely implement interventions at the practice or provider level, necessitating the use of cluster randomized controlled trials (cRCTs). The intervention delivery requires cluster-level randomization instead of participant-level, affecting sample size calculation and statistical analyses to incorporate correlation between participants within a practice. Practical challenges exist in the conduct of these cRCTs due to unique trial network infrastructures, including the possibility of unequal participant accrual totals and rates and staggered study initiation by clusters, potentially with differences between randomized arms. Execution of cRCT designs can be complex, ie, if some clusters do not accrue participants, unintended cluster-level crossover occurs, how best to identify appropriate cluster-level stratification, timing of randomization, and multilevel eligibility criteria considerations. This article shares lessons learned with potential mitigation strategies from 3 NCORP cRCTs.

Patient-reported outcomes (PROs) are often collected in cancer clinical trials. Data obtained from trials with PROs are essential in evaluating participant experiences relating to symptoms, financial toxicity, or health-related quality of life. Although most features of clinical trial design, implementation, and analyses apply to trials with PROs, several considerations are unique. In this paper, we focus on specific issues such as selection of the tool, timing and frequency of assessments, and data collection methods. We discuss how the estimand framework can be used in connection with PROs, properties of common estimation methods, and handling of missing outcomes. With a plethora of literature available, we aim to summarize best practices and pragmatic approaches to the design and analysis of the studies incorporating PROs.

One-dose prophylactic HPV vaccination of pre-adolescents may reduce cervical cancer deaths dramatically in lower-resource settings, but the benefits of achieving immediate high coverage among pre-adolescents would not be realized for 20 to 40 years. Prophylactic vaccine efficacy is reduced after sexual debut, and current therapeutic intervention candidates designed to treat existing HPV infections or precancerous lesions have yielded insufficient evidence to warrant widespread use. However, we are developing a feasible, scalable, high-quality cervical screening approach that could prevent hundreds of thousands of deaths, while we work to achieve high coverage of one-dose vaccination for adolescent cohorts. A time-limited "one screen" campaign approach for lower-resource settings could complement parallel efforts to achieve high coverage with one-dose vaccination. This screen-triage-treat strategy would target the highest risk groups of screening age (ie, 25 to 49 years) for once-in-a-lifetime HPV testing of self-collected samples using a low-cost accurate HPV test; subsequent triage relying on extended genotyping and a validated deep-learning algorithm for automated visual evaluation (AVE) would stratify management based on risk to provide treatment for those most likely to develop cancer without overburdening health care systems. Early efficacy of this approach has been demonstrated in 9 countries within the HPV-AVE (PAVE) Study Consortium. We estimate that the cost per death averted of a screen-triage-treat campaign is of similar magnitude to prophylactic vaccination. We do not envision perpetual investment in ubiquitous brick-and-mortar screening programs if "one dose, one screen" is implemented with high coverage and targets the highest-risk populations. In collaboration with in-country stakeholders, efforts to ensure acceptability, risk communication, and cost-effectiveness are underway.

Background: The World Health Organization recommends a single-dose human papillomavirus (HPV) vaccination schedule for girls and boys to accelerate progress toward cervical cancer elimination. We applied the Theoretical Framework of Acceptability (TFA) within the context of HPV vaccination to assess the acceptability of a single-dose schedule among health-care professionals in Kenya.

Methods: A REDCap survey was developed using relevant Theoretical Framework of Acceptability domains and validated with health-care professionals. Descriptive analyses and multivariate Poisson regression were conducted to assess factors associated with increased acceptability. Free-text responses were analyzed using a rapid qualitative approach, and findings were presented using a joint display.

Results: Among 385 responses, 74.2% of health-care professionals were female and 48.6% were nurses. On average, respondents had been in their position for 60 months, and one-third (33.2%) were based at level-4 facilities. The majority (75.84%) thought that giving a single-dose of the HPV vaccine to adolescent girls and young women was either acceptable or very acceptable. Qualitative findings highlighted that lack of information was the underlying reason for health-care professionals who were resistant, and most clinicians thought that a singled-dose schedule was less burdensome to clinicians and patients. Hospital directors had a non-statistically significantly lower acceptability likelihood than nurses (incident rate ratio = 0.93, 95% confidence interval = 0.45 to 1.71) and health-care professionals at urban facilities had a non-statistically significantly lower acceptability likelihood than clinicians in rural facilities (incident rate ratio = 0.97, 95% confidence interval = 0.83 to 1.13).

Conclusion: Although not statistically significant, predictors of increased acceptability provide information to tailor strategies to increase HPV vaccination coverage and accelerate progress toward cervical cancer elimination.

Background: In low- and middle-income countries, resource constraints remain a critical factor limiting access to cervical cancer preventive measures. The option of single-dose immunization could help improve access to human papillomavirus vaccination and attain cervical cancer elimination.

Methods: With simulation models adapted to country-specific data and scenarios for single-dose protection derived from International Agency for Research on Cancer India vaccine trial data, we estimated the expected impact of single-dose vaccination in India, Rwanda, and Brazil, three countries with varying profiles of cervical cancer risk and vaccination timelines. In combination with single-dose vaccination, we explored different resource reallocation strategies based on dose efficiency, elimination attainment, and cervical cancer cases prevented, with the existing 2-dose program as a comparator.

Results: Assuming lifelong single-dose protection, switching from 2-dose to 1-dose vaccination and reallocating resources to female catch-up could prevent 467-1336, 94-194, and 15-207 additional cervical cancer cases (per 100 000 women born) in cohorts aged 11-30 years in India, Rwanda, and Brazil, respectively. Resource reallocation to improve the current routine coverage could help eliminate cervical cancer in India and across all Brazilian states but not in Rwanda. For each country, we found a dose-efficient reallocation strategy (or a combination of strategies) together with 1-dose vaccination that could prevent more cervical cancers vs 2-dose vaccination, even in the worst-case scenario of single-dose protection.

Conclusion: Adopting single-dose vaccination with resource reallocation is a resource-efficient approach to enhance progress toward cervical cancer elimination. The overall impact of vaccination can be maximized by fine-tuning resource reallocation to a country's needs.

Background: The Costa Rica HPV Vaccine Trial provided initial evidence that 1 dose of the bivalent human papillomavirus (HPV) vaccine induces stabilizing antibody levels that may provide extended protection against HPV-16/18 infections. We report antibody seropositivity and stability 11 to 16 years after vaccination.

Methods: We invited a random subset of Costa Rica HPV Vaccine Trial participants (n = 398) who had received 3 doses and all women (n = 203) who had received 1 dose at 18 to 25 years of age to follow-up visits 11, 14, and 16 years after vaccination. We calculated HPV-16 and HPV-18 seropositivity and assessed change in enzyme-linked immunosorbent assay antibody levels 11 to 16 years after vaccination among 500 participants.

Results: By year 16, 99.4% (95% confidence interval [CI] = 96.8% to 100.0%) and 100.0% (95% CI = 98.9% to 100.0%) of 1-dose and 3-dose recipients, respectively, were HPV-16 seropositive and 98.8% (95% CI = 95.9% to 99.9%) and 100% (95% CI = 98.9% to 100.0%) of 1-dose and 3-dose recipients, respectively, were HPV-18 seropositive. Between years 11 and 16, women who had received 3 doses had a small but statistically significant decrease in the geometric mean concentration for HPV-16 of ‒12.4% (95% CI = ‒16.3% to ‒8.4%) and HPV-18 of ‒13.4% (95% CI = ‒17.2% to ‒9.4%). Among women who had received 1 dose, the decrease was statistically significant for HPV-16 at ‒8.9 (95% CI = ‒14.2% to ‒3.1%) but nonsignificant for HPV-18. Geometric mean concentration ratios of 3:1 dose (year 16) were 3.0 and 2.2 for HPV-16 and HPV-18, respectively.

Conclusions: HPV-16/18 seropositivity remained exceedingly high 16 years after vaccination. Over 5 years, small declines in antibodies were observed. Women should have protection for at least 20 years and likely much longer at the observed rate of decline.

Background: A concern in high-income countries is that switching to 1-dose human papillomavirus (HPV) vaccination could cause a rebound in HPV infection and cervical cancer if 1-dose efficacy or duration were inferior to 2 doses. Using mathematical modeling and up-to-date trial-based data, we projected the population-level effectiveness of switching from 2-dose to 1-dose vaccination under different vaccine efficacy and duration assumptions in high-income countries.

Methods: We used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), a transmission-dynamic model of HPV infection and cervical cancer, varying key model assumptions to identify those with the greatest impact on projections of HPV-16 and cervical cancer incidence over time: 1) 1-dose vaccine efficacy and vaccine duration, 2) mechanisms of vaccine efficacy and duration over time, 3) midadult (>30 years of age) sexual behavior, 4) progression to cervical cancer among midadults, and 5) vaccination coverage and programs.

Results: In high-income countries, 1-dose vaccination would cause no appreciable rebound in HPV-16 infection, except for a limited rebound under the most pessimistic assumptions of vaccine duration (average, 25 years), because 1) the switch would occur when HPV prevalence is low because of high 2-dose vaccination coverage and 2) individuals would be protected during their peak ages of sexual activity (<35 to 40 years of age). Our model projects a more limited rebound in cervical cancer because of a shift to older age at infection, resulting in fewer life-years left to potentially develop cancer. Projections were robust when varying key model assumptions.

Conclusions: High protection during peak ages of sexual activity in high-income countries would likely mitigate any potential rebounds in HPV infection and cervical cancer under the most pessimistic assumptions of 1-dose efficacy and duration.

Background: There is limited evidence on the magnitude of the potential program cost savings associated with the World Health Organization-endorsed single-dose schedule for the human papillomavirus (HPV) vaccine. The objective of this analysis was to model the delivery and vaccine procurement cost implications of the new schedule.

Methods: The analysis leveraged primary data during a study evaluating the HPV vaccine delivery costs and operational context in 5 countries (Ethiopia, Guyana, Rwanda, Sri Lanka, and Uganda) implementing a two-dose schedule. To estimate the cost for the single-dose schedule, we adjusted the two-dose schedule cost estimates to account for differences in the frequency of activities, whether activities differed by HPV vaccine dose or session, and differences in relative quantity or storage volume of HPV vaccines delivered. We estimated the cost per dose and cost per adolescent receiving the full (single-dose or two-dose) vaccination schedule in 2019 US dollars from a health system perspective.

Results: Modeled results found that cost per dose would increase under a single-dose schedule, whereas cost per adolescent receiving the full schedule would decrease. The financial cost for vaccine procurement and delivery per adolescent receiving the full schedule ranged from $9.64 (Sri Lanka) to $23.43 (Guyana) under a two-dose schedule and decreased to $4.84 and $12.34, respectively, under a single-dose schedule, reflecting savings up to 50%. For economic costs, the range for a single-dose schedule was $7.86 (Rwanda) to $28.53 (Guyana).

Conclusion: A single-dose HPV vaccination schedule could provide cost savings to immunization programs and enhance program affordability and sustainability.

Human papillomavirus (HPV) prophylactic vaccines were first licensed in 2006 with the primary goal of preventing HPV-related cancers, with cervical cancer accounting for the highest morbidity and mortality globally. Six HPV vaccines have been licensed; 4 of these have been prequalified by the World Health Organization, and additional products are in the pipeline. This article provides an overview of HPV vaccine coverage and current and anticipated vaccine supply vs expected demand. Given that the 2022 World Health Organization position paper on HPV vaccines includes a 1-dose regimen as an alternate schedule, we will discuss the evidence for using licensed vaccines in single-dose regimens and the approach to generating similar supportive data for other current and future vaccines. The broad adoption of a single-dose HPV vaccine regimen would expand access to vaccines by improving the supply-demand balance, increasing affordability, and simplifying logistics, which will ultimately impact HPV-related morbidity and mortality.