Background
Following the World Health Organization’s call for cervical cancer elimination, many countries in Southeast Asia have launched or expanded cervical cancer screening policies, with several transitioning from opportunistic to organised, population-based programmes. Despite these efforts, implementation remains uneven, and screening uptake and follow-up continue to be suboptimal in many low-and-middle income countries in the region. Existing research has largely focused on identifying individual and system barriers and facilitators, including demand-side factors like behavioural factors, and supply-side constraints. However, these factors are often examined in isolation. A systems thinking perspective is needed to understand how interactions between policy, service delivery, workforce, and referral pathways shape programme performance over time.
 
Objectives
To map health system factors and their interactions in shaping the performance of cervical cancer screening programs in Southeast Asian countries using the WHO health system building blocks,
 
Methods
We reviewed primary studies published between 2020 and 2025 on cervical cancer screening in Southeast Asia. Included studies provided observed evidence on health system-level factors influencing policy and program success. We excluded commentaries, opinion pieces, systematic reviews, epidemiological studies, cross sectional studies, and feasibility and acceptability studies of individual technologies, and studies that focused purely on knowledge, attitudes and perceptions of individuals about cervical cancer screening without link to participation in screening. Findings were synthesised using the WHO health system building blocks framework, with demand-side behaviours analysed as outputs of system design. Descriptive causal pathways were developed to capture recurrent system interactions based on established archetypes used in health.
 
Results
Fifty-one studies across eight Southeast Asian countries were included. Across studies, cervical cancer screening performance was shaped less by choice of screening modality and more by persistent system-level constraints.
 
Limited public health financing constrained population coverage and reinforced socioeconomic and geographic inequities, particularly where screening was only partially subsidized and required out-of-pocket payments. Although national screening policies were introduced, these were not consistently matched with commensurate investment in workforce training, infrastructure, or facility-level operationalization, creating a functional ceiling on programme scale-up. Investment in information systems improved programme performance where they enabled linkage across screening and downstream services but also required parallel workforce training and feedback to governance structures.
 
Capacity for treatment and linkages across levels of care emerged as a critical bottleneck. Screening expansion often outpaced diagnostic and treatment capacity, leading to loss to follow-up among screen-positive women, and accumulation of untreated precancerous lesions. These downstream failures negatively influenced perception of screening programs, demonstrating that expanding screening without strengthening downstream capacity ultimately undermines programme effectiveness.
 
Community awareness and mobilisation interventions improved initial participation and reduced access barriers for hard-to-reach populations but shifted the burden to community health workers in some settings. In the absence of accessible, reliable referral and treatment services, these interventions were insufficient to sustain completion of the care cascade.
 
Conclusions
Cervical cancer screening programmes in Southeast Asia are constrained by reinforcing system-level bottlenecks across financing, workforce, referral pathways, and information systems. Addressing these dynamics requires coordinated investments across the screening cascade rather than isolated technological or behavioural interventions.