Highlights
In a national cohort of Commission on Cancer-accredited hospitals, National Accreditation Program for Rectal Cancer (NAPRC) accreditation was associated with a mean increase of 4.3 rectal cancer cases per hospital per year.
The increase appeared to be driven in part by higher stage I procedural volume, while stage II/III surgical volume did not significantly change.
NAPRC accreditation was not associated with a measurable increase in care fragmentation, suggesting growth in referrals or case capture may have occurred without worsening continuity of care.
These findings position accreditation not only as a quality-improvement framework, but also as a potential institutional strategy with market and referral implications.
Background
Rectal cancer care has become increasingly specialized over the past two decades. Optimal treatment often requires careful pretreatment staging, high-quality pelvic magnetic resonance imaging, multidisciplinary discussion, coordinated sequencing of chemoradiation and surgery, and technically demanding total mesorectal excision. These requirements distinguish rectal cancer from colon cancer and have driven efforts to regionalize care and standardize processes across institutions.
The National Accreditation Program for Rectal Cancer was developed to codify these expectations. NAPRC accreditation, administered through the American College of Surgeons, requires participating centers to demonstrate multidisciplinary care pathways, quality monitoring, structured documentation, external review, and disease-specific expertise. In principle, such accreditation should improve process quality and possibly outcomes. However, accreditation is resource-intensive. It may require investments in personnel, imaging pathways, data infrastructure, tumor board operations, and regulatory compliance. For hospital leaders, an important practical question is whether accreditation changes referral patterns, patient volume, and procedural mix in ways that offset some of these costs.
The present study by Loria and colleagues addresses that question directly. Rather than asking only whether accreditation improves quality, the investigators assessed whether NAPRC accreditation is associated with broader institutional effects: increased rectal cancer volume, altered stage-specific surgical volume, and changes in care fragmentation. These are highly relevant outcomes for clinicians, health systems, and payers because they sit at the intersection of quality policy, cancer service-line strategy, and access to specialized care.
Study Design and Methods
Design
This was a cohort study using a quasi-experimental difference-in-differences design. That approach is well suited to policy and systems research when randomization is not feasible. It estimates whether changes over time differ between exposed and unexposed groups, here comparing hospitals that achieved NAPRC accreditation with matched hospitals that did not.
Data Source and Setting
The investigators used the National Cancer Database, a large hospital-based oncology registry that captures cases from Commission on Cancer-accredited institutions across the United States. The study period spanned 2010 through 2022, and the analysis was conducted from April 2025 to August 2025.
Hospitals and Patients
The initial hospital sample included 1336 Commission on Cancer-accredited facilities, of which 80 became NAPRC-accredited and 1256 never attained accreditation. After propensity score matching, the final analytic sample included 316 hospitals: 80 NAPRC-accredited centers and 236 nonaccredited comparison facilities.
The patient population comprised adults diagnosed with primary rectal adenocarcinoma. Because the outcomes were measured at the hospital level, the central unit of analysis was the annual institutional burden of rectal cancer care rather than individual patient survival or recurrence.
Exposure
The exposure was hospital-level NAPRC accreditation. Accreditation requires adherence to multidisciplinary standards for rectal cancer management, specialized training, external auditing, and institutional commitment to disease-specific quality processes.
Outcomes
The primary outcome was annual hospital-level rectal cancer patient volume. Secondary outcomes included stage-specific procedural volume, divided into stage I and stage II/III disease, and care fragmentation.
Care fragmentation was defined as cases in which diagnosis and first-course treatment, or the decision not to treat, were not completed at the reporting Commission on Cancer-accredited facility. This is an important systems-level endpoint because accreditation could plausibly increase referrals while also increasing split-site care, which may create coordination challenges for patients.
Statistical Approach
The authors used linear fixed-effects multivariable regression models. This framework helps control for unobserved time-invariant institutional characteristics and secular changes affecting all hospitals. Propensity score matching further improved comparability between accredited and nonaccredited facilities. As with all difference-in-differences studies, the validity of inference depends heavily on the plausibility of parallel preintervention trends, although the abstract does not provide detailed diagnostics.
Key Findings
Overall Rectal Cancer Volume Increased After Accreditation
NAPRC accreditation was associated with a mean annual increase of 4.29 rectal cancer patients per institution compared with matched nonaccredited centers. The 95% confidence interval was 0.55 to 8.03, and the P value was .03.
From an institutional perspective, this is a modest but meaningful change. Rectal cancer volumes are much lower than those seen for common medical conditions, so an increase of approximately four additional cases per year may be important for service-line economics, multidisciplinary conference activity, and operative case concentration. The effect size also supports the idea that accreditation may serve as a signal to referring physicians, patients, and regional networks that a center offers specialized rectal cancer care.
Temporal Pattern Suggested Early Postaccreditation Gains
Sensitivity analyses suggested that increases began in the first year after accreditation and that point estimates became larger in subsequent years, although later-year estimates did not reach statistical significance. This pattern is plausible. Accreditation may initially improve visibility and referral confidence, but year-to-year variation and limited sample size may widen confidence intervals over time. The absence of later statistical significance should not automatically be interpreted as loss of effect; it may reflect limited power for event-time estimates.
Stage I Procedural Volume Rose, but Stage II/III Surgery Did Not
Accreditation was associated with an increase in stage I procedural volume, with a beta coefficient of 1.01, a 95% confidence interval of 0.016 to 1.99, and a P value of .05. By contrast, there was no significant increase in stage II/III surgical volume.
This stage-specific pattern deserves careful attention. Several explanations are possible. First, accredited centers may attract more early-stage cases through stronger local referral networks, improved diagnostic pathways, or increased public and clinician awareness. Second, stage I management may be particularly sensitive to specialist evaluation because decisions around local excision, transanal approaches, or organ-preserving strategies may prompt referral to centers perceived as highly specialized. Third, the lack of a significant increase in stage II/III surgery may reflect contemporary treatment trends, including greater use of total neoadjuvant therapy, watch-and-wait pathways in selected complete responders, or referral complexities that are not captured solely by surgical counts.
Another possibility is that advanced-stage disease referral was already concentrated at baseline among institutions likely to seek NAPRC accreditation, leaving less room for measurable postaccreditation growth. Without more granular clinical and referral data, the precise mechanism remains uncertain.
No Detectable Increase in Care Fragmentation
The study found no significant change in care fragmentation after accreditation. This is reassuring. A common concern is that disease-specific accreditation may concentrate surgical procedures at specialized centers while dispersing diagnostic workup or neoadjuvant therapy across multiple sites. Such fragmentation can burden patients, complicate care transitions, and weaken accountability.
The absence of a measurable increase suggests that accredited centers may be expanding volume without simply accumulating partially managed cases. It also raises the possibility that accreditation standards, which emphasize multidisciplinary coordination, may help preserve continuity even as referral volume grows.
Clinical and Policy Interpretation
This study is important because it broadens the conversation about accreditation. Accreditation programs are often justified on quality grounds alone, but hospital decision-makers must also weigh operational and financial consequences. The findings suggest that NAPRC accreditation may bring a business case alongside its quality mission: modest growth in rectal cancer case volume without evidence of greater fragmentation.
For clinicians, the results may validate the practical value of participating in structured disease-specific programs. For hospitals, the data suggest accreditation can function as a reputational signal that influences patient flow. For payers and policymakers, the study offers evidence that specialty accreditation may support concentration of expertise without obviously worsening continuity of care.
These findings also intersect with the literature on volume-outcome relationships in rectal cancer surgery. Higher-volume centers and surgeons have often been associated with better adherence to oncologic principles and, in some studies, better outcomes. If accreditation contributes to volume concentration at capable institutions, it could theoretically reinforce quality improvement. However, this study did not examine margin status, local recurrence, permanent stoma rates, functional outcomes, or survival, so the link between increased volume and improved patient outcomes remains inferential.
Strengths of the Study
The study has several methodological strengths. First, it used a quasi-experimental design rather than a simple cross-sectional comparison. That matters because hospitals choosing accreditation are likely systematically different from those that do not. Second, propensity score matching improved comparability between accredited and nonaccredited centers. Third, the use of fixed-effects models helps account for stable institutional differences that are otherwise difficult to measure. Fourth, the study addressed not just overall volume but also stage-specific procedural patterns and fragmentation, yielding a more nuanced systems-level picture.
Another strength is the use of a national oncology database across a long time horizon. This improves relevance for US practice and allows examination of adoption effects over time during the early national rollout of NAPRC accreditation.
Limitations and Caveats
Despite its strengths, the study should not be overinterpreted. As an observational analysis, it cannot establish causality with the certainty of a randomized trial. Hospitals that pursue NAPRC accreditation may differ in unmeasured ways from controls, including leadership culture, preexisting referral networks, colorectal surgeon availability, teaching status, or broader investments in oncology infrastructure.
Difference-in-differences analyses also rely on the assumption that accredited and comparison hospitals would have followed parallel trends in the absence of accreditation. The abstract does not detail formal testing or graphical inspection of that assumption. If preaccreditation trends differed, estimated effects could be biased.
The outcome of care fragmentation, while clinically meaningful, is imperfectly captured in registry data. A split-site care pathway does not always imply poor coordination, and registry definitions may miss subtler discontinuities, such as delayed communication, duplicated testing, or handoff failures between institutions.
In addition, stage-specific procedural volume is not equivalent to stage-specific incidence or treatment appropriateness. For example, changes in stage I procedures could reflect evolving use of local excision, changing thresholds for operative intervention, or better case capture rather than a simple increase in patient numbers.
Most importantly, the study did not report patient-centered clinical outcomes. Accreditation-associated growth is not inherently beneficial unless it translates into better staging, more appropriate treatment sequencing, improved oncologic outcomes, preserved function, equitable access, or higher patient experience. That remains the key unanswered question.
How This Fits With Existing Literature
Prior research has shown that rectal cancer outcomes are sensitive to multidisciplinary organization, surgeon experience, and high-quality staging. International experience, especially from Europe, has demonstrated that structured quality initiatives and standardization of total mesorectal excision can improve rectal cancer care. In the United States, the NAPRC was designed in this spirit, but empirical evidence on its system-level effects has been limited.
This study adds an important dimension by showing that accreditation may alter institutional patient flow. It complements rather than replaces research on direct quality outcomes. Future work should connect accreditation status with process measures such as pelvic MRI use, multidisciplinary tumor board review, neoadjuvant treatment adherence, circumferential resection margin status, sphincter preservation, local recurrence, and overall survival.
Implications for Practice
For hospital leaders considering NAPRC accreditation, these data suggest that investment in accreditation may be accompanied by modest service-line growth. That may be particularly relevant for centers with established colorectal surgery programs seeking to strengthen regional identity in rectal cancer care.
For referring clinicians, accreditation may offer a practical marker of structured multidisciplinary expertise. Still, referral decisions should remain individualized and should consider surgeon experience, access, patient preference, and actual quality outcomes rather than accreditation status alone.
For health systems and policymakers, the lack of increased fragmentation is encouraging, but equity questions remain. If accreditation preferentially increases volume at already advantaged centers, policymakers should ensure that patients from rural, low-income, or underserved communities are not left behind. Support for care navigation, transportation, tele-oncology, and shared-care pathways may be necessary to ensure that centralization does not worsen disparities.
Conclusion
In this national difference-in-differences study, NAPRC accreditation was associated with a statistically significant increase in annual rectal cancer patient volume and a modest rise in stage I procedural volume, without evidence of increased care fragmentation. The findings suggest that rectal cancer accreditation may deliver institutional benefits beyond quality signaling alone, potentially influencing referral patterns and service-line growth. At the same time, the study stops short of proving improved patient outcomes. The next phase of research should test whether accreditation-driven volume changes translate into better oncologic, functional, and equity outcomes for patients with rectal cancer.
Funding and ClinicalTrials.gov
The abstract as provided does not report a funding source. No ClinicalTrials.gov registration is applicable or reported for this observational database study.
References
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