Rationale
The goal of precision medicine is to improve health outcomes by tailoring healthcare based on an individual’s genomic and other relevant information, including patient preferences [
1]. One example is systematic screening of colorectal cancer (CRC) tumors to identify all patients whose CRC may be related to Lynch syndrome (LS) [
2,
3]. LS is the most common form of inherited CRC and is also associated with significant risk for endometrial, ovarian, gastric, small bowel, and renal cancers, among others [
4,
5]. LS most commonly results from the inactivation of the DNA mismatch repair (MMR) system. A first step in screening for LS in patients with cancer involves testing tumor tissue for signs of MMR deficiency in one of four genes (
MLH1, MLH2, MLH6, and
PMS2) [
2]. Following a positive tumor screening test, additional testing for the presence of a germline pathogenic variant in one of the MMR genes is needed to confirm diagnosis of LS. A diagnosis of LS influences cancer screening and surveillance guidelines to be followed and treatment options for those already diagnosed with cancer. Patients with CRC who have LS benefit from treatment with immunotherapy [
6] and have the option for more extensive colonic surgery to decrease the risk of metachronous malignancy, which is more common in LS [
4,
5]. Additionally, prophylactic hysterectomy, and salpingoophorectomy can reduce risk of endometrial and ovarian cancer (90–100%) in women with LS [
7].
Approximately one million people in the US have LS, of which only about 2% are aware [
8,
9]. Therefore, most are not receiving potentially life-saving surveillance and treatment. In addition, at-risk family members, who are at 50% risk to also have LS, are not being identified. Cost-effective, evidence-based systematic screening strategies to identify cancer patients with LS are available and have broad recommendation for implementation [
2,
10‐
16], yet LS screening is inconsistently applied within healthcare systems, if at all [
17‐
19]. Systematic (also called, “universal”) screening of all newly diagnosed cases of CRC for LS is cost-effective by most measures [
20,
21] and is classified by the Centers for Disease Control (CDC) as having top-tier evidence for reducing cancer morbidity and mortality and improving quality of life [
11,
22]. LS screening was first recommended by the Evaluation of Genetic Application in Practice and Prevention (EGAPP) working group in 2009, and is currently recommended by multiple professional organizations, including the National Comprehensive Cancer Network (NCCN), and the Healthy People 2020 initiative [
3,
10,
12‐
16,
23]. LS screening was also recently recommended by the Blue Ribbon Panel Precision Prevention and Early Detection Working Group to meet the goals of the Cancer Moonshot [
9].
Contextual factors such as organization mission, patient population, and costs may all influence decisions to implement genomic technologies in healthcare systems [
17,
24‐
27]. However, there is poor understanding of how these and other contextual factors impede or facilitate LS screening implementation in healthcare systems and under what circumstances [
17,
18]. Factors specific to LS screening implementation may include: variable involvement of multiple key stakeholders and champions, availability of genetic counseling, genetic testing costs, and perception of value to the healthcare system [
18,
19,
28]. Previous research has shown that institutional testing costs, number of CRC patients diagnosed per year, local prevalence of LS, and perceived cost of screening older cancer patients are key determinants for organizational decision makers and likely key barriers to LS screening implementation [
28‐
30]. Additionally, there are multiple evidence-based protocols that provide different recommendations for LS screening [
4,
10,
31]. These conflicting recommendations are not surprising in the face of evolving evidence, but they are likely contributors to variability in implementation. For instance, the NCCN guidelines suggest that if all CRCs cannot be tested, then testing should occur on tumors of patients diagnosed under age 70 and for patients with CRC over age 70 who meet complex criteria using family history or tumor characteristics associated with increased LS risks [
4,
15]. This conflicts with evidence demonstrating that imposing age restrictions can result in substantive loss of LS index case finding, is challenging to implement, and assessment of family history and other risk factors often fails to identify individuals who are appropriate candidates for LS testing [
8,
32].
However, LS screening is only successful if patients who screen positive (by tumor tissue testing) are informed and follow-through with confirmatory germline testing so that patients and their family members can access appropriate cancer treatment, screening, and prevention options. A functional tracking system and/or other processes to ensure program success is therefore an additional component of critical importance to LS screening. A study of several medical centers found that positive results were often not disclosed and poor rates of patient follow-through to germline confirmation occurred until such procedures were included in LS screening programs [
19]. Finally, healthcare systems vary in implementation across a spectrum from no organized LS screening to optimal LS screening. The latter is defined as including implementation or maintenance of cost-effective tumor screening protocols, procedures to ensure disclosure of positive screening, and active processes to facilitate patient follow-through to germline genetic testing for diagnosis of LS [
33‐
35]. An additional file shows a typical optimal LS screening program design [see Additional file
1].
Objectives and aims
The goal of this project is to utilize the CFIR and other tools from implementation science to describe, compare, and explain variations in LS screening across multiple healthcare systems and create a comprehensive, customizable organizational toolkit for implementing and improving LS screening programs. To achieve this goal, this study has four specific aims:
Aim 1: Describe variations in LS screening, implementation processes, and contextual conditions facilitating or impeding implementation across multiple healthcare systems.
Aim 2: Explain current practice variation and identify contextual conditions that influence variation in LS screening, including follow-up procedures, and implementation processes to identify which combinations are minimally sufficient and necessary for optimal implementation.
Aim 3: Determine the relative effectiveness and costs of different LS screening protocols using decision analytic models developed from previous work [
29,
30] and data specific to each healthcare system to demonstrate the relative effectiveness and efficiency of various LS screening protocols used by healthcare systems based on their local data.
Aim 4: Develop an organizational toolkit to facilitate LS screening implementation and optimization and disseminate to all sites. Further assess the toolkit’s utility for facilitating LS screening implementation or optimization then refine and for broader dissemination.