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Q&A: Protocols needed to overcome ‘diffusion of responsibility,’ maximize Lynch syndrome testing
Researchers have identified inconsistent beliefs among medical specialists as to who is responsible for ordering tumor microsatellite instability and immunohistochemistry tests for Lynch syndrome.
Jordan J. Karlitz, MD, director of the GI Hereditary Cancer and Genetics Program at Tulane University School of Medicine, and colleagues distributed a 21-question web-based survey to physicians on the ACG email listserv, to identify opinions and barriers experienced by gastroenterologists involving screening tests for Lynch syndrome.
The survey was completed by 509 physicians, 442 confirmed gastroenterologists were analyzed.
Less than half (33.4%) of those surveyed felt that gastroenterologists were responsible for ordering MSI and/or IHC testing while 38.6% of respondents believed pathologists were considered to be the most responsible for ordering microsatellite instability (MSI) and/or immunohistochemistry (IHC) tests.
Healio Gastroenterology and Liver Disease spoke with Karlitz, senior author on the study, about the results, the importance of the inconsistencies and how they impact patient testing, as well as the overall importance of genetic testing. – by Ryan McDonald
Healio: What is the take-home message of these results?
Karlitz: Prior studies have shown that Lynch syndrome screening by MSI and/or IHC testing in colorectal cancer is low. MSI/IHC testing is an important first step that may be followed by germline genetic testing to confirm Lynch syndrome. We published a paper in the American Journal of Gastroenterology in 2015 in which we used population-based data to assess MSI/IHC testing rates in early-onset colorectal cancer and found that the testing rate was only 23%. We designed our current survey study in order to uncover barriers that may indicate why testing rates are low. We focused our survey questions on early-onset colorectal cancer as these patients may be at the highest risk of having a hereditary syndrome. We also focused our survey on gastroenterologists as they are frequently the first to identify colorectal cancer during colonoscopy.
We uncovered a number of important barriers including testing cost concerns, unfamiliarity in being able to interpret results and unavailable genetic counseling services. Many of the barriers we uncovered seemed to cluster in rural locations and non-academic settings.
Another key barrier we termed “diffusion of responsibility.” More specifically, we asked survey respondents which specialist in the cancer care continuum they felt was responsible for ordering MSI/IHC. Only 33.4% felt GI doctors should be responsible. The most common response was that the pathologist should be responsible. Other responses included surgeons, oncologists and genetic counselors. The bottom line is if there is no clear specialist type that is felt responsible for ordering testing, one provider may assume another provider is ordering testing and that other provider may think someone else should order testing. The end result may be that the testing never actually gets performed.
The take-home message from all of this is that any specialist type (gastroenterologist, pathologist, surgeon, oncologist, etc.) involved in taking care of colorectal cancer patients should actively inquire how Lynch syndrome testing is performed at their home institution. They should not assume that a testing protocol is already in place. If a consistent protocol is not in place, multidisciplinary discussions between different providers in the cancer care continuum should take place to develop one.
Healio: How do you recommend overcoming this diffusion of responsibility?
Karlitz: As discussed above, the best way to overcome this issue is to assure there are very specific protocols for testing at institutions. One of the best approaches is termed “reflex testing.” In this type of protocol, MSI and/or IHC testing is done automatically on tumor tissue and this takes the question of who should be ordering the testing out of the equation. However, it is important to emphasize that even if testing is done, there must be someone responsible for acting on the results. The specialist acting on results may vary at different institutions depending on level of expertise, available resources and the physician-patient relationship; however, roles should be clearly defined with closed-loop communication between different specialists.
Healio: What about timing of testing, is this important?
Karlitz: Yes. Another key issue that must be discussed is timing of MSI/IHC testing. Ideally, the testing should be done on the colonoscopy biopsy specimen so that results are available preoperatively. These results will guide germline genetic testing decisions and can impact extent of colonic resection. As Lynch syndrome patients can have a high risk of developing a second colorectal cancer, guidelines recommend extended colonic resection for cancer risk reduction. Having the results available preoperatively will allow providers to have risk/benefit discussion regarding the operative approach. We found that in our survey, only 46.1% felt that MSI or IHC should be routinely performed on preoperative colonoscopy biopsies. If testing is only done on the surgical resection specimen, abnormal results could return postoperatively and there will be no opportunity to discuss extended colonic resection with the patient prior to the operation.
An important barrier that we identified in our study is that some providers had concerns that it may take too long for testing results (MSI/IHC and germline) to return, which they felt might delay colonic resection and therefore negatively impact patient outcomes and hence could prevent initial test ordering. This may reflect a perceived or actual higher turnaround time for results in certain settings. This is an important barrier that we need to overcome. Having streamlined protocols that focus on expedited test result availability can be useful. Even asking genetic testing companies to expedite test results in the face of a pending cancer operation can be helpful.
Healio: What do these study results mean moving forward for physicians in practice?
Karlitz: As above, we want to make sure that there are clear testing protocols established and that we make every effort to assure results are available preoperatively. We want it to be clear at a given institution who is going to act on the abnormal results and that’s going to require clear communication between different specialists in the cancer care continuum.
Other important issues include assuring services are available in underserved populations, where barriers may be more pronounced including financial/insurance coverage and access to specialists. Assuring there are no out-of-pocket costs for genetic testing is another important issue. We also need to make genomics education a priority throughout training, including medical school, residency and fellowship, and assure there are adequate, clinically focused genomic educational activities available to those already in practice.
As we also mentioned in our paper, the divergent practice patterns we have demonstrated in our survey underscore needs to investigate other approaches to Lynch syndrome screening. New technologies – including single up-front tumor next generation sequencing – are currently under active investigation. Another recent potential approach, which is discussed in the NCCN guidelines, includes performing multipanel (Lynch syndrome and other genes associated with hereditary colorectal cancer) germline testing in early-onset cases or those with a strong family history.
Healio: Why is it important that patients consider undergoing genetic screening for Lynch syndrome?
K arlitz : Lynch syndrome is one of the most common hereditary syndromes. It has been estimated that 1 in 300 people may be Lynch syndrome carriers. However, many people are unaware of their carrier status.
Genetic testing can affect not only management of the patient with cancer, but family members as well. In terms of the patient, as we have discussed, important decisions need to be made regarding management of colorectal cancer. However, patients with Lynch syndrome are at risk for a number of other cancers including uterine cancer, ovarian cancer, stomach cancer, pancreatic cancers and several others. So test results are important for monitoring for other malignancies as well.
As Lynch syndrome is autosomal dominant, family members have a 50% chance of inheritance and it is critical that they are identified. The lifetime risk to develop colon cancer can be up to 80%. The other cancers mentioned above can also have a high lifetime risk. For example, the risk of endometrial cancer may be up to 60%.
It is important to mention that there are other hereditary syndromes that may need to be tested for in addition to Lynch syndrome. These include familial adenomatous polyposis, MUTYH-associated polyposis and others. It is also very important to highlight that many patients harboring Lynch syndrome or other hereditary syndromes may have no personal history of cancer. It is for this reason that we must assure that we take a comprehensive family history for risk assessment and update this family history regularly during subsequent clinical visits.
Healio: Once protocols are established at health care facilities and screening rates are improving, how would you better advise physicians to talk with patients about genetic screening?
Karlitz: It is key that providers are well versed in the work up of hereditary syndromes so that they can have informed discussions with their patients. I think we all understand that discussions with patients about genetic information can be very sensitive and the more knowledge both the provider and the patient have about hereditary syndromes, the easier a clinical visit can be. To reiterate, it can’t be underestimated how important taking a comprehensive family history is.
Reference:
Karlitz JJ. Am J Gastroenterol. 2015; doi: 10.1038/ajg.2014.417.
Noll A, et al. Clin Transl Gastroenterol. 2018; doi:10.1038/s41424-018-0047-y.
Disclosure: Karlitz reports serving on the speakers bureau for Myriad Genetics and serves as an advisor for Exact Sciences.