Choosing Wisely in oncology: are guidelines effective at preventing unnecessary diagnostics? The example of surveillance positron emission tomography for patients with localised colorectal cancer

Introduction

In all healthcare systems around the world, using appropriate diagnostic approaches is important for both patients and payers. For patients, it is important to balance the need to diagnose serious disease, against the risk of overdiagnosis. For payers, the costs of using diagnostic testing must be balanced against the clinical benefit that the testing provides. For healthcare systems with finite availability of certain tests, the appropriate policy must ensure that such tests are available for those that need them. It has been well recognised that sometimes, there is overuse of certain diagnostic techniques. In order to provide a framework to consider such overuse, the ‘Choosing Wisely’ campaign was developed by the American Board of Internal Medicine, and its recommendations have been adopted by many professional organisations around the world.1 The recommendations have been considered to be only for advisory purposes to guide clinician decision-making.

In the field of oncology, many ‘Choosing Wisely’ recommendations focus on the appropriate use of advanced imaging technologies such as positron emission tomography (PETCT). One such recommendation specifically stated in 2013 ‘Avoid using PET or PET-CT scanning as part of routine follow-up care to monitor for a cancer recurrence in asymptomatic patients who have finished initial treatment to eliminate the cancer unless there is high-level evidence that such imaging will change the outcome’.2 In the field of colorectal cancer (CRC), it is recommended that patients treated with surgery and adjuvant chemotherapy should not undergo surveillance with PETCT imaging. This recommendation against surveillance PETCT is supported by guidelines of the American Society of Clinical Oncology,3 The European Society of Medical Oncology,4 The National Comprehensive Cancer Network (NCCN),5 American Society of Colon and Rectal Surgeons,6 The Society of Surgical Oncology7 and The Association of Coloproctology of Great Britain and Ireland.8 The recommendations are underpinned by randomised controlled clinical trial data reported in 2018 by Sobhani et al.9 In this study, 239 patients undergoing surveillance with physical examination, liver ultrasound, carcinoembryonic antigen (CEA) and CT were randomised to groups with or without PETCT every 6 months. There was no difference in rates of unresectable recurrence or death from any cause.

It is currently unknown how effective these non-binding guidelines are in reducing the overuse of such imaging approaches. An American study demonstrated the increasing use of surveillance PETCT in a cohort of patients with CRC prior to the launch of the Choosing Wisely campaign.10 To the best of our knowledge, no data exist as to how effective the Choosing Wisely campaign and other professional guidelines are in their effort to reduce the use of surveillance PETCT imaging in patients with CRC treated with curative intent. Therefore, our objective was to analyse the usage of surveillance PETCT for patients with localised CRC who had received adjuvant chemotherapy with curative intent.

Methods

Results

The study cohort consisted of 1799 patients who underwent adjuvant chemotherapy for CRC (figure 1). Table 1 demonstrates the characteristics of these patients together with the number of PETCTs performed and the monthly interval that PETCT is performed. The median age of patients in the cohort was 66, and 54% of the cohort was male. Follow-up duration was a median of 3.6 years.

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Figure 2 provides a breakdown of the number of PETCTs performed for each patient in the study. The median number of PETCTs was 3 with 489 patients (27.2%) not undergoing any PETCTs during the study period. 364 patients (20.2%) underwent 1 PETCT, and 946 (52.6%) patients underwent more than 1 PETCT. Notably, 25 patients underwent 10 or more PETCTs. In a sensitivity analysis (online supplemental figure 1), we present the results when patients with eGFR<30 are removed from the main cohort. These analyses demonstrate that the impact of removing this subset of patients only has a minor impact on the results.

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In figure 3, we attempted to demonstrate how many of the PETCTs are guideline-concordant and guideline-discordant. However, there may be some debate as to the definition of concordant and discordant. For example, some consider that PETCT is appropriate at staging while others do not. As our data collection included all PETCTs performed, some may have been for the purpose of staging and need to be considered differently. Furthermore, sometimes it may be appropriate to follow a standard CT with a PETCT in order to characterise a suspicious lesion potentially informing clinical decision-making. Therefore, we present these data as pie charts, using a choice of definitions for guideline-concordant and discordant. When one PETCT is considered acceptable (eg, for staging), 69% of PETCTs performed are ‘guideline-discordant’. When two PETCTs (eg, one for staging and one for characterisation of a suspicious lesion) are considered acceptable, 47% of PETCTs performed are ‘guideline-discordant’.

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We evaluated the average number of PETCTs performed annually according to year of follow-up, in order to assess whether there are any temporal trends in PETCT usage. The median number of PETCTs performed annually per patient per year of follow-up was 0.85 (online supplemental table 1). The results should be interpreted with caution due to differing amounts of follow-up.

Discussion

Healthcare overuse is a recognised problem around the world, and different guidelines have attempted to address this problem. In this study, we explored robust real-world data relating to one particular example of imaging overuse. Despite multiple guidelines, including ‘Choosing Wisely’, advocating against the use of PETCT for surveillance of patients with cancer treated with curative intent, we see widespread PETCT imaging. Notably, 489 patients do not undergo any PETCTs in the course of their treatment, which is guideline-concordant, and in line with the view that PETCT is not necessary routinely even at staging. 364 patients underwent 1 PETCT—presumably for the purpose of staging. However, patients undergoing more than one PETCT should usually be considered guideline-discordant. Almost half of the patients appear to be undergoing guideline-discordant surveillance. The financial impact of PETCT imaging is significant to most healthcare systems—for example, in Israel, according to the non-discounted price tariffs, CHS spends approximately US$70 million (ILS255 million) annually on PETCT imaging.

The Choosing Wisely guideline regarding this issue was published in 2013.2 Why is inappropriate imaging still taking place, up to 10 years after the publication of these guidelines? There are multiple reasons. Perhaps some clinicians are not aware of the guidelines. Perhaps some clinicians perceive PETCT to be a superior test, despite no data to support such a claim in this setting. Perhaps some patients pressure clinicians to order a PETCT, also with the perception that it is a superior test. Perhaps some clinicians find it easier to independently review the PET images rather than CT images, given the colour enhanced view. Perhaps some clinicians are not aware of the significant difference in cost between PETCT compared with standard CT. Perhaps PETCT appointments are paradoxically more available for patients than regular CT scans. Perhaps clinicians perceive an improvement in PETCT technology in the intervening years since the Choosing Wisely guideline in 2013, rendering these guidelines less relevant.

What approach is necessary in order to decrease the use of unnecessary imaging? One could argue that the payer approval process should be more stringent, and not approve all PETCT requests, rather only in specific clinical circumstances. However, the challenge with this approach is that all clinicians worldwide suffer from large amounts of bureaucracy, and one must be very careful before considering introducing more paperwork and approval processes. Another approach would be to develop a far more extensive outreach and educational process than the current Choosing Wisely programme, in order to specifically educate clinicians about the overuse of such tests, and to request more consideration prior to ordering such tests. The downside of this approach is that if the clinician and patient do not have financial ‘skin in the game’, they may not adjust their practice accordingly, even when there is no clinical disadvantage for patients. It is likely that the most appropriate approach is a combination of a policy change in approval processes, together with educational outreach.

What does this study tell us about the ‘Choosing Wisely’ programme and other efforts by professional societies and guidelines, to reduce unnecessary medical testing? Cliff et al performed a systematic analysis evaluating 131 studies analysing the impacts of Choosing Wisely recommendations.17 Of these 131 articles, 15% were in the field of oncology. They found that active interventions were more likely to generate intended results (65% vs 13%) as were interventions with multiple components. These approaches and guidelines are largely ineffective in fully solving the problem, on their own.17 18 They will only be effective when combined with educational programmes and perhaps also policy change.

As with all research, this study has some limitations. When calculating the total number of PETCTs performed, our results are likely an underestimation, due to the lack of long-term follow-up. For example, a patient diagnosed in December 2021 will only have 15 months of follow-up, until March 2023, in our analysis. To help to correct this limitation, we also calculated the interval of PETCT use per patient—for example, a patient undergoes a PETCT with an average interval of a specific number of months. We delineated patients as receiving adjuvant therapy based on the drugs that they received. However, it is possible that the cohort included an unknown number of metastatic patients who were precluded from biological agents for any reason, including poor performance status, KRAS/BRAF mutations and/or contraindications to bevacizumab (eg, coagulopathies). It should also be noted that using chemotherapy alone without the use of a biological agent is an NCCN-recommended standard of care option for the treatment of metastatic disease.5 In any case, if these patients were included in our cohort, PETCT imaging would not be indicated either in their clinical situation of metastatic disease. This lack of support for routine PETCT imaging in the metastatic setting is declared in NCCN guidelines as follows: ‘PETCT is not indicated with the exception of selected patients who are considered for image-guided liver-directed therapies for hepatic metastases (ie, thermal ablation, radioembolisation) or serial CEA elevation during follow-up’.5 While some US-based studies demonstrate significant proportions of metastatic patients not receiving biological therapy,19–21 we believe that these studies are less relevant to the Israeli setting. Some of these studies included only elderly patients.19 21 Additionally, financial barriers in the form of copays and deductibles form considerable barriers to compliance in the USA, however, this does not apply in Israel where these medications are fully funded publicly. It is possible that some PETCT scans were performed and paid for in the private setting, and thus not captured by the CHS database. However, if this was the case, it would mean that our data would be underestimating the level of overuse. Future studies could incorporate into the algorithm the receipt of colon resection surgery in order to increase the sensitivity and specificity of the algorithm to identify patients with localised disease. This study identified predominantly patients with high-risk stage 2 disease and stage 3 disease who received adjuvant chemotherapy. It is possible that clinicians are more sparing in their use of surveillance PETCT in patients with low-risk stage 2 disease.

Healthcare overuse is a significant challenge for patients, providers and payers around the world. Despite professional efforts to curb this problem, this study demonstrates that such efforts are so far unsuccessful in solving the problem. More consideration is required to strengthen the efforts to decrease healthcare overuse.