Intended Versus Inferred Care After PET Performed for Initial Staging in the National Oncologic PET Registry

DISCUSSION

The NOPR management plan reflects the physician’s intentions shortly after receiving the PET report and not necessarily the patient’s agreement to the plan. Agreement between claims-inferred management (assuming these are complete and accurate) and the NOPR plan may be affected by patient treatment preferences revealed in subsequent consultations or the physician’s level of commitment to his or her plan. Unexpected shifts in a patient’s symptoms and clinical course could also impact the intended plans’ feasibility. This analysis of 5 cancer types when PET was used as part of initial staging found claims-validated monotherapy plans in over three fourths of patients within 60 d. However, for combination therapy, a 60-d window was too short to fully capture clinical actions inferred from claims analysis. One relevant NOPR data limitation was that the post-PET questionnaire did not document whether combination therapy plans were to be concurrent or sequential. Therefore, for sequential plans, it is likely that the decision to give the anticipated second therapy encompassed a further decision point dependent on reassessment. For combined chemoradiotherapy plans, claims for both therapies increased by over 10% using a 180- vs. 60-d window. A second decision point was even more likely with surgery-based combination therapies where the chemotherapy sequencing was not specified (neoadjuvant vs. adjuvant).

Although this study uses as its starting point the unverified NOPR plan data and claims-inferred actions as the actual care, it is notable that there is no gold standard for the study design under which maximum concordance between plan and execution occurs and how high that concordance is. A more ideal design might involve a structured interview with each physician after PET once a care plan is established with the patient, documenting nuances of the plan, and a manual chart or electronic record review. Additionally, one might also collect information on patient perspective—after initial post-PET clinical consultation.

Outside oncology, there are many examples in surgical randomized trials showing that actual delivery rates of randomly assigned therapy are often substantially different from intention to treat. For example, 2 y after treatment assignment for lumbar spinal stenosis, 43% had surgery after being assigned nonsurgical treatment and only 67% completed assigned surgery (22). In coronary artery disease trials, crossover from medical therapy to surgical intervention occurs in 10%–20% of patients and surgical refusal in 2%–10% (23,24). Crossover in abdominal aortic aneurysm trials are even higher (25). Thus, even if our plan and execution data points were obtained by more resource-intensive methodologies, it is unlikely that high (e.g., >90%) agreement would occur.

There is a substantial, growing literature addressing the desire of cancer patients for information and participation in decision making in their care (26,27). These studies have predominantly addressed preference-based primary therapy decisions in breast and prostate cancer. In general, older patients and those with metastatic cancers deferred more to physician recommendations (26,28). To the best of our knowledge, few studies address discrepancies between physician plan, patient preference, and actual therapy received, factors that may explain some observed differences in intended versus claims-inferred management. One notable report is CanCORS, which assessed over 5,000 newly diagnosed lung or colorectal cancer patients, one fifth presenting with metastatic disease; 24% of CanCORS patients did not receive the treatment discussed (26,28).

Agreement studies within cancer registries focus on registry classification accuracy either when an independent record reabstraction (29) is made or when registry treatments are compared with claims-inferred care. Since 2000, numerous SEER–Medicare linkage reports have assessed claims completeness in identifying chemotherapy type (30–32), surgery (33), and radiation (34). Most studies did not focus on the claims’ temporal accuracy. Since 2004, SEER guidelines require that all information be gathered through completion of first-course surgery or be available within 4 mo of diagnosis in the absence of disease progression (29). Our analysis shows that a 60-d window is likely too narrow for assessing planned treatment completion, particularly in patients with less-aggressive, local disease and for combination therapies. However, lengthening this window may also result in false-positives if claims are made for reasons not closely associated with the original post-PET plan (e.g., unplanned treatment at 3–6 mo for unexpectedly aggressive metastatic disease).

Two recent reports provide some context for our findings. In a comparison of Medicare administrative claims against clinical trial data (as a reference standard), Lamont et al. assessed patient cohorts from 6 CALGB first-line chemotherapy trials in breast, colorectal, and lung cancer (30). They found that 78% of claims correctly identified the drugs given and the correct treatment schedule. In a second study, Lund et al. reported National Cancer Institute Patterns of Care studies in 4 cancer types where SEER initial treatment plans were directly validated against hospital and outpatient records that were reabstracted for chemotherapy (35). They found that the claim sensitivities were time dependent, ranging from 36%–50% at 2 mo to 84%–96% at 6 mo.

Our analysis was not powered to, and did not attempt to, stratify patients by stage within each cancer type, and we did not assess whether either the planned or the claims-inferred management in each patient agreed with authoritative clinical practice guidelines. Our findings that about 90% of patients with an intended plan including chemotherapy had E&M (office visit) claims from a medical oncologist within 60 d even in the absence of chemotherapy claims suggest appropriate consultation for informed decision making was available—that is, patients who did not receive chemotherapy did not fail to see an oncologist.

The above concerns should not divert attention from the primary clinical endpoint and findings that NOPR was designed to measure—does PET as part of initial cancer staging lead to a change in (intended) clinical management? We have previously reported that during the first 2 y of NOPR data collection, PET was associated with a 40% change in intended management if additional imaging was a post-PET option or a 13% change if no benefit was assumed in cases where additional imaging was chosen. Using a design similar to that of the NOPR, Scott et al. from Australia have reported series involving smaller patient numbers (range, 71–129) and centers (n = 3–6) but with detailed medical record follow-up to assess intended versus actual management (36–38). They found that PET (without CT) used for initial staging of head and neck and esophageal cancer and lymphoma was associated with a 34%–38% change in intended management and that the agreement at 3–6 mo between the post-PET plan and actual care ranged from 53% in esophageal cancer to 74% in lymphoma and head and neck cancer. Our results from a national registry with little control over center-to-center data quality are quite similar.

We have previously noted that PET-associated changes in intended management would not always be beneficial (because PET has both false-negative and false-positive results) (14). Moreover, changes in intended actions have a presumed, but uncertain, relationship to more tangible health outcomes, such as progression-free or overall survival (39). However, given the above limitations, we were gratified to observe that claims at 60 d confirmed chemotherapy plans in 90% of SCL cancer patients and surgery in 80% with stomach cancer, assuming that in most cases PET results were accurate and accepted contemporary treatment is beneficial.