We found an underutilization of histologic confirmation in clinical staging during the years 1998–2005. This practice was inconsistent with evidence based guidelines. The failure of physicians to follow clinical practice guidelines is well documented across different specialties. A review by Cabana et al. described reasons that guidelines are not followed which are discussed below.22
Physicians might be unaware of evidence supporting recommendations for invasive staging in IIIA lung cancer patients. The extensive evidence base supporting the guidelines and the lack of an obvious change following publication of the American College of Chest Physician guidelines in 2003 suggest that this is not the case.
Clinicians might disagree with guidelines even at a population level. This seems unlikely given the lack of debate in the literature regarding the value of staging IIIA NSCLC. However, diagnostic and therapeutic nihilism related to the perception that little can be done for patients with lung cancer may be pertinent23,24
Clinicians might agree with guidelines on a population level but feel they were not relevant to an individual patient. For example, a physician might believe that the positive predictive value of CT and PET in an individual patient is sufficiently reliable to obviate the need for histologic confirmation while acknowledging that this position is not supported by evidence. Many clinicians may not feel confident in their ability to perform invasive staging techniques specified by guidelines. This may subconsciously increase the likelihood of a physician recommending guideline discordant care for a particular patient.
Limited access to invasive staging procedures may discourage adherence to guidelines. Only approximately 12% of pulmonologists perform TBNA25–27
and less than 10% of lung cancer surgery is performed by dedicated thoracic surgeons28
. General surgeons or cardiac surgeons performing thoracic surgery are less likely to truly be comfortable with mediastinoscopy. However, shifting all NSCLC care to specialized expertise is anything but simple. Even if all NSCLC cancer treatment was centralized at large centers, it is not clear if there are sufficient physicians trained to meet the needs of this large group of patients. Moreover, in the United States, such centralization would require a major cultural shift and many elderly patients would likely be unwilling to travel for this care.
The data suggests that some physicians routinely performed invasive staging and did so throughout the study period; while another larger group, routinely did not. Simply publishing guidelines and evidence supporting them is not sufficient to change practice. The rate of invasive staging is likely to reflect the availability of physicians with the skills and training to routinely perform invasive mediastinal staging. To actually improve patient care, leaders need to ensure that physicians have the resources needed to provide the recommended care and that incentives are aligned to encourage best practices.
Training physicians who currently care for lung cancer patients in invasive staging techniques and providing institutional resources for them may be the key to achieving guideline adherent care. For example, both practicing pulmonologists and practicing surgeons have successfully adopted EBUS-TBNA.29
However, the process of becoming an expert in a new procedure is arduous and the profession’s experience with the introduction of laparoscopy taught us to be cautious.30
Medical simulation is expensive but can reduce the learning curve for a new procedure and has been used in thoracic surgery.31
Even after use of simulation training, many physicians still want mentoring during their initial procedures. Unfortunately, there are many regulatory barriers to obtaining this mentoring including lack of reciprocity for licensing and credentialing. Addressing the need for effective continuing medical education should be a priority for medical leaders who desire to increase the rate of invasive staging of NSCLC.
Physicians and institutions also need incentives to pursue the difficult and expensive process of safely introducing invasive staging into their lung cancer practices. One policy based approach that may be effective is using the rate of invasive staging as quality indicator for the care of lung cancer patients. The recent past has shown us examples of how selection of quality indicators can dramatically impact practice in areas such as management of myocardial infarction.
The rate of use of invasive staging was not impacted by the increased use of PET. This shows that at least in stage IIIA patients PET was not replacing invasive staging, because this would have led to a decrease in invasive staging. Moreover, identification of PET avid lymph nodes did not prompt invasive staging for confirmation as recommended by guidelines since an increase in invasive would have accompanied this later scenario. This again suggests that guidelines alone are insufficient to change practice.
Our analysis is consistent with and expands on previous work.17
By separating patients invasively staged from those staged with a combination of CT scan and PET, we can appreciate how actual practice is differing from guidelines and expert opinion. We noted even higher rates of utilization of PET scanning than reported by Farjah et al17
. This may be due to our inclusion of additional CPT codes for PET scanning not utilized in their study as well as our extended study period. Additionally, we did not observe the decline in utilization of invasive staging procedures that they reported. This is likely related to our inclusion of TBNA as an invasive staging procedure and our focus on patients with stage IIIA NSCLC who may be more likely to receive invasive staging than patients with either earlier or more advanced stages.
Our study has several limitations. First, data are only available on patients diagnosed through 2005. The impact of the dissemination of technologies such as EBUS and EUS over the last 5 years cannot be assessed. Second, we specifically evaluated an older Medicare population, and the results may not be generalizable to younger patients with other insurance. However, while age and insurance status are known to impact cancer therapies, most lung cancer patients are older than 65 years of age. Third, the use of SEER regions to examine geographic variability does not reflect geographic distribution of healthcare resources. However, our point in including this variation is only to provide additional evidence that variability in the use of staging techniques is due to factors other than patient characteristics. Further, due to the fact that patients may have diagnostic and treatment procedures at multiple institutions, assigning the responsibility for their care to single institution for research purposes is difficult. Therefore, we do not have data on the providers that treated any particular patient. Fourth, the SEER-Medicare database does not allow the determination of the results of an individual staging procedure in any given patient. Additionally, we are subject to the limitations of using an administrative database. For example, if a TBNA were to be performed but not billed, we would classify the patient incorrectly as not having had a TBNA. However, since this billing database is how providers are reimbursed, we are likely to capture the majority of procedures. The presence of patients in whom the absence of invasive staging would be considered medically acceptable is a potential confounder in our study.
Some patients may have been classified as IIIA in the SEER database but were only found postoperatively to have N2 involvment (“incidental N2”). However, one can argue these patient should have had invasive staging to prevent this situation, and studies indicate the rate of incidental N2 should be small. Another group for whom invasive staging can be questioned is those with mediastinal infiltration of tumor to the extent that individual nodes can no longer be discerned. However, in clinical practice this group would clearly be a minority of patients with stage IIIA disease. Finally, comorbidities may preclude considering curative intent treatment. Data from this study suggest that over 36% had no co-mordbidities.
In the end, the lack of invasive staging cannot be explained away as having been appropriate due to tumor extent or comorbidities. Even in the most favorable subgroups and youngest patients without comorbidities the rate of invasive staging was remarkably low (<30%). Furthermore, our analyses excluding surgical patients (and thus any incidental N2 patients) did not affect the results. Although the exact rate of invasive staging that should be performed cannot be determined, there is little doubt it should be substantially higher than <25%.