In this study we demonstrate that American Indian cancer patients receiving PN services while undergoing curative RT as part of their cancer treatment have significantly fewer RT interruptions than their historical counterparts who did not undergo PN. Furthermore, our data reveal a high rate of clinical trial enrollment among AI cancer patients receiving PN services when compared to previous studies which have shown low rates (<1%) of clinical trial participation for AIs. 34, 35, 41
We also describe PN utilization patterns for AI patients receiving cancer treatment to provide insight into the resources necessary to provide cancer treatment navigation services to this or a similar population. Specifically, our study contributes unique information about the number of navigator-patient interactions, the time resources typical of these interactions, and the types of services requested in these interactions during cancer treatment for a population with significant health access barriers. Patients who underwent more intensive treatment regiments tended to more heavily utilize PN services.
Much of the PN literature addressing care of cancer patients focuses on increasing screening incidence and/or decreasing intervals between screening and diagnostic management of initiation of treatment for various cancers,28-30, 42, 43
and most studies do show improvement in the corresponding outcomes when PN is available. American Indians specifically have been shown to benefit from PN in the setting of facilitating screening and timely diagnostic follow-up.29, 44
However, few studies report upon the role of PN after a patient is diagnosed and undergoing the rigors of cancer treatment, 30, 45
arguably a time when patients may experience more barriers due logistical complexities and financial burden of receiving many weeks or months of treatment e.g., RT or chemotherapy. Some of the reports that have been published on PN during cancer treatment show improvement in patient satisfaction or decrease in barriers to care.46, 47
Ell and colleagues 24
showed that treatment adherence was improved compared to previous studies among patients who were randomized to either enhanced usual care (written resource navigation information) or active PN, although there was no statistical difference between the two navigation approaches. Only one other study offers utilization data regarding the types of barriers addressed and the amount of time navigators spend with cancer patients.48
Our finding of fewer treatment interruptions for patients undergoing curative RT is one that has important implications for this population that has been shown to have disparately high cancer mortality. It has been demonstrated that prolonged RT interruption is a predictor for loco-regional relapse among patients treated for head and neck cancers.32, 33
Similarly, it has been established that prolongation of the RT course during treatment for cervical cancer—a disease that disproportionately affects poor and minority women, and for which AI women in the Northern plains have the highest incidence and mortality 6, 49
-- is associated with increased risk for local recurrence and poorer survival outcomes.31
Patient navigation, in this study, seems to offer an effective strategy to mitigate barriers that may prolong definitive cancer treatment.
Multiple studies have indicated that clinical trial participation among AI cancer patients is low with trial accrual rates of < 1%.34, 35, 41
Reasons underpinning low minority participation in clinical trials are multi-factorial and may differ across regions as well as between racial/ethnic groups.50, 51
In this region, it has previously been shown that AI cancer patients exhibit relatively high rates of medical mistrust and dissatisfaction with prior health care received.14
Our PN program specifically targets health access barriers in this population and seeks to address them in a culturally-sensitive manner while partnering with tribal communities. This effort toward establishing rapport with AI patients and communities to meet their needs may account for our relatively higher proportion of AI patients willing to enroll on clinical trials.
Our study supports the role of PN in addressing health access barriers to cancer treatment, but it does so with certain limitations. First, our study is not a randomized trial and our analyses did not include a temporally parallel control group against which to compare outcomes. To ensure community-based participation and engagement it simply was not feasible for the purposes of comparison to deny half of AI patients the types of logistical support, financial assistance, and one-on-one advocacy offered by our navigators. In other words, community engagement necessary for the implementation of our effort might have been hindered if we had attempted to provide these services to fewer than all of the patients who desired PN services given the high level of need in the community being served.
More investigation is needed into the impact of PN,30, 45
and a coordinated, national effort is underway to provide critical insight into the role of PN in cancer care delivery as well as its cost-effectiveness. 52, 53
Until such data are available, data on working models that deliver care effectively via PN provide guidance that can be developed and tailored to various populations.
In conclusion, we have shown that PN is associated with fewer treatment interruptions among AI patients receiving curative RT for their cancer. We have also observed a high rate of clinical trial participation among AI, which have historically been underrepresented in clinical trial research. Furthermore, we characterize utilization specifics for our program to provide insight into resources entailed in administering a PN program in a regional health care center that provides health care to an underserved population. Further research is needed, not only into the cost-effectiveness of PN, but into other metrics of quality of care that may be improved with PN during cancer treatment.