Abstract
Background:
Cancer therapy and outcomes are known to be affected by various demographic features and hospital types. We aimed to identify the characteristics of non-Hodgkin’s lymphoma (NHL) patients associated with receipt of care at academic centers.
Method:
This is a retrospective study of all patients diagnosed with nodal NHL between 2000 and 2011 in the National Cancer Database (NCDB), who received the diagnosis, and all or part of their initial therapy in the reporting hospital (n = 243,436). Characteristics of patients receiving care in academic versus nonacademic centers were compared using the Chi-square test.
Results:
Approximately 27% received care in academic centers. Patients receiving care in nonacademic centers, compared with academic centers, were more likely to be ⩾60 years (69% versus 58%, p < .0001), White (89% versus 80%, p < .0001) and have lower educational attainment (>12% without high school diploma: 72% versus 69%, p < .0001) and economic status (household income <$49,000: 66% versus 61%, p < 0.0001). Patients receiving care in nonacademic centers were less likely to travel ⩾25 miles (21% versus 26%, p < 0.0001). White patients, compared with non-Whites, were more likely to be ⩾60 years (70% versus <50%, p < 0.0001), which probably explains less care in academic centers.
Conclusions:
Patients ⩾60 years and those with poorer educational attainment and economic status were less likely to receive care in academic centers. Care in academic centers required a longer commute. Elderly patients frequently have inferior outcomes and may benefit from clinical trials with novel agents and expertise at academic centers.
Introduction
Cancer therapy and outcomes are known to be affected by various demographic features such as age, race, education, socioeconomic status, insurance status and hospital types [Goodwin et al. 1993; Shavers and Brown, 2002; Albano et al. 2007; Bilimoria et al. 2009; Murphy et al. 2009; Aarts et al. 2010]. Variation in cancer management related to these factors has been studied in many malignancies including breast cancer, prostate cancer, colon cancer and pancreatic cancer [Blackman and Masi, 2006; Olopade et al. 2006; Polite et al. 2006; Chen et al. 2008; Halpern et al. 2008]. Prior studies in melanoma demonstrated that hospital type was one of the factors influencing compliance with National Comprehensive Cancer Network (NCCN) treatment guidelines [Erickson et al. 2008; Bilimoria et al. 2009]. These studies raise a possibility that the quality of care and possibly outcomes may differ by hospital type. Complex cases of nodal non-Hodgkin’s lymphoma (NHL) such as NHL in elderly patients or patients with comorbidities, or diagnoses such as double-HIT lymphoma or gray-zone lymphoma may benefit from expertise in academic centers. The aim of the study was to determine the patient characteristics that may determine receipt of care at academic centers for initial diagnosis and therapy.
Methods
This is a retrospective study of patients with nodal NHL in the National Cancer Database (NCDB) who received the diagnosis between 2000 and 2011 and all or part of their initial therapy in the reporting hospital (this is one of the NCDB’s classification style). NCDB, a joint program of the Commission on Cancer of the American College of Surgeons and the American Cancer Society, contains about 70% of new cancer diagnosis from more than 1500 American College of Surgeons-accredited cancer programs in the United States and Puerto Rico. Data are collected and submitted by certified tumor registrars at the Commission on Cancer accredited cancer program registries using standard data item and coding definitions, and data transmission format specifications. All data undergo evaluation for data integrity and quality monitoring [Seidler et al. 2010; American College of Surgeons 2013].
The institutional review board waiver was obtained from the University of Nebraska Medical Center Institutional Review Board. Data abstracted from NCDB include age, race, education, income, distance traveled for health care, hospital type, insurance and Charlson Comorbidity Score. Hospital types were categorized into two: academic centers (associated with university medical schools or designated as National Cancer Institute Comprehensive Cancer Care Programs) and nonacademic centers (other hospitals including Comprehensive Community Cancer Programs, which may need referral for a portion of therapy, as defined by NCDB). The categorization was based on the facts that nonacademic centers may need referral for a portion of therapy, whereas academic centers do not need a referral. We compared the characteristics of patients receiving therapy in academic and nonacademic centers. The NCDB uses US census data of 2000
The chi-square test of independence was used to calculate any statistical difference in the distribution of demographic and other variables between academic and nonacademic centers.
Results
A total of 243,436 patients with nodal NHL received the diagnosis between 2000 and 2011 and all or part of their initial therapy in the hospital reporting to the NCDB. The study population comprised of predominantly men (54%), patients ⩾60 years (66%) and White (83%). The majority of patients lived in areas with >12% population without high school diploma (71%) and household income <$49,000 (65%). Different histologies of NHL managed with various therapeutic approaches were included (supplementary file, Tables 1–4). White patients, compared with non-Whites, were more likely to be ⩾60 years (70% versus <50%, p < 0.0001).
Approximately 27% (n = 66,436) received care in academic centers associated with university medical schools or designated as Comprehensive Cancer Care Programs. The remainders of the patients were treated in nonacademic centers. Of 161,072 patients ⩾60 years, only 24% (n = 38,758) received care in academic centers. Patients receiving care in nonacademic centers, compared with academic centers, were more likely to be ⩾60 years (69% versus 58%, p < 0.0001) and White (89% versus 80%, p < 0.0001). Patients receiving care in nonacademic centers versus academic centers had lower educational (>12% without high school diploma: 72% versus 69%, p < 0.0001) and economic status (household income <$49,000: 66% versus 61%, p < 0.0001). Patients receiving care in nonacademic centers, compared with academic centers, were less likely to travel ⩾25 miles (21% versus 26%, p < 0.0001). Patients receiving care in nonacademic centers versus academic centers were more likely to have Medicare (53% versus 44%, p < 0.0001) or other government insurance (4% versus 1%, p < 0.0001). Patients receiving care in nonacademic centers were also less likely to have a zero Charlson Comorbidity score (76% versus 78%, p < 0.0001) (Table 1).
Characteristics of nodal non-Hodgkin’s lymphoma managed in academic versus nonacademic centers.
Patients with missing data were excluded in the table, so the sum may not always add up to the total.
Discussion
Patients ⩾60 years accounted for about two-thirds of all nodal NHL cases in this study. Prior studies have shown that age is an independent prognostic factor for inferior outcomes in malignancy [Austin et al. 1994]. Additionally, many older patients have comorbid conditions at the time of cancer diagnosis [Janssen-Heijnen et al. 2005], which complicates their management plan. Hence, older patients with nodal NHL are the patient group most likely to benefit from expertise at academic centers and enrollment in clinical trials with novel agents. Our study demonstrated that only 24% of all patients ⩾60 years received care in academic centers. White and Medicare insured patients were more likely to be elderly, which probably explains less care in academic centers.
Care in academic centers required a longer commute. This may be ones of the reasons for fewer older patients receiving care in academic centers. Prior studies have demonstrated that distance traveled for healthcare depends on patients’ age. Elderly patients are less likely to travel more because of impairments in mobility or cognition. Thus, improving the access of older patients to academic centers may increase their enrollment in clinical trials [Gross et al. 2005]. Prior studies have also shown that patients who travel farther to enroll into studies have better outcomes [Lamont et al. 2003]. Although this may be partly related to selection of healthier subset of elderly patients, older patients benefit from enrollment in clinical trials of novel agents. Low receipt of care at academic centers by elderly patients, thus, arguably has the potential to negatively influence outcomes of nodal NHL. A low receipt of care at academic centers by elderly patients may also mean less representation of elderly patients in clinical trials. This may limit the generalizability of trial results to elderly patients. Many community centers do participate in clinical trials, although arguably to a much lower extent compared with larger universities. In one study, survival of advanced-stage lung cancer patients did not differ between academic and nonacademic centers even when the patients from nonacademic centers were older and had worse performance status [Lamont et al. 2010]. Hence, improving access of community centers to clinical trials on elderly patients is necessary and may also improve outcomes. Furthermore, low receipt of care at academic centers by elderly patients may possibly restrict the educational experience of hematology–oncology fellows in the field of geriatric oncology.
To our knowledge, this large national dataset-based study is the first to compare the patient characteristics associated with care of nodal NHL at different centers. The limitations of this study include a retrospective study design with lack of patient-level data for multivariate analysis. The study included patients with NHL with different histology, who were managed with different therapy options. Although some of the differences between the two groups are statistically significant, the actual clinical difference may be small. We acknowledge such findings are noticeable in studies with very large sample size. Many community cancer centers offer clinical trials, have residency/fellowship programs, and closely work with academic centers; this is not reflected in this database. Our data was derived from the NCDB, hence it does not include patients seeking care in non-commission on cancer-approved hospitals, which are usually smaller, located away from urban locations and have less cancer-related services available to patients.
Footnotes
Authors’ note
This paper was presented as an abstract at the 2014 Pan Pacific Lymphoma Conference, Kohala Coast, Hawaii, USA, on 21–25 July 2014.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest statement
J.O.A. reports receiving consulting fees from Ziopharm Oncology, GlaxoSmithKline IDMC, Spectrum Pharmaceuticals, Roche, Conatus – IDMC, and serving on the board of directors for Tesaro bio Inc. P.T.S. reports receiving payment for lectures from Bristol Myers and Celgene in the past. There are no conflicts of interest for any other authors.
References
Supplementary Material
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