Increased Travel Burden Decreases Likelihood of Receiving Radiation Therapy for Rectal Cancer Treatment
Increased travel distance to a cancer treatment facility negatively impacts the likelihood that patients with stage II/III rectal cancer will receive radiation therapy to treat their disease, according to a study analyzing 26,845 patient records from the National Cancer Data Base (NCDB) published by Lin et al in the International Journal of Radiation Oncology • Biology • Physics. While travel burden was associated with receipt of radiation therapy, physician availability related to the geographic concentration of radiation oncologists was not.
Standard treatment for stage II/III rectal cancer, as outlined in National Comprehensive Cancer Network (NCCN) guidelines, includes radiation therapy, chemotherapy, and surgery, yet as this retrospective study of NCDB patient records indicates, many eligible patients do not receive radiation therapy to treat their cancer. Approximately 30% of the rectal cancer patients in this national study did not receive radiation therapy within the time frame recommended by NCCN or at all.
Study Findings
In total, 69% of patients in the study cohort received radiation therapy within 180 days of their diagnosis or within 90 days of surgery, with median times of 38 days from diagnosis to radiation therapy start and 84 days between radiation therapy start and surgery. The reasons patients did not receive radiation included radiation therapy not being “part of first course of treatment,” according to the NCDB records (86%), patients receiving radiation therapy outside of the specified time frame (7%), patient refusal (6%), physician refusal due to risk factors (3%), and incomplete data (4%).
After controlling for patient sociodemographics in multivariate analyses, travel distance for treatment—but not density of radiation oncologists geographically near the patient—was associated with likelihood of receiving radiation therapy. The influence of travel burden differed, however, for patients who were diagnosed and treated at the same facility than for those who received their diagnosis and surgical treatment from different facilities. Among patients who were diagnosed and received surgical treatment at the same facility, individuals who traveled 50 miles or more were less likely to receive radiation therapy than those traveling fewer than 12.5 miles. Among patients diagnosed and treated surgically at different facilities, conversely, travel distance did not significantly impact probability of receiving radiation therapy.
“Travel burden clearly creates a barrier to radiation therapy access for rectal cancer patients, but this barrier is far from absolute,” said lead author Chun Chieh “Anna” Lin, PhD, MBA, Director of Health Services Research at the American Cancer Society. “When patients seek a referral and travel to a different location for their treatment than the facility where they were diagnosed, they are more likely to be treated and to follow through with their treatment. In this sense, patients' treatment intentions seem to mediate the influence of factors such as travel burden and physician availability.”
Travel distance for cancer treatment was determined by measuring the distance from the center of each patient's postal area to the facility where she or he received treatment. Travel distances were grouped into four categories based on previous scientific literature: 0 to 12.49 miles (46% of the study cohort), 12.5 to 49.9 miles (40%), 50 to 249 miles (13%), and 250 miles or more (1%).
Density level, an indicator of physician availability, was determined by calculating the number of radiation oncologists for every 100,000 residents in each of the 3,436 hospital service areas delineated by the Dartmouth Atlas of Health Care. The average density level across the nation was 1.28 radiation oncologists per 100,000 residents. Density level was matched to each patient depending on her or his residential HSA at time of diagnosis.
More than one-fourth of patients (28%) resided in hospital service areas with no radiation oncologist. Compared to patients in areas with a density level greater than zero, these patients traveled nearly three times as far for treatment. They also were more likely to travel to receive radiation therapy at an NCI-designated or comprehensive academic facility. The influence of density level was not significant in multivariate analyses controlling for patient characteristics such as age, race, and insurance status, however, indicating that, unlike travel distance, physician availability does not directly impact likelihood of receiving radiation therapy to treat stage II/III rectal cancer.
Previous research cited in the article found that radiation oncologists, compared to other oncology specialists, are less geographically diverse and less geographically accessible, as they tend to be more concentrated around academic hubs. Findings from this study, however, suggest that the potential negative impact of this geographic maldistribution is circumvented by a network of referrals between physicians and facilities, as well as the willingness of many patients to travel for their cancer care.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
