Increased travel distance linked to lower radiation receipt for rectal cancer

Increased travel burden appeared associated with decreased likelihood of receiving radiation therapy for patients with stage II or stage III rectal cancer, according to retrospective study results.

Physician density in relation to geographic concentration was not associated with the likelihood of receiving radiation therapy, results showed.

A trimodal therapeutic approach of chemotherapy, radiation and surgery serves as the standard of care for patients diagnosed with stage II or stage III rectal cancer, according to study background.

However, up to one-third of patients do not receive radiation therapy.

Chun Chieh Lin, PhD, MBA, director of health services research at the American Cancer Society, and colleagues sought to determine the degree to which geographic density of radiation oncologists, in addition to travel burden of patients, contributed to these statistics.

Lin and colleagues used the National Cancer Data Base to retrospectively identify 26,845 adults diagnosed with stage II to stage III rectal cancer from 2007 to 2010.

Researchers identified radiation oncologists (n = 4,253) through the Physician Compare dataset and counted the number of unique radiation oncologists per hospital service area They estimated clustering by hospital service area to examine the association between geographic access and radiation receipt in analyses controlled for patient sociodemographic and clinical characteristics.

Approximately one-quarter of patients (n = 7,467; 27.8%) resided in an area with no radiation oncologist.

Seventy percent of patients (n = 18,676) received radiation therapy within 180 days of rectal cancer diagnosis or within 90 days of surgery.

A univariate analysis indicated that patients traveling less than 12.5 miles had lower rates of receipt of radiation therapy. Untreated patients in this subset were more likely to be female, nonwhite, older ( 50 years), have comorbid conditions, lack insurance or public insurance coverage, and reside in areas with lower median incomes (P < .05 for all).

Upon multivariate analysis that adjusted for these factors, patients with travel distance greater than 50 miles appeared less likely to receive radiation therapy (50-249 miles, adjusted OR = 0.75, P < .001; 250 miles, adjusted OR = 0.46, P = .002).

The geographic density of practicing radiation oncologists did not significantly affect radiation receipt.

Patients more likely to receive radiation therapy included those who were uninsured but self-paid for their treatment, who were diagnosed elsewhere but sought treatment at a reporting facility, and who resided in the Midwest (P < .05 for all).

The researchers acknowledged several study limitations. Because the National Cancer Data Base only includes data from Committee on Cancer-affiliated treated centers, the patients included in this study may not be representative of the entire U.S. population.

Further, they noted that their reliance on postal codes to determine travel distances may lead to inaccuracies.

“Travel burden clearly creates a barrier to radiation therapy access for rectal cancer patients, but this barrier is far from absolute,” Lin said in a press release. “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.” – by Cameron Kelsall

Disclosure: The researchers report no relevant financial disclosures.