Delays in IMRT Initiation May Contribute to Certain Disparities in Cancer Outcomes

Delays in the initiation of intensity-modulated radiotherapy (IMRT) among non-Hispanic Black, Hispanic, and Asian patients may contribute to the known differences in cancer outcomes, according to a study published in JCO Oncology Practice.

“The benefits of IMRT over standard radiotherapy (RT), including decreased acute and late toxicities, improved quality of life, and opportunities for dose escalation, have been demonstrated in many disease sites,” study researchers wrote. “As a result, IMRT is often the preferred modality for radiotherapy delivery.”

However, delays in initiation of IMRT may contribute to inferior outcomes. In this study, researchers used data from the National Cancer Database to look at the differences in magnitude of delay in initiation of IMRT in different subsets of patients with cancer at the 10 sites most commonly treated with IMRT.

The study included 350,425 treated with IMRT from 2004 to 2017. The 10 disease sites with the highest number of cases treated with IMRT, in descending order, were prostate, lung, head and neck (H&N), rectum, esophagus, anus, pancreatic, stomach, cervix, and uterus.

The researchers found that non-Hispanic Black, Hispanic, and Asian patients were significantly more likely to have delayed initiation of treatment with IMRT for nearly all diseases sites compared with non-Hispanic White patients.

“In this study, we excluded patients treated with adjuvant RT to eliminate delays because of postoperative complications,” the researchers explained. “Delays observed in this study population are therefore more specific to the clinical processes required for RT including referral patterns, clinic scheduling, insurance authorization/approval, and treatment planning time.”

These 3 groups had significantly longer median interval to initiation of therapy than non-Hispanic White patients. For non-Hispanic Black patients the interval was 87 days; for Hispanic patients, 76 days; and for Asian patients, 74 days compared with 67 for non-Hispanic White patients (P<.01 for all).

Although non-Hispanic White patients, Hispanic patients, and Asian patients with private insurance had shorter time to initiation of treatment than those with Medicare (P<.01), non-Hispanic Black patients with private insurance had longer time to initiation than those with Medicare (P<.01).

“Significant racial and ethnic disparities in the likelihood and duration of treatment delay were observed,” the researchers wrote. “Delays in initiation of IMRT among Black, Hispanic, and Asian patients may contribute to the previously documented differences in cancer outcomes.”

Reference

Racial and ethnic health disparities in delay to initiation of intensity-modulated radiotherapy