Disparities in Diagnostic Imaging for Initial Local Staging for Rectal Cancer

To assess the presence, quality, and timeliness of initial staging imaging for rectal cancer patients, and to evaluate demographic factors associated with disparities.

We conducted a chart review of consecutive rectal adenocarcinoma cancer registry cases from a single institution for the period from 2015 to 2020. We recorded whether initial staging MRI or endoscopic ultrasound (EUS) was performed, and whether it was performed in or outside the institution. MRI quality was assessed based on compliance to the Society of Abdominal Radiology rectal cancer disease-focused panel protocol recommendations. The times between diagnosis and imaging were calculated. Patients' age, race, ethnicity, sex, body mass index, address, and primary payer were acquired from the electronic medical record. Descriptive analysis, odds ratios, and Student's t tests were used for analysis.

Of 346 patients, 39% were female, and the average age was 59 years. A total of 93 patients (26.8%) had no initial staging MRI or endoscopic ultrasound. Of the 142 MRIs evaluated for image quality, 100 patient exams (72.4%) met the criteria for adequate quality. The mean time interval from diagnosis to imaging was 30.9 days. A lower likelihood of receiving initial local staging was associated with being of Hispanic ethnicity (P < .01), having Medicaid or no insurance (P < .01), and residing in a low-income census block (P < .01). Higher quality of imaging was associated with residence in a census block with high median income (P < 0.01), more recent diagnosis (P < .01), and MRI performed at the institution presented (P < .01).

Although radiologic workup variability was found across all demographics, sociodemographic factors have an effect on local initial imaging of rectal cancer, emphasizing the need to improve image acquisition for underserved patients and improve quality standardization at low-volume centers.