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Liver tumor sizes at criteria margins may be subject to inaccurate reports

Researchers found evidence suggesting that tumor sizes at the margins of hepatocellular carcinoma-related transplantation criteria may be subject to inaccurate reporting, according to results of a recently published study.

“The fairness of a liver transplant allocation policy for hepatocellular carcinoma is predicated on the accurate reporting of patient’s tumor measurements,” Mariya L. Samoylova, MD, from the UCSF School of Medicine, California, and colleagues wrote. “Because small changes in tumor size may mean the difference between potentially curative transplant and exclusion from the waiting list, providers may be inaccurately reporting measurements of tumors at the margins of size criteria.”

The researchers gathered data on 12,958 patients who were on the liver transplant waitlist with a diagnosis of HCC between Jan. 1, 2011, and Oct. 31, 2013, from the UNOS database. The researchers analyzed patients by the tumor size criteria applicable to their category: either one lesion between 2 cm and 5 cm in size, or two to three lesions less than 3 cm in size.

Most patients were men (77%), white (66%), had liver disease due to hepatitis C (61%), and 70% received exception points for a single tumor with a median tumor size of 2.3 cm (range, 2-3 cm).

Among patients with one lesion at a minimum size of 2 cm, the difference between the 745 patients who were listed as eligible and those who met exact criteria at 2 cm was 238.3, amounting to 2.7% of the single-tumor waitlist population. Regarding patients in the 5-cm upper limit category, the difference was 65.7, or 0.7% of the waitlist.

Of the 3,790 patients with two to three tumors less than 3 cm in size, there was an excess of 110 patients with tumors 2 cm in size compared with the expected value and a deficit of 110 patients with tumors 1.9 cm, 2.1 cm and 2.2 cm in size compared with the expected value. The researchers also observed an excess of 96 patients with tumors 2.8 cm and 2.9 cm in size.

The researchers followed 6,049 patients for a median of 2.4 years (range, 1-4.7 years) posttransplant. At a median of 14 months posttransplant, 435 patients experienced HCC (range, 7 months to 2.4 years) and 981 patients died (range, 4 months to 2.6 years).

The observed to expected ratio for HCC recurrence by tumor size ranged from 0.57 cm to 1.37 cm. Only tumors 2 cm in size had a significantly adjusted observed-expected ratio (r = 0.73; 95% CI, 0.57-0.94). The researchers suggest that patients listed with 2 cm tumors had smaller than expected chance of HCC recurrence potentially because of inaccurate reports of tumor size.

“We suggest that adaptations of the forensic accounting methods used to find biases and other anomalies in micro and macro-level organizational data may be used by transplant centers to assess the accuracy and validity of their reported data, and also in other clinical settings where a high level of accuracy is critical,” the researchers wrote. “As inaccurate data entry into a Federal system potentially represents a criminal offense, there is sufficient motivation for the center and the OPTN to monitor for bias.” – by Talitha Bennett

Disclosure: The researchers report no relevant financial disclosures.