Aims and background: We evaluated some standardized criteria for classifying incident cases of liver cancer into either primary liver cancer (PLC) or unspecified liver cancer (ULC) on the basis of the diagnostic examinations performed and their results.
Methods: A pilot hospital-based study (98 cases) was carried out in Verona, northern Italy, with the main aim of assessing the feasibility of the method. The same procedures were subsequently applied in a population-based study (349 cases) in Brescia, northern Italy.
Results: Diagnosis was made on histologic data in 38.7% and 41.8% of the hospital based and population-based studies, respectively, with a wide variation among different hospitals. The percentage of cases classified as PLC was 78.6% in the hospital-based study and 78.8% in the population-based study. No differences in the proportion of cases attributed to PLC were found according to patients' age and sex or hospital of admission. The repeatibility of the procedure was assessed by a cross-panel review of 198 cases, and concordance was found in 91.9% of them.
Conclusions: An operational method for case definition of PLC based on the results of the diagnostic examinations currently performed and some suggestions for cancer registration are proposed.