De novo malignancies following liver transplantation: results from a multicentric study in central and southern Italy, 1990-2008

Objective The objective of this study was to quantify incidence rates (IR) and risks of de novo tumors (except nonmelanoma skin cancers) in patients who underwent orthotopic liver transplantation (OLT) in central and southern Italy. Methods Data were collected on 1675 patients (75.5% males) who underwent OLT in six Italian transplantation centers in central and southern Italy (1990-2008). The time at risk of cancer (person years [PY]) was computed from OLT to the date of cancer diagnosis, death, or last follow-up, whichever occurred first. The number of observed cancer cases were compared with the expected one using data from population-based cancer registries. We computed gender- and age-standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). Results During 10,104.3 PYs (median follow-up, 5.2 years), 98 patients (5.9% of the total) were diagnosed with a de novo malignancy (for a total of 100 diagnoses). Twenty-two of these cancers were post-transplantation lymphoproliferative disorders (PTLD; 18 non-Hodgkin lymphoma [NHL] and 2 Hodgkin's lymphoma [HL]), 6 were Kaposi's sarcoma (KS), and 72 were solid tumors (19 head and neck [H&N], 13 lung, 11 colon-rectum, 6 bladder, and 4 melanoma). The overall incidence was 9.9 cases/103 PYs, with a 1.4-fold significantly increased SIR (95% CI, l.2-1.7). Significantly increased SIRs were observed for KS (37.3), PTLD (3.9), larynx (5.7), melanoma (3.1), tongue (7.1), and H&N (4.5) cancers. Conclusions These results confirmed that OLT patients are at greater risk for cancer, mainly malignancies either virus-associated or related to pre-existent factors (eg, alcohols). These observations point to the need to improve cancer surveillance after OLT. The on-going enrollment of patients in the present cohort study will help to elucidate the burden of cancer after OLT and better identify risk factors associated with its development.