Hepatocellular carcinoma usually afflicts individuals in their later years following longstanding liver disease. In Peru, hepatocellular carcinoma exists in a unique clinical presentation, which affects patients around age 25 with a normal, healthy liver. In order to deepen our understanding of the molecular processes ongoing in Peruvian liver tumors, mutation spectrum analysis was carried out on hepatocellular carcinomas from 80 Peruvian patients. Sequencing analysis focused on nine genes typically altered during liver carcinogenesis, i.e. ARID2, AXIN1, BRAF, CTNNB1, NFE2L2, H/K/N-RAS, and TP53. We also assessed the transcription level of factors involved in the control of the alpha-fetoprotein expression and the Hippo signaling pathway that controls contact inhibition in metazoans. The mutation spectrum of Peruvian patients was unique with a major class of alterations represented by Insertions/Deletions. There were no changes at hepatocellular carcinoma-associated mutation hotspots in more than half of the specimens analyzed. Furthermore, our findings support the theory of a consistent collapse in the Hippo axis, as well as an expression of the stemness factor NANOG in high alpha-fetoprotein-expressing hepatocellular carcinomas. These results confirm the specificity of Peruvian hepatocellular carcinoma at the molecular genetic level. The present study emphasizes the necessity to widen cancer research to include historically neglected patients from South America, and more broadly the Global South, where cancer genetics and tumor presentation are divergent from canonical neoplasms.

In the developing world, most patients with hepatocellular carcinoma present with advanced-stage disease, considered to be incurable based on current therapeutic algorithms. Here, we demonstrate that curative liver resection is achievable in a portion of Peruvian patients not addressed by these treatment algorithms. We conducted a retrospective cohort study of 253 hepatocellular carcinoma patients that underwent a curative hepatectomy between 1991 and 2011 at the National Cancer Institute of Peru. The median age of the cohort was 36 years, and merely 15.4% of the patients displayed cirrhosis. The average tumor size was over 14 cm in diameter, resulting in 76.3% of major hepatectomies performed. The 5-and 10-year survival probability estimates were 37.5% and 26.2%, respectively. Age (>44 vs. ≤44 years old; P = 0.005), tumor size (>10 cm vs. ≤10 cm in diameter; P = 0.009), cirrhosis (P < 0.001), satellite lesions (P < 0.001), macroscopic vascular invasion (P < 0.001), allogeneic blood transfusion (P = 0.011), and spontaneous rupture of the tumor (P = 0.006) were independent predictive factors for prognosis. Hepatocellular carcinomas in Peru are characterized by a distinct clinical presentation with notable features compared with those typically described throughout relevant literature. Despite a large number of advanced-stage hepatocellular carcinomas, the outcomes of liver resection observed in the present study were in good standing with the results previously described in other series.It thus appears that staging systems and associated therapeutic algorithms designed for use in the developed world remain inadequate in certain populations, especially in the context of Peruvian patients. Our findings suggest that clinicians in the developing world should reconsider management guidelines pertaining to hepatocellular carcinoma. Indeed, we hypothesize that, in developing countries, a strict adherence to these therapeutic algorithms might create a selection bias resulting in the dismissal of patients who could eventually be treated.