Colorectal Cancer Liver Metastases Effects of Chemotherapy on Liver Parenchyma and Resections

Abstract: Current multimodal treatment of colorectal cancer liver metastasis often combines liver resections with preoperative chemotherapy with a 5-year survival of 40-50%. Preoperative chemotherapy includes conversion of initially non-resectable situation and control of micrometastatic disease. Despite its potential advantages also problems with associated steatosis, steatohepatitis and sinusoidal injury has been discussed. Paper I focused on prospective steatosis evaluation prior to resections using proton MR spectroscopy, most sensitive non-invasive method. Proton MR spectroscopy showed high concordance with digital quantification of steatosis and was also able to predict steatohepatitis with 100% sensitivity and 89% specificity without knowing lobular inflammation or hepatocyte ballooning. Paper II focused on portal vein hemodynamics changes in patients treated with oxaliplatin-based treatment and with sinusoidal injury. Magnetic resonance imaging flowmetry demonstrated portal vein dilatation associated with oxaliplatin treatment. Patients with SI showed a tendency towards decreased mean portal flow velocity. Portal vein flow was not changed. This may indicate that SI is associated with an increased resistance to blood flow in the liver parenchyma and stasis in splanchnic system. Paper III attempted to enlighten the effects of FOLFOX treatment on human liver tissue 6 weeks after treatment cessation by quantification of protein expression changes using label-free global proteome analysis. Deep proteome analysis identified 5891 proteins, where machine learning algorithm identified 3% of classifying proteins, associated with changes in DNA replication through upregulation of the minichromosome maintenance complex and with the innate immune response. Significant changes were observed in 1% of proteins, associated with DNA replication and cell cycle entry. Results support the hypothesis that liver has already regenerated from the FOLFOX treatment injury after 6 weeks. Paper IV aimed to identify possible patient, disease and chemotherapy characteristics associated with liver specific and severe general complications in a retrospective single centre cohort composed of 516 consecutive resections. Chemotherapy with more than 4 cycles of oxaliplatin was associated with post-hepatectomy hemorrhage. Underlying liver disease and diabetes mellitus were associated with 90-day mortality. Size of resection, intraoperative blood loss and transfusions were verified as independent predictors of liver specific complications to resections.