Radiological diagnostics of colorectal cancer liver metastases and immunohistochemical characteristics after drug treatment

More than 50% of patients with colorectal cancer (CRC) suffer from different types of metastatic lesions. Liver resection is the only radicaltreatment option, but R0 resection is possible only in 10-30% of patients. Chemotherapy (CT) with targeted agents allows to increase resectability and improve distant treatment results. Multidisciplinary board approves any treatment options for these patients and its decision is directly dependent on the level and quality of methods of radiological diagnostics (Magnetic Resonance Imaging - MRI, Multispiral Computed Tomography - MSCT).The purpose of the study is to evaluate the significance of diagnostic and immunohistochemical characteristics after drug treatment in the surgical clinic.Materials and methods: 59 patients with colorectal cancer liver metastases were prospectively analyzed during the study. The median age was 57±10,2 years. Primary tumor in rectum was detected in 32,2% (n=19) cases and in colon in 67,8% (n=40) of patients. Synchronous metastases were detected in 78% (n=46) of patients. 35,6% (n=21) of patients had solitary metastases. Location of lesions: right lobe of liver - 44% (n=26), left lobe of liver - 17% (n=10) and bilobar involvement - 39% (n=23). FOLFOX (81,4%) and FOLFIRI (8,5%) were used as induction therapy in combination with targeted agents (44%): bevacizumab (n=14), panitumumab (n=9) and cetuximab (n=3). The amount of treatment courses was 5,8±2,1 (from 2 to 12). MRI and/or MSCT were performed for all patients before CT and after treatment. Efficacy was evaluated using RECIST criteria. Immunohistochemistry (IHC) was performed for 14 patients using antibodies to PML, Bax and BCL-2.Results: 95% of patients responded to the treatment. Metastases regression was achieved in 49,2% (n=29) of cases, disease stabilization in 44% (n=26) and complete response had 1 (1,7%) patient. 3 (5%) of patients experienced disease progression. Presence of «borderline» layer in MSCT/MRI after treatment was detected in 7 (11,9%) cases. Hepatic steatosis (mainly after treatment with irinotecan) was diagnosed in 3 patients and «blue» liver due to sinusoid distension (after oxaliplatin therapy) in 14 patients. 13 (22%) patients had inconsistencies between preoperative and expert evaluation data. False-positive results were received from 3 patients, false-negative from10. Sensitivity of MSCT and MRI was 85% and 89% respectively.Positive expression of PML vs control group ( p =0,01) was detected in patients after bevacizumab treatment using immunohistochemistry. The expression was absent in 9% of untreated patients, but there were no patients with absence of this marker after preoperative combined therapy including targeted anti-VEGF agent (bevacizumab). Increase of expression of antiapoptotic protein Bcl-2 was detected in 79% of patients after CT vs 54% in control group. There were no significant differences from control group ( p =0,1) after bevacizumab therapy.Conclusion: Current CT in combination with targeted agents can change resectability, elevating the amount of surgical patients. Radiological diagnostics and modern immunohistochemical methods play a large role in multidisciplinary strategy.

colorectal cancer metastases, liver resection, magnetic resonance imaging, multispiral computed tomography, immunohisto-chemical examination