Hepatic sinusoidal obstruction syndrome (SOS) reduces the effect of oxaliplatin in colorectal liver metastases

Vreuls C P H, Van Den Broek M A, Winstanley A, Koek G H, Wisse E, Dejong C H, Olde Damink S W M, Bosman F T & Driessen A (2012) Histopathology 61, 314–318 Hepatic sinusoidal obstruction syndrome (SOS) reduces the effect of oxaliplatin in colorectal liver metastases Aims: Oxaliplatin is an important chemotherapeutic agent used to reduce hepatic colorectal metastases, resulting in tumour reduction and permitting surgical resection. This treatment has significant side effects, as oxaliplatin can induce sinusoidal obstruction syndrome (SOS) in the non‐tumour‐bearing liver, resulting in increased morbidity. We hypothesized that SOS might impede hepatic perfusion, thereby interfering with the tumour environment and attenuate the response to the chemotherapy. Methods and results: From the prospective database of the Maastricht University Medical Centre we collected 50 patients with hepatic colorectal carcinoma metastases. All patients received neo‐adjuvant oxaliplatin followed by partial hepatectomy. Metastases and non‐tumour‐bearing liver were studied histopathologically. Thirty‐two of 50 (64%) patients showed SOS lesions, classified as mild (26%) and moderate–severe (38%). The response to treatment, as expressed in the tumour regression grade (TRG), was grade 1 (10%); grade 2 (14%); grade 3 (28%); grade 4 (32%) and grade 5 (16%). Statistical analysis showed that a higher grade of SOS was associated with a higher grade of TRG ( P = 0.016). Conclusion: Developing SOS is associated with a lower tumour response to neo‐adjuvant oxaliplatin treatment. Hepatic hypoperfusion due to sinusoidal obstruction syndrome might induce hepatic hypoxia, diminishing the response to chemotherapy.