Lizhi Niu, M.D., Kecheng Xu, M.D.*, Weibing He, M.D., Yisong He, M.D., Jiansheng Zuo, M.D.
Cryosurgery Center for Cancer, Fuda Cancer Hospital Guangzhou, Guangzhou 510300, China

*Corresponding Author: Kecheng Xu, M.D., Email: xukc@vip.163.com

Introduction

Hepatic metastases are the main causes of death in patients with colorectal carcinoma. Hepatic resection is the choice for the treatment of the liver colorectal metastases if the tumors are confined to the liver and may achieve 5-year survival of 25% to 39%. However, only 10%-20% of patients with hepatic colorectal metastases are suitable for resection. Cryosurgery recently has been applied for unresectable liver tumors, showing encouraging results. Between March 2001 and February 2007, 1090 patients with malignant liver tumors were treated by cryosurgery in our hospital. There were 680 patients with hepatocellular carcinoma (HCC), 326 patients with metastases originating from colorectal carcinoma, and 84 patients with liver metastases from cancer of noncolorectal origin. This study describes the results of percutaneous cryosurgery for the treatment of unresectable hepatic colorectal metastases with the purpose of determining the efficacy and safety of this modality.

Technique

From 852 patients with different types of liver tumors treated by cryosurgery in a 5-year period, the authors evaluated the results of 326 patients with unresectable hepatic colorectal metastases. Cryosurgery was performed under the guidance of ultrasound or CT percutaneously. Most of the patients received transarterial chemoembolization (TACE) after cryosurgery. Follow-up was obtained at 1 month and every 4 months thereafter postoperatively by assessment of liver function test results, tumor markers, liver ultrasonography and abdominal CT. Some of the patients received follow-up with positron emission tomography-CT (PET-CT). For lesions suspicious of recurrence, an ultrasound-guided liver biopsy was performed for histological study. Subsequent re-cryosurgery was performed if histology was positive cancer.

Results

All patients underwent a total of 526 sessions of cryosurgery. There were 201 patients who received single cryosurgery, 151 patients underwent multiple cryosurgery for recurrent tumors in the liver and extrahepatic places. 3 month after cryosurgery, CEA level in 197 of patients (77.5%) with elevated markers decreased to normal range. According to the imaging study, cryotreated lesions showed CR in 41 patients (14.6%), PR in 115 patients (41.1%), SD in 68 patients (24.3%) and PD in 56 patients (20%). The recurrence rate was 47.2% during a median follow-up of 32 months (range, 7-61). The liver was main area of recurrence, 61% of which occurred in liver only and 13.9% in liver and some extrahepatic places. Extrahepatic recurrence was mainly seen in lungs and lymph nodes. The recurrence rate at cryosite, including at cryosite only as well as cryosite and the remaining area of liver, was only 6.4% for all cases. During a median follow-up of 36 months (7-62months), the median survival of all patient was 29 months (range 3-62months). 196 patients (60.1%) have died and 130 patients are alive, with a median survival of 26 and 36 months, respectively. Overall survival was 78%, 62%, 41%, 34% and 23% at 1, 2, 3, 4 and 5 year, respectively, after the treatment. Patients with tumor size less than 3 cm, tumor located in right lobe of liver, the lower CEA levels (<100 ng/dl) and post-cryosurgery TACE had higher survival rate. There was no significant difference in survival bases on tumor number, pre-cryosurgery chemotherapy and the timing of the development of metastases (synchronous vs. metachronous). Patients who underwent 2-3 procedures of cryosurgery had an increased survival as compared to patients who received one time of cryosurgery only (Figure 1).There was no intra-cryosurgery mortality. Common adverse effects were temporal pain, fever, increased liver enzyme and thrombocytopenia, which were generally self-limited without poor outcome. Severe adverse effects, such as hepatic bleeding, cryo-shock, biliary fistula, liver failure, renal insufficiency and liver abscess were observed in 0.3%-1.5% of patients.

Conclusion

The percutaneous cryosurgery was a safe modality for treatment of hepatic colorectal metastases. Rather than an alternative to resection, this technique is to be regarded as a complement to hepatectomy and as an additional means to achieve tumor eradication when the total excision can not be accomplished.

Keywords: Hepatic colorectal metastases, Cryosurgery

Figure 1: Patient survival after cryosurgery