Systemic irinotecan or regional floxuridine chemotherapy prolongs survival after hepatic cryosurgery in patients with metastatic colon cancer refractory to 5-fluorouracil

Progress toward Optimization of Cryosurgery

Cryosurgery for diverse neoplastic and non-neoplastic diseases has expanded in applicability in recent years, especially since intraoperative ultrasound became available as a method of monitoring the process of tissue freezing. However, persistence of disease after presumably adequate cryosurgical treatment has disclosed deficiencies in the technique, perhaps due to faulty application of the freeze-thaw cycles or due to shortcomings in the imaging method. Clearly cryosurgical technique is less than optimal. The optimal dosimetry for tissue freezing, the recent improvements in imaging techniques, and the need for adjunctive therapy are defined in this review, which assesses the progress toward improving the efficacy of cryosurgery.

Cryosurgery for Tumors — A Clinical Overview

Cryosurgery, a method of treating disease by the production of freezing temperatures in the tissue, is a useful technique for the treatment of tumors. When the modern era of cryosurgery began in the mid 1960's, the technique was used only for tumors easily accessible by direct observation or via endoscopy, such as those of the skin, oral cavity, and prostate gland. In general, the technique had limited usefulness in the next two decades. However, with the advent of intraoperative ultrasound as a method of monitoring the process of freezing and with the development of more effective cryosurgical apparatus, the cryosurgical treatment of tumors of the viscera and other deep tissues became practical in the 1990's. This review assesses the present day status of cryosurgery in the management of diverse tumors.

Systematic review of tumour number and outcome after radical treatment of colorectal liver metastases

Background

Resection of colorectal liver metastases (CLMs) is potentially curative but the effect of tumour number on prognosis is uncertain. This study compared the prognosis after resection and/or ablation of between one and three, or four or more CLMs.

Methods

A systematic literature review from January 2000 to June 2008 was performed. Study selection and data extraction were standardized, and analysis included assessment of methodological quality, heterogeneity and bias. Main outcomes were 3- and 5-year survival. A meta-analysis comparing radical treatment in the two groups was performed using the hazard ratio for overall survival.

Results

Of 1307 studies screened, 46 (9934 patients) were included in the analysis. Methodological quality was variable, and there was significant heterogeneity and reporting bias. The overall 5-year survival rate after radical treatment ranged from 7 to 58 per cent. Pooled hazard ratio for overall survival was 1·67 (95 per cent confidence interval 1·43 to 1·95; P < 0·001). Median reported 5-year survival for patients with four or more CLMs was 17·1 per cent.

Conclusion

Radical treatment of more than three CLMs results in poorer overall survival. Nevertheless, 5-year survival is achievable and the number of lesions should not, of itself, be used to exclude patients from surgery.

Cryosurgery--a putative approach to molecular-based optimization

Cryosurgery must be performed in a manner that produces a predictable response in an appropriate volume of tissue. In present-day clinical practice, that goal is not always achieved. Concerns with cryosurgical techniques in cancer therapy focus in part on the incidence of recurrent disease in the treated site, which is commonly approximately 20-40% in metastatic liver tumors, and prostate cancers. Whether the cause of this failure is disease-based or technique related, cryosurgery for cancer commonly needs the support of adjunctive therapy in the form of anti-cancer drugs or radiotherapy to increase the rate of cell death in the peripheral zone of the therapeutic lesion where cell survival is in balance for several days post-treatment. Recent evidence has identified a third mechanism of cell death associated with cryosurgery. This mechanism, apoptosis or gene regulated cell death, is additive with both the direct ice-related cell damage that occurs during the operative freeze-thaw intervals and coagulative necrosis that occurs over days post-treatment. In this manuscript we discuss, through a combination of literature review and new data, the combined roles of these distinct modes of cell death in a prostate and colorectal cancer. Data are presented suggesting that sub-freezing temperatures, when sequentially applied with low dose chemotherapy, may provide improved cancer cell death in the freeze zone periphery. Since the mechanism of action of most common chemotherapeutic agents is to initiate apoptosis in cancer cells, the observation that sub-freezing exposures yields a similar effect provides a possible route toward molecular-based procedural optimization to improve therapeutic outcome.

Arterial chemotherapy as adjuvant and palliative treatment of hepatic colorectal metastases: an update

Regional hepatic chemotherapy with FUDR significantly improves local recurrence rates and may impact overall survival in patients with hepatic colorectal metastases. The results of prospective randomized trials confirm that careful patient selection, a thorough knowledge of intricate hepatic arterial anatomy, and an understanding of the pharmacokinetics and delivery of FUDR optimize treatment efficacy. A multimodality approach that includes adjuvant therapy in addition to cytoreductive surgery offers promise for the treatment of unresectable hepatic metastases. Because many tumors recur in extrahepatic sites, the addition of novel systemic agents such as CPT-11 may further reduce recurrences. Molecular analysis of the tumor may ultimately help select patients who are good candidates for regional chemotherapy.

Systemic irinotecan and regional floxuridine after hepatic cytoreduction in 185 patients with unresectable colorectal cancer metastases

BACKGROUND

This study evaluated our 7-year experience treating unresectable colorectal cancer (CRC) hepatic metastases refractory to systemic 5-fluorouracil.

METHODS

A total of 185 patients with unresectable 5-fluorouracil-resistant CRC hepatic metastases underwent surgical cytoreduction. Postoperatively patients received either hepatic arterial floxuridine (FUDR) and systemic irinotecan as part of a phase II trial or no further treatment.

RESULTS

Of the 185 patients undergoing surgical cytoreduction, 71 patients received adjuvant irinotecan/FUDR. There were no appreciable differences in synchronous or metachronous lesions or the median number or size of lesions between treatment groups. At a median follow-up of 20 months, there were fewer recurrences in patients treated with postoperative irinotecan/FUDR compared with untreated patients for both hepatic and extrahepatic recurrences. Progression-free and overall survival were longer for patients who received irinotecan/FUDR compared with patients who did not receive adjuvant therapy. The 2-year survival rate was significantly better for patients receiving adjuvant therapy compared with patients receiving no additional treatment. Predictors of improved survival included a preoperative carcinoembryonic antigen level <100 ng/dl, >30% postoperative reduction in carcinoembryonic antigen level, and adjuvant therapy.

CONCLUSIONS

Combined therapy with irinotecan/FUDR may improve the results of surgical cytoreduction for unresectable CRC hepatic metastases.