Impact of expanding criteria for resectability of colorectal metastases on short- and long-term outcomes after hepatic resection

BACKGROUND

An expansion of resectability criteria of colorectal liver metastases (CLM) is justified provided "acceptable" short-term and long-term outcomes. The aim of the present study was to ascertain this paradigm in an era of modern liver surgery.

METHODS

All consecutive patients who underwent hepatic resection for CLM at our institute between 1990 and 2010 were included in the study. Ninety-day mortality and morbidity rates were determined in the total study population and in 2 separate time periods (group I: 1990-2000; group II: 2000-2010). Similarly, overall and progression-free survival rates were determined. Independent predictors of postoperative morbidity were identified at multivariate analysis.

RESULTS

Between 1990 and 2010, 1394 hepatectomies were performed in 1028 patients. Overall perioperative mortality and postoperative morbidity rates were 1.3% and 33%, respectively. Although patients in group II were older, had more often comorbid illnesses, and presented with more extensive liver disease, similar perioperative mortality rates were observed (1.1% in group I and 1.4% in group II; P = 0.53). A trend toward a higher morbidity rate was observed in group II (34% vs 31% in group I; P = 0.16). Independent predictors of postoperative morbidity were: treatment between 2000 and 2010, total hepatic ischemia time of 60 minutes or more, maximum size of CLM of 30 mm or more at histopathology, and presence of abnormalities in the nontumoral liver parenchyma. Although a trend toward lower overall survival was observed in patients with significant postoperative complications, no significant differences were observed in long-term outcomes between both treatment periods.

CONCLUSION

After an aggressive multidisciplinary treatment of CLM, acceptable overall mortality and morbidity rates were observed. Perioperative mortality rates did not differ according to treatment period; however, more recently operated patients experienced more postoperative complications. These favorable short-term outcomes, without worsening of long-term outcomes, justify an expansion of the criteria for resectability in this patient category.

The surgical treatment of hepatic metastases in colorectal carcinoma

BACKGROUND

Colorectal carcinoma with hepatic metastases was long considered an incurable disease. Recent advances in surgical treatment have substantially improved the affected patients' prognosis. At first, surgery was only performed in patients whose hepatic tumor burden was small (<4 nodes, <5 cm). Currently, however, the main issue is the feasibility of curative resection of all metastases.

METHOD

The PubMed literature database was selectively searched for articles with the keywords "colorectal liver metastases," "chemotherapy," and "surgery." Particular attention was devoted to studies of large groups of patients, randomized trials, the German guidelines, and an analysis of the authors' own patient population.

RESULTS

Only 10% to 20% of all patients are candidates for surgical therapy (hepatic resection), as the rest are disqualified either by extensive liver involvement or by extrahepatic neoplasia. A further 10% of patients have hepatic metastases that are primarily considered inoperable, yet later become amenable to surgery after interdisciplinary treatment involving preoperative chemotherapy, portal-vein embolization, two-stage hepatectomy, and/or locally ablative procedures. Chemotherapy is probably beneficial after hepatic resection, although the benefit has not yet been definitively demonstrated by clinical trials. Therefore, chemotherapy should only be given perioperatively in selected cases, when recommended by an interdisciplinary treatment team.

CONCLUSION

A multimodal approach to the treatment of hepatic metastases of colorectal carcinoma has led to an increase in the number of resections and to an improved long-term survival rate (currently more than 40% at 5 years).

Urgent need for a new staging system in advanced colorectal cancer

Despite recent advances in the medical treatment of metastatic colorectal cancer (mCRC), which include irinotecan- and oxaliplatin-based first-line regimens, the concept of planned sequential therapy involving three active agents during the course of a patient's treatment and the increasing use of targeted monoclonal antibodies, 5-year survival rates for patients with advanced CRC remain unacceptably low. For patients with CRC liver metastases, liver resection remains the only chance of cure, with 5-year survival rates ranging from 25% to 40%. However, 80% to 85% of patients with stage IV CRC have liver disease which is considered unresectable at presentation. The rapid expansion in the use of improved combination chemotherapy regimens plus or minus biologics, to render initially unresectable metastases resectable has increased the percentage of patients eligible for potentially curative surgery. However, the current staging criteria for CRC patients with metastatic disease do not reflect these recent changes or the fact that there is also a large variation in the survival of patients with stage IV CRC. For example the survival for a patient with a solitary, resectable liver metastasis is better than that for a patient with stage III disease. A new staging system is therefore needed that acknowledges both the improvements that have been made in surgical techniques for resectable metastases and the impact of modern chemotherapy on rendering initially unresectable CRC liver metastases resectable, while at the same time distinguishing between patients with a chance of cure at presentation and those for whom only palliative treatment is possible.

Neoadjuvant Chemotherapy Before Liver Resection for Patients With Unresectable Liver Metastases From Colorectal Carcinoma

Colorectal carcinoma is one of the most common cancers in the world, and more than 50% of these patients develop liver metastases. Despite recent advances, systemic chemotherapy for metastatic disease without the use of surgery is considered palliative, as there are rarely long-term survivors. However, patients who are candidates for surgical resection of their liver metastases can have a prolonged survival or possibly a cure. Consensus guidelines on criteria for resection and prognostic scores help facilitate patient selection, yet only 25% of patients with liver metastases are considered to have resectable metastases. Neoadjuvant chemotherapy has been explored in an attempt to render more patients candidates for resection. First reports using neoadjuvant systemic chemotherapy in patients with unresectable disease found that 13% to 16% of patients could be rendered resectable. Efforts to increase response rates using hepatic arterial infusion or biologic agents may increase resection rates. This review summarizes the current data on neoadjuvant chemotherapy, the rationale for this approach, potential complications, and future prospects.