Resection of colorectal liver metastases

Introduction: Surgical resection is presently the only approach that offers patients with liver metastases from colorectal carcinoma substantial chanc e of cure. This article summarizes the current literature as well as the au thor's personal experience. Background and discussion: Since 1980, 5-year s urvival figures have ranged from 21% in collected series to 48% in single-i nstitution series. The 30-day mortality of elective liver resection in non- cirrhotic patients ranges now between 0% and 5%. The overwhelming indicator of prognosis is the completeness of tumor removal according to the R-class ification. The specific impact of all other factors should therefore be ana lyzed by excluding nonradical procedures and operative mortality. Among pat ient characteristics, age and gender do not significantly affect outcome, w hile the Karnofski stage is important. Regarding the primary tumor, the eff ect of staging and location is predominantly apparent in patients with sync hronous metastases. Timing of metastasis detection is of some importance, a s most authors found a slightly better outcome for metachronously detected metastases. With respect to the liver involvement, multiplicity of metastas es and bilateral disease both seem to be of minor importance after R0-resec tion, while satellite lesions are significant in many series. The actual nu mber of metastases is of minor effect, with a slight superiority in 5-year survival for patients with one to three nodules relative to patients with f our nodules or more in most series, but identical results in the author's o wn experience. The maximum diameter as an indicator of tumor burden represe nts a significant prognosticator in half of the reports analyzed. Extrahepa tic disease reduces 5-year survival, but direct tumor invasion to adjacent structures, local recurrent disease, or one or few pulmonary metastases are no contraindication to liver resection as long as a R0-situation can be ac hieved. In contrast, lymph-node metastases at the liver hilum predict a poo r outcome. They are likely to prove as a clear contraindication. With respe ct to the operative approach, a clear margin of 1 cm or more should be aime d at but, if the size or location of metastases do not allow a 1-cm margin, resection should still be performed, making every surgical effort to ensur e a complete rim of unaffected tissue. Anatomic resections reduce the incid ence of non-radical procedures and may improve survival. Whether there is a n independent effect of operative blood loss, need for blood transfusion, a nd intraoperative hypotension on prognosis is still unclear. Adjuvant chemo therapy or radiotherapy after R0-resection is unlikely to improve results. There are also no convincing data available demonstrating a prognostic bene fit when a non-curative resection is supplemented by any medical treatment. In patients with recurrent disease, a re-resection is possible in roughly 20%. Survival from the time of re-intervention ranges from 21% to 57% after 5 years and, thus, justifies a close follow-up policy after R0-resection o f the initial liver metastases. Conclusion: The previous "clear" contraindi cations to liver resection have become less important. Future efforts may b e directed to more accurate patient selection and new approaches of neoadju vant and adjuvant therapeutic strategies.