Hepatic Colorectal Metastases
Over the past decade there has been an increasing acceptance of
liver resection as the best treatment for hepatic colorectal metastases. Liver resection
is now a well-controlled procedure and several centers have recently shown that mortality
for resection of hepatic colorectal metastases is now approaching zero. Major centers and
multi-institutional series have retrospectively reported their survival on hepatic
resection for colorectal metastases and the natural history of unresected hepatic
colorectal metastases.
In spite of this, there is still disagreement regarding the subsets
of patients benefiting most from the procedure and some doubts have even been casted
regarding the actual long-term survival and the likelihood of curing patients from their
colorectal recurrence. This uncertainty comes as a result of the absence of randomized
studies, the small numbers generated by single institutional studies precluding a
meaningful multivariate analysis of patient subsets, the retrospective nature of these
analyses, and the inclusion of patients incompletely resected (positive margins of
resection, positive portal nodes, etc.).
The group of Erlangen, Germany has recently reported the long-term
results of hepatic resection for colorectal metastases. This study includes 366 patients
who underwent complete, potentially curative resection of hepatic colorectal metastases.
It is the largest prospective single institutional study ever published on this. The
patients in this study were followed with CEA, ultrasound, and chest x-ray every 4-6
months allowing for proper evaluation of disease-free survival and survival. This study
shows that following complete curative resection, some 40% of patients are still at five
years and that 30% remain disease-free at 5 years.
The likelihood of remaining free of a definite cancer recurrence
after a tumor-free period of 1-7 years was determined for 350 patients who survived
hepatic resection. The likelihood of remaining tumor-free increased as time elapsed
following curative liver resection. Importantly, after seven years the chance of remaining
tumor-free or being cured was 100% as determined by the ultimate analysis of patients
remaining at risk at seven years. This paper provides today the best presumptive evidence
that cure is possible following hepatic resection.
The factors affecting disease-free survival were analyzed in
multivariate stepwise regression analysis. The factor most adversely affecting survival
was the presence of satellite metastases (secondary tumor site around a metastatic tumor)
followed by high-grade tumors, synchronous diagnosis of metastasis, metastasis equal to or
larger than 5cm, non-anatomic type of liver resection, resection performed before 1980,
and presence of metastatic lymph nodes in the primary. Interestingly, the factors
affecting tumor-free survival in multivariate analysis were identical to factors affecting
overall survival but in a different order of significance although satellite metastases
still most adversely affected survival. Importantly, neither the size of resection margin
or the number of metastases affected long-term survival. Importantly, neither the size of
resection margin or the number of metastases affected long-term survival provided the
patients was completely resected. In this paper, several patients survived more than five
years having had four or more metastases and even up to seven metastases completely
resected. Thus the number of tumor nodules is not, per se, a factor of survival provided
complete excision can be performed. The main difficulty resides in the fact that the
likelihood of complete resection surgically decreases as the number of lesions increases.
In these difficult cases, we believe that there is also a place for "a test of
time." In these patients, we recommend a period of observation during which patients
can receive chemotherapy. Repeat imaging is planned after 8-12 weeks to allow further
assessment of the biologic behavior of the tumor.
