Management of Primary and Metastatic Tumors to the Liver
Management of Primary and Metastatic Tumors to the Liver
This comprehensive report summarizes the current management of primary liver cancer and of metastatic colorectal cancer in the liver. Numerous tests to help define the location and stage of disease have been evaluated. It now appears that spiral CT with arterial portography is superior to other nonoperative methods in evaluating liver tumors. Immunoscintography using monoclonal antibodies is currently under development and appears to be of potential great value. Subclinical, micrometastatic disease is the bane of all efforts at surgical control of cancer. An ability to detect this would have far-reaching consequences. Complete evaluation of patients with these diseases must include a medical evaluation, including liver function tests and a chest CT. Particular attention must also be paid to cardiac, pulmonary, and renal function.
It is worth noting that exploratory laparotomy need not have the adverse effects described by the authors. Rarely have I seen patients harmed by a simple laparotomy. An incisional biopsy can spread cancer, which appears as accelerated tumor growth in the occasional patient with advanced disease and is best avoided. Usually, incurable patients are on a downhill course and the operation is merely an incidental event.
The use of intraoperative ultrasound is reported to have changed management in 15% to 49% of patients. Bimanual examination of a mobilized liver by an experienced liver surgeon is very accurate. In such instances, intraoperative ultrasound (IOUS) usually finds additional lesions that are best undetected, ie, small hemangiomas or harmatomas. Intraoperative ultrasound is useful in locating intrahepatic vascular structures and perhaps in detecting disease by less experienced surgeons.
The beneficial effect of porta hepatis and celiac axis lymph node dissection combined with hepatic resection has had limited attention. I know of no systematic study of this procedure. The operation is technically difficult. Piecemeal removal of lymph nodes is a futile gesture, and fracturing any positive lymph node would spread cancer. Careful preparation in cadaveric dissections by participating surgeons would be a prerequisite to adequate evaluation of this procedure.
Adjuvant chemotherapy given either by hepatic arterial infusion or systemically should be used only in controlled studies where its as yet undetermined benefit can be evaluated.
It is helpful to remember that highly selected patients with metastatic colorectal cancer to the liver and lung can be surgically salvaged occasionally .
Contrary to the authors' conclusion, post-resection follow-up CT scans at 6-month intervals, along with the appropriate carcinoembryonic antigen (CEA) or alpha-fetoprotein estimation every 2 months and, if metastatic colorectal cancer, annual colonoscopy, have proven desirable and practical in my experience. Surgical removal or freezing of any recurrent disease may be possible. Chemotherapy should probably await symptomatic colorectal recurrence in order to obtain the longest possible longevity benefit. The use of current chemotherapy in patients with recurrent hepatoma merely make the remaining life span more miserable and possibly shorter.
Transplantation Useful for Highly Selected Patients Only
Liver transplantation appears useful for highly selected patients with primary hepatomas. Although some studies appear to demonstrate the superiority of this procedure for hepatoma in general, surgical resection with adequate margins is a safer and more practical option. Removing more nonmalignant liver does not improve cure rates. The risks of multifocal disease are real, but may not appear or may become manifest only many years after the initial operation, when it may be handled again by resection, cryosurgery, or local injection. Multifocal primary cancer also may be accompanied by previously occult metastatic disease.
Early and more recent experiences with liver transplantation for metastatic cancer have consistently shown its utter futility. Hopefully, this lesson will not have to be relearned in the future.
Surgical resection of primary and metastatic liver cancer is fairly well defined. The development of adjuvant therapies to deal with disease beyond surgical boundaries and therapies directed at inoperable cancer continues to pose challenges. The astonishingly good results achieved by alcohol injection and cryosurgery are very encouraging. The true place of these technologies vs standard resection remains to be determined, and should be vigorously investigated.
Preliminary results from the extensive vaccination program against hepatitis carried out in Asia and Africa should become evident soon. These efforts, combined with education about aflatoxin exposure, offer hope for a marked reduction in primary liver cancer on those continents. Some decrease in liver cancer may become evident in this country, but there remain a large number of hepatomas with no known etiologic factors.
The conflicting reports about chemoembolization may relate to technique, the disease stage of treated patients, and the functional reserve of nonmalignant hepatic parenchyma. Cirrhosis and hepatoma are predominantly secondary to hepatitis C infection in Japan and, to some extent, in other parts of Asia. Functional damage of hepatic cells is much less than for comparable degrees of hepatitis B or alcoholic cirrhosis.
Hepatic artery infusion chemotherapy seems to provide worthwhile palliation, but it only marginally prolongs the life of patients with colorectal carcinoma. Intra-arterial chemotherapy has been compared with systemic chemotherapy, which may itself adversely affect patients' health, appetite, and resistance. At best, the survival advantage is measured in months, which seems an inadequate reward for the time, expense, discomfort, and toxicity of treatment.
Finally, it cannot be overemphasized that patients with primary or secondary liver cancer should be treated at medical centers by experienced liver surgeons. The complexity of liver surgery and the good therapeutic results achieved at these centers with low mortality are the bases for this plea. The occasional liver surgeon is a dangerous person who cannot do justice to patients with liver tumors.
1. Smith W, Burt ME, Fortner JG: Resection of hepatic and pulmonary metastasis from colorectal cancer. J Surg Oncol 1:399-404, 1992.