Annals of the Royal College of Surgeons of England (1990) vol. 72, 199-205
SURGICAL DEBATE
Resection of liver metastases from a colorectal carcinoma does not benefit the patient Trevor M Hunt MS FRCS Research Registrar
Nick Carty
FRCS
Research Registrar
Colin D Johnson
MChir FRCS
Senior Lecturer
Department of Surgery, Southampton General Hospital
Key words: Liver metastases; Liver resection; Colorectal carcinoma
This paper presents arguments for and against the motion that 'Resection of liver metastases from colorectal carcinoma does not benefit the patient'. The case for this proposition is summarised as follows: survival after resection of smali metastases is not markedly different from the natural history of similar tumours; patients with metastases apparently localised to one area of the liver are uncommon, and thorough investigation further reduces the proportion of such patients; the operative mortality of liver resection has a significant adverse effect on survival after resection, and may cancel out the benefits of surgery, and finally the alternative non-operative methods of treating these patients may offer similar benefits to resection. The counter argument is simple: for a patient with liver metastases the only hope of eradication of liver disease lies in surgical resection. If this can be achieved then the prognosis is as good as for a similar primary tumour without liver metastases.
Present appointments T Hunt, Surgical Registrar, Queen Alexandra Hospital, Cosham, Portsmouth N Carty, Surgical Registrar, Basingstoke District Hospital, Basingstoke Correspondence to: C D Johnson, Department of Surgery, F Level, Centre Block, Southampton General Hospital, Tremona Road, Southampton S09 4XY
Between 15 and 25% of patients who undergo resection of a colorectal carcinoma have palpable synchronous liver metastases (1). A further 15% of patients have metastases which are demonstrable on special investigations in the perioperative period (2,3). These occult metastases are thought to be those which subsequently present as 'metachronous' liver secondaries. Liver resection of colorectal metastases has been proposed for cure, to increase the length of survival, or for symptomatic relief. It is now accepted that resection of metastases for relief of symptoms is unrewarding. Such symptomatic tumours are better palliated with appropriate analgesia and hepatic artery embolisation (4-6). The value of hepatic resection for colorectal liver metastases remains controversial, despite the fact that the first hepatic resection for metastases was performed over 100 years ago (7). It is accepted that the majority of patients with metastases are not helped by any therapy currently available, but there is a small group, variously estimated at between 10% and 25% of patients with metastases (8,9) who might benefit from resection of liver metastases. These patients have solitary metastases or small multiple deposits in one area of the liver, and can be offered resection for cure, in that all remaining liver appears normal.
The case for the motion Patients with hepatic metastases can be divided into two groups according to the size and extent of their tumour.
T M Hunt et al.
200
Table I. Survival of patients with untreated, potentially resectable, low volume liver metastases. Survival times are mean or median in various series (PHR = percent
hepatic replacement) First author (reference)
Pettavel Wood Wanebo Goslin Wagner Wood Daly
(23) (16) (24)
(25) (9)
Type of metastases
Survival % (months) 5 years
Solitary/small
22
'Resectable' Solitary Less than four
19
(26)
Solitary Solitary
(19)
24
Patients with extensive tumour do not benefit from resection (10-14). The criteria used to define extensive disease include the number of metastases (>3), a percentage hepatic replacement (PHR) with tumour that is greater than 25%, the presence of extrahepatic disease at the time of resection, or residual tumour at the margins of resection in the liver. Patients with small metastatic tumours confined to one area of the liver are clearly suitable for resection. However, it can be argued in support of this motion that these patients do not benefit from such an operation on the following grounds: Survival after liver resection of small metastatic is no better than the natural history of such disease; 2 More sophisticated methods of investigation reveal multifocal disease in an increasing proportion of patients and it is doubtful whether any metastasis is truly solitary; 3 The operative mortality of liver resection significantly influences the overall survival, so that any potential benefit of the operation is cancelled out; 4 Finally, the alternative non-resectional methods of treating such patients offer similar benefits to resection, without the operative morbidity and mortality. 1
tumours
The natural history of patients with small hepatic metastases
The survival of patients with colorectal liver metastases is well established to be related to the extent of hepatic tumour, whether expressed as crude operative estimates (15,16), or somewhat more refined semiquantitative estimates of the PHR by imaging or operative techniques (14,17-22). The natural history of patients with lowvolume, potentially resectable liver metastases has not been extensively investigated. The results of the few reported series are shown in Table I. The inclusion criteria varied in the different studies, but all included patients with low-volume metastases who would be considered for hepatic resection. The reported mean or median survival times were between 19 and 24 months, and in the study of Daly et al. (19) more than half the
untreated patients with less than 20% PHR were still alive after 24 months' follow-up. These results, and the observation of 5-year survivors in patients with untreated low-volume resectable metastases, show little difference from the results of hepatic resection (Table II).
Identification of resectable metastases If it is accepted that multifocal metastases are not suitable for resectional surgery, then it is essential to exclude as many patients as possible with small multifocal deposits. Improvements in investigation technology have reduced the numbers of patients thought to have solitary deposits, although even current techniques are disappointingly insensitive. The diagnostic sensitivity for colorectal liver metastases of isotope scintigraphy, ultrasound and computed tomography (CT) are between 70% and 95%. The accurate quantification and localisation of individual metastases is less reliable. For example Snow et al. (32) report 35 patients with bilobar hepatic disease at operation which was incorrectly diagnosed as unilobar disease in 24% of cases by ultrasound, 25% of cases by CT, and 39% by isotope imaging. Smith et al. (33) report the sensitivity of these different methods for the detection of 82 individual histologically proven lesions in 18 patients. The sensitivity for isotope imaging was only 27%, ultrasound 29%, and CT 38%. It was commented that detection of lesions greater than 3 cm was good, whereas lesions less than 2 cm were frequently missed. Sugarbaker et al. (34) report the results of CT enhanced by intravenous ethiodised oil emulsion. Although 83% of individual lesions between 1 and 2 cm were detected, the diagnosis of lesions less than 1 cm was still disappointingly inaccurate. Peroperative contact ultrasonography has been advocated to detect individual lesions at operation. However, Thomas et al. (35) report an in vitro study of contact ultrasonography on freshly resected specimens in which only 45 of 67 (67%) metastases were detected. When analysed by size of lesion, this represented detection of 95% of metastases greater than 1 cm, 67% of 0.5-1.0 cm lesions, and none of the smallest lesions (
SURGICAL DEBATE
Resection of liver metastases from a colorectal carcinoma does not benefit the patient Trevor M Hunt MS FRCS Research Registrar
Nick Carty
FRCS
Research Registrar
Colin D Johnson
MChir FRCS
Senior Lecturer
Department of Surgery, Southampton General Hospital
Key words: Liver metastases; Liver resection; Colorectal carcinoma
This paper presents arguments for and against the motion that 'Resection of liver metastases from colorectal carcinoma does not benefit the patient'. The case for this proposition is summarised as follows: survival after resection of smali metastases is not markedly different from the natural history of similar tumours; patients with metastases apparently localised to one area of the liver are uncommon, and thorough investigation further reduces the proportion of such patients; the operative mortality of liver resection has a significant adverse effect on survival after resection, and may cancel out the benefits of surgery, and finally the alternative non-operative methods of treating these patients may offer similar benefits to resection. The counter argument is simple: for a patient with liver metastases the only hope of eradication of liver disease lies in surgical resection. If this can be achieved then the prognosis is as good as for a similar primary tumour without liver metastases.
Present appointments T Hunt, Surgical Registrar, Queen Alexandra Hospital, Cosham, Portsmouth N Carty, Surgical Registrar, Basingstoke District Hospital, Basingstoke Correspondence to: C D Johnson, Department of Surgery, F Level, Centre Block, Southampton General Hospital, Tremona Road, Southampton S09 4XY
Between 15 and 25% of patients who undergo resection of a colorectal carcinoma have palpable synchronous liver metastases (1). A further 15% of patients have metastases which are demonstrable on special investigations in the perioperative period (2,3). These occult metastases are thought to be those which subsequently present as 'metachronous' liver secondaries. Liver resection of colorectal metastases has been proposed for cure, to increase the length of survival, or for symptomatic relief. It is now accepted that resection of metastases for relief of symptoms is unrewarding. Such symptomatic tumours are better palliated with appropriate analgesia and hepatic artery embolisation (4-6). The value of hepatic resection for colorectal liver metastases remains controversial, despite the fact that the first hepatic resection for metastases was performed over 100 years ago (7). It is accepted that the majority of patients with metastases are not helped by any therapy currently available, but there is a small group, variously estimated at between 10% and 25% of patients with metastases (8,9) who might benefit from resection of liver metastases. These patients have solitary metastases or small multiple deposits in one area of the liver, and can be offered resection for cure, in that all remaining liver appears normal.
The case for the motion Patients with hepatic metastases can be divided into two groups according to the size and extent of their tumour.
T M Hunt et al.
200
Table I. Survival of patients with untreated, potentially resectable, low volume liver metastases. Survival times are mean or median in various series (PHR = percent
hepatic replacement) First author (reference)
Pettavel Wood Wanebo Goslin Wagner Wood Daly
(23) (16) (24)
(25) (9)
Type of metastases
Survival % (months) 5 years
Solitary/small
22
'Resectable' Solitary Less than four
19
(26)
Solitary Solitary
(19)
24
Patients with extensive tumour do not benefit from resection (10-14). The criteria used to define extensive disease include the number of metastases (>3), a percentage hepatic replacement (PHR) with tumour that is greater than 25%, the presence of extrahepatic disease at the time of resection, or residual tumour at the margins of resection in the liver. Patients with small metastatic tumours confined to one area of the liver are clearly suitable for resection. However, it can be argued in support of this motion that these patients do not benefit from such an operation on the following grounds: Survival after liver resection of small metastatic is no better than the natural history of such disease; 2 More sophisticated methods of investigation reveal multifocal disease in an increasing proportion of patients and it is doubtful whether any metastasis is truly solitary; 3 The operative mortality of liver resection significantly influences the overall survival, so that any potential benefit of the operation is cancelled out; 4 Finally, the alternative non-resectional methods of treating such patients offer similar benefits to resection, without the operative morbidity and mortality. 1
tumours
The natural history of patients with small hepatic metastases
The survival of patients with colorectal liver metastases is well established to be related to the extent of hepatic tumour, whether expressed as crude operative estimates (15,16), or somewhat more refined semiquantitative estimates of the PHR by imaging or operative techniques (14,17-22). The natural history of patients with lowvolume, potentially resectable liver metastases has not been extensively investigated. The results of the few reported series are shown in Table I. The inclusion criteria varied in the different studies, but all included patients with low-volume metastases who would be considered for hepatic resection. The reported mean or median survival times were between 19 and 24 months, and in the study of Daly et al. (19) more than half the
untreated patients with less than 20% PHR were still alive after 24 months' follow-up. These results, and the observation of 5-year survivors in patients with untreated low-volume resectable metastases, show little difference from the results of hepatic resection (Table II).
Identification of resectable metastases If it is accepted that multifocal metastases are not suitable for resectional surgery, then it is essential to exclude as many patients as possible with small multifocal deposits. Improvements in investigation technology have reduced the numbers of patients thought to have solitary deposits, although even current techniques are disappointingly insensitive. The diagnostic sensitivity for colorectal liver metastases of isotope scintigraphy, ultrasound and computed tomography (CT) are between 70% and 95%. The accurate quantification and localisation of individual metastases is less reliable. For example Snow et al. (32) report 35 patients with bilobar hepatic disease at operation which was incorrectly diagnosed as unilobar disease in 24% of cases by ultrasound, 25% of cases by CT, and 39% by isotope imaging. Smith et al. (33) report the sensitivity of these different methods for the detection of 82 individual histologically proven lesions in 18 patients. The sensitivity for isotope imaging was only 27%, ultrasound 29%, and CT 38%. It was commented that detection of lesions greater than 3 cm was good, whereas lesions less than 2 cm were frequently missed. Sugarbaker et al. (34) report the results of CT enhanced by intravenous ethiodised oil emulsion. Although 83% of individual lesions between 1 and 2 cm were detected, the diagnosis of lesions less than 1 cm was still disappointingly inaccurate. Peroperative contact ultrasonography has been advocated to detect individual lesions at operation. However, Thomas et al. (35) report an in vitro study of contact ultrasonography on freshly resected specimens in which only 45 of 67 (67%) metastases were detected. When analysed by size of lesion, this represented detection of 95% of metastases greater than 1 cm, 67% of 0.5-1.0 cm lesions, and none of the smallest lesions (
