Aggressive repeat liver resection for hepatic metastases of colorectal carcinoma

Although hepatectomy for liver metastases from colorectal carcinoma is an effective treatment, recurrence in the liver is still the most common site after hepatectomy. Thirty patients underwent hepatectomy for hepatic metastases and 17 of them had recurrence in the remnant liver during the following 12-year period. Six of the 17 patients underwent a removal of isolated hepatic recurrences. Two of the six patients underwent a third hepatectomy, and three patients underwent partial lung resection on a total of five occasions. There were no operative deaths while complications after a third hepatectomy contributed to a high morbidity rate of 40 per cent. The mean length of survival of the six patients was 28.5 months from the second hepatectomy. The prognosis of the six patients who underwent a repeat hepatectomy was significantly better than that of patients with unresectable recurrence after an initial hepatectomy (p<0.01). The overall 5-year survival of 29 patients excluding one inhospital death was 44.7 per cent. Our results reveal that aggressive removal of isolated and resectable recurrent disease has the potential to improve the prognosis of selected patients with metastatic cancer.     

Role of node dissection for lymphatic remetastasis in repeat hepatectomy for colorectal liver metastasis

BACKGROUND: Although the prognosis after hepatectomy for colorectal liver metastasis with hilar node remetastasis is poor, the role of node dissection for lymphatic remetastasis at repeat hepatectomy for hepatic recurrence is unknown. METHODS: Fifty patients who underwent node dissection plus hepatectomy were retrospectively reviewed and divided into three groups: group I, 38 patients with a negative node; group II, 6 with a positive node at initial hepatectomy, and group III, 6 with a positive node at repeat hepatectomy. RESULTS: The 5-year survival rate after initial hepatectomy in group I was 46%. All patients in group II died within 2 years after surgery. In group III, the median survival time was 42 months after repeat hepatectomy, and 4 patients survived for more than 5 years after initial hepatectomy. Disease-free time was more than 1 year after initial hepatectomy in all long-term survivors. In addition, node metastasis was limited around the hepatic pedicle and postpancreatic area in 3 of 4 long-term survivors. CONCLUSIONS: Node dissection for lymphatic remetastasis may contribute to longer survival only when node metastasis is limited around the hepatic pedicle and postpancreatic area at repeat hepatectomy performed more than 1 year after the initial hepatectomy.     

Treatment strategy for hepatic metastases of colorectal cancer

Over the past 25 years, 125 patients with colorectal liver metastases underwent 167 hepatectomies in our department. The 1-, 3-, and 5-year survival rates after the initial hepatectomy were 90%, 58%, and 51%, respectively, and those after repeated hepatectomy were 88%, 60%, and 42%, respectively. The predictive factors significantly associated with poor prognosis after initial hepatectomy were maximal diameter of metastasis (> or = 5 cm), distribution pattern in the liver (multiple bilobar), number of nodules (> or = four), and presence of extrahepatic metastases. A disease-free interval of > 6 months after initial hepatectomy was a significant factor for prolongation of survival after repeat hepatectomy. Patients with hilar node metastases at the initial hepatectomy did not receive a survival benefit from hepatectomy, while 5 patients underwent repeat hepatectomy with lymphadenectomy for remnant liver and hilar node metastases with a disease-free interval of > 8 months and 4 of them survived for > 5 years. Our treatment strategies for colorectal hepatic metastases are as follows: 1) hepatectomy is the first choice for < 4 liver metastases without extrahepatic disease; 2) a careful evaluation for liver resection is performed for patients with > or = 4 liver metastases receiving hepatic arterial infusion chemotherapy because of the high frequency of hepatic and/or extrahepatic recurrence after initial hepatectomy; 3) the presence of hilar node metastases at the initial hepatectomy should be excluded from surgical indications; 4) simultaneous single metastasis limited to the lung is an indication for lung resection; and 5) a suitable indication for repeat hepatectomy for hepatic recurrence is patients with a longer disease-free interval. Aggressive surgery based on the optimum patient selection can contribute to clinical benefit, including long-term survival in patients with colorectal liver metastases.     

Resection of hepatic metastases of colorectal carcinoma: 20 years' experience

We analyzed the results and the prognostic factors influencing survival in 79 patients with metastases of colorectal carcinoma who underwent hepatectomy at our hospital in the 20-year period 1978–1998. The 5- and 10-year survival rates were 49% and 33%, respectively. Repeat hepatectomy was done 29 times in 24 patients with relapse of liver tumors. The 3- and 5-year survival rates after repeat hepatectomy were 58% and 14%, respectively. The distribution of and number of tumors in the liver, the disease-free interval from initial to second hepatectomy, and the presence of extrahepatic disease were significantly associated with survival (P < 0.01). Seven of 43 patients who underwent hilar node dissection had metastasis and 2 of them survived for more than 5 years. Repeat hepatectomy and hilar lymphadenectomy may be effective in prolonging the sur-vival of selected patients with hepatic metastasis. We also discuss prognostic factors after extensive surgery for hepatic metastases of colorectal carcinoma. Received for publication on Aug. 30, 1998; accepted on Nov. 2, 1998     

Impact of repeat hepatectomy on recurrent colorectal liver metastases

BACKGROUND. Hepatic recurrence is seen in approximately 40% of patients undergoing hepatectomy for colorectal metastases. This study was designed to assess the risks and clinical benefits of repeat hepatectomy for those patients. METHODS. Twenty-six patients underwent repeat hepatectomy for hepatic recurrence, and their clinical data were retrospectively reviewed for operative morbidity and mortality, performance level, and survival. RESULTS. There was no operative mortality after repeat hepatectomy. Operative bleeding was significantly increased in the second hepatectomy; but operating time, duration of hospital stay, and performance status after the second hepatectomy were comparable with those of the initial hepatectomy. The median survival time from the second hepatectomy was 31 months, and the 3- and 5-year survival rates were 62% and 32%, respectively. A short disease-free interval (6 months or less) between the initial hepatectomy and diagnosis of hepatic recurrence in the remnant liver was significantly associated with poor survival after the second hepatectomy. CONCLUSIONS. Repeat resection contributed to clinical benefits for selected patients with hepatic recurrence after the initial hepatectomy for colorectal liver metastases. However, appearance of hepatic recurrence within 6 months or less after the initial hepatectomy is a poor prognostic factor for repeat hepatectomy.     

Prognostic factors for poor survival after repeat hepatectomy in patients with colorectal liver metastases

BACKGROUND: The recurrence rate for colorectal liver metastases after repeat hepatic resection is high, and selection criteria for repeat hepatectomy are still controversial. METHODS: Clinical data of patients undergoing repeat hepatectomy for metastatic colon cancer were reviewed retrospectively and compared with those of initial hepatectomy and other treatments to determine criteria for repeat hepatectomy and to confirm its efficacy. RESULTS: For 22 patients who underwent repeat hepatectomy, no mortality and an 18% morbidity rate were observed. The 3-year survival rate after repeat hepatectomy was 49%. The only poor prognostic factor after repeat hepatectomy was a serum carcinoembryonic antigen level greater than 50 ng/mL before initial hepatectomy. The prognosis for patients who underwent repeat hepatectomy and had shown high carcinoembryonic antigen levels before initial hepatectomy was approximately equal to that for the patients who received systemic chemotherapy or hepatic arterial infusion for unresectable tumors in the remnant liver. CONCLUSION: Repeat hepatectomy for colorectal liver metastases can be performed safely and appears to be as effective as initial hepatectomy. However, for patients with a carcinoembryonic antigen level greater than 50 ng/mL before the initial hepatectomy, repeat hepatic resection alone may not be as effective, and a new strategy is needed.     

Surgery for colorectal liver metastases with hepatic lymph node involvement: a systematic review

BACKGROUND: Liver resection for colorectal metastases is the only known treatment associated with long-term survival; extrahepatic disease is usually considered a contraindication to such treatment. However, some surgeons do not regard spread to the hepatic lymph nodes as a contraindication provided that these nodes can be excised adequately. A systematic review of the literature was undertaken to address this issue. METHODS: An electronic search using Medline, Cancerlit and Embase databases was performed for studies reporting liver resection for colorectal metastases from 1964 to 1999. Data were extracted from papers reporting outcome for patients with positive hepatic nodes and analysed according to predetermined criteria. RESULTS: Fifteen studies were identified that gave survival data on 145 node-positive patients. Five patients were reported to have survived 5 years after liver resection; one was disease free, two had recurrent disease and the disease status was not described in the remaining two. Five studies containing 83 patients specified a formal lymph node dissection as part of the surgical procedure and four of the five node-positive 5-year survivors were from these studies. CONCLUSION: There are few 5-year survivors after liver resection, with or without lymph node dissection, for colorectal hepatic metastases involving the hepatic lymph nodes.     

Impact of microscopic hepatic lymph node involvement on survival after resection of colorectal liver metastasis

BACKGROUND: Macroscopic hepatic lymph node involvement is usually a contraindication to hepatic resection. Only a few studies have investigated the impact of hepatic lymph node involvement on survival. The aim of this retrospective study was to assess microscopic hepatic lymph node involvement in resectable colorectal liver metastasis and outcomes in patients with such involvement. STUDY DESIGN: From January 1985 to December 2000, 156 patients underwent curative liver resection in association with systematic hepatic lymph node dissection for colorectal liver metastasis. A first analysis was performed to assess the association between hepatic lymph node metastasis and patients' characteristics. A second analysis assessed survival after resection of liver colorectal metastasis by using the Kaplan-Meier method. RESULTS: Twenty-three of the 156 patients (15%) had microscopically involved hepatic lymph nodes. No predictive factor of lymph node metastasis was identified. Multivariate analysis showed that lymph node metastasis, preoperative carcinoembryonic antigen level, number of metastases, and morbidity were factors influencing survival. The 3- and 5-year survival rates of patients with lymph node metastasis were 27% and 5%, respectively, compared with 56% and 43% without lymph node metastasis (p = 0.0001). CONCLUSIONS: During resection of liver colorectal metastasis, microscopic lymph node involvement occurred in 15% of the patients and was associated with a poor 5-year survival. Hepatic lymph node dissection should be performed systematically to select high-risk patients.     

Repeat hepatic resection for recurrent colorectal liver metastases is associated with favourable long-term survival

BACKGROUND: The management of patients with recurrent colorectal liver metastases (RCLM) remains controversial. This study aimed to determine whether repeat liver resection for RCLM could be performed with acceptable morbidity, mortality and long-term survival. METHODS: Of 1121 consecutive liver resections performed and prospectively analysed between 1987 and 2005, 852 'curative' resections were performed on patients with colorectal liver metastases. Single liver resection was performed in 718 patients, and 71 repeat hepatic resections for RCLM were performed in 66 patients. RESULTS: There were no postoperative deaths following repeat hepatic resection compared with a postoperative mortality rate of 1.4 per cent after single hepatic resection. Postoperative morbidity was comparable following single and repeat hepatectomy (26.1 versus 18 per cent; P = 0.172), although median blood loss was greater during repeat resection (450 versus 350 ml; P = 0.006). Actuarial 1-, 3- and 5-year survival rates were 94, 68 and 44 per cent after repeat hepatic resection for RCLM, compared with 89.3, 51.7 and 29.5 per cent respectively following single hepatectomy. CONCLUSION: The beneficial outcomes observed after repeat liver resection in selected patients with RCLM confirm the experience of others and support its status as the preferred choice of treatment for such patients.     

Multiple Repeat Resections of Intra- and Extrahepatic Recurrencesin Patients Undergoing Initial Hepatectomy for Colorectal CarcinomaMetastases

Recent evidence suggests that single repeat metastasectomy may provide survival benefits for selected patients experiencing hepatic or pulmonary recurrences following initial hepatectomy for colorectal carcinoma metastases. The aim of this retrospective study was to clarify the efficacy of multiple repeat resections of intra- and extrahepatic recurrences following initial hepatectomy. A total of 100 patients underwent curative partial hepatectomy as the initial procedure for colorectal carcinoma metastases. Tumor relapse after initial hepatectomy was seen in 72 patients, of whom 28 underwent 45 repeat metastasectomies of various sites: 18 patients underwent a single repeat metastasectomy, and 10 underwent multiple repeat metastasectomies. The overall survival rate at 5 years after initial hepatectomy was 36.6%, while the 5-year survival rate after repeat metastasectomy in the 28 patients was 43.6%. The outcome of initial hepatectomy was comparable with that of repeat metastasectomy (p = 0.6924). Among the 28 patients undergoing repeat metastasectomy, the outcome of resection of intrahepatic recurrences in 11 patients was comparable with the outcome of resection of extrahepatic recurrences in 17 patients(p = 0.3926). The outcome of multiple repeat metastasectomies compared favorably with single repeat metastasectomy(p = 0.1803). Multivariate analysis(p < 0.0001) showed that repeat metastasectomy was the strongest prognostic factor. In conclusion, both single and multiple repeat resections of intra- and extrahepatic recurrences after initial hepatectomy are efficacious in colorectal carcinoma patients.Repeat resection should be considered for any resectable recurrences after hepatectomy.     

Extrahepatic disease does not contraindicate hepatectomy for colorectal liver metastases

BACKGROUND: Extrahepatic disease has always been considered an absolute contraindication to hepatectomy for liver metastases. The present study reports the long-term outcome and prognostic factors of patients undergoing resection of extrahepatic disease simultaneously with hepatectomy for liver metastases. METHODS: From January 1987 to January 2001, 111 (30 per cent) of 376 patients who had hepatectomy for colorectal liver metastases underwent simultaneous resection of extrahepatic disease with curative intent. RESULTS: Surgery was considered R0 in 77 patients (69 per cent) and palliative (R1 or R2) in 34 patients (31 per cent). The mortality rate was 4 per cent and the morbidity rate 28 per cent. After a median follow-up of 4.9 years, the overall 3- and 5-year survival rates were 38 and 20 per cent respectively. The 5-year overall survival rate of patients with R0 resection only (n = 75) was 29 per cent. The difference in survival between patients with and without extrahepatic disease discovered incidentally at operation was significant, as was the number of liver metastases. CONCLUSION: Extrahepatic disease in patients with colorectal cancer who also have liver metastases should no longer be considered an absolute contraindication to hepatectomy. However, the presence of more than five liver metastases and the incidental intraoperative discovery of extrahepatic disease remain contraindications to hepatic resection.     

Sequential resection of lung metastasis following partial hepatectomy for colorectal cancer

BACKGROUND: Multiple organ metastases from colorectal carcinoma may be considered incurable, but long survival after both liver and lung resection for metastases has been reported. METHODS: A retrospective analysis of 48 patients who underwent lung resection for metastatic colorectal cancer between 1992 and 1999 was undertaken. Twenty-seven patients had lung metastasis alone, 15 had previous partial hepatectomy, and six had previous resection of local or lymph node recurrence. The relationship of clinical variables to survival was assessed. Survival was calculated from the time of first pulmonary resection. RESULTS: Five-year survival rates after resection of lung metastasis were 73 per cent in patients without preceding recurrence, 50 per cent following previous partial hepatectomy and zero after resection of previous local recurrence. Independent prognostic variables that significantly affected survival after thoracotomy were primary tumour histology and type of preceding recurrence. There was no significant difference in survival after lung resection between patients who had sequential liver and lung resection versus those who had lung resection alone. CONCLUSION: Sequential lung resection after partial hepatectomy for metastatic colorectal cancer may lead to long-term survival.     

Value of lymph node dissection during resection of intrahepatic cholangiocarcinoma.

BACKGROUND: Hepatectomy with extensive lymph node dissection is the standard operation for intrahepatic cholangiocarcinoma (IHCC). However, lymph node dissection may not always be effective at reducing tumour recurrence. METHODS: Forty-nine patients with IHCC who underwent hepatectomy were investigated to determine patterns of tumour recurrence and to estimate the value of lymph node dissection during resection. RESULTS: At hepatectomy most metastatic lymph nodes were identified at least to the level of group 2 lymph nodes. Among 23 patients who developed recurrence, 17 had liver metastases and the other six had recurrence at other sites, mainly in the peritoneum. Poorly differentiated histology was related to the development of liver metastases. No patient with the intraductal growth type of IHCC had tumour recurrence. Lymph node dissection did not appear to improve patient survival. Histological findings of lymph node metastases and intrahepatic metastases were independent indicators of poor prognosis. CONCLUSION: Lymph node metastases were seldom limited to the regional lymph nodes; most tumour recurrence occurred in the liver. Lymph node dissection did not appear to improve patient survival. Lymph node dissection alone is not likely to improve the prognosis without further control of liver metastases.     

Combined inguinal and pelvic lymph node dissection for stage III melanoma

BACKGROUND: The incidence of melanoma is increasing in the UK and a significant number of patients are still presenting with primary lesions of poor prognosis. As a consequence there is likely to be an increasing number of patients with lymph node metastases for whom the appropriate extent of groin dissection remains controversial. This review summarizes the evidence to enable surgeons to make an informed decision about the management of patients with melanoma metastases to the groin lymph nodes. METHODS: A Medline search was performed to identify all English language articles about melanoma containing the words lymphadenectomy, lymph nodes, inguinal or lymphoedema. Eighty-seven relevant articles were selected from 3904 abstracts retrieved; 34 were related directly to the aim of this review. RESULTS: There are no randomized controlled trials comparing the outcome of combined inguinal and pelvic lymph node dissection (CLND) and superficial inguinal lymph node dissection (SLND). Excision of pelvic lymph node metastases is reported to yield a 5-year survival rate of 0-35 per cent. Recurrence within the pelvis occurs in 9-18 per cent of patients after SLND and in less than 5 per cent after CLND. Morbidity following either CLND or SLND is poorly reported. Major long-term lymphoedema limiting patient activity affects 6-20 per cent of patients after groin dissection. Cloquet's node was demonstrated in one study to be a useful predictor of pelvic lymph node involvement. Patients may be selected for pelvic node dissection on the basis of clinical findings, the results of pelvic computed tomography and the status of Cloquet's node. CONCLUSION: The controversy surrounding the appropriate management of cytologically positive inguinal nodes in melanoma can be resolved only by a prospective randomized trial comparing CLND with SLND. Morbidity and local disease control must be measured as outcomes in addition to disease-free and overall survival.     

Repeat Hepatectomy for Recurrent Colorectal Metastases

Purpose To determine the risks and benefits of repeat hepatectomy for hepatic metastases from colorectal cancer.Methods During a recent 10-year-period, 106 patients underwent hepatectomy for hepatic metastases from colorectal cancer, in our hospital. Recurrence developed in the liver in 57 of these patients, 27 of whom underwent repeat hepatectomy. We reviewed the outcomes of these 27 patients.Results There were three complications after the first hepatectomy and six complications after the second hepatectomy, but there was no perioperative mortality after the first or second hepatectomy. The median survival from the date of second hepatectomy was 41 months with an actuarial 5-year survival rate of 48.7%. Patients who underwent repeat hepatectomy had significantly higher survival rates from the time of first hepatectomy than those who did not. Univariate analysis showed that among the prognostic factors of repeat hepatectomy, only a disease-free interval (DFI) between the first and second hepatectomy of more than 1 year was significantly predictive of a better outcome (P = 0.047).Conclusion Repeat hepatectomy for recurrent colorectal metastases can be performed safely with acceptable mortality and morbidity rates, and can help to extend survival, if the DFI between the first and second hepatectomy is longer than 1 year.     

Repeat liver resection for recurrent colorectal liver metastases

BACKGROUND: This study aimed to delineate the role of surgery for recurrent colorectal cancer in the liver and to identify prognosticators for better patient selection and outcome. METHODS: Data from 90 repeat hepatectomies (second = 75; third = 12; fourth = 3) for recurrent colorectal cancer were collected. RESULTS: After the second hepatectomy, the 3-and 5-year survival rates were 48% and 31%, respectively. Twenty-seven percent (20 of 75) of patients are alive without recurrence after a median follow-up of 27 months, and 9 survived more than 5 years. Four or more tumors, positive regional lymph node metastases, concomitant extrahepatic disease, and residual tumor were independent poor prognostic factors after the second hepatectomy. CONCLUSIONS: Repeat hepatectomy should be applied for recurrent colorectal cancer, when curative removal of the tumor is possible, although the benefit from treatment was limited in a patient with regional lymph node metastases, 4 or more metastases, or extrahepatic disease.     

Major anatomical hepatic resection with regional lymph node dissection for liver metastases from colorectal cancer

Sixty-four patients with liver metastases from colorectal cancer were studied to clarify the characteristics of the regional spread of liver metastases (secondary invasive factors) and the effects of major anatomical hepatic resection with lymph node dissection on reducing liver recurrence. No secondary invasive factors, i.e., lymph node metastasis, portal or hepatic vein involvement, bile duct involvement, micrometastasis, and direct invasion, were observed in patients with liver metastases less than 3 cm in diameter (5-year survival rate; 100%). Secondary invasive factors were seen in 19.2% of the patients with liver metastases from 3 cm to less than 6 cm (5-year survival rate; 28.7%), and in 45.2% of those with liver metastases 6 cm and over (5-year survival rate; 14.6%). Secondary invasive factors were noted in 45% of the patients with recurrence in the remmant liver. Although 31% of all 64 patients exhibited secondary invasive factors, major anatomical hepatic resection with lymph node dissection achieved a low liver recurrence rate of 31.3%. In conclusion, considering the risks attributed to secondary invasive factors, major anatomical hepatic resection with lymph node dissection is an appropriate surgical procedure for patients with liver metastases exceeding 3 cm in diameter.     

Unilateral lymphadenectomy in intraoperative stage I nonseminomatous germinal testis cancer

Bilateral retroperitoneal lymphadenectomy is mainly a staging procedure in patients with stage I nonseminomatous testis cancer, and it causes permanent loss of antegrade ejaculation in approximately two-thirds of the cases. Between May 1978 and August 1981, 61 consecutive patients with no intraoperative evidence of lymph node involvement underwent unilateral retroperitoneal lymph-adenectomy for nonseminomatous germinal testis tumors. Microscopic metastases were found in 1 to 4 retroperitoneal nodes in 6 cases (9.8 per cent). Antegrade ejaculation was absent postoperatively in 11 patients (18 per cent), with no significant difference between patients who underwent lymph node dissection on the left or right side. Ejaculation returned spontaneously in 3 patients, 1 of whom fathered a child. The disease recurred in 10 patients 3 to 35 months after lymphadenectomy (median 6 months). Disease recurred in 8 of 55 patients (14.5 per cent) with negative nodes and 2 of 6 (33.3 per cent) with positive histological findings. No patient suffered retroperitoneal recurrence. The more than 3-year survival rates free of disease were 96.4 and 83.3 per cent in patients with pathological stages I and II disease, respectively. Unilateral retroperitoneal lymphadenectomy in patients with intraoperative stage I nonseminomatous germinal testis cancer preserves antegrade ejaculation in more than 80 per cent of the cases without apparently compromising the long-term survival.     

Unique distribution patterns of metastatic lymph nodes in patients with superficial carcinoma of the thoracic oesophagus.

BACKGROUND: Lymph node metastasis is commonly found in carcinoma of the thoracic oesophagus, even when the tumour invades only the submucosa. Although lymph node status greatly influences the outcome, the pattern of early lymphatic spread has not been investigated, and the role of lymph node dissection is still a matter of controversy. METHODS: A series of 110 patients with superficial carcinoma who underwent systematic extended lymph node dissection was investigated retrospectively. RESULTS: Lymph node involvement was found in 0 per cent (none of nine), 23 per cent (five of 22) and 49 per cent (38 of 78) of tumours that invaded the lamina propria, muscularis mucosa and submucosa respectively. Anatomically distant lymph nodes (recurrent nerve nodes and perigastric nodes) were involved more frequently than other intrathoracic nodes adjacent to the main tumour. Only three patients had involvement limited to the intrathoracic group, and in carcinoma that invaded only the muscularis mucosae, all metastatic nodes were located at the thoracocervical junction or in the abdomen. The 5-year survival rate was 89 per cent in the node-negative group and 54 per cent in the node-positive group (P < 0.0003). CONCLUSION: The recurrent nerve nodes and perigastric nodes are the principal proximal regional lymph nodes involved in superficial carcinoma of the thoracic oesophagus. Systematic lymph node dissection, which included these nodes, yielded an acceptable and favourable outcome in patients with node-positive superficial carcinoma.     

Incidence and prognostic significance of lateral lymph node metastasis in patients with advanced low rectal cancer

BACKGROUND: Lateral lymph node metastases occur in some patients with low rectal cancer and may cause local recurrence after total mesorectal excision. The aims of this study were to identify risk factors for lateral node metastases in patients with pathological tumour (pT) stage 3 or pT4 low rectal adenocarcinoma, and to evaluate the prognostic significance of lateral node metastases. METHODS: A retrospective analysis was performed of the outcome of 237 patients with pT3 or pT4 low rectal adenocarcinoma who underwent R0 resection with systematic lateral node dissection. RESULTS: Lateral lymph node metastases were found in 41 patients (17.3 per cent). Increased risk of lateral lymph node metastases was associated with a distal tumour margin close to the anal margin, histological type other than well or moderately differentiated adenocarcinoma, and the presence of mesenteric lymph node metastases. Patients with lateral node metastases had a significantly shorter postoperative survival (5-year survival rate 42 versus 71.6 per cent; P < 0.001) and an increased risk of local recurrence (44 versus 11.7 per cent; P < 0.001) compared with those without lateral node metastases. CONCLUSION: Tumour site, histological type and the presence of mesenteric lymph node metastasis are factors predicting the risk of lateral node metastasis. The poor prognosis of patients with lateral lymph node metastases after systematic lateral dissection suggests the need for adjuvant therapy.