Local recurrence in patients with synchronous or metachronous colorectal liver metastases--is there a difference?

To determine whether the seemingly high rate of local recurrence after colorectal cancer surgery in the presence of liver metastases results from factors related to the surgical excision of the primary tumour or greater biological aggressiveness of the tumour.

A retrospective study comparing local recurrence rates and surgical and pathological variables noted in operation and pathology reports was undertaken in 65 patients being treated for synchronous liver metastases (Group 1), and 42 patients being treated for metachronous liver metastases (Group 2).

Local recurrence occurred in 15.4% of those from Group 1 and 9.5% of those from Group 2 (p=0.38). The local recurrence after rectal cancer excision in the two groups was 27.3% and 12.5% respectively (p=0.28). Although not significantly different, the rates in Group 1 (in particular) seem undesirably high. There was no significant difference in resected specimens between the groups in respect of length of bowel removed, numbers of lymph nodes removed, or involved surgical margins. Neither was there any significant difference between the tumour grade, stage, or venous invasion. Considerable variation was noted between pathology reports in respect of 13 variables thought to be important in such reports. Under-reporting was especially evident in respect of numbers of lymph nodes, venous invasion, and the measurement of the radial resection margin of rectal tumours.

Although a high local recurrence rate was found in Group 1 in particular, there is no evidence that this relates to the extent of resection at the time of primary tumour removal. Neither is there clear evidence for greater biological aggressiveness based on light microscopy features. Deficiencies in, and considerable variation in the quality of, pathological reporting was noted, thus diminished the ability of the study to deliver firm conclusions.