Histopathological growth patterns and positive margins after resection of colorectal liver metastases.

BACKGROUND

Histopathological growth patterns (HGPs) of colorectal liver metastases (CRLM) may be an expression of biological tumour behaviour impacting the risk of positive resection margins. The current study aimed to investigate whether the non-desmoplastic growth pattern (non-dHGP) is associated with a higher risk of positive resection margins after resection of CRLM.

METHODS

All patients treated surgically for CRLM between January 2000 and March 2015 at the Erasmus MC Cancer Institute and between January 2000 and December 2012 at the Memorial Sloan Kettering Cancer Center were considered for inclusion.

RESULTS

Of all patients (n = 1302) included for analysis, 13% (n = 170) had positive resection margins. Factors independently associated with positive resection margins were the non-dHGP (odds ratio (OR): 1.79, 95% confidence interval (CI): 1.11-2.87, p = 0.016) and a greater number of CRLM (OR: 1.15, 95% CI: 1.08-1.23 p < 0.001). Both positive resection margins (HR: 1.41, 95% CI: 1.13-1.76, p = 0.002) and non-dHGP (HR: 1.57, 95% CI: 1.26-1.95, p < 0.001) were independently associated with worse overall survival.

CONCLUSION

Patients with non-dHGP are at higher risk of positive resection margins. Despite this association, both positive resection margins and non-dHGP are independent prognostic indicators of worse overall survival.