The tendency of segmental distribution of hepatic metastasis according to couinaud classification: a comparison of portal versus systemic route of metastatis due to primary colorectal and breast tumors

OBJECTIVE: The liver is the commonest site of metastatic disease for patients with colorectal cancer (CRC), with at least 25% of patients developing liver metastasis (LM) during their illness. About 50% of patients diagnosed with metastatic breast cancer develop LM, and 5–12% of these patients develop LM as the main site of breast cancer recurrence. This study aims to determine the frequency of segmental distribution of LM seeding from portal versus systemic routes of dissemination due to primary CRC and breast carcinoma, respectively. MATERIAL AND METHODS: This retrospective study was conducted in a tertiary care teaching hospital in Pakistan. Ethical approval was taken from the institutional review board. A total of 587 patients were included in the study with 297 CRC patients with LM and 300 breast carcinoma patients with LM. Segment I involvement was excluded from the calculation because of the dual blood supply. Patients’ detailed demographics and other information were collected on a predesigned proforma. The authors evaluated axial and multiplanar reformatted computed tomography images for LM and CRC metastasis. Data analysis was done using SPSS version 25. P value less than or equal to 0.05 was considered statistically significant. RESULTS: A study population of 587 patients was employed that comprised 287 CRC and 300 breast carcinoma patients. There were 179 (30.5%) male and 408 (69.5%) female patients. The mean age of patients was 54.9±13.3. The study revealed that 204 (34.8%) CRC patients showed right lobe (V, VI, VII, VIII) and 83 (14.1%) CRC patients showed left lobe involvement of metastasis while 192 (32.7%) breast carcinoma patients showed right lobe involvement and 108 (18.4%) breast carcinoma patients showed left lobe involvement in metastasis (P=0.02). We also found 40 (6.8%) colorectal and 55 (9.4%) breast carcinoma patients showed left lateral segment (II, III) involvement. Medial segment involvement (IV) was seen in 43 (7.3%) CRC patients and 53 (9%) breast carcinoma patients (P=0.03). CONCLUSION: The right hepatic lobe is the predominant site of metastasis independent of the portal or systemic route of dissemination in primary carcinoma. Moreover, in left lobe metastasis medial segment (IV) is more affected in CRC while the lateral segment (II, III) is more affected in breast carcinoma.