Rectal cancer with synchronous liver metastasis at presentation represents a particular challenge with treatment at two sites.

The 2 main strategies include operating either the liver-first or, the primary-first.

Choice of therapy stratification is largely decided by tumour volume and tumour burden.

Liver-first strategy was chosen in most patients who needed pre-operative radiotherapy of the primary.

Recurrence rates were high, but overall survival as reported by others.

Management of primary rectal cancer presenting with synchronous liver metastases (CRLM) is debated as there several treatment strategies to consider. The aim of this study was to evaluate the strategies used in an unselected cohort.

An observational, population-derived cohort of patients treated for synchronous CRLM and rectal cancer within a prospective biomarker trial (ACROBATICC).

Of 192 patients operated for CRLM, 35 (18%) had rectal cancer and synchronous CRLM. A total of 22 patients (63%) were treated with liver-first followed by primary resection, while 13 patients (37%) had the primary-first approach. Four patients having liver-first developed further metastasis and did not proceed to rectal surgery. A significantly higher rate of pre-operative primary tumour radiation occurred in the liver-first group, 19 (86%) vs 6 (46%) in the primary first (P = 0.038), suggesting a more advanced stage for the primary rectal cancer with planned liver surgery-first as part of operating in the “window” between radiation and eventual primary rectal cancer surgery. Also, the liver-first group received fewer cycles of chemotherapy (median 4 (4-8) vs median 8 (5-11) cycles; P = n.s.), indicating need to ‘control’ or ‘convert’ liver metastasis in the primary-first group prior to hepatectomy. Follow-up time for the cohort was 36 months (IQR 21-69), with 21 (96%) recurrences in the liver first group and 7 (58%) in the primary first (P = 0.014).

Treatment sequencing reflects overall tumour presentation at diagnosis. The liver-first strategy was preferentially used in patients with more advanced rectal disease and was associated with high recurrence, reflecting tumour biology rather than treatment sequence.

Rectal cancer

Synchronous liver metastasis

Strategy

Hepatectomy

Recurrence

Overall survival

© 2026 The Authors. Published by Elsevier Ltd.