Role of Neoadjuvant Chemotherapy Before Simultaneous Resection of Colon Cancer and Liver Metastases: A Propensity-Score Matched Analysis.

Background: There has been a controversy about the optimal management of colorectal liver metastases (CLM). Both upfront surgery and neoadjuvant chemotherapy are viable options for CLM. The present study aimed to assess the short-term and survival outcomes of neoadjuvant chemotherapy before simultaneous resection of primary colon cancer and liver metastases.

Methods: This retrospective cohort study used data from the National Cancer Database (2015-2019) on patients with primary colon cancer and synchronous liver metastases. The main exposure was neoadjuvant chemotherapy before simultaneous resection of colon cancer and hepatic metastases. Propensity-score matching was used to match patients who had upfront surgery without neoadjuvant chemotherapy with patients who received neoadjuvant chemotherapy. The primary outcome was 5-year overall survival (OS). Secondary outcomes included hospital stay, 30-day and 90-day mortality, 30-day unplanned readmission, conversion to open surgery, surgical margins, and disease downstaging.

Results: Overall, neoadjuvant chemotherapy was given to 38.3% of 4060 patients. After matching, 1446 patients (53% male) were included; 482 were in the neoadjuvant group and 964 were in the no-neoadjuvant group. Neoadjuvant chemotherapy was associated with a longer restricted mean OS (46.7 vs. 40.6 months, P < .001) and significantly lower rates of 90-day mortality (3% vs. 6.5%, P = .008), 30-day unplanned readmission (4.8% vs. 8.8%, P = .002), positive surgical margins (6.5% vs. 15.1%, P < .001), and administration of adjuvant therapy (47.3% vs. 79.5%, P < .001). The 2 groups were comparable in hospital stay, 30-day mortality, and number of examined lymph nodes.

Conclusions: Giving neoadjuvant chemotherapy before simultaneous resection of colon cancer and hepatic metastases was associated with extended mean OS and reduced rates of 90-day mortality, 30-day unplanned readmission, and positive surgical margins.