Table 1.
Controversial issues involving surgical strategies for colorectal cancer with synchronous resectable liver metastases
| Controversial issue | Advantages | Disadvantages |
| Surgical strategies for synchronous CRLM: | ||
| • Traditional "staged" or "classic" approach | Risks of CRR and LR are not cumulated; CHT can be usefully administered before the LR | May determine progression of CRLM, sometimes up to unresectability; manipulation of metastatic CRC may have adverse effects on distant metastases and oncological outcome |
| • "Reverse" or "liver-first" approach | Avoids progression of borderline resectable CRLM; permits appropriate NACHRT for locally advanced rectal cancer, sometimes up to complete response | Comparative results with the traditional approach are still uncertain |
| • Simultaneous colorectal and liver resection | Reduces the number of surgical procedures; may reduce the duration of perioperative CHT; may decrease the cumulative costs of hospitalization | Requires accurate selection of candidates; may increase perioperative morbidity and mortality; oncological outcomes are still uncertain |
| NACHT of resectable CRLM | May reduce the extent of LR; may increase the R0 resection rates; eradicates micrometastases; may select patients with favourable oncological prognosis after LR | May determine progression of CRLM, sometimes up to unresectability; may determine parenchymal damage and increase perioperative morbidity; its overall beneficial impact on oncological outcomes has not been confirmed |
| Nonanatomic/parenchymal-sparing vs anatomic LR | May reduce the extent of LR; may increase resectability; may achieve better perioperative results; may favour reresection in case of hepatic recurrence, with consequent improvement of oncological results | May reduce the extent of the RM; its overall impact on oncological outcomes is still controversial |
| The prognostic role of the RM: | ||
| • ≥ 10 mm | May reduce the overall risk of recurrence; may achieve better oncological outcomes | May reduce resectability |
| • 1 to 10 mm | May reduce the extent of LR; may increase resectability | May favour tumour recurrence; may determine worse oncological outcomes |
| • < 1 mm (R1 resection) | May increase resectability | Determines worse oncological outcomes; perioperative CHT is mandatory |
| • “R1 vascular” RM (detachment of CRLM from vessels) | May reduce the extent of LR; may increase resectability | May favour tumour recurrence; may determine worse oncological outcomes |
| Evaluation of genetic mutations of CRLM | Predict response to CHT; may predict response to perioperative CHT; may predict oncological results of LR; may predict positive RM in candidates for LR; may suggest more extensive/anatomical LR; may predict response to local (RFTA) and loco-regional (chemo and radioembolization) treatments | Its overall role in establishing individualized therapeutic strategies is still uncertain; its overall impact on oncological outcomes is still uncertain |
| Treatment of multiple bilobar CRLM: | ||
| • NACHT of multiple resectable CRLM | May favour curative LR; may reduce the extent of LR; may increase the R0 resection rates; eradicates micrometastases; may select patients with favourable oncological prognosis after LR | May determine progression of CRLM, sometimes up to unresectability; may determine parenchymal damage and increase perioperative morbidity; its overall beneficial impact on oncological outcomes is uncertain |
| • PSLR vs major LR, including PVE, TSH and ALPPS | Reduces the extent of LR; may increase resectability; reduces the risk of PHLF; may achieve better perioperative results; may favour reresection in case of hepatic recurrence | May reduce the extent of the RM; its overall impact on oncological outcomes is still controversial |
| • Intraoperative local ablation techniques | May reduce the extent of LR; may increase resectability; may favour curative LR | Higher risk of local recurrence, especially for larger tumours; its overall beneficial impact on oncological outcomes is still uncertain |
| The impact of PSLR on simultaneous resections | May reduce the extent of LR; may increase resectability of CRLM; may improve the propensity for simultaneous resection; may achieve better perioperative results | May reduce the extent of the RM of LR; its overall impact on oncological outcomes is still controversial |
CRLM: Colorectal liver metastases; CRR: Colorectal resection; LR: Liver resection; CHT: Chemotherapy; CRC: Colorectal cancer; NACHRT: Neoadjuvant chemoradiotherapy; RM: Resection margin; RFTA: Radiofrequency thermal ablation; NACHT: Neoadjuvant CHT; PSLR: Parenchymal-sparing liver resection; PVE: Portal vein embolization; TSH: Two-stage hepatectomy; ALPPS: Associating liver partition and portal vein ligation for staged hepatectomy; PHLF: Posthepatectomy liver failure.