Planned Treatment of Advanced Metastatic Disease with Completion Ablation After Hepatic Resection

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

Locoregional treatment for colorectal liver metastases aiming for precision medicine

In patients with colorectal liver metastases (CLM), surgery is potentially curative. The use of novel surgical techniques and complementary percutaneous ablation allows for curative-intent treatment even in marginally resectable cases. Resection is used as part of a multidisciplinary approach, which for nearly all patients will include perioperative chemotherapy. Small CLM can be treated with parenchymal-sparing hepatectomy (PSH) and/or ablation. For small CLM, PSH results in better survival and higher rates of resectability of recurrent CLM than non-PSH. For patients with extensive bilateral distribution of CLM, two-stage hepatectomy or fast-track two-stage hepatectomy is effective. Our increasing knowledge of genetic alterations allows us to use them as prognostic factors alongside traditional risk factors (e.g. tumor diameter and tumor number) to select patients with CLM for resection and guide surveillance after resection. Alteration in RAS family genes (hereafter referred to as "RAS alteration") is an important negative prognostic factor, as are alterations in the TP53, SMAD4, FBXW7, and BRAF genes. However, APC alteration appears to improve prognosis. RAS alteration, increased number and diameter of CLM, and primary lymph node metastasis are well-known risk factors for recurrence after CLM resection. In patients free of recurrence 2 y after CLM resection, only RAS alteration is associated with recurrence. Thus, surveillance intensity can be stratified by RAS alteration status after 2 y. Novel diagnostic instruments and tools, such as circulating tumor DNA, may lead to further evolution of patient selection, prognostication, and treatment algorithms for CLM.

Prognostic and Therapeutic Implications of Tumor Biology, Including Gene Alterations, in Colorectal Liver Metastases

BACKGROUND

For patients with colorectal liver metastases (CLM), the combination of surgical resection with other therapeutic options is essential. This article shows how recent advances in knowledge of tumor biology, including genetic alterations, affect the choice of therapeutic approach for patients with CLM.

METHODS

We reviewed the literature on recent advances in knowledge about CLM tumor biology including genetic profiles, clinical risk score models for CLM, preoperative therapy for CLM, and liver-directed therapy for CLM.

RESULTS

Studies showed that RAS alteration is a negative prognostic factor in addition to traditional clinical risk factors (e.g., larger diameter and higher number of CLM, spread of the primary tumor to regional lymph nodes). Although the response to preoperative chemotherapy is an important predictor of survival, poor response is not a contraindication to surgical resection. The combination of surgical therapy and percutaneous ablation can be considered in marginally resectable cases; however, a wider ablation margin is required for RAS-mutant CLM. More recently, genetic analysis using next-generation sequencing showed the negative prognostic impact of alterations in TP53, SMAD4, FBXW7, and RAS/BRAF in patients with CLM. In RAS-mutant CLM, intensive follow-up is required in patients who remain recurrence free 2 years after surgery.

DISCUSSION

In patients with CLM, RAS mutation status is important in predicting postoperative survival, selecting the treatment approach, and tailoring postoperative follow-up. In addition, more recent genetic analyses of CLM have identified additional predictors of survival.

Comprehensive Complication Index Validates Improved Outcomes Over Time Despite Increased Complexity in 3707 Consecutive Hepatectomies

OBJECTIVE

The aim of this study was to evaluate trends over time in perioperative outcomes for patients undergoing hepatectomy.

BACKGROUND

As perioperative care and surgical technique for hepatectomy have improved, the indications for and complexity of liver resections have evolved. However, the resulting effect on the short-term outcomes over time has not been well described.

METHODS

Consecutive patients undergoing hepatectomy during 1998 to 2015 at 1 institution were analyzed. Perioperative outcomes, including the comprehensive complication index (CCI), were compared between patients who underwent hepatectomy in the eras 1998 to 2003, 2004 to 2009, and 2010 to 2015.

RESULTS

The study included 3707 hepatic resections. The number of hepatectomies increased in each era (794 in 1998 to 2003, 1402 in 2004 to 2009, and 1511 in 2010 to 2015). Technical complexity increased over time as evidenced by increases in the rates of major hepatectomy (20%, 23%, 30%, P < 0.0001), 2-stage hepatectomy (0%, 3%, 4%, P < 0.001), need for portal vein embolization (5%, 9%, 9%, P = 0.001), preoperative chemotherapy for colorectal liver metastases (70%, 82%, 89%, P < 0.001) and median operative time (180, 175, 225 minutes, P < 0.001). Significant decreases over time were observed in median blood loss (300, 250, 200 mL, P < 0.001), transfusion rate (19%, 15%, 5%, P < 0.001), median length of hospitalization (7, 7, 6 days, P < 0.001), rates of CCI ≥26.2 (20%, 22%, 16%, P < 0.001) and 90-day mortality (3.1%, 2.6%, 1.3%, P < 0.01). On multivariable analysis, hepatectomy in the most recent era 2010 to 2015 was associated with a lower incidence of CCI ≥26.2 (odds ratio 0.7, 95% confidence interval 0.6-0.8, P < 0.0001).

CONCLUSION

Despite increases in complexity over an 18-year period, continued improvements in surgical technique and perioperative outcomes yielded a resultant decrease in CCI in the most current era.

Innovation and Future Perspectives in the Treatment of Colorectal Liver Metastases

Technological advances and investigation into tumor biology have enhanced treatments of patients with colorectal liver metastases (CLM). This article briefly summarizes paradigm shifts in treatments of this disease in the following 4 sections. (1) Small metastases: The treatment of multiple and small CLM has evolved from anatomic resection to parenchyma-sparing hepatectomy. Survival after parenchyma-sparing hepatectomy was similar to or better than anatomic resection. The use of preoperative chemotherapy may cause tumor disappearance. However, the use of fiducial markers may aid in intraoperative localization. Post-resection completion ablation is a new useful treatment concept. It was defined as percutaneous ablation under cross-sectional imaging guidance to eradicate CLM which were intentionally unresected during latest surgery. (2) Bilateral (bilobar) metastases: Two-stage hepatectomy (TSH) is a well-established approach for treating multiple bilateral CLM. The use of hybrid operating room accelerates this sequence because it allows first-stage hepatectomy, portal vein embolization, and computed tomography in one hospitalization. This accelerated TSH sequence enables the second-stage hepatectomy within 4 weeks compared to 8 weeks using conventional TSH sequence. (3) Synchronous lung metastases: For patients with synchronous liver and lung metastases, simultaneous surgical approach is feasible. Specifically, a transdiaphragmatic approach enables simultaneous resection of liver and lung metastases via one abdominal incision. (4) Multiple mutation: Somatic gene mutation testing is increasingly used to evaluate tumor biology. Mutations in TP53, RAS, and SMAD4 affect prognosis through three different signaling pathways of colorectal carcinogenesis. This information can be used to change clinical decision-making regarding surveillance intensity and treatments for liver recurrence.

Two-Stage Hepatectomy vs One-Stage Major Hepatectomy with Contralateral Resection or Ablation for Advanced Bilobar Colorectal Liver Metastases

BACKGROUND

Both 2-stage hepatectomy (TSH) and 1-stage hepatectomy (OSH) represent feasible strategies for resection of advanced bilobar colorectal liver metastases (CLM). However, the influence of the surgical approach on postoperative outcomes and overall survival (OS) is unknown. To define the optimal surgical approach for advanced bilobar CLM requiring right hemihepatectomy, we compared short-term and long-term outcomes after TSH and OSH with contralateral resection or radiofrequency ablation (RFA).

STUDY DESIGN

We retrospectively reviewed 227 patients with bilobar CLM, who underwent right or extended right hepatectomy with treatment of synchronous CLM in segments I, II, and/or III, between 1998 and 2015. Postoperative outcomes and OS were compared between patients who underwent TSH and those who underwent OSH.

RESULTS

Of the 227 patients, 126 (56%) underwent at least the first stage of TSH, and 101 (44%) underwent OSH, 29 (13%) without RFA and 72 (32%) with RFA. Two-stage hepatectomy was associated with a lower incidence of postoperative major complications (14% vs 26%, p = 0.03) and postoperative hepatic insufficiency (6% vs 20%, p = 0.001) than OSH. The 5-year OS rate was higher for patients assigned to TSH than for those who underwent OSH (35% vs 24%, p = 0.016). Patients who completed both stages of TSH had a higher 5-year OS rate than patients who underwent OSH without RFA (50% vs 20%, p = 0.023) or OSH with RFA (50% vs 24%, p < 0.0001).

CONCLUSIONS

In patients with advanced bilobar CLM, TSH is associated with fewer complications than OSH. Both TSH in intention-to-treat analysis and completed TSH in as-treated analysis were associated with better OS than OSH.