Curative-intent treatment of pulmonary metastases from colorectal cancer: A comparison between imaging-guided thermal ablation and surgery

Contemporary Outcomes for the Curative Treatment of Colorectal Cancer Pulmonary Metastases

PURPOSE

Treatment of pulmonary metastases (PM) from colorectal cancer (CRC) is the standard of care by several guidelines from Europe and the USA, but the validity of this strategy has been recently questioned, and the available evidence supporting this strategy is weak. We report the outcomes of a curative intent strategy in a very recent and homogenous series of patients.

METHODS

We did a retrospective review of all curative intent surgical or ablative treatment of PM from CRC performed consecutively in 3 French institutions from January 2015 to December 2019. Demographics, clinicopathological, and molecular characteristics were evaluated. Cox regression models were used to identify prognostic factors related to local recurrence and disease-free survival.

RESULTS

Records from 152 patients were reviewed. One-hundred thirty-five patients (88%) had surgical metastasectomy. Median age was 67 years. Most of the patients had a single lesion (66%), and 16% had synchronous PM. Eighty-one patients (53%) experienced recurrence, and the thorax was the most common site of recurrence. Median disease-free survival and overall survival were 35 months and 78 months after PM treatment. At the end of the study, only 17% of the patients died. Pulmonary tumor burden was correlated with disease-free survival in univariate analysis, but multivariate analysis did not find any prognostic factor independently associated with local recurrence or survival.

CONCLUSION

Our finds corroborate existing recommendation for the invasive treatment of PM from CRC in selected patients.

Oligometastatic Colorectal Cancer: A Review of Definitions and Patient Selection for Local Therapies

PURPOSE

Nearly one-third of patients diagnosed with colorectal cancer (CRC) will ultimately develop metastatic disease. While a small percentage of patients can be considered for curative resection, more patients have limited disease that can be considered for local therapy. Challenges remain in defining oligometastatic CRC as well as developing treatment strategies guided by high level evidence.

METHODS

In this review, we present the challenges in defining oligometastatic CRC and summarize the current literature on treatment and outcomes of local therapy in patients with metastatic CRC.

RESULTS

For patients with liver- and/or lung-confined CRC metastases, surgical resection is the standard of care given the potential for long-term progression-free and overall survival. For patients with liver- or lung-confined disease not amenable to surgical resection, non-surgical local therapies, such as thermal ablation, hepatic arterial infusion pump (HAIP), or stereotactic body radiation therapy (SBRT), should be considered. For patients with more advanced disease, such as lymph node or bony metastases, the role of metastasis-directed therapy is controversial. Emerging data suggests that SBRT to ablate all metastases can improve progression-free and overall survival.

CONCLUSION

Multidisciplinary management is critical for patients with metastatic CRC due to the complexity of their cases and the nuanced patient, tumor, biological, and anatomical factors that must be weighed when considering local therapy. High-quality prospective randomized data in CRC are needed to further clarify the role of local ablative therapy in patients with unresectable oligometastatic CRC with ongoing studies including the RESOLUTE trial (ACTRN12621001198819) and the upcoming NCTN ERASur trial (NCT05673148).

The percutaneous management of pulmonary metastases

Local treatment of lung metastases has been in the front scene since late 90s when an international registry of thoracic surgery reported a median overall survival of 35 months in resected patients versus 15 months in non-resected patients. Today, other local therapies are available for patients with oligometastatic lung disease, including image guided thermal ablation, such as ablation, microwave ablation, and cryoablation. Image-guided ablation is increasingly offered, and now recommended in guidelines as option to surgery. Today, the size of the target tumour remains the main driver of success and selection of patients with limited tumour size allowing for local tumour control in the range of 90% in most recent and larger series targeting lung metastases up to 3.5 cm. Overall survival exceeding five-years in large series of thermal ablation for lung metastases from colorectal origin are align with outcome of same patients treated with surgical resection. Moreover, thermal ablation in such population allows for one-year chemotherapy holidays in all comers and over 18 months in lung only metastatic patients, allowing for improved patient quality of life and preserving further lines of systemic treatment when needed. Tolerance of thermal ablation is excellent and better than surgery with no lost in respiratory function, allowing for repeated treatment when needed. In the future, it is likely that practice of lung surgery for small oligometastatic lung disease will decrease, and that minimally invasive techniques will replace surgery in such indications. Randomized study will be difficult to obtain as demonstrated by discontinuation of many studies testing the hypothesis of surgery versus observation, or surgery versus SBRT.