Systemic Therapy Plus Thermal Ablation Versus Systemic Therapy Alone for Oligometastatic Liver Metastases from Non-small Cell Lung Cancer

A prognostic model for predicting progression-free survival in patients with advanced non-small cell lung cancer after image-guided microwave ablation plus chemotherapy

OBJECTIVES

This study aimed to build and validate a prediction model that can predict progression-free survival (PFS) in patients with advanced non-small cell lung cancer (NSCLC) after image-guided microwave ablation (MWA) plus chemotherapy.

METHODS

Data from a previous multi-center randomized controlled trial (RCT) was used and assigned to either the training data set or the external validation data set according to the location of the centers. Potential prognostic factors were identified by multivariable analysis in the training data set and used to construct a nomogram. After bootstraps internal and external validation, the predictive performance was evaluated by concordance index (C-index), Brier Score, and calibration curves. Risk group stratification was conducted using the score calculated by the nomogram. Then a simplified scoring system was built to make risk group stratification more convenient.

RESULTS

In total, 148 patients (training data set: n = 112; external validation data set: n = 36) were enrolled for analysis. Six potential predictors were identified and entered into the nomogram, including weight loss, histology, clinical TNM stage, clinical N category, tumor location, and tumor size. The C-indexes were 0.77 (95% CI, 0.65-0.88, internal validation) and 0.64 (95% CI, 0.43-0.85, external validation). The survival curves of different risk groups also displayed significant distinction (p < 0.0001).

CONCLUSIONS

We found weight loss, histology, clinical TNM stage, clinical N category, tumor location, and tumor size were prognostic factors of progression after receiving MWA plus chemotherapy and constructed a prediction model that can predict PFS.

CLINICAL RELEVANCE STATEMENT

The nomogram and scoring system will assist physicians to predict the individualized PFS of their patients and decide whether to perform or terminate MWA and chemotherapy according to the expected benefits.

KEY POINTS

• Build and validate a prognostic model using the data from a previous randomized controlled trial to predict progression-free survival after receiving MWA plus chemotherapy. • Weight loss, histology, clinical TNM stage, clinical N category, tumor location, and tumor size were prognostic factors. • The nomogram and scoring system published by the prediction model can be used to assist physicians to make clinical decisions.

Evidence on percutaneous radiofrequency and microwave ablation for liver metastases over the last decade

Purpose

This review aimed to summarize the treatment outcomes of percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for metastatic liver tumors based on the findings of published studies over the last decade.

Materials and methods

Literature describing the survival outcomes of ablation therapy for liver metastases was explored using the PubMed database on April 26, 2022, and articles published in 2012 or later were selected. The included studies met the following criteria: (i) English literature, (ii) original clinical studies, and (iii) literature describing overall survival (OS) of thermal ablation for metastatic liver tumors. All case reports and cohort studies with fewer than 20 patients and those that evaluated ablation for palliative purposes were excluded.

Results

RFA was the most commonly used method for ablation, while MWA was used in several recent studies. RFA and MWA for liver metastases from various primary tumors have been reported; however, majority of the studies focused on colorectal cancer. The local control rate by RFA and MWA varied widely among the studies, ranging approximately 50–90%. Five-year survival rates of 20–60% have been reported following ablation for colorectal liver metastases by a number of studies, and several reports of 10-year survival rates were also noted.

Conclusion

Comparative studies of local therapies for colorectal liver metastases demonstrated that RFA provides comparable survival outcomes to surgical metastasectomy and stereotactic body radiation therapy.

Percutaneous Radiofrequency Ablation Is an Effective Method for Local Control of Liver Metastases From Lung Cancer

Objective

To investigate the clinical value of percutaneous radiofrequency ablation (RFA) for liver metastasis from lung cancer (LCLM).

Materials and Methods

We retrospectively enrolled 58 patients who underwent RFA for LCLM between January 2014 and December 2019. Primary lung cancer histology included 38 adenocarcinomas, 15 squamous carcinomas, and 5 small cell carcinomas. For 83 metastatic lesions (mean tumor diameter 3.3 ± 1.1 cm, range 0.9-5.0 cm), 65 RFA sessions were performed. Before RFA, 17 and 41 patients presented no and stable extrahepatic metastasis, respectively, whereas 18 and 40 patients had synchronous and metachronous liver metastasis, respectively. Survival was analyzed using the Kaplan-Meier method. Cox proportional hazards model was used for multivariable analysis.

Results

The technical success rate was 96.3% (80/83 lesions). Local tumor progression was observed in 8 (9.8%, 8/82) lesions of 57 (14.0%, 8/57) patients at 4-12 months after RFA. New liver metastases occurred in 27 (46.6%) patients. The overall survival (OS) rates at 1, 2, 3, and 5 years after RFA were 55.2%, 26.0%, 22.0%, and 14.4%, respectively. The median OS after RFA and after liver metastasis were 14.0 ± 1.6 and 20.0 ± 1.5 months, respectively. Based on the univariable analysis, tumor size (p=0.017), histological type (p=0.015), and timing of liver metastasis (p=0.046) were related to OS. In further multivariable analyses, squamous carcinoma (hazard ratio= 2.269, 95% confidence interval: 1.186-4.339, p=0.013) was an independent unfavorable prognostic factor for OS. Based on the univariable analysis, histological type (p=0.010) was identified as parameters significantly related to local tumor progression (LTP)-free survival. Further multivariable analyses revealed that squamous carcinoma (hazard ratio=2.394, 95% confidence interval: 1.260-4.550, p=0.008) was an independent unfavorable prognostic factor for LTP-free survival.

Conclusion

RFA is a safe therapeutic option for LCLM with acceptable local tumor control, especially in patients with a tumor size ≤3 cm, adenocarcinoma/small cell carcinoma, and metachronous liver metastases.

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

Local ablative therapy in oncogenic-driven oligometastatic non-small cell lung cancer: present and ongoing strategies-a narrative review

Oligometastatic (OM) disease is defined by a low metastatic tumor spread. OM non-small cell lung cancer (NSCLC) treatment aims to improve the patient's prognosis and quality of life, in an attempt-to-cure objective. Oncogenic-driven metastatic NSCLC accounts for about 20-25% of NSCLCs, with an ever-increasing number of potentially druggable molecular alterations. Due to specific targeted therapy, the care and prognosis of mutated NSCLC is quite different from non-oncogenic-driven NSCLC. However, OM-NSCLC treatment guidelines do not specifically discuss oncogenic-driven OM-NSCLC patients. We conducted a narrative review regarding retrospective and prospective studies published from inception to May 2020 dealing with oncogenic-driven OM-NSCLC in order to: (I) describe the specific patterns of metastatic spread of oncogenic-driven NSCLC (i.e., bone and pleural tropism in EGFR mutated NSCLC and serous and brain metastases in ALK NSCLC); (II) review the low level of current evidence for local ablative therapy (LAT) strategies in patients with oncogenic-driven OM-NSCLC, focusing on the benefit/risk of tyrosine kinase inhibitors (TKI) and LATs combination and (III) present strategies to help to select the best candidate for an attempt-to-cure approach. Finally, the optimal strategy may be to introduce a targeted therapy, then treat all tumor sites with LAT, and finally continue TKI for unknown prolonged duration in an attempt to prolong progression free survival in most patients, improve overall survival for some patients, and potentially lead to a cancer cure for a few patients.