Value of ablation therapy in the treatment of lung metastases

Surgical and Interventional Management of Lung Metastasis: Surgical Assessment, Resection, Ablation, Percutaneous Interventions

The lungs are the second most common site of metastases for colorectal cancer after the liver. Pulmonary metastases can be identified at the time of diagnosis of the primary tumor, or metachronously. About 20% of patients with colorectal cancer will develop pulmonary metastases. The best options for treatment include a multidisciplinary treatment approach consisting of surgical resection whenever possible, and chemotherapy. Surgical options most often include minimally invasive segmentectomy or wedge resection, while patients unable to have surgery may benefit from radio frequency ablation or radiation treatment. Prognosis is dependent on preoperative carcinoembryonic antigen level, number, and location of metastatic lesions, and resectability of primary tumor. Overall, pulmonary metastases are best treated by complete resection whenever possible.

Transvenous Pulmonary Chemoembolization and Optional Microwave Ablation for Colorectal Lung Metastases

(1) Purpose: To evaluate tumor response and survival of patients with colorectal pulmonary metastases treated by transvenous pulmonary chemoembolization (TPCE) alone with palliative intent or TPCE followed by microwave ablation (MWA) with potentially curative intent. (2) Material and methods: A total of 164 patients (64 women and 100 men; mean age: 61.8 ± 12.7 years) with unresectable colorectal lung metastases and not responding to systemic chemotherapy, who either received repetitive TPCE (Group A) or TPCE followed by MWA (Group B), were retrospectively enrolled. The revised response evaluation criteria in solid tumors were used to assess treatment response in Group A. The oncological response in Group B was divided into local tumor progression (LTP) and intrapulmonary distant recurrence (IDR) after MWA. (3) Results: The 1-, 2-, 3-, and 4-year survival rates were 70.4%, 41.4%, 22.3%, and 5%, respectively, for all patients. In Group A; the rates of stable disease; progressive disease; and partial response were at 55.4%, 41.9%, and 2.7%, respectively. The rates of LTP and IDR were 3.8%, and 63.5%, respectively, in Group B. Conclusion: TPCE is an effective treatment for colorectal lung metastases, which can be performed alone or combined with MWA.

Ablation of pulmonary neoplasms: review of literature and future perspectives

Thermal ablation is a minimally invasive technology used to treat many types of tumors, including lung cancer. Specifically, lung ablation has been increasingly performed for unsurgical fit patients with both early-stage primi-tive lung cancer and pulmonary metastases. Image-guided available techniques include radiofrequency ablation, microwave ablation, cryoablation, laser ablation and irreversible electroporation. Aim of this review is to illustrate the major thermal ablation modalities, their indications and contraindications, complications, outcomes and notably the possible future challenges.

Radiomics in Lung Metastases: A Systematic Review

Due to the rich vascularization and lymphatic drainage of the pulmonary tissue, lung metastases (LM) are not uncommon in patients with cancer. Radiomics is an active research field aimed at the extraction of quantitative data from diagnostic images, which can serve as useful imaging biomarkers for a more effective, personalized patient care. Our purpose is to illustrate the current applications, strengths and weaknesses of radiomics for lesion characterization, treatment planning and prognostic assessment in patients with LM, based on a systematic review of the literature.

CT-guided percutaneous microwave ablation for pulmonary metastases from colorectal cancer: Prognosis analyses based on the origin of the primary tumor

BACKGROUND

Microwave ablation (MWA) is becoming an effective therapy for inoperable pulmonary metastases from colorectal cancer (CRC). However, it is unclear whether the primary tumor location affects survival after MWA.

OBJECTIVE

This study aims to investigate the survival outcomes and prognostic factors of MWA based on different primary origins between colon and rectal cancer.

METHODS

Patients who underwent MWA for pulmonary metastases from 2014 to 2021 were reviewed. Differences in survival outcomes between colon and rectal cancer were analyzed with the Kaplan-Meier method and log-rank tests. The prognostic factors between groups were then evaluated by univariable and multivariable Cox regression analyses.

RESULTS

A total of 118 patients with 154 pulmonary metastases from CRC were treated in 140 MWA sessions. Rectal cancer had a higher proportion with seventy (59.32% ) than colon cancer with forty-eight (40.68% ). The average maximum diameter of pulmonary metastases from rectal cancer (1.09 cm) was greater than that of colon cancer (0.89 cm; p = 0.026). The median follow-up was 18.53 months (range 1.10 - 60.63 months). The disease-free survival (DFS) and overall survival (OS) in colon and rectal cancer groups were 25.97 vs 11.90 months (p = 0.405), and 60.63 vs 53.87 months (p = 0.149), respectively. Multivariate analyses showed that only age was an independent prognostic factor in patients with rectal cancer (HR = 3.70, 95% CI: 1.28 - 10.72, p = 0.023), while none in colon cancer.

CONCLUSIONS

Primary CRC location has no impact on survival for patients with pulmonary metastases after MWA, while a disparate prognostic factor exists between colon and rectal cancer.

Differentiation of Lung Metastases Originated From Different Primary Tumors Using Radiomics Features Based on CT Imaging

RATIONALE AND OBJECTIVES

To explore the feasibility of differentiating three predominant metastatic tumor types using lung computed tomography (CT) radiomics features based on supervised machine learning.

MATERIALS AND METHODS

This retrospective analysis included 252 lung metastases (LM) (from 78 patients), which were divided into the training (n = 176) and test (n = 76) cohort randomly. The metastases originated from colorectal cancer (n = 97), breast cancer (n = 87), and renal carcinoma (n = 68). An additional 77 LM (from 35 patients) were used for external validation. All radiomics features were extracted from lung CT using an open-source software called 3D slicer. The least absolute shrinkage and selection operator (LASSO) method selected the optimal radiomics features to build the model. Random forest and support vector machine (SVM) were selected to build three-class and two-class models. The performance of the classification model was evaluated with the area under the receiver operating characteristic curve (AUC) by two strategies: one-versus-rest and one-versus-one.

RESULTS

Eight hundred and fifty-one quantitative radiomics features were extracted from lung CT. By LASSO, 23 optimal features were extracted in three-class, and 25, 29, and 35 features in two-class for differentiating every two of three LM (colorectal cancer vs. renal carcinoma, colorectal cancer vs. breast cancer, and breast cancer vs. renal carcinoma, respectively). The AUCs of the three-class model were 0.83 for colorectal cancer, 0.79 for breast cancer, and 0.91 for renal carcinoma in the test cohort. In the external validation cohort, the AUCs were 0.77, 0.83, and 0.81, respectively. Swarmplot shows the distribution of radiomics features among three different LM types. In the two-class model, high accuracy and AUC were obtained by SVM. The AUC of discriminating colorectal cancer LM from renal carcinoma LM was 0.84, and breast cancer LM from colorectal cancer LM and renal carcinoma LM were 0.80 and 0.94, respectively. The AUCs were 0.77, 0.78, and 0.84 in the external validation cohort.

CONCLUSION

Quantitative radiomics features based on Lung CT exhibited good discriminative performance in LM of primary colorectal cancer, breast cancer, and renal carcinoma.

Tumor-Specific CD4+ T Cells Restrain Established Metastatic Melanoma by Developing Into Cytotoxic CD4– T Cells

Cytotoxic CD8+ T cells are the main focus of efforts to understand anti-tumor immunity and immunotherapy. The adoptive transfer of tumor-reactive cytotoxic CD8+ T lymphocytes expanded and differentiated in vitro has long been considered the primary strategy in adaptive anti-tumor immunity, however, the majority of the transferred tumor antigen-specific CD8+ T cells differentiated into CD39+CD69+ exhausted progenies, limiting its effects in repressing tumor growth. Contrarily, less attention has been addressed to the role of CD4+ T cells during tumorigenesis. Using a mouse model of metastatic melanoma, we found that transferring tumor-specific CD4+ T cells into recipients induces substantial regression of the established metastatic tumors. Notably, in vitro activated CD4+ T cells developed into cytotoxic CD4- T cells in vivo and get exhausted gradually. The blockade of PD-L1 signaling resulted in an expansion of tumor specific CD4+ T cells, which could better control the established metastatic melanoma. Moreover, the tumor-specific memory CD4+ T cell can prevent mice from tumor metastasis, and the tumor-specific effector CD4+ T cells can also mitigate the established metastatic tumor. Overall, our findings suggest a novel mechanism of CD4+ T cells in curtailing tumor metastasis and confirm their therapeutic role in combination with PD-L1 blockade in cancer immunotherapy. Hence, a better understanding of cytotoxic CD4- T cell-mediated tumor regression could provide an alternative choice for patients exhibiting suboptimal or no response to CD8+ T cell-based immunotherapies.

Liver tumor ablation enhancement by induction-heating system with bitter-like deep magnetic field coil

The heated metal needle used for tumor thermotherapy is considered crucial for enhancing the practicality of cauterization using electromagnetic induction-heating techniques. In this study, a novel coil capable of producing a deep magnetic field is designed. In the proposed design, the coil structure is improved to enhance the intensity of the coil's deep magnetic field and its suitability for deep-tissue cauterization. Furthermore, a series of experiments are conducted using a single and consistent input current. The heating experiments are conducted at varying depths by placing the needle beneath the coil. The proposed coil significantly increases the induction-heating temperature and provides a solution to the long-standing problem of insufficient needle temperature. This research has also improved the usability of the induction-heating equipment in the field of deep tumor ablation.

Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology

PURPOSE

To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung.

MATERIALS AND METHODS

A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 63 studies, including existing systematic reviews and meta-analysis, retrospective cohort studies, and single-arm trials were identified. The expert writing group developed and agreed on 7 recommendations on the use of image-guided thermal ablation in the lung.

CONCLUSION

SIR considers image-guided thermal ablation to be an acceptable treatment option for patients with inoperable Stage I NSCLC, those with recurrent NSCLC, as well as patients with metastatic lung disease.

Novel strategy to treat lung metastases: Hybrid therapy involving surgery and radiofrequency ablation

BACKGROUND

This study was performed to evaluate the clinical outcomes of hybrid treatment involving surgical resection and percutaneous radiofrequency ablation for patients with multiple lung metastases.

METHODS

Seventeen patients (6 men, 11 women; median age, 52 years; range, 16-78 years) underwent hybrid treatment involving surgery and radiofrequency ablation to treat multiple lung metastases (median number, 4; range, 2-26) between May 2014 and February 2020. The primary lesions were colorectal carcinoma (n = 9), uterine endometrial carcinoma (n = 3), osteosarcoma (n = 2), renal cell carcinoma (n = 1), glottic carcinoma (n = 1), and fibrolamellar hepatocellular carcinoma (n = 1). Twenty-four sessions each of surgery and radiofrequency ablation were performed. Safety, disease-free survival, and overall survival were evaluated. Safety was assessed according to the Clavien-Dindo Classification.

RESULTS

A grade IVa adverse event of empyema developed in one patient (4%, 1/24) after surgery. A grade IIIa adverse event of pneumothorax and a grade II adverse event of lung abscess occurred in four (17%, 4/24) and one session (4%, 1/24) after radiofrequency ablation, respectively. During the median follow up of 34 months (range, 8-67 months), 10 patients (59%, 10/17) developed new metastases. The 5-year disease-free survival rate was 32%. Four or fewer lung metastases (p = 0.008) and metastases from colorectal carcinoma (p = 0.02) were factors significantly associated with longer disease-free survival. One patient (6%, 1/17) died of tumor progression 29 months after initial treatment. The 5-year overall survival rate was 88%.

CONCLUSIONS

The strategy of hybrid treatment involving surgery and radiofrequency ablation may offer good outcomes for patients with multiple lung metastases.

Surgery for Pulmonary Metastases: Long-Term Survival in 281 Patients

BACKGROUND

 Despite weak evidence, pulmonary metastasectomy (PM) is widely performed with intent to improve patient survival. Our single-institution analysis aims to evaluate outcomes and to identify factors influencing survival of patients undergoing PM for metastases from wide range of primary tumors.

MATERIALS AND METHODS

 All patients undergoing curative-intent PM between 2008 and 2018 were retrospectively analyzed. The impact of factors related to primary tumor, metastases, and associated therapy on overall survival (OS) was evaluated using univariable and multivariable Cox proportional hazard models. Cutoff values of continuous variables were determined by a receiver operating characteristic analysis.

RESULTS

 In this study, 281 patients (178 male, median age 61 years) underwent PM. Two (0.7%) perioperative deaths and 23 (8.2%) major complications occurred. Median interval between the treatment of primary tumor and PM was 21 months. Median size of largest metastasis was 1.4 cm. After the median follow-up of 29 months, 134 patients (47.7%) had died. Five-year OS rate after first PM was 47.1%. Complete resection was achieved in 274 (97.5%) patients. Multivariable analysis identified genitourinary origin (hazard ratio [HR]: 0.30, 95% confidence interval [CI]: 0.15-0.60, p = 0.0008) as independent positive survival prognosticator; incomplete resection (HR: 3.53, 95% CI: 1.40-8.91, p = 0.0077) and age at PM of ≥66 years (HR: 1.97, 95% CI: 1.36-2.85, p = 0.0003) were negative prognosticators.

CONCLUSION

 The use of PM as a part of multimodal treatment is in selected population justified. Our analysis identified age, primary tumor origin, and completeness of resection as independent survival prognosticators.

Nanoparticle-mediated tumor cell expression of mIL-12 via systemic gene delivery treats syngeneic models of murine lung cancers

Treatment of cancers in the lung remains a critical challenge in the clinic for which gene therapy could offer valuable options. We describe an effective approach through systemic injection of engineered polymer/DNA nanoparticles that mediate tumor-specific expression of a therapeutic gene, under the control of the cancer-selective progression elevated gene 3 (PEG-3) promoter, to treat tumors in the lungs of diseased mice. A clinically tested, untargeted, polyethylenimine carrier was selected to aid rapid transition to clinical studies, and a CpG-free plasmid backbone and coding sequences were used to reduce inflammation. Intravenous administration of nanoparticles expressing murine single-chain interleukin 12, under the control of PEG-3 promoter, significantly improved the survival of mice in both an orthotopic and a metastatic model of lung cancer with no marked symptoms of systemic toxicity. These outcomes achieved using clinically relevant nanoparticle components raises the promise of translation to human therapy.

Self-assembly of pentapeptides in ethanol to develop organogels

Organogels have a wide variety of applications in the fields of chemistry, electricity, biomedicine and environmental engineering, which call for robust strategies for designing and developing novel organogelators. Here, we reported a pentapeptide, ECAYF, which was capable of forming a self-healing ethanol gel exhibiting viscoelastic and solid-like properties. The ethanol gel of ECAYF was stable for at least several months, suggesting strong non-covalent interactions between ethanol and the peptide in the gel. In the ethanol gel, self-assembled peptide fibrils were found to immobilize the ethanol molecules for gelation. Results also suggested that the EAF-5 peptide adopted H-bonding β-sheet secondary structures, which further assembled into fibrils. Meanwhile, the self-assembly of the ECAYF peptide in mixtures of differently fractioned ethanol and H₂O was observed, which clearly indicated that ethanol promoted the assembly of ECAYF in the solutions. These findings are helpful in understanding the roles of organic solvents as well as the complicated interactions between the solvent and gelator molecules in gelation.

Long-Term Outcomes in Percutaneous Radiofrequency Ablation for Histologically Proven Colorectal Lung Metastasis

Introduction

To evaluate the long-term outcome of image-guided radiofrequency ablation (RFA) when treating histologically confirmed colorectal lung metastasis in terms of overall survival (OS), progression-free survival (PFS) and local tumour control (LTC).

Materials and Methods

Retrospective single-centre study. Consecutive RFA treatments of histologically proven lung colorectal metastases between 01/01/2008 and 31/12/14. The primary outcome was patient survival (OS and PFS). Secondary outcomes were local tumour progression (LTP) and complications. Prognostic factors associated with OS/ PFS were determined by univariate and multivariate analyses.

Results

Sixty patients (39 males: 21 females; median age 69 years) and 125 colorectal lung metastases were treated. Eighty percent (n = 48) also underwent lung surgery for lung metastases. Mean metastasis size (cm) was 1.4 ± 0.6 (range 0.3–4.0). Median number of RFA sessions was 1 (1–4). During follow-up (median 45.5 months), 45 patients died (75%). The estimated OS and PFS survival rates at 1, 3, 5, 7, 9 years were 96.7%, 74.7%, 44.1%, 27.5%, 16.3% (median OS, 52 months) and 66.7%, 31.2%, 25.9%, 21.2% and 5.9% (median PFS, 19 months). The LTC rate was 90% with 6 patients developing LTP with 1-, 2-, 3- and 4-year LTP rates of 3.3%, 8.3%, 10.0% and 10.0%. Progression-free interval < 1 year (P = 0.002, HR = 0.375) and total number of pulmonary metastases (≥ 3) treated (P = 0.037, HR = 0.480) were independent negative prognostic factors. Thirty-day mortality rate was 0% with no intra-procedural deaths.

Conclusion

The long-term OS and PFS following RFA for the treatment of histologically confirmed colorectal lung metastases demonstrate comparable oncological durability to surgery.

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02623-1) contains supplementary material, which is available to authorized users.

Independent prognostic value of HIF-1α expression in radiofrequency ablation of lung cancer

Radiofrequency ablation (RFA) is widely used in the treatment of lung cancer. Hypoxia-inducible factor-1α (HIF-1α) is a crucial transcription factor regulating oxygen homeostasis that is involved in tumor cell metastasis. The present study investigated the impact of HIF-1α expression and other factors, such as postoperative blood CD4⁺/CD8⁺ ratio, on the prognosis of patients with lung cancer who had received RFA treatment. A total of 80 patients with lung cancer were recruited between January 2011 and October 2016 at The Shenzhen People's Hospital. Lung cancer was confirmed following pathological or histological examination. All patients underwent RFA treatment. Patients were followed up for 6–66 months. HIF-1α expression in lung cancer tissues was assessed by immunohistochemistry. Multivariate survival analysis was performed using Cox proportional hazards model. The results demonstrated that HIF-1α level was low in 36 patients and overexpressed in 44 patients with lung cancer. Kaplan-Meier (KM) curve analysis demonstrated that the overall survival time of patients with high HIF-1α expression was significantly shorter compared with patients with low HIF-1α expression (P<0.05). Furthermore, the results from the KM model and log-rank test revealed that age, Union for International Cancer Control stage, primary or metastatic cancer, chemotherapy, postoperative blood CD4⁺/CD8⁺ ratio, Eastern Cooperative Oncology Group performance status and HIF-1α expression had significant effects on overall survival of patients with lung cancer. The results from Cox analysis demonstrated that high HIF-1α expression, advanced age, clinical staging and chemotherapy were independent risk factors for the prognosis of lung cancer following RFA treatment, and that high HIF-1α expression was associated with the increased risk (5.91-fold) of mortality. In conclusion, the present study demonstrated that HIF-1α expression was increased in lung cancer tissues and was associated with the prognosis of patients with lung cancer who were treated with RFA. These findings suggest that HIF-1α expression may be considered as a marker for evaluating the prognosis of these patients.

Percutaneous image-guided ablation: From techniques to treatments

Image-guided ablation is performed by percutaneously introducing ablation probes to deliver energy into a tumor to destroy it in a controlled and localized fashion. Ablation modalities can be broadly classified as thermal or non-thermal based on the mechanism of tumor destruction and are performed using different types of image guidance for planning, delivering and follow-up of the treatment. Ablation is performed in a minimally invasive fashion, providing greater residual organ preservation with minimal morbidity to the patient. Image-guided ablation is being used in the clinic for the treatment of primary and metastatic tumors, and this article reviews state of the art for the treatment of malignancies in the liver, lung, kidney and musculoskeletal tissue.

Local treatment of oligometastatic disease: current role

The presence of distant metastases has long been a predictor of poor outcome in solid cancer. However, in an oncologic situation called oligometastatic disease (OMD), multiple studies have revealed a survival benefit with aggressive treatment of these metastases. Besides surgery and radiation therapy, local thermal therapies have developed into a treatment option for OMD. Most studies concerning local therapy of OMD are available for colorectal cancer, which is therefore the focus of this article. Furthermore, this review gives a basic overview of the most popular ablation techniques for treatment of OMD.

Comparison of stereotactic body radiotherapy versus metastasectomy outcomes in patients with pulmonary metastases

Background

We compared the treatment outcomes of stereotactic body radiotherapy (SBRT) and metastasectomy in patients with pulmonary metastases.

Methods

Twenty‐one patients received SBRT (total radiation doses 60 Gy in 3 fractions or 48 Gy in 4 fractions) and 30 underwent metastasectomy, most (93.3%) with wedge resection. The patients were followed for a median of 13.7 months. The tumor size in the SBRT group was larger than in the metastasectomy group (median 2.5 vs. 1.25 cm; P = 0.015). Patients with synchronous metastases were more likely to be treated with SBRT than with metastasectomy (P = 0.006).

Results

There was no significant difference in the local control rates of the treatment groups (P = 0.163). Progression‐free survival (PFS) was longer in the metastasectomy than in the SBRT group (P = 0.02), with one and two‐year PFS rates of 51.1% and 46% versus 23.8% and 11.9%, respectively. The one and two‐year overall survival (OS) rates were 95% and 81.8% in the metastasectomy group and 79.5% and 68.2%, in the SBRT group, respectively. In multivariate analysis, synchronous metastasis was related to poor PFS, and tumor size was the most significant factor affecting OS. There were no significant differences in PFS and OS between treatment groups after dividing patients according to the presence or absence of synchronous metastases.

Conclusions

SBRT is considered a suitable local modality against pulmonary metastases; however, patients with synchronous metastases are only likely to obtain a small benefit from local treatment with either SBRT or surgery.