The roles of surgery, stereotactic radiation, and ablation for treatment of pulmonary metastases

Factors associated with receipt of pulmonary metastasectomy in patients with lung-limited metastatic colorectal cancer: Disparities in care and impact on overall survival

OBJECTIVES

Pulmonary metastasectomy (PM) for colorectal cancer may provide respite from systemic therapy and prolonged disease-free intervals. We sought to identify factors associated with PM and to characterize the differential impact on overall survival for those offered lung resection.

METHODS

The National Cancer Database was queried for stage IV colorectal cancer patients with lung-limited metastatic disease between 2010 and 2016. Among patients who underwent primary tumor resection, those who underwent PM were compared with those who did not. Penalized regression with the least absolute selection and shrinkage operator was used to determine factors associated with receiving metastasectomy as well as overall survival.

RESULTS

In total, 867 (15.1%) patients underwent resection of both primary tumor and pulmonary metastases whereas 4864 (84.8%) had primary tumor resection alone. In unadjusted analyses, metastasectomy patents were younger, more often privately insured, more educated, and traveled farther to receive care (all P < .001). In multivariable analyses, younger age, traveling >25 miles, and care at high-volume hospitals were associated with PM (P < .01). In addition, primary site surgery without PM was associated with worse overall survival (hazard ratio, 1.35; confidence interval, 1.23-1.49), even after adjusting for patient, tumor, and hospital-related factors.

CONCLUSIONS

Patients who were older, who received care closer to home, and who were treated at low-volume hospitals were less likely to receive metastasectomy for lung-limited colorectal cancer after definitive resection of their primary tumor. Failure to receive PM resulted in worse overall survival, emphasizing the strong need for efforts to provide uniform, equitable care to all patients.

A retrospective study comparing the efficacy of microwave ablation and stereotactic body radiotherapy in colorectal cancer lung metastases

The purpose of the present study was to assess and compare the efficacy of microwave ablation (MWA) and stereotactic body radiotherapy (SBRT) in the treatment of lung metastases from patients with colorectal cancer (CRC) and to identify the preferable treatment modality based on patient and tumor characteristics. Records of 118 patients with CRC with a total of 307 lung metastases who underwent SBRT or MWA between January 2015 and December 2022 were retrospectively analyzed, including the essential clinicopathological information on patients (age, sex and underlying diseases), diagnosis and treatment information [primary tumor site, levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9], imaging data [diameter of lung metastasis, location of the metastasis (i.e., whether or not the tumor was adjacent to the vessel or bronchus) and internal features] and follow-up data (postoperative therapy, complications or adverse effects and survival outcomes). For statistical analysis of the local tumor progression (LTP), disease-free survival and overall survival (OS) rates, Cox regression analysis, along with the Kaplan-Meier method adjusted using inverse probability of treatment weighting (IPTW), were performed. The median follow-up duration in the present study was 31.5 months. Multivariable Cox regression analysis revealed that the CEA level, metastasis diameter and internal features were independent predictors of OS. In the IPTW-adjusted analysis, no significant difference in the 1-year OS rate was observed between the SBRT and MWA groups (92.9 vs. 93.9%; P=0.483); however, a notable discrepancy in the treatment modalities was noted, leading to significant differences in the 2- and 3-year OS rates (65.9 vs. 57.6%, P=0.001, and 44.7 vs. 36.4%, P<0.001, respectively). A significant interaction effect for the treatment modality was observed for LTP (P=0.021). In conclusion, the present study revealed that SBRT and MWA have similar therapeutic effects in terms of prolonging the survival of patients with CRC with lung metastases; however, regarding the local control of lung metastases, MWA is associated with a number of significant advantages.

Recurrence-free survival curve for pulmonary metastasectomy in colorectal cancer plateaus at 3 years

Pulmonary metastasectomy in colorectal cancer (CRC) has encouraging results; however, specific criteria for lung resection and the timing of resection remain undetermined. Therefore, in this study, we aimed to examine the long-term prognosis and 10-year survival rates and analyze poor prognostic factors in patients who underwent resection of pulmonary metastases from CRC. This retrospective, single-institution study included 156 patients with controlled primary CRC and metastases confined to the lungs or liver who underwent pulmonary metastasectomy between 2005 and 2022. Statistical analyses were conducted using the X2 and two-tailed Student's t test to compare variables. The receiver operating characteristic (ROC) curve was used to determine the appropriate cut-off point for tumor size as a predictive factor of survival. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and non-parametric group comparisons were performed using log-rank tests. The 5- and 10-year OS rates were 67% and 59%, respectively. Further, there was no recurrence 38 months post-surgery, and the RFS curve plateaued. Moreover, by 88 months post-surgery, no deaths occurred, and the OS curve plateaued. Multivariate analysis revealed that a pulmonary metastatic tumor >14 mm and disease-free interval <2 years indicated poor prognosis. The RFS curve for pulmonary metastasectomy may plateau approximately 3 years after surgery. Pulmonary metastasectomy can achieve long-term survival in selected patients with CRC. Furthermore, surgical resection of recurrence after pulmonary metastasectomy may lead to better results. Thus, tumor size and disease-free interval may be independent prognostic factors.

Long-Term Follow-Up after Laser-Assisted Pulmonary Metastasectomy Shows Complete Lung Function Recovery

Preserving maximum lung function is a fundamental goal of parenchymal-sparing pulmonary laser surgery. Long-term studies for follow-up of lung function after pulmonary laser metastasectomy are lacking. However, a sufficient postoperative lung function is essential for quality of life and reduces potential postoperative complications. In this study, we investigate the extent of loss in lung function following pulmonary laser resection after three, six, and twelve months. We conducted a retrospective analysis using a prospective database of 4595 patients, focusing on 126 patients who underwent unilateral pulmonary laser resection for lung metastases from 1996 to 2022 using a 1318 nm Nd:YAG laser or a high-power pure diode laser. Results show that from these patients, a median of three pulmonary nodules were removed, with 75% presenting central lung lesions and 25% peripheral lesions. The median preoperative FEV1 was 98% of the predicted value, decreasing to 71% postoperatively but improving to 90% after three months, 93% after six months, and 96% after twelve months. Statistical analysis using the Friedman test indicated no significant difference in FEV1 between preoperative levels and those at six and twelve months post-surgery. The findings confirm that pulmonary laser surgery effectively preserves lung function over time, with patients generally regaining their preoperative lung function within a year, regardless of the metastases' location.

The Real-Life Impact of Primary Tumor Resection of Synchronous Metastatic Colorectal Cancer-From a Clinical Oncologic Point of View

AIM

The complex medical care of synchronous metastatic colorectal (smCRC) patients requires prudent multidisciplinary planning and treatments due to various challenges caused by the primary tumor and its metastases. The role of primary tumor resection (PTR) is currently uncertain; strong arguments exist for and against it. We aimed to define its effect and find its best place in our therapeutic methodology.

METHOD

We performed retrospective data analysis to investigate the clinical course of 449 smCRC patients, considering treatment modalities and the location of the primary tumor and comparing the clinical results of the patients with or without PTR between 1 January 2013 and 31 December 2018 at the Institute of Oncotherapy of the University of Pécs.

RESULTS

A total of 63.5% of the 449 smCRC patients had PTR. Comparing their data to those whose primary tumor remained intact (IPT), we observed significant differences in median progression-free survival with first-line chemotherapy (mPFS1) (301 vs. 259 days; p < 0.0001; 1 y PFS 39.2% vs. 26.6%; OR 0.56 (95% CI 0.36-0.87)) and median overall survival (mOS) (760 vs. 495 days; p < 0.0001; 2 y OS 52.4 vs. 26.9%; OR 0.33 (95% CI 0.33-0.53)), respectively. However, in the PTR group, the average ECOG performance status was significantly better (0.98 vs. 1.1; p = 0.0456), and the use of molecularly targeted agents (MTA) (45.3 vs. 28.7%; p = 0.0005) and rate of metastasis ablation (MA) (21.8 vs. 1.2%; p < 0.0001) were also higher, which might explain the difference partially. Excluding the patients receiving MTA and MA from the comparison, the effect of PTR remained evident, as the mOS differences in the reduced PTR subgroup compared to the reduced IPT subgroup were still strongly significant (675 vs. 459 days; p = 0.0009; 2 y OS 45.9 vs. 24.1%; OR 0.37 (95% CI 0.18-0.79). Further subgroup analysis revealed that the site of the primary tumor also had a major impact on the outcome considering only the IPT patients; shorter mOS was observed in the extrapelvic IPT subgroup in contrast with the intrapelvic IPT group (422 vs. 584 days; p = 0.0026; 2 y OS 18.2 vs. 35.9%; OR 0.39 (95% CI 0.18-0.89)). Finally, as a remarkable finding, it should be emphasized that there were no differences in OS between the smCRC PTR subgroup and metachronous mCRC patients (mOS 760 vs. 710 days, p = 0.7504, 2 y OS OR 0.85 (95% CI 0.58-1.26)).

CONCLUSIONS

The role of PTR in smCRC is still not professionally justified. Our survey found that most patients had benefited from PTR. Nevertheless, further prospective trials are needed to clarify the optimal treatment sequence of smCRC patients and understand this cancer disease's inherent biology.

Non-invasive detection of orthotopic human lung tumors by microRNA expression profiling of mouse exhaled breath condensates and exhaled extracellular vesicles

Aim

The lung is the second most frequent site of metastatic dissemination. Early detection is key to improving survival. Given that the lung interfaces with the external environment, the collection of exhaled breath condensate (EBC) provides the opportunity to obtain biological material including exhaled miRNAs that originate from the lung.

Methods

In this proof-of-principal study, we used the highly metastatic MDA-MB-231 subline 3475 breast cancer cell line (LM-3475) to establish an orthotopic lung tumor-bearing mouse model and investigate non-invasive detection of lung tumors by analysis of exhaled miRNAs. We initially conducted miRNA NGS and qPCR validation analyses on condensates collected from unrestrained animals and identified significant miRNA expression differences between the condensates of lung tumor-bearing and control mice. To focus our purification of EBC and evaluate the origin of these differentially expressed miRNAs, we developed a system to collect EBC directly from the nose and mouth of our mice.

Results

Using nanoparticle distribution analyses, TEM, and ONi super-resolution nanoimaging, we determined that human tumor EVs could be increasingly detected in mouse EBC during the progression of secondary lung tumors. Using our customizable EV-CATCHER assay, we purified human tumor EVs from mouse EBC and demonstrated that the bulk of differentially expressed exhaled miRNAs originate from lung tumors, which could be detected by qPCR within 1 to 2 weeks after tail vein injection of the metastatic cells.

Conclusion

This study is the first of its kind and demonstrates that lung tumor EVs are exhaled in mice and provide non-invasive biomarkers for detection of lung tumors.

Lung surveillance following colorectal cancer pulmonary metastasectomy: Utilization of clinicopathologic risk factors to guide strategy

BACKGROUND

Appropriately selected patients clearly benefit from resection of colorectal cancer (CRC) pulmonary metastases (PMs). However, there remains equipoise surrounding optimal chest surveillance strategies following pulmonary metastasectomy. We aimed to identify risk factors that may inform chest surveillance in this population.

METHODS

Patients who underwent CRC pulmonary metastasectomy were identified from a single institution's prospectively maintained surgical database. Clinicopathologic and genomic characteristics were collected. Patients were stratified by diagnosis of subsequent PM within 6 months of the index lung resection. Multivariate modeling was used to evaluate risk factors.

RESULTS

A total of 197 patients met the study's inclusion criteria, of whom 52.3% (n = 103) developed subsequent PM, at a median of 9.51 months following the index metastasectomy. Patients with KRAS alterations (odds ratio [OR], 3.073; 95% confidence interval [CI], 1.363-6.926; P = .007), TP53 alterations (OR, 3.109; 95% CI, 1.318-7.341; P = .010) were found to be at risk of PM diagnosis within 6 months of the index metastasectomy, while those with an APC alteration (OR, .218; 95% CI, 0.080-0.598; P = .003) were protected. Moreover, patients who received systemic therapy within 3 months of the initial PM diagnosis also were more likely to develop early lung recurrence (OR, 2.105; 95% CI, 0.971-4.563; P = .059).

CONCLUSIONS

Patients with KRAS alterations, TP53 alterations, and no APC alterations developed early recurrence in the lung following pulmonary metastasectomy, as did those who received chemotherapy after their initial PM diagnosis. As such, these groups benefit from early lung imaging after metastasectomy, as chest surveillance protocols should be based on patient-centered clinicopathologic and genomic risk factors.

Do resected colorectal cancer patients need early chest imaging? Impact of clinicopathologic characteristics on time to development of pulmonary metastases

BACKGROUND AND OBJECTIVES

For patients with colorectal cancer (CRC), the lung is the most common extra-abdominal site of distant metastasis. However, practices for chest imaging after colorectal resection vary widely. We aimed to identify characteristics that may indicate a need for early follow-up imaging.

METHODS

We retrospectively reviewed charts of patients who underwent CRC resection, collecting clinicopathologic details and oncologic outcomes. Patients were grouped by timing of pulmonary metastases (PM) development. Analyses were performed to investigate odds ratio (OR) of PM diagnosis within 3 months of CRC resection.

RESULTS

Of 1600 patients with resected CRC, 233 (14.6%) developed PM, at a median of 15.4 months following CRC resection. Univariable analyses revealed age, receipt of systemic therapy, lymph node ratio (LNR), lymphovascular and perineural invasion, and KRAS mutation as risk factors for PM. Furthermore, multivariable regression showed neoadjuvant therapy (OR: 2.99, p < 0.001), adjuvant therapy (OR: 6.28, p < 0.001), LNR (OR: 28.91, p < 0.001), and KRAS alteration (OR: 5.19, p < 0.001) to predict PM within 3 months post-resection.

CONCLUSIONS

We identified clinicopathologic characteristics that predict development of PM within 3 months after primary CRC resection. Early surveillance in such patients should be emphasized to ensure timely identification and treatment of PM.

Repeated Pulmonary Metastasectomy: Third Operations and Beyond

BACKGROUND

For extrathoracic malignant neoplasms that have metastasized to the lungs, previous investigations have demonstrated both oncologic and survival benefits after pulmonary and repeated metastasectomy. Little is known about the feasibility of incrementally increasing numbers of subsequent metastasectomy procedures.

METHODS

We conducted a retrospective review of patients who underwent ≥3 pulmonary resection procedures for recurrent, metachronous metastatic disease of nonlung primary malignant neoplasms at a single institution between 1992 and 2020. Primary outcomes collected pertained to safety and feasibility, including estimated blood loss (EBL), hospital length of stay, and details of postoperative complications.

RESULTS

There were 117 patients who met inclusion criteria, having undergone at least 3 metastasectomy operations, with 55 (47.1%) undergoing a fourth operation and 20 (17.1%) undergoing a fifth operation. EBL did not differ between first and second operations (106.6 mL vs 102.5 mL; P = .76). It was, however, significantly greater at third operations (102.5 mL vs 238.7 mL; P = .000016). We noted an increase in wound complications between the second and third operations (0.9% vs 6.8%; P = .02) and incremental increases in likelihood of prolonged air leak with each subsequent operation. The need for reoperation was low for all and similar between operations. Importantly, hospital length of stay was similar for all procedures, as were the frequencies of hospital readmission.

CONCLUSIONS

Third-time redo pulmonary metastasectomy can be performed safely and feasibly in select patients. Further repeated resection should remain a therapeutic option for patients, although risks for potentially longer operating time, greater EBL, and prolonged air leaks may be anticipated.

Salvage surgery in lung cancer following definitive therapies

Salvage surgery refers to operative resection of persistent or recurrent disease in patients initially treated with intention-to-cure nonoperative management. In non-small-cell lung cancer, salvage surgery may be effective in treating selected patients with locally progressive tumors, recurrent local or locoregional disease, or local complications after nonoperative therapy. Importantly, those patients who may be candidates for salvage surgery are evolving, in terms of disease stage as well as the types of attempted definitive therapy received.

Pulmonary Metastasectomy

The lung represents the most common site for metastatic spread of extrathoracic primary malignancies. Pulmonary metastatic disease occurs in a wide breadth of cancers with a multitude of histologies, and, historically, has been managed predominantly with systemic therapy. However, in appropriately selected patients, pulmonary metastasectomy can provide extended disease-free intervals, relief from systemic therapy, and prolonged survival. Thus, pulmonary metastasectomy serves a vital role in the armamentarium against a multitude of primary malignancies. Moreover, as systemic agents improve and more patients live longer with stage IV cancer, pulmonary metastasectomy will likely have increasing relevance in the future.

The role of FOXP3 in non-small cell lung cancer and its therapeutic potentials

Although in the last few decades we have witnessed the rapid development of treatments for non-small cell lung cancer (NSCLC), it still remains the leading cause of cancer-related death. Increasing efforts have been devoted to exploring potential biomarkers and molecular targets for NSCLC. Foxp3, a transcription factor that was discovered as a master regulator of regulatory T cells (Tregs), has been found to express abnormally in tumoral cells including lung cancer cells. In recent years, increasing evidence have surfaced, revealing the carcinogenic effect of FOXP3 in lung cancer. In this review, we analyzed and summarized the function of FOXP3, its regulation and therapeutic potentials in NSCLC, with a hope to facilitate the development of novel treatments for NSCLC.

Issues and prospects of image-guided thermal ablation in the treatment of primary and metastatic lung tumors

The precise local minimally invasive or noninvasive treatment represents the important orientation for advancing the treatment of pulmonary malignant tumors. New local treatment methods have emerged as solutions to the shortcomings of minimally invasive or local treatment methods. Image-guided thermal ablation (IGTA) comes with the characteristics such as more accurate localization, less trauma, more definite efficacy, higher safety, stronger repeatability, fewer complications, and lower cost in treating lung tumors. This paper investigates the existing problems of IGTA in the treatment of lung tumors and puts forward the orientation of studies.

Comparison of clinical outcomes between cone beam CT-guided thermal ablation and helical tomotherapy in pulmonary metastases from hepatocellular carcinoma

Objective

This retrospective study compares the clinical results of cone beam CT (CBCT)-guided thermal ablation with those of helical tomotherapy in hepatocellular carcinoma (HCC) patients with pulmonary metastases.

Methods

A total of 110 patients undergoing thermal ablation or helical tomotherapy for pulmonary metastases from April 2014 to December 2020 were included in the study. The endpoints were local tumor progression-free survival (LTPFS), overall survival (OS), and complications. Univariate and multivariate analyses using the Cox proportional hazard model were conducted to identify independent factors (univariate: P &lt; 0.1; multivariate: P &lt; 0.05). The Kaplan–Meier method was used to calculate the LTPFS and OS rates.

Results

The results of 106 patients were taken into the final analysis. The 1- and 3-year LTPFS rates were 50 and 19% for the thermal ablation group and 65 and 25% for the helical tomotherapy group. The median LTPFS in the thermal ablation group was 12.1 months, while it was 18.8 months in the helical tomotherapy group (P = 0.25). The 1- and 3-year OS rates were 75 and 26% for the thermal ablation group and 77 and 37% for the helical tomotherapy group. The median OS was 18.0 months in the thermal ablation group and 23.4 months in the helical tomotherapy group (P = 0.38). The multivariate analyses found that α-fetoprotein (AFP) at &lt;400 ng/ml (P = 0.003) was significantly associated with better LTPFS. Tumor number &lt;3 and AFP &lt;400 ng/ml were favorable prognostic factors for OS. There were no grades 3–5 adverse events in both groups. Grade 2 was recorded in three patients (4.8%) in the thermal ablation group and two patients (4.7%) in the helical tomotherapy group.

Conclusions

For pulmonary metastases from HCC, CBCT-guided thermal ablation and helical tomotherapy provided comparable clinical effects and safety.

Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomised controlled trial: a systematic review of published responses

OBJECTIVES

The objective of this review was to assess the nature and tone of the published responses to the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomized controlled trial.

METHODS

Published articles that cited the PulMiCC trial were identified from Clarivate Web of Science (©. Duplicates and self-citations were excluded and relevant text extracted. Four independent researchers rated the extracts independently using agreed scales for the representativeness of trial data and the textual tone. The ratings were aggregated and summarized. Two PulMiCC authors carried out a thematic analysis of the extracts.

RESULTS

Sixty-four citations were identified and relevant text was extracted and examined. The consensus rating for data inclusion was a median of 0.25 out of 6 (range 0 to 5.25, IQR 0-1.5) and for textual tone the median rating was 1.87 out of 6 (range 0 to 5.75, IQR 1-3.5). The majority of citations did not provide adequate representation of the PulMiCC data and the overall the textual tone was dismissive. Although some were supportive, many discounted the findings because the trial closed early and was underpowered to show non-inferiority. Two misinterpreted the authors' conclusions but there was acceptance that five-year survival was much higher than widely assumed.

CONCLUSIONS

Published comments reveal a widespread reluctance to consider seriously the results of a carefully conducted randomized trial. This may be because the results challenge accepted practice because of 'motivated reasoning'. But there is a widespread misunderstanding of the fact that though PulMiCC with 93 patients was underpowered to test non-inferiority, it still provides reliable evidence to undermine the widespread belief in a major survival benefit from metastasectomy.

The Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) burden of care study: Analysis of local treatments for lung metastases and systemic chemotherapy in 220 patients in the PulMiCC cohort

AIM

The aim of this work was to examine the burden of further treatments in patients with colorectal cancer following a decision about lung metastasectomy.

METHOD

Five teams participating in the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) study provided details on subsequent local treatments for lung metastases, including the use of chemotherapy. For patients in three groups (no metastasectomy, one metastasectomy or multiple local interventions), baseline factors and selection criteria for additional treatments were examined.

RESULTS

The five teams recruited 220 patients between October 2010 and January 2017. No lung metastasectomy was performed in 51 patients, 114 patients had one metastasectomy and 55 patients had multiple local interventions. Selection for initial metastasectomy was associated with nonelevated carcinoembryonic antigen, fewer metastases and no prior liver metastasectomy. These patients also had better Eastern Cooperative Oncology Group scores and lung function at baseline. Four sites provided information on chemotherapy in 139 patients: 79 (57%) had one to five courses of chemotherapy, to a total of 179 courses. The patterns of survival after one or multiple metastasectomy interventions showed evidence of guarantee-time bias contributing to an impression of benefit over no metastasectomy. After repeated metastasectomy, a significantly higher risk of death was observed, with no apparent reduction in chemotherapy usage.

CONCLUSION

Repeated metastasectomy is associated with a higher risk of death without reducing the use of chemotherapy. Continued monitoring without surgery might reassure patients with indolent disease or allow response assessment during systemic treatment. Overall, the carefully collected information from the PulMICC study provides no indication of an important survival benefit from metastasectomy.