Anatomical Resections Improve Survival Following Lung Metastasectomy of Colorectal Cancer Harboring KRAS Mutations

Metabolism of asparagine in the physiological state and cancer

Asparagine, an important amino acid in mammals, is produced in several organs and is widely used for the production of other nutrients such as glucose, proteins, lipids, and nucleotides. Asparagine has also been reported to play a vital role in the development of cancer cells. Although several types of cancer cells can synthesise asparagine alone, their synthesis levels are insufficient to meet their requirements. These cells must rely on the supply of exogenous asparagine, which is why asparagine is considered a semi-essential amino acid. Therefore, nutritional inhibition by targeting asparagine is often considered as an anti-cancer strategy and has shown success in the treatment of leukaemia. However, asparagine limitation alone does not achieve an ideal therapeutic effect because of stress responses that upregulate asparagine synthase (ASNS) to meet the requirements for asparagine in cancer cells. Various cancer cells initiate different reprogramming processes in response to the deficiency of asparagine. Therefore, it is necessary to comprehensively understand the asparagine metabolism in cancers. This review primarily discusses the physiological role of asparagine and the current progress in the field of cancer research.

Clinical score for colorectal cancer patients with lung-limited metastases undergoing surgical resection: Meta-Lung Score

BACKGROUND

Radical resection of isolated lung metastases (LM) from colorectal cancer (CRC) is debated. Like Fong's criteria in liver metastases, our study was meant to assign a clinical prognostic score in patients with LM from CRC, aiming for better surgery selection.

METHODS

We retrospectively analyzed data from 260 CRC patients who underwent curative LM resection from December 2002 to January 2022, verifying the impact of different clinicopathological features on the overall survival (OS).

RESULTS

At the univariate analysis: higher baseline CEA levels (p = 0.0001), disease-free survival less than or equal to 12 months (m) (p = 0.0043), LM size larger than 2 cm (p = 0.0187), multiple resectable nodules (p = 0.0083), and positive nodal status of the primary tumor (p = 0.0011) were associated with worse prognosis. In a Cox regression model, these characteristics retained their independent role for OS (p < 0.0001) and were chosen as criteria to be assigned one point each for clinical risk score. The 5-year survival rate in patients with 0 points was 88%, while no patients with a 5-point score survived at 2 years. Based on the 0-1 vs. 2-5 score range, we obtained a significant difference in median OS: not reached vs. 40.8 months (95 %CI 36 to 87.5), respectively (p < 0.0001) stratifying patients into good and poor prognosis. The prognostic role of the score was also confirmed in terms of median RFS: not reached in 0-1 scored patients vs. 30.5 months (95 %CI 19.4 to 42) in patients with 2-5 scores (p = 0.0006).

CONCLUSIONS

When LM from CRC is resectable, the Meta-Lung Score provides valuable prognostic information. Indeed, while upfront surgery should be considered in patients with scores of 0 to 1, it should be cautiously suggested in patients with scores of 2 to 5, for whom a prognosis comparison between preventive surgery and other treatments should be investigated in prospective randomized clinical trials.

Overview of predictive and prognostic biomarkers and their importance in developing a clinical pharmacology treatment plan in colorectal cancer patients

INTRODUCTION

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Although overall survival for CRC patients has improved with earlier screening, survival continues to vary substantially across stages. Also, while the introduction of targeted therapies, including VEGF and EGFR inhibitors, has contributed to improving survival, better tools are needed to optimize patient selection and maximize therapeutic benefits. Emerging biomarkers can be used to guide pharmacologic decision-making, as well as monitor treatment response, clarify the need for adjuvant therapies, and indicate early signs of recurrence. This is a narrative review examining the current and evolving use of predictive and prognostic biomarkers in colorectal cancer.

AREAS COVERED

Areas covered include mutations of the MAPK (KRAS, BRAF) and HER2 pathways and their impacts on treatment decisions. In addition, novel methods for assessing tumor mutations and tracking treatment responses are examined.

EXPERT OPINION

The standard of care pathway for staging, and treatment selection and surveillance, of CRC will expand to include novel biomarkers in the next 5 years. It is anticipated that these new biomarkers will assist in decision-making regarding selection of targeted therapies and, importantly, in risk stratification for treatment decisions in patients at high risk for recurrence.

Precision surgery for colorectal liver metastases: Current knowledge and future perspectives

Precision surgery for colorectal liver metastases (CRLM) includes optimal selection of both the patient and surgery. Initial attempts of using clinical risk scores to identify patients for whom technically feasible surgery is oncologically futile failed. Since then, patient selection for single-stage hepatectomy followed three distinct approaches, all of which incorporated biomarkers. The BRAF V600E mutation, the G12V KRAS variant, and the triple mutation of RAS, TP53, and SMAD4 appear to be the most promising, but none can be used in isolation to deny surgery in otherwise resectable cases. Combining biomarkers with clinicopathologic factors that predict poor prognosis may be used to select patients for surgery, but external validation and matched analyses with medically treated counterparts are needed. Patient selection for special surgical procedures (two-stage hepatectomy [TSH], Associating Liver Partition and Portal vein Ligation for staged hepatectomy [ALPPS], and liver transplant [LT]) has been recently refined. Specifically, BRAF mutations and right-sided laterality have been proposed as separate contraindications to LT. A similar association of right-sided laterality, particularly when combined with RAS mutations, with very poor outcomes has been observed for ALPPS and has been suggested as a biologic contraindication. Data are scarce for TSH but RAS mutations may portend very poor survival following TSH completion. The selection of the best single-stage hepatectomy (optimal margin and type of resection) based on biomarkers remains debated, although there is some evidence that RAS may play a significant role. Lastly, although there are currently no criteria to select among the three special techniques based on their efficacy or appropriateness in different settings, RAS mutational status may be used to select patients for TSH, while right-sided tumor in conjunction with a RAS mutation may be a contraindication to LT and ALPPS.

Association of Simultaneous vs Delayed Resection of Liver Metastasis With Complications and Survival Among Adults With Colorectal Cancer

IMPORTANCE

Simultaneous or delayed resection of synchronous liver metastasis (SLM) with primary colorectal cancer (CRC) remains a controversial topic.

OBJECTIVE

To investigate the outcomes of simultaneous vs delayed resection in patients with resectable SLM.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness research study included 1569 patients with resectable SLM who underwent curative-intent liver resection at 3 independent centers in China between January 1, 2000, to December 31, 2019. A 1:1 propensity score matching was performed. Follow-up was completed on August 31, 2021, and the data were analyzed from April 1 to 30, 2022.

MAIN OUTCOMES AND MEASURES

Primary outcome was the percentage of patients with at least 1 major complication within 60 days after surgery. Secondary outcomes were intraoperative and postoperative complications, overall survival (OS), and cancer-specific survival (CSS) rates.

RESULTS

Among the 1569 patients included, 1057 (67.4%) underwent delayed resection (719 men [68.0%] with a mean [SD] age of 57.4 [11.2] years), and 512 patients (310 men [60.5%] with a mean [SD] age of 57.1 [10.5] years) underwent simultaneous resection. Matching yielded 495 pairs of patients underwent simultaneous resection. The percentage of major perioperative complications did not differ between the simultaneous and delayed resection groups (34.1% vs 30.0%; P = .89). The OS rates were 65.2% at 3 years, 47.1% at 5 years, and 38.0% at 8 years for the delayed resection group and 78.0% at 3 years, 65.4% at 5 years, and 63.1% at 8 years for the simultaneous resection group (hazard ratio [HR], 1.42; 95% CI, 1.10-1.85, P = .003). The CSS rates were 68.3% at 3 years, 48.5% at 5 years, and 37.1% at 8 years for the delayed resection group and 79.2% at 3 years, 67.2% at 5 years, and 65.9% at 8 years for the simultaneous resection group (HR, 1.45; 95% CI, 1.14-1.98; P = .004). On subgroup analysis comparing the 2 strategies according to the KRAS sequence variation status, the OS rates (HR, 1.61; 95% CI, 1.45-2.18; P < .001) and CSS rates (HR, 1.62; 95 CI, 1.40-1.87; P = .003]) in the simultaneous resection group were significantly better than those in the delayed resection group in patients with KRAS wild-type tumors.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that complication rates did not differ when CRC and SLM were resected simultaneously and that the survival benefits of simultaneous resection were restricted to patients with KRAS wild-type tumors. Integrating molecular features into the treatment decision is a basis for accurate, individualized treatments.

New insights into the unique nature of colorectal cancer peritoneal metastases-rethinking HIPEC

Colorectal peritoneal metastases (CRPM) can be resistant to the chemotherapy agent (oxaliplatin) most employed, up until recently, as hyperthermic intraperitoneal chemotherapy (HIPEC). Glutathione-mediated inactivation of oxaliplatin can be substantially reduced by genomic deletion of the gene or pharmacological inhibition of glutamate-cysteine ligase in CRPM tumouroids. These discoveries may rekindle the enthusiasm for HIPEC in concert with cytoreductive surgery, which has been employed to manage patients with this once-nihilistic form of stage-IV disease.

Study Protocol for a Randomised Controlled Trial on Pulmonary Metastasectomy vs. Standard of Care in Colorectal Cancer Patients With ≥ 3 Lung Metastases (PUCC-Trial)

This is a multicentre prospective randomised controlled trial for patients with 3 or more resectable pulmonary metastases from colorectal carcinoma. The study investigates the effects of pulmonary metastasectomy in addition to standard medical treatment in comparison to standard medical treatment plus possible local ablative measures such as SBRT. This trial is intended to demonstrate an overall survival difference in the group undergoing pulmonary metastasectomy. Further secondary and exploratory endpoints include quality of life (EORTC QLQ-C30, QLQ-CR29 and QLQ-LC29 questionnaires), progression-free survival and impact of mutational status. Due to the heterogeneity and complexity of the disease and treatment trajectories in metastasised colorectal cancer, well powered trials have been very challenging to design and execute. The goal of this study is to create a setting which allows treatment as close to the real life conditions as possible but under well standardised conditions. Based on previous trials, in which patient recruitment in the given setting hindered successful study completion, we decided to (1) restrict inclusion to patients with 3 or more metastases (since in case of lesser, surgery will probably be the preferred option) and (2) allow for real world standard of care (SOC) treatment options before and after randomisation including watchful waiting (as opposed to a predefined treatment protocol) and (3) possibility that patient can receive SOC externally (to reduce patient burden). Moreover, we chose to stipulate 12 weeks of systemic treatment prior to possible resection to further standardize treatment response and disease course over a certain period of time. Hence, included patients will be in the disease state of oligopersistence rather than primary oligometastatic. The trial was registered in the German Clinical Trials Register (DRKS-No.: DRKS00024727).

Lung Resections for Elderly Patients with Lung Metastases: A Comparative Study of the Postoperative Complications and Overall Survival

Background: Pulmonary metastasectomy (PM) is an established treatment option for selected patients with stage IV solid tumors. The aim of this study was to investigate the feasibility of and survival rate in PM for elderly patients. Methods: We retrospectively analyzed all of the patients who underwent PM with curative intention at our institution. The patients were categorized into two groups: the elderly group (≥70 years old) and the non-elderly group (<70 years old). Results: The elderly group consisted of 222 patients versus 538 patients in the non-elderly group. The median number of resected metastases was 2 ± 3 in the elderly group and 4 ± 5 in the non-elderly group (p < 0.01). No difference in the rate of postoperative complications was observed between the two groups (p = 0.3). The median length of hospital stay in each group was comparable (10 ± 5 vs. 10 ± 4.3 days, p = 0.3). The 5-year survival rate was 67% in the elderly group and 78% in the non-elderly group (p = 0.117). In the univariate analysis, COPD was associated with poor survival in the elderly group (p = 0.002). Conclusion: The resection of pulmonary metastases in elderly patients is safe, is not associated with increased risks of postoperative complication, and the survival benefit is not reduced in selected patients.

Anatomical Resection Improves Disease-Free Survival After Lung Metastasectomy of Colorectal Cancer

Purpose

This study aimed to evaluate the role of anatomical resection (AR) in lung metastasectomy (LM) of colorectal cancer (CRC) and to investigate clinically relevant prognostic factors.

Patients and Methods

The medical records of 350 consecutive patients who underwent LM of CRC from 2011 to 2019 were reviewed. The patients were designated into AR group (lobectomy and segmentectomy), and non-anatomical resection (NAR) group (wedge resection), respectively. Kaplan–Meier method was used to analyze disease-free survival (DFS), pulmonary-specific disease-free survival (PDFS) and overall survival (OS). Cox proportional hazards regression model was performed to analyze the factors associated with DFS, PDFS and OS.

Results

A total of 92 (31.2%) patients were enrolled in AR group and 203 (68.8%) in non-anatomical resection (NAR) group. AR significantly improved the 3-year DFS (64.1% vs 46.8%, HR 0.587, 95% CI 0.397–0.867, P = 0.007) and PDFS (75.0% vs 60.1%, HR 0.565, 95% CI 0.356–0.899, P = 0.016) compared with NAR. However, the extent of resection did not significantly impact the 3-year OS (AR 92.4% vs NAR 85.7%, HR 0.511, 95% CI 0.224–1.165, P = 0.110). In multivariate analysis, AR was identified as a protective factor for DFS (HR 0.576, 95% CI 0.356–0.934, P = 0.025) and PDFS (HR 0.631, 95% CI 0.409–0.973, P = 0.037). Preoperative abnormal CA19-9 was identified as the only prognostic factor for OS.

Conclusion

AR was superior to NAR for DFS and PDFS after LM from CRC.

How often segmentectomy is feasible in lung cancer surgery: a population-based evaluation

OBJECTIVES

Despite promising outcomes in lung cancer surgery, segmentectomy has not gained wide acceptance at the population level. Our aim was to evaluate the potential role of segmentectomy in real-world practice.

METHODS

All patients diagnosed with lung cancer and operated between January 2013 and December 2019 in Central Finland and Ostrobothnia were included. This intent-to-treat analysis sub-grouped segmentectomy patients by indications: (i) high-risk patients with stage I disease (n = 40), (ii) ≤20 mm ground-glass opacity (n = 12), (iii) carcinoid (n = 12), (iv) special indication (n = 20) including synchronous and metachronous disease, fissure-crossing tumour, and synchronous other solid cancers requiring surgery, (v) solid ≤2 cm tumour (n = 14) in medically fit patient. To evaluate the potential role of segmentectomy, all preoperative CT scans were re-evaluated.

RESULTS

Of 269 patients, in 98 (36.4%) intention of surgery was segmentectomy. Indication was high risk in 40 (14.9%), ground-glass opacity in 12 (4.5%), carcinoid in 12 (4.5%), special indication in 20 (7.4%) and ≤2 cm solid tumour in medically fit patients in 14 (5.2%). The major complication rate was ≤15% in all groups with excellent 3-year recurrence-free survival between 76.5% and 100%. Segmentectomy could have been technically potential in up to 46.8% of patients. This was exactly the rate performed in the last 3-year period of this study.

CONCLUSIONS

Performed and potential segmentectomy rates underline the importance of adaptation of this technique with possibility to offer curative surgery to many high risk and special patients with low morbidity and mortality.

Prognostic value of KRAS mutation in patients undergoing pulmonary metastasectomy for colorectal cancer: A systematic review and meta-analysis

BACKGROUND

The purpose of the study was to evaluate whether KRAS mutation could be an independent prognostic biomarker in patients undergoing pulmonary metastasectomy (PM) for colorectal cancer (CRC).

METHODS

A systemic review was performed by searching online databases to identify studies reporting overall survival (OS) and recurrence free survival (RFS) of CRC patients undergoing PM. Pooled HRs were calculated for OS and RFS.

RESULTS

A total of 15233 patients from 60 studies were included. Pooled analysis showed that KRAS mutation was associated with worse OS (HR: 1.86, 95 % Cl: 1.35-2.57) and RFS (HR: 1.68, 95 % Cl: 1.38-2.04). A significant effect on OS and/or RFS was also shown by other 18 factors.

CONCLUSIONS

This meta-analysis found that KRAS mutation is an important prognostic predictor for OS and RFS in CRC patients undergoing PM, supporting a comprehensive model including clinicopathological and biological factors for optimal patients selection and prognosis for surgical treatment.

Impact and clinical usefulness of genetic data in the surgical management of colorectal cancer liver metastasis: a narrative review

Importance

In patients who undergo surgery for colorectal cancer liver metastases (CRLM), a number of somatic mutations have been associated with worse overall (OS) and recurrence-free survival (RFS). Although useful, an association with prognosis does not necessarily equate to an impact on surgical management.

Objective

The aim of this review was to investigate whether the best-studied somatic mutations impact surgical management of CRLM by informing: (I) post-hepatectomy surveillance; (II) selection of surgical technique; (III) selection of optimal margin width; and (IV) selection of patients for surgery. Lastly, we discuss the refinement of genetic data from overall mutation status to specific variants, as well as lesser studied somatic mutations.

Evidence Review

We conducted a computerized search using PubMed and Google Scholar for reports published so far, using mesh headings and keywords related to genetic data and CRLM.

Findings

Genetic data may impact surgical management of CRLM in three ways. Firstly, KRAS mutations can predict lung recurrences. Secondly, KRAS mutations may help tailor margin width. Thirdly, KRAS mutations may help tailor surgical technique.

Conclusions

Although genetic data may impact post-hepatectomy surveillance, selection of surgical technique and optimal margin width, their use to guide surgical selection remains elusive, as the data cannot support denying surgery to patients according to their somatic mutation profile.

Proctor-guided virtual reality-enhanced three-dimensional video-assisted thoracic surgery: an excellent tutoring model for lung segmentectomy

OBJECTIVE

Lung segmentectomy using video-assisted thoracoscopic surgery (VATS) is an effective strategy to treat early-stage lung cancer. The objective of this case report is to show the efficacy of Hyper Accuracy 3D™ (HA3D) reconstruction as a tool for trainee surgeons and expert surgeons to perform complex procedures.

METHODS

An 84-year-old man was treated for colon-rectal cancer. During follow-up, a pulmonary nodule on the right anterior upper lobe suspected for intestinal metastasis was revealed by a computed tomography scan. According to functional tests and radiology, a right anterior upper lobe segmentectomy was planned. HA3D lung reconstruction was used during surgery.

RESULTS

Using the HA3D virtual model, the procedure was performed with healthy tissue sparing, ensuring safe resection margins. No postoperative morbidities were noted. The patient referred good pain control. The hospital stay was 6 days.

CONCLUSIONS

VATS segmentectomy is a technically demanding procedure. HA3D lung reconstruction can help surgeons effectively perform the resection, aiding at individuating intersegmental planes, bronchi, and vessels, guaranteeing oncologic radicality and safe surgical margins, and preserving respiratory function.

Anatomic Resection Is Not Required for Colorectal Liver Metastases with RAS Mutation

BACKGROUND

Non-anatomic resection (NAR) has emerged as a safe and effective technique for resection of colorectal liver metastases (CRLM). More recently, RAS mutation has been identified as an important indicator of aggressive disease, which may require anatomic resection (AR). In this retrospective study, we compared the long-term outcomes of AR versus NAR in CRLM patients with and without RAS mutations.

METHODS

Patients with known RAS mutation status who underwent AR or NAR for CRLM between 2006 and 2016 were included. Differences in baseline characteristics were adjusted using 1:1 propensity score matching, including the most important factors that contributed to the decision to use the resection technique. Overall survival (OS), recurrence-free survival (RFS), and liver-specific recurrence-free survival (L-RFS) were compared between cohorts.

RESULTS

Among 622 total patients, 338 (54%) underwent AR and 284 (46%) NAR. There was no difference in OS or L-RFS between the AR and NAR groups, regardless of mutation status. There was increased RFS in the RAS WT patients with NAR (P = 0.034), but no difference in RFS in the whole cohort or RAS mutant group. After propensity score matching, 360 patients were analyzed, and no differences in OS, RFS, or L-RFS rates were seen between any groups. There was also no difference in margin recurrence.

CONCLUSIONS

Similar outcomes can be achieved with both AR and NAR, regardless of RAS mutation status. These data do not support a universal requirement for AR in RAS mutant CRLM when not necessary to achieve an R0 resection.

Lung metastasectomy after colorectal cancer: prognostic impact of resection margin on long term survival, a retrospective cohort study

BACKGROUND

Pulmonary metastasectomy is considered a potentially curative treatment for selected patients with metastatic colorectal cancer (CRC). Several prognostic factors have been analysed, but to date, it is still not well defined which is the optimal resection margin during lung metastasectomy (LM). This study analyses the long-term results and prognostic factors after LM in CRC patients with particular attention to the resection margins. Primary endpoint of this study is to assess the correlation between resection margins and long-term outcomes.

METHODS

Observational cohort study on all proven cases of CRC lung metastases (2000-2016) resected with curative intent in a single centre.

RESULTS

The series included 210 consecutive patients (M/F 133/77) with a mean age of 65.4 (± 9.96) years, 75% (159/210) of them with a solitary metastasis. Mean size of metastasis was 2.57 cm (± 1.45). One hundred sixty-eight patients underwent wedge resections (80%) and lymphadenectomy was carried out in 90 cases (42.9%). With a mean follow-up of 56 months (range 5-192), we observed a 1-, 3- and 5-year overall survival (OS) of 95%, 74% and 54%, respectively. The patients were divided into three groups according to the resection margin distance from the tumour: (a) ≥ 2 cm (145 cases); (b) < 2, ≥ 1 cm (37 cases); and (c) < 1 cm (12 cases). The OS was significantly different between the three groups (p = 0,020); univariate and multivariate analyses showed that a narrow resection margin was an independent prognostic factor of worse survival (p = 0.006 and HR 3.4 p = 0.009).

CONCLUSIONS

Long-term survival of patients after LM is strongly associated with a greater distance between the lesion and the resection margin.

Significance of RAS mutations in pulmonary metastases of patients with colorectal cancer

BACKGROUND

RAS/BRAF mutations of colorectal cancer (CRC) play a crucial role in carcinogenesis and cancer progression and need to be considered for the therapeutic strategy choice. We used next-generation-sequencing (NGS) technology to assess RAS/BRAF mutation differences between primary CRC and corresponding pulmonary metastases (PMs).

METHODS

We examined the mutation statuses of the KRAS 12/13/61/146, NRAS 12/13/61/146, and BRAF 600 codons in genomic DNA from fresh-frozen or formalin-fixed paraffin-embedded tissues derived from 34 primary lesions and 52 corresponding PMs from 36 patients with CRC.

RESULTS

We found RAS mutations in 76% (26/34) of primary CRC lesions and in 86% (31/36) of PMs. While 27% (7/26) of the primary CRC RAS mutations were heterogeneous, all the RAS mutations in PMs were homogeneous. Of the mutations in PMs, 71% (22/31) were KRAS G>A transitions, of which 82% (18/22) were KRAS G12D or G13D. The RAS mutation discordance between primary tumors and PMs was 12.1% (4/33). RAS mutations with the same genotyping were detected in all synchronous and metachronous PMs from 9 patients. We found no BRAF mutations in either primary or pulmonary tissues.

CONCLUSION

Our NGS analysis suggests that RAS mutations of PM of patients with CRC are more common than initially thought. The presence of KRAS mutations in CRC specimens, especially G12D or G13D mutations, seems to promote PM formation.

Near-Infrared-Guided Pulmonary Segmentectomy After Endobronchial Indocyanine Green Injection

BACKGROUND

The aim of this study is to prospectively determine the feasibility and safety of near-infrared fluorescence-guided pulmonary segmentectomy after endobronchial indocyanine green (ICG) injection using virtual bronchoscopy.

METHODS

Fifteen patients who underwent pulmonary segmentectomy were prospectively enrolled. Using preoperative computed tomography datasets a bronchial road map was created to determine the bronchus for ICG injection. Immediately after intubation ICG was injected into the target bronchi using an ultrathin bronchoscope. During the operation a near-infrared thoracoscope was used to detect ICG fluorescence and determine the intersegmental plane. The assessment points were (1) whether the ICG demarcation lines corresponded to the intersegmental lines expected from the pulmonary veins, (2) whether it was possible for the planned segmentectomy to be completed by electrocautery and 1 or fewer uses of an automated suturing device according to the demarcation plane, (3) whether any surgical complications occurred intraoperatively or (4) in the 1 month after surgery, and (5) whether the target lesion was removed completely with sufficient surgical margin to evaluate the feasibility and safety of this procedure.

RESULTS

In 13 cases (87%) a segmentectomy was completed in the planned way with sufficient surgical margins. The failure in 2 cases was due to a technical issue in the bronchial injection. No complications developed intraoperatively. Recurrent air leakage occurred in 1 case. No procedure-related adverse event was noted postoperatively.

CONCLUSIONS

Near-infrared-guided pulmonary segmentectomy with endobronchial ICG injection using virtual bronchoscopy was safe and feasible, and minor technical revision can make this procedure more reliable.

An overview on clinical, pathological and molecular features of lung metastases from colorectal cancer

Introduction: Lung metastases occur in 10-20% of patients with colorectal cancer (CRC). Most of them are treated with palliative intent and have a poor prognosis. Pulmonary metastasectomy may be a curative option for carefully selected patients with 5-year survival rates ranging from 25% to 60%. However, up to 70% of patients develop recurrence after pulmonary metastasectomy. Therefore, the identification of prognostic factors is essential in CRC patients with resectable lung metastases. Areas covered: This review aims at summarizing the actual body of knowledge available on lung metastases from CRC focusing on their clinical, pathological and molecular profile. Moreover, we provide an update on experts' attitudes towards lung metastasectomy, adjuvant or perioperative chemotherapy. Expert opinion: Traditional clinical prognosticators such as the total number of pulmonary metastases, carcinoembryonic antigen (CEA) serum levels before surgery, and presence of lymph node metastases cannot provide reliable criteria to predict survival after lung metastasectomy. Indeed, research efforts have been directed in recent years toward studying the biological characteristics of lung lesions to better define prognosis and response to treatment, and ultimately shed new light on their proper local and systemic management.

Surgical management of colorectal lung metastases

Pulmonary metastasectomy for colorectal cancer is an established means of treatment for select patients. This article will highlight the recent evidence published in the literature related to current practices for the surgical management of colorectal lung metastases and propose a diagnostic algorithm for use in clinical practice. It will also discuss controversies related to pulmonary metastasectomy, including the optimal timing of surgery, the extent of lymph node sampling/dissection, and the extent of surgical resection.

Mutation status and surgical selection

Current evidence cannot support denying metastasectomy in otherwise resectable patients solely based on their overall KRAS or BRAF mutational status. The combination of KRAS or BRAF mutational status with certain clinicopathologic characteristics has defined groups of patients who may not derive benefit from metastasectomy, but external validation is needed. The effect of certain KRAS or BRAF variants on survival may be more pronounced and therefore future studies should consider them for surgical selection.