Pulmonary staging in colorectal cancer: a review

A prediction model for lung metastases in patients with indeterminate pulmonary nodules in newly diagnosed colorectal cancer

INTRODUCTION

Multidisciplinary teams treating patients with newly diagnosed Colorectal Cancer (CRC) often encounter the appearance of Indeterminate Pulmonary Nodules (IPNs) that warrants follow-up with repetitive medical imaging and anxiety for patients. We determined the incidence of IPNs in patients with newly diagnosed CRC and developed and validated a model for individualized risk prediction of IPNs being lung metastases.

MATERIAL AND METHODS

Newly diagnosed CRC who underwent surgery between November 2011 to June 2014 were included to create the risk model, developed using both clinical experience and statistical selection. Discrimination and calibration slopes of the risk score were evaluated in an independent temporal validation sample. A nomogram is presented to assist clinicians in estimating an individual risk score.

RESULTS

Out of 2111 CRC patients staged with chest CT, 204 (9.6%) had IPNs and 54/204 (26%) had lung metastases. We identified 4 predictors: "location of primary tumour", "pathological nodal stage", "size of the largest nodule" and "extrapulmonary synchronous metastases at diagnosis". Discrimination of the final model in the validation sample was demonstrated by the difference in mean predicted risk between progressed cases en non-progressed cases (49% versus 21%, p = <0.001).

CONCLUSION

A prediction model with 4 clinical risk factors can be used to assist multidisciplinary teams in the prediction of individualized risk of lung metastases and imaging strategy in patients with IPNs and newly diagnosed colorectal cancer. The model performed well in new patients not included in the model development.

Machine learning for predicting liver and/or lung metastasis in colorectal cancer: A retrospective study based on the SEER database

OBJECTIVE

This study aims to establish a machine learning (ML) model for predicting the risk of liver and/or lung metastasis in colorectal cancer (CRC).

METHODS

Using the National Institutes of Health (NIH)'s Surveillance, Epidemiology, and End Results (SEER) database, a total of 51265 patients with pathological diagnosis of colorectal cancer from 2010 to 2015 were extracted for model development. On this basis, We have established 7 machine learning algorithm models. Evaluate the model based on accuracy, and AUC of receiver operating characteristics (ROC) and explain the relationship between clinical pathological features and target variables based on the best model. We validated the model among 196 colorectal cancer patients in Beijing Electric Power Hospital of Capital Medical University of China to evaluate its performance and universality. Finally, we have developed a network-based calculator using the best model to predict the risk of liver and/or lung metastasis in colorectal cancer patients.

RESULTS

51265 patients were enrolled in the study, of which 7864 (15.3 %) had distant liver and/or lung metastasis. RF had the best predictive ability, In the internal test set, with an accuracy of 0.895, AUC of 0.956, and AUPR of 0.896. In addition, the RF model was evaluated in the external validation set with an accuracy of 0.913, AUC of 0.912, and AUPR of 0.611.

CONCLUSION

In this study, we constructed an RF algorithm mode to predict the risk of colorectal liver and/or lung metastasis, to assist doctors in making clinical decisions.

Identification and prognostic analysis of candidate biomarkers for lung metastasis in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent types of malignant tumors. It's vital to explore new biomarkers and potential therapeutic targets in CRC lung metastasis through adopting integrated bioinformatics tools. Multiple cohort datasets and databases were integrated to clarify and verify potential key candidate biomarkers and signal transduction pathways in CRC lung metastasis. DAVID, STRING, UALCAN, GEPIA, TIMER, cBioPortal, THE HUMAN PROTEIN ATLAS, GSEA 4.3.2, FUNRICH 3.1.3, and R 4.2.3 were utilized in this study. The enriched biological processes and pathways modulated by the differentially expressed genes (DEGs) were determined with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes. The search tool Retrieval of Interacting Genes and Cytoscape were used to construct a protein-protein interaction network among DEGs. Four hundred fifty-nine colorectal primary cancer and lung metastatic gene expression profiles were screened from 3 gene expression profiles (GSE41258, GSE68468, and GSE41568). Forty-one upregulated genes and 8 downregulated genes were identified from these 3 gene expression profiles and verified by the transcriptional levels of hub genes in other GEO datasets and The Cancer Genome Atlas database. Two pathways (immune responses and chemokine receptors bind chemokines), 13 key DEGs, 6 hub genes (MMP3, SFTPD, ABCA3, CLU, APOE, and SPP1), and 2 biomarkers (APOE, SPP1) with significantly prognostic values were screened. Forty-nine DEGs were identified as potential candidate diagnostic biomarkers for patients with CRC lung metastasis in present study. Enrichment analysis indicated that immune responses and chemokine receptors bind chemokines may play a leading role in lung metastasis of CRC, and further studies are needed to validate these findings.

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.

A machine learning-based model for predicting distant metastasis in patients with rectal cancer

Background

Distant metastasis from rectal cancer usually results in poorer survival and quality of life, so early identification of patients at high risk of distant metastasis from rectal cancer is essential.

Method

The study used eight machine-learning algorithms to construct a machine-learning model for the risk of distant metastasis from rectal cancer. We developed the models using 23867 patients with rectal cancer from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2017. Meanwhile, 1178 rectal cancer patients from Chinese hospitals were selected to validate the model performance and extrapolation. We tuned the hyperparameters by random search and tenfold cross-validation to construct the machine-learning models. We evaluated the models using the area under the receiver operating characteristic curves (AUC), the area under the precision-recall curve (AUPRC), decision curve analysis, calibration curves, and the precision and accuracy of the internal test set and external validation cohorts. In addition, Shapley's Additive explanations (SHAP) were used to interpret the machine-learning models. Finally, the best model was applied to develop a web calculator for predicting the risk of distant metastasis in rectal cancer.

Result

The study included 23,867 rectal cancer patients and 2,840 patients with distant metastasis. Multiple logistic regression analysis showed that age, differentiation grade, T-stage, N-stage, preoperative carcinoembryonic antigen (CEA), tumor deposits, perineural invasion, tumor size, radiation, and chemotherapy were-independent risk factors for distant metastasis in rectal cancer. The mean AUC value of the extreme gradient boosting (XGB) model in ten-fold cross-validation in the training set was 0.859. The XGB model performed best in the internal test set and external validation set. The XGB model in the internal test set had an AUC was 0.855, AUPRC was 0.510, accuracy was 0.900, and precision was 0.880. The metric AUC for the external validation set of the XGB model was 0.814, AUPRC was 0.609, accuracy was 0.800, and precision was 0.810. Finally, we constructed a web calculator using the XGB model for distant metastasis of rectal cancer.

Conclusion

The study developed and validated an XGB model based on clinicopathological information for predicting the risk of distant metastasis in patients with rectal cancer, which may help physicians make clinical decisions. rectal cancer, distant metastasis, web calculator, machine learning algorithm, external validation.

Imaging of colon and rectal cancer

Colon and rectal cancer imaging has traditionally been performed to assess for distant disease (typically lung and liver metastases) and to assess the resectability of the primary tumor. With technological and scientific advances in imaging and the evolution of treatment options, the role of imaging has expanded. Radiologists are now expected to provide a precise description of primary tumor invasion extent, including adjacent organ invasion, involvement of the surgical resection plane, extramural vascular invasion, lymphadenopathy, and response to neoadjuvant treatment, and to monitor for recurrence after clinical complete response.

Applying machine learning techniques to predict the risk of lung metastases from rectal cancer: a real-world retrospective study

Background

Metastasis in the lungs is common in patients with rectal cancer, and it can have severe consequences on their survival and quality of life. Therefore, it is essential to identify patients who may be at risk of developing lung metastasis from rectal cancer.

Methods

In this study, we utilized eight machine-learning methods to create a model for predicting the risk of lung metastasis in patients with rectal cancer. Our cohort consisted of 27,180 rectal cancer patients selected from the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2017 for model development. Additionally, we validated our models using 1118 rectal cancer patients from a Chinese hospital to evaluate model performance and generalizability. We assessed our models' performance using various metrics, including the area under the curve (AUC), the area under the precision-recall curve (AUPR), the Matthews Correlation Coefficient (MCC), decision curve analysis (DCA), and calibration curves. Finally, we applied the best model to develop a web-based calculator for predicting the risk of lung metastasis in patients with rectal cancer.

Result

Our study employed tenfold cross-validation to assess the performance of eight machine-learning models for predicting the risk of lung metastasis in patients with rectal cancer. The AUC values ranged from 0.73 to 0.96 in the training set, with the extreme gradient boosting (XGB) model achieving the highest AUC value of 0.96. Moreover, the XGB model obtained the best AUPR and MCC in the training set, reaching 0.98 and 0.88, respectively. We found that the XGB model demonstrated the best predictive power, achieving an AUC of 0.87, an AUPR of 0.60, an accuracy of 0.92, and a sensitivity of 0.93 in the internal test set. Furthermore, the XGB model was evaluated in the external test set and achieved an AUC of 0.91, an AUPR of 0.63, an accuracy of 0.93, a sensitivity of 0.92, and a specificity of 0.93. The XGB model obtained the highest MCC in the internal test set and external validation set, with 0.61 and 0.68, respectively. Based on the DCA and calibration curve analysis, the XGB model had better clinical decision-making ability and predictive power than the other seven models. Lastly, we developed an online web calculator using the XGB model to assist doctors in making informed decisions and to facilitate the model's wider adoption (https://share.streamlit.io/woshiwz/rectal_cancer/main/lung.py).

Conclusion

In this study, we developed an XGB model based on clinicopathological information to predict the risk of lung metastasis in patients with rectal cancer, which may help physicians make clinical decisions.

Survival nomograms for colorectal carcinoma patients with lung metastasis and lung-only metastasis, based on the SEER database and a single-center external validation cohort

Background

We analysed the survival of colorectal cancer (CRC) patients with lung metastasis and lung-only metastasis and determined the risk factors for lung metastasis in CRC patients.

Methods

Data from colorectal cancer patients with lung metastasis diagnosed from 2010 to 2015 were obtained from the SEER database. Survival was analysed using the Kaplan–Meier method and log-rank test, the Cox proportional hazards regression model, and a competing risk model. The predictive ability of the nomgram was assessed by the concordance index (C-index) and calibration curves. The data from the SEER database for the period 2016–2019 was used as an external validation set. The characteristics of 70 CRC patients treated at Shanghai East Hospital between 2016 and 2019 were retrospectively analysed and data from China was chosen as an external validation set.

Results

The median survival time for colorectal cancer patients with lung metastasis was 12 months, while this value was 24 months in patients with lung-only metastasis. Among all CRC patients with lung metastasis, age, grade, T stage, N stage, presence of liver, brain or bone metastasis, anatomic site and surgery were related to overall survival (OS). In CRC patients with lung-only metastasis, age, T stage, marital status, chemotherapy and surgery were independent prognostic factors affecting OS. Two nomograms predicting OS were established, with great discrimination (C-index between 0.67 and 0.81) and excellent calibration. Factors including age, race, sex, tumour grade, T stage, N stage, presence of liver, brain or bone metastasis, marital status, insurance status and anatomic location were related to the occurrence of lung metastasis in CRC patients.

Conclusion

We developed two reliable clinical prediction models among CRC patients to predict the OS rates in patients with lung metastasis and lung metastasis only.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02547-9.

Recent Advance in the Surgical Treatment of Metastatic Colorectal Cancer-An English Version

Stage IV colorectal cancer (CRC) has heterogeneous characteristics in tumor extent and biology. The overall survival of patients with metastatic CRC has improved with the development of multimodal treatments and new chemotherapeutic drugs. Resection of metastatic CRC is performed for liver, lung, or peritoneal metastases. Conversion surgeries to resect oligometastatic lesions have been developed with tumor regression using chemotherapeutic agents. Two-stage hepatectomy has extended the surgical indications for patients with metastatic CRC. Synchronous liver and primary tumor resection can be considered in patients with adequate conditions. Local ablation with radiotherapy can be used to treat lung metastasis. In the treatment of patients with CRC with peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be considered. Surgical treatments should be performed in patients with symptomatic primary tumors with unresectable metastasis. However, primary tumor resection in patients with asymptomatic CRC with synchronous, unresectable metastases did not show overall survival benefits in recent studies. Therefore, the treatment of metastatic CRC is challenging due to the variable tumor extent and heterogenous characteristics. Tailored surgical treatments and multidisciplinary approaches may improve survival and the quality of life in patients with metastatic CRC.

A novel diagnostic model for differentiation of lung metastasis from primary lung cancer in patients with colorectal cancer

Objective

This study aimed to evaluate the ¹⁸F-FDG PET/CT in differentiating lung metastasis(LM) from primary lung cancer(LC) in patients with colorectal cancer (CRC).

Methods

A total of 120 CRC patients (80 male, 40 female) who underwent ¹⁸F-FDG PET/CT were included. The diagnosis of primary lung cancer or lung metastasis was based on histopathology The patients were divided into a training cohort and a validation cohort randomized 1:1. Independent risk factors were extracted through the clinical information and ¹⁸F-FDG PET/CT imaging characteristics of patients in the validation cohort, and then a diagnostic model was constructed and a nomograms was made. ROC curve, calibration curve, cutoff, sensitivity, specificity, and accuracy were used to evaluate the prediction performance of the diagnostic model.

Results

One hundred and twenty Indeterminate lung lesions (ILLs) (77 lung metastasis, 43 primary lung cancer) were analyzed. No significant difference in clinical characteristics and imaging features between the training and the validation cohorts (P > 0. 05). Using uni-/multivariate analysis, pleural tags and contour were identified as independent predictors. These independent predictors were used to establish a diagnostic model with areas under the receiver operating characteristic curves (AUCs) of 0.92 and 0.89 in the primary and validation cohorts, respectively. The accuracy rate of the diagnostic model for differentiating LM from LC were higher than that of subjective diagnosis (P < 0.05).

Conclusions

Pleural tags and contour were identified as independent predictors. The diagnostic model of ILLs in patients with CRC could help differentiate between LM and LC.

PET-Uptake in Liver Metastases as Method to Predict Tumor Biological Behavior in Patients Transplanted for Colorectal Liver Metastases Developing Lung Recurrence

The objective of the study was to determine the impact of PET uptake on liver metastases on overall survival (OS) after resection of pulmonary metastases in patients who had received liver transplantation (LT) due to unresectable colorectal liver-only metastases. Resection of pulmonary colorectal metastases is controversial. Some hospitals offer this treatment to selected patients, whereas other hospitals do not perform the procedure in colorectal cancer patients who develop pulmonary metastases. All patients included in the LT studies who developed pulmonary metastases as first site of relapse, and had resection of these as first treatment, were included in this report. Metabolic tumor volume (MTV) in liver was derived from the pre-transplant PET examinations. OS from time of resection was calculated by the Kaplan−Meier method. Patients with low MTV (<70 cm3) had significantly longer OS from time of resection of pulmonary metastases compared to patients with high MTV (>70 cm3). Patients with low MTV in the liver had 10-year OS from time of pulmonary resections of 86%. Liver MTV values from pre-transplant PET examinations may predict long OS in colorectal cancer patients with a resection of pulmonary metastases developing after LT. Thus, in selected colorectal cancer patients developing pulmonary metastases resection of these metastases should be the treatment of choice.

Surgical treatment for metastatic colorectal cancer

Background: Stage IV colorectal cancer (CRC) exhibits heterogeneous characteristics in tumor extent and biology. The overall survival of patients with metastatic CRC has improved with the development of multimodal treatments and new chemotherapeutic drugs.Current Concepts: Resection of metastatic CRC is performed for liver, lung, or peritoneal metastases. Conversion surgeries to resect oligometastatic lesions have been developed with tumor regression using chemotherapeutic agents. Two-stage hepatectomy has extended the surgical indications for patients with metastatic CRC. Synchronous liver and primary tumor resection can be considered in patients with adequate conditions. Local ablation with radiotherapy can be used to treat lung metastasis. Meanwhile, for treating patients with CRC with peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be considered. Surgical treatments should be performed in patients with symptomatic primary tumors with unresectable metastasis. However, in recent studies, primary tumor resection in patients with asymptomatic CRC with synchronous, unresectable metastases did not show overall survival benefits.Discussion and Conclusion: The treatment of metastatic CRC is challenging because of the variable tumor extent and heterogenous characteristics. Tailored surgical treatments and multidisciplinary approaches may improve the survival and quality of life of patients with metastatic CRC.

Comparison of Ultrashort TE Lung MRI and HRCT Lungs for Detection of Pulmonary Nodules in Oncology Patients

Purpose The purpose of this study is to evaluate the detection rate of pulmonary nodules in ultrashort echo time (UTE) lung magnetic resonance imaging (MRI) and to compare it with computed tomography (CT) in oncology patients.

Materials and Methods All individuals undergoing radiotherapy/chemotherapy/regular follow-up or visiting the oncology department and referred to radiology department for nodule detection, during the period of 1 year, were subjected to UTE lung MRI using the sequence Flash 3d_spiralvibe coronal 1.25 mm iso and high-resolution CT lungs and the images were analyzed.

Results Among the total number of nodules detected in both lungs of all patients, nodules detected by CT were 241, and nodules detected by MRI were 212. The nodule detection rate by MRI was 87.96%. The detection rate of nodules for size equal to or more than 5 mm was nearly 100%. For nodules less than 5 mm, and equal to or more than 4 mm, MRI showed a comparable detection rate of 75%, while for nodules less than 4 mm, the detection rate was only 25%.

Conclusion Our study results indicate that lung MRI had a near-complete detection rate for nodules equal to or more than 5 mm in size. Hence, in oncology patients who are undergoing regular follow-up of the lung nodules, lung MRI using UTE can replace low-dose CT, which in turn reduces the radiation dose to the patient.

High Yield of Chest X-ray in the Follow-Up of Colorectal Cancer

Purpose: Worldwide, colorectal carcinoma (CRC) has a high incidence and a substantial cancer-related mortality. The recurrence risk is 30–50% and lung metastases are common. Treatment of lung metastases with stereotactic ablative radiotherapy (SABR) or metastasectomy may increase survival. The best modality for thoracic screening in the follow-up, however, remains controversial. In this study, we aimed to unravel the additional value of routine chest X-ray (CXR) for detecting lung metastases during the follow-up of CRC patients treated with curative surgery. Methods: Between 2013 and 2017, 668 CRC patients were treated with curative intent, of whom 633 patients were included in follow-up, which consisted of CXR, serum Carcino-Embryonic Antigen (CEA) and ultrasound of the liver. Patients who developed lung metastases, diagnosed with CXR and characterised by a normal concomitant serum CEA level, were identified. Number, size and treatment of lung metastases were described. Results: Thirty-four (5.4%) patients developed lung metastases. Seventeen (50%) were detected by CXR without pathological CEA levels. Eleven (65%) of these patients were treated with curative intent, whereas 21% of patients with lung metastases and elevated CEA levels were treated with curative intent (p = 0.049). Higher numbers of lung metastases were associated with a lower chance of curative treatment. Conclusions: More than 50% of patients with lung metastases on CXR in the follow-up would not have been detected with CEA-triggered imaging only. In addition, patients with colorectal lung metastases without elevated CEA levels were often suitable for curative treatment and, therefore, CXR seems to have additional value within the follow-up of CRC.

Management of single pulmonary metastases from colorectal cancer: State of the art

Colorectal cancer (CRC) is one of the most common causes of death from cancer. Lung seeding occurs in approximately 10% of patients surgically treated for primary CRC with radical intent: the lung is the most common site of metastases after the liver. While surgical treatment of liver metastases is widely accepted to affect long-term outcomes, more controversial and not standardized is the therapy for CRC patients developing lung metastases. Experience suggests the potential curative role of pulmonary metastasectomy, especially in oligometastatic disease. However, the optimal strategy of care and the definition of prognostic factors after treatment still need to be defined. This review focused on the uncommon scenario of single pulmonary metastases from CRC. We explored pertinent literature and provide an overview of the epidemiology, clinical characteristics and imaging of single pulmonary metastases from CRC. Additionally, we identified the best available evidence for overall management. In particular, we analyzed the role and results of locoregional approaches (surgery, radiotherapy or ablative procedures) and their integration with systemic therapy.

The Colorectal Cancer Tumor Microenvironment and Its Impact on Liver and Lung Metastasis

Simple Summary

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastasis to secondary organs, such as the liver and lungs, is a key driver of CRC-related mortality. The tumor microenvironment, which consists of the primary cancer cells, as well as associated support and immune cells, significantly affects the behavior of CRC cells at the primary tumor site, as well as in metastatic lesions. In this paper, we review the role of the individual components of the tumor microenvironment on tumor progression, immune evasion, and metastasis, and we discuss the implications of these components on antitumor therapies.

Abstract

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastases, most frequently to the liver and lung. In the primary tumor, as well as at each metastatic site, the cellular components of the tumor microenvironment (TME) contribute to tumor engraftment and metastasis. These include immune cells (macrophages, neutrophils, T lymphocytes, and dendritic cells) and stromal cells (cancer-associated fibroblasts and endothelial cells). In this review, we highlight how the TME influences tumor progression and invasion at the primary site and its function in fostering metastatic niches in the liver and lungs. We also discuss emerging clinical strategies to target the CRC TME.

Prevalence of Lung Metastases among 19,321 Metastatic Colorectal Cancer Patients in Eight Countries of Europe and Asia

Background: Colorectal cancer is one of the most common malignancies in the Western world, and is responsible for about 10% of annual cancer-related deaths. Especially for UICC stage IV, the probability of survival is significantly reduced. Little is known about risk factors for specific metastatic patterns of colorectal cancer that may also influence patients’ overall survival. Methods: We used data from the IQVIA oncology dynamics (OD) database to determine the prevalence of pulmonary metastases in 19,321 patients with UICC stage IV colorectal cancer in eight European and Asian countries. Results: In total, 6132 of 19,321 (31.7%) study patients had lung metastases, with a higher prevalence among patients with rectal (37.5%) than colon (30.1%) cancer. When compared to China as the country with the lowest lung metastases prevalence, the odds for lung metastases were highest in UK (OR: 2.02, 95%CI: 1.80–2.28), followed by Italy (OR: 1.86, 95%CI: 1.52–2.27), Spain (OR: 1.85, 95%CI: 1.64–2.09), and Germany (OR: 1.47, 95%CI: 1.26–1.71). Conclusion: The prevalence of pulmonary metastases in UICC stage IV colorectal cancer varies widely among the different analyzed countries. Although the present data are purely descriptive, a possible combination of ethnic, environmental, and health care system-associated differences could be discussed as the underlying cause. Further studies are needed to investigate the reasons for differences in the prevalence of lung metastases.

Effects of mediastinal lymph node dissection in colorectal cancer-related pulmonary metastasectomy

Background

The benefits of mediastinal lymph node dissection (MLND) in colorectal cancer‐related pulmonary metastasectomy (PM) have been poorly reported. This study aimed to determine whether MLND affects survival in patients undergoing PM and to identify the prognostic factors for survival.

Methods

We retrospectively reviewed 275 patients who had undergone colorectal cancer‐related PM from January 2010 to December 2016. MLND was defined as the resection of at least six mediastinal lymph node stations according to the International Association for the Study of Lung Cancer criteria (N1, ≥3 stations; N2, ≥3 stations). The propensity score matching method was used to reduce bias.

Results

Thirty‐three (12%) patients underwent MLND, and 13 (4.7%) patients had mediastinal lymph node involvement. This study showed no difference in 5‐year overall survival (no MLND, 52.7% vs. MLND, 53.5%; p = 0.81). On multivariable analysis, negative prognostic factors for overall survival were preoperative carcinoembryonic antigen (CEA) level (p < 0.001), a higher number of metastatic nodules (p < 0.001), metastatic nodule size ≥2 cm (p < 0.001), and lymph node involvement (p = 0.006).

Conclusions

Mediastinal lymph node involvement, preoperative CEA level, higher metastatic nodule number, and nodule size negatively affected survival whereas MLND in PM was not associated with survival.

Pulmonary metastasectomy in colorectal carcinoma

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. It is estimated that 50% of all patients with CRC develop metastases, most commonly in the liver and the lung. Lung metastases are seen in approximately 10–15% of all patients with CRC. A large number of these patients with metastatic CRC can only receive palliative treatment due to invasion of other organs and disseminated disease. However, a subset of these patients present with potentially resectable metastases. Pulmonary metastasectomy is considered to be a potentially curative treatment for selected patients with resectable metastatic CRC. Current data suggest that patients that undergo pulmonary metastasectomy have 5-year survival rates of approximately 40%. However, the majority of data published regarding lung metastasectomy is based on small, retrospective case series. Due to this lack of prospective data, it is still unclear which subset of patients will benefit most from curative-intent surgery. Furthermore, there is also controversy regarding which prognostic and genetic factors are related to survival outcomes and whether there is a difference between open and thoracoscopic approaches in terms of overall and disease-free survival. In this review, we aim to summarize the latest data on prognostic factors and survival outcomes after pulmonary metastasectomy in patients with metastatic CRC.

The clinical relevance of indeterminate lung nodules in patients with locally recurrent rectal cancer

AIM

To evaluate the clinical relevance of indeterminate lung nodules (ILN) in patients with locally recurrent rectal cancer (LRRC) treated in a tertiary referral centre.

METHODS

All patients with LRRC diagnosed between 2000 and 2017 were retrospectively reviewed. Reports of staging chest CT-scans were evaluated for ILN. Patients with distant metastases including lung metastases at time of LRRC diagnosis were excluded. Overall (OS), progression-free survival (PFS) and the cumulative incidence of lung metastases were compared between patients with and without ILN.

RESULTS

In total 556 patients with LRRC were treated during the study period. In the 243 patients eligible for analysis, 68 (28%) had ILN at LRRC diagnosis. Median OS was 37 months for both the patients with and without ILN (p = 0.37). Median PFS was 14 months for the patients with ILN and 16 months for patients without ILN (p = 0.80). After correction for potential confounding, ILN present at LRRC diagnosis was not associated with impaired OS or PFS (adjusted hazards ratio [95% confidence interval]: 0.81 [0.54-1.22] and 1.09 [0.75-1.59]). The 5-year cumulative incidence of lung metastases was 31% in patients with ILN and 28% in patients without ILN (p = 0.19).

CONCLUSION

Our study shows that ILN are present in roughly a quarter of patients with LRRC. No differences in OS, PFS, or the cumulative incidence of lung metastases were found between patients with and without ILN at LRRC diagnosis. These results suggest that ILN are of little to no clinical relevance in patients with LRRC.

Clinicopathological and mutational differences between tumors with multiple metastases and single lung metastasis in colorectal cancer

Cancer metastasis, particularly multiple metastatic cancer, is a significant event that affects patient prognosis. However, single metastasis can be treated by partial resection, although the clinicopathological and molecular profile of single lung metastasis has not been thoroughly elucidated. The present study examined tumor heterogeneity by comparing the mutation status between primary colorectal cancer (CRC) and corresponding metastatic lesions to identify prognostic factors associated with single lung metastasis and multiple metastases. The present study enrolled 31 cases of CRC; 20 cases with multiple metastases and 11 cases with single lung metastasis. Clinicopathologically, all cases with multiple metastases were tubular adenocarcinoma, and 3/11 cases with single metastasis were mucinous adenocarcinoma originating from the left side, the remaining 8 cases were tubular adenocarcinoma from the left side. CRC cases with multiple metastases exhibited more frequent vascular invasion, but not lymphatic invasion, than those with single lung metastasis. Furthermore, CRC with multiple metastases was associated with strong tumor budding (P=0.04). Patients with CRC with multiple metastases had lower recurrence-free survival rates compared with those with single lung metastasis (P=0.02). However, there was no significant difference between these two groups in terms of overall survival rates. A next-generation sequencing cancer hotspot panel was used to analyze a heterochronous multiple metastases case, including brain metastasis. Sanger sequencing, immunohistochemistry and microsatellite instability were examined for all 31 cases to reveal the molecular features. KRAS and TP53 mutation signatures were largely preserved throughout the metastatic events. TP53/APC mutations and overexpression of p53 appeared to be associated with the presence of lymphovascular invasion and strong tumor budding, respectively, although these differences were not statistically significant. Early relapses in patients with CRC could be a sign for eventual multiple metastases, although these may not affect the overall survival of patients with CRC. Considerable mutational changes were seemingly rare during metastatic events in patients with CRC.

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.

Is Adjuvant Chemotherapy Worthwhile After Radical Resection for Single Lung Metastasis From Colorectal Cancer? A Multicentric Analysis Evaluating the Risk of Recurrence

Background: Adjuvant chemotherapy after resection of colorectal cancer (CRC) lung metastases may reduce recurrences and improve survival. The choice of best candidates for adjuvant chemotherapy in this setting is controversial, especially when a single lung metastases (SLM) is resected. The aim of this study is to evaluate the risk of recurrence after radical resection for single lung metastasis from CRC.

Patients and methods: Demographic, clinical, and pathological data were retrospectively collected for patients radically operated on for single pulmonary metastasis from CRC in 4 centers. Survival was computed by Kaplan-Meyer methods. Chi-square, log-rank test, and for multivariate analysis, Cox-regression and binary logistic regression were used when indicated.

Results: The sample consisted of 344 patients, mean age 65 yrs. Overall 5 yrs survival was 61.9%. Recurrence occurred in 113 pts (32.8%). At univariate analysis, age > 70 (p = 0.046) and tumor size > 2 cm (p = 0.038) were predictive of the worst survival chance, while synchronous lung metastasis (p = 0.039), previous resection of extrathoracic metastasis (p = 0.017), uptake at FDG-PET scan (p = 0.006) and short (<12 months) disease-free interval (DFI) prior to lung metastasectomy (p = 0.048) were risk factors for recurrence. At multivariate analysis, only high CEA (>4 ng/mL) was associated with worst survival (HR: 4.3, p = 0.014), while prior abdominal surgery (HR: 3, p = 0.033), PET positivity (HR: 2.7, p = 0.041), and DFI > 12 months (HR: 0.14, p < 0.001) confirmed to predict recurrence of disease.

Conclusions: Surgical resection of solitary lung metastases from CRC is associated with prolonged survival. High value of CEA, PET positivity, previous extrathoracic resected metastasis, and short (<12 months) DFI were found to be predictive of death or disease recurrence and might identify in this scenario patients at higher risk which could potential benefit of chemotherapy.

Management of incidental lung nodules <8 mm in diameter

Due to the increase of incidentally detected pulmonary nodules and the information obtained from several screening programs, updated guidelines with new recommendations for the management of small pulmonary nodules have been proposed. These international guidelines coincide in proposing periodic follow-up for small nodules, less than 8 mm of diameter. Fleischner and British Thoracic Society guidelines are the most recent and popular guidelines for incidental pulmonary nodules management. They have specific recommendations according to nodule characteristics (density and size) and cancer risk of the patient. Both guidelines separate recommendations for solid and subsolid nodules. Predictive risk models have been developed to improve the nodule management. In certain cases follow up may not be the best option. We discuss the scenarios and options to achieve a histologic diagnosis of these tiny pulmonary nodules.

Lysyl oxidase: A colorectal cancer biomarker of lung and hepatic metastasis

Background

Colorectal cancer (CRC) is a common and lethal disease in which distant metastasis remains the primary cause of death. Paradoxical roles of LOX have been reported in CRC, and the intracellular function of LOX has also recently been determined. Correlations of LOX expression and its intracellular localization with clinicopathological features in CRC patients remain largely unknown. The aim of the present study was to explore the potential roles of LOX in CRC.

Methods

LOX messenger RNA expression was assayed by quantitative PCR in eight paired normal mucosa and tumor tissues. Immunohistochemistry was conducted using tissue arrays to investigate LOX expression in 201 CRC patients. Regulation of LOX by YAP and TEAD4 was explored by YAP or TEAD4 short hairpin RNA interference in a LoVo cell line.

Results

LOX messenger RNA expression was elevated in some CRC specimens, and LOX nuclear localization was detected in CRC tumor tissues. LOX nuclear localization was found to correlate with lung/hepatic metastasis, elevated serum carcinoembryonic antigen concentration, and mucinous tumor type (P < 0.05). Nuclear LOX expression was found to be associated with poor overall and disease‐free survival (P < 0.05), and postoperative lung/hepatic metastasis (P < 0.05). Knockdown of YAP or TEAD4 induced downregulation of LOX expression.

Conclusions

LOX nuclear localization was significantly associated with poor survival in patients with CRC. Nuclear LOX expression was correlated with synchronous or postoperative lung/hepatic metastasis. LOX may prove to be a potential target gene of YAP and TEAD4.

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Treatment of Colon Cancer

The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than to dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient.

Staging Rectal Cancer: The Utility of Chest Radiograph and Chest Computed Tomography

The National Comprehensive Cancer Network recommends that patients who are newly diagnosed with rectal cancer undergo staging CT scan of the chest. It is unclear whether posteroanterior and lateral chest radiography (X-ray) alone would provide adequate staging for most of these patients. A retrospective review was performed on all patients who had a two-view chest X-ray along with a chest CT for rectal cancer staging from 2007 to 2015. A total of 74 patients had both modalities. Sixty-three (85%) had a normal chest X-ray and 11 (15%) had an abnormal chest X-ray. Of the 63 patients with a normal chest X-ray, 40 (63%) had a corresponding normal chest CT and 23 (37%) had a lesion only noted on chest CT. Four patients (17%) in the latter group had metastatic cancer to the lung at the time of workup and four out of five of the tumors found to metastasize were within 5 cm from the anal verge. Our data suggest that a staging chest X-ray is unlikely to diagnose metastatic lungs lesions from a primary rectal cancer. Conversely, staging chest CT will accurately stage metastatic disease but will also reveal benign lung lesions in this patient population.

Should preoperative chest computed tomography be performed in all patients with colorectal cancer?

AIM

This study evaluated the accuracy of chest computed tomography (CCT) in the preoperative staging of patients with potentially resectable colorectal cancer (CRC). An attempt was made to determine whether CCT has a significant influence on management and clinical outcome.

METHOD

A review was conducted of all preoperative CCTs and X-rays performed in patients submitted to elective resection of CRC at our institution between 2005 and 2012. All scans were revised by an independent radiologist who was unaware of the circumstances of each case. The findings were classified as benign, malignant or indeterminate. Patients were followed for at least 12 months after surgery to assess the clinical evolution of any lesion found on CCT and the oncological outcome.

RESULTS

Two hundred and twenty-three patients were included. The CCT showed normal or benign findings in 157 (70.4%) patients, a malignant lesion in 17 (7.6%), and an indeterminate lung lesion (ILL) in 49 (22%). Of the 30 patients with proven lung metastases, a plain X-ray detected lesions in only 11 (36.7%) patients. During the postoperative follow-up, 14 (28.6%) of the 49 patients with ILL demonstrated malignant progression of the lung lesions. Among all 223 patients, only six (2.7%) underwent lung resection.

CONCLUSION

CCT is superior to plain X-ray for the detection of lung metastases. Despite the medical and financial implications of preoperative CCT, only a small number of patients will eventually undergo lung resection. We call into question the role of routine CCT in the staging of patients with CRC. A more selective approach, reserving CT for patients at high risk of lung metastases, is suggested.

Radiographic staging practices of newly diagnosed colorectal cancer vary according to medical specialty

BACKGROUND

Since 2008, multiple guidelines have endorsed incorporation of chest CT in the radiographic staging assessment of newly diagnosed colorectal cancer (CRC). Radiographic staging practices performed after CRC is detected have not been studied.

OBJECTIVE

To evaluate radiographic staging practices for newly diagnosed CRC between gastroenterologists versus non-gastroenterologists.

DESIGN

Observational cohort study.

SETTING

Single, tertiary-care referral center.

PATIENTS

Patients newly diagnosed with a T1 or higher stage CRC at time of colonoscopy between 2008 and 2013.

INTERVENTIONS

Radiographic staging.

MAIN OUTCOME MEASUREMENTS

Radiographic preoperative staging examinations ordered by gastroenterologists in comparison to those ordered by non-gastroenterology specialists.

RESULTS

This study included 277 patients with CRC newly diagnosed by colonoscopy. There were 141 total ordering physicians (68 gastroenterologists and 73 non-gastroenterologists). The majority of preoperative radiographic staging was performed by gastroenterologists (59.2% of patients, n = 164). Colorectal surgeons managed staging in 28.7% of patients (n = 47). Gastroenterologists were more likely to omit a staging chest CT than were non-gastroenterologists (64.6% vs 46.9%; P < .001). Physician practice setting, rectal location of tumor, and advanced endoscopic appearance of tumors were predictors of chest CT inclusion.

LIMITATIONS

Single center, moderate sample size of both providers and patients.

CONCLUSION

Gastroenterologists more frequently ordered the initial radiographic staging studies in newly diagnosed CRC patients. However, gastroenterologists were less likely to include chest CT in the initial staging of CRC despite current guideline recommendations to do so. If confirmed with further studies, educational efforts to improve compliance and standardization may be needed.

Nationwide trends in incidence, treatment and survival of colorectal cancer patients with synchronous metastases

The aim of this study was to determine trends in incidence, treatment and survival of colorectal cancer (CRC) patients with synchronous metastases (Stage IV) in the Netherlands. This nationwide population-based study included 160,278 patients diagnosed with CRC between 1996 and 2011. We evaluated changes in stage distribution, location of synchronous metastases and treatment in four consecutive periods, using Chi square tests for trend. Median survival in months was determined, using Kaplan-Meier analysis. The proportion of Stage IV CRC patients (n = 33,421) increased from 19 % (1996-1999) to 23 % (2008-2011, p < 0.001). This was predominantly due to a major increase in the incidence of lung metastases (1.7-5.0 % of all CRC patients). During the study period, the primary tumor was resected less often in Stage IV patients (65-46 %) and the use of systemic treatment has increased (29-60 %). Also an increase in metastasectomy was found in patients with one metastatic site, especially in patients with liver-only disease (5-18 %, p < 0.001). Median survival of all Stage IV CRC patients increased from 7 to 12 months. Especially in patients with metastases confined to the liver or lungs this improvement in survival was apparent (9-16 and 12-24 months respectively, both p < 0.001). In the last two decades, more lung metastases were detected and an increasing proportion of Stage IV CRC patients was treated with systemic therapy and/or metastasectomy. Survival of patients has significantly improved. However, the prognosis of Stage IV patients becomes increasingly diverse.

The diagnostic yield of preoperative staging computed tomography of the thorax in colorectal cancer patients without hepatic metastases

BACKGROUND

National UK guidelines recommend preoperative computed tomography (CT) examination of the chest for all patients with colorectal cancer (CRC) as identification of thoracic metastatic disease may influence treatment plans. The diagnostic yield of this approach for patients without radiological evidence of hepatic metastases remains unclear. The aim of this study was to establish the impact upon treatment of chest CT examination for CRC patients without metastatic liver disease.

PATIENTS AND METHODS

All patients diagnosed with CRC without liver metastases disease between December 2006 and December 2013 in a single institution were identified from a prospectively recorded departmental database. Data collected included patient demographics, disease stage and chest CT findings.

RESULTS

There were 358 CRC patients (183 male, 175 female, median age 70 years, range 24-96 years) without liver metastases. Colon cancer accounted for 68% of cases with 32% of patients diagnosed with rectal cancer. The majority of patients (n=292, 81.6%) had no evidence of thoracic pathology during the study period. Lung metastases were identified in five (1.4%) patients, one of them subsequently diagnosed with benign pulmonary nodule. In 61 (17.0%) patients the lung nodules were classified as intermediate with only three subsequently reclassified as pulmonary metastases (n=1) or primary lung cancer (n=2).

CONCLUSION

In the absence of liver metastases, CRC rarely spreads to the lung. Consequently, preoperative chest CT examination for patients without evidence of liver metastases may not be necessary in the majority of patients. Future studies are required to identify patients at high risk for pulmonary metastases who may benefit from this preoperative investigation.

Optimisation of preoperative assessment in patients diagnosed with rectal cancer

AIMS

Treatment decision making for patients with rectal cancer is complex and optimal preoperative assessment is important to ensure patients receive appropriate and high-quality care. Therefore, our objective was to develop an evidence-based, multidisciplinary guideline to assist physicians treating rectal cancer to ensure that preoperative assessment is optimal.

MATERIALS AND METHODS

A multidisciplinary expert panel of physicians who treat rectal cancer was selected as members of the Cancer Care Ontario Preoperative Assessment for Rectal Cancer Guideline Development Group (GDG). This group initially met to identify important clinical questions with respect to optimisation of preoperative assessment in patients diagnosed with rectal cancer. A systematic review, specific to each of these clinical questions, was then conducted using MEDLINE, EMBASE and the Cochrane Library databases. The GDG met at regular intervals to review the evidence and to develop guidelines to address each of the clinical questions.

RESULTS

The GDG identified seven important clinical questions with respect to the optimisation of preoperative assessment in patients diagnosed with rectal cancer. The clinical questions pertained to: (i) investigations required to assess distant metastasis (one question); (ii) imaging for local staging of rectal cancer (five questions); (iii) multidisciplinary cancer conference (MCC) (one question); (iv) restaging-magnetic resonance imaging (one question). The systematic reviews related to these clinical questions yielded 31 articles that were abstracted and reviewed by the GDG. Based on the systematic reviews, a guideline was developed containing seven recommendations that were either adapted from existing guidelines, based on review of the evidence or by consensus when evidence was limited.

CONCLUSIONS

A set of seven recommendations have been developed in order to optimise pretreatment assessment in patients with rectal cancer by promoting evidence-based practice. These guidelines are based on the best available evidence and have been peer reviewed by two independent multidisciplinary expert panels for relevance and validity.

Preoperative staging CT thorax in patients with colorectal cancer: its clinical importance

BACKGROUND

Recent studies suggest that there is little benefit to routine preoperative staging CT of the thorax in colorectal cancer.

OBJECTIVE

The current study hypothesized that staging CT of the thorax is not mandated in all patients with colorectal cancer.

DESIGN

This study was a tertiary-care center retrospective observational study.

PATIENTS

Patients with a diagnosis of colon and rectal adenocarcinoma during 2006 to 2011 were included in a hospital database. Demographic, pathological, radiological, survival, and clinical factors were recorded. Three hundred eighty-two patients were included in the analysis (234 male, 148 female).

INTERVENTIONS

All patients underwent preoperative staging CT of the thorax to determine the presence of pulmonary metastasis and/or indeterminate lesions.

MAIN OUTCOME MEASURES

Patients demographics were reviewed, and the factors associated with pulmonary metastasis and indeterminate lesions were evaluated.

RESULTS

Distant metastases were evident in 61 patients (16%). CT scans revealed pulmonary metastasis in 23 patients (6%), and indeterminate lesions in 33 (8.6%). Only one-third of pulmonary lesions were evident on chest x-ray. On logistic regression analysis, nodal positivity was associated with an increased risk for pulmonary metastasis (p = 0.03). There was no difference in overall survival between patients with pulmonary metastasis and indeterminate lesions (p = 0.35, Kaplan-Meier estimate, log rank analysis). Pulmonary metastasis developed during postoperative surveillance in 7 patients with indeterminate lesions (21.2%).

LIMITATIONS

This is a retrospective, single-center study with a relatively small sample size.

CONCLUSIONS

Pulmonary metastasis is relatively rare in colorectal cancer, and staging CT of the thorax may not be mandated in low-risk patients.

The availability of computed tomography for pulmonary staging in colorectal cancer

Purpose

Chest computed tomography is performed frequently for the preoperative pulmonary staging in colorectal cancers (CRCs) regardless of the result of chest x-ray (CXR) due to its high sensitivities and specificities. The advancement of CT technology detects more indeterminate lung lesions that may require further investigations, referrals and follow-up. The aim of this study was to suggest a guideline for performing chest CT for preoperative pulmonary staging in colorectal cancer.

Methods

We performed a retrospective analysis of the records of patients who had chest CT preformed without the evidence of metastasis on CXR for preoperative pulmonary staging.

Results

Of 21 patients with metastatic nodules on chest CT, 23.8% showed pulmonary metastasis on positron emission tomography, 47.6% showed extrapulmonary metastasis on preoperative evaluation and 61.9% showed elevated serum carcinoembryonic antigen level above 10 ng/mL. These results showed significant value compared to patients without metastatic nodules. But, in analyzing patients with or without indeterminate nodules in the three contents listed above, there was no significance.

Conclusion

In the patients with CRC who show normal CXR and exhibit positivity in PET, preoperative extrapulmonary metastasis and elevated serum CEA level above 10 ng/mL preoperatively, chest CT would be helpful in preoperative staging.

Should preoperative chest CT be recommended to all colon cancer patients?

OBJECTIVE

The aim of this study was to evaluate the efficacy of preoperative chest computed tomography (CT) and the risk factors for lung metastasis in colon cancer patients without liver metastasis who had negative findings on initial chest X-ray (CXR).

BACKGROUND

Preoperative staging with chest CT is recommended in colon cancer patients. However, there have been only scant data on the clinical efficacy.

METHODS

Three hundred nineteen consecutive colon cancer patients without liver metastasis were retrospectively reviewed and analyzed. The patients had negative findings on preoperative CXR, and they underwent surgery for colon cancer during the period of January 2008 to April 2010.

RESULTS

Lung nodule on chest CT was found in 136 patients (42.6%). Twenty of those were definitely diagnosed with lung metastasis (6.3%) by follow-up chest CT or pathologic confirmation. There was no case of delay in surgery due to findings of lung nodule. Comparing the group with lung metastases to that without lung metastases, postoperative pathologic findings reported more advanced T and N status (P = 0.004, P < 0.001, respectively), and lymphatic invasion was more frequent (P = 0.003) in the group with lung metastasis. By multivariate analysis, CT-predicted lymph node metastases and pathologic lymph node metastases were risk factors for lung metastases.

CONCLUSIONS

Preoperative staging chest CT is not beneficial to colon cancer patients without liver metastasis and lymph node metastasis suggested on abdominal and pelvic CT who had negative finding on initial CXR.

Recurrence pattern depends on the location of colon cancer in the patients with synchronous colorectal liver metastasis

BACKGROUND

The veins from the lower rectum drain into the systemic venous system, while those from other parts of the colon drain into the portal venous system. The aim of this study was to investigate recurrence pattern and survival according to the anatomical differences in patients with colorectal liver metastases (CRLM).

METHODS

From October 1994 to December 2009, synchronous CRLM patients who underwent surgery were identified from our prospectively collected database. The patients were excluded if there had been extrahepatic metastases. The patients were divided into two groups according to the location of the primary colorectal cancer: lower rectal cancer (group 1) and upper rectal or colon cancer (group 2). The recurrence patterns and survival were investigated.

RESULTS

A total of 316 patients were included: 53 patients in group 1 and 263 patients in group 2. After a median follow-up of 37 months, the extrahepatic recurrence curve of group 1 was superior to that of group 2 (P < 0.001), although there was no difference between the hepatic recurrence curves (P = 0.93). The disease-free and overall survival curves of group 1 were inferior to those of group 2 (P = 0.004) (P < 0.001). Lower rectal cancer was a significant risk factor for extrahepatic recurrence in Cox proportional hazard model analysis (hazard ratio = 1.7, P = 0.04).

CONCLUSIONS

The extrahepatic recurrence rate is high in lower rectal cancer patients after surgical treatment for synchronous CRLM.

Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

OBJECTIVES

Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence in primary CC.

MATERIAL AND METHODS

PET/CT for preoperative staging was performed in 66 prospectively included patients with primary CC. Diagnostic accuracy for PET/CT and CT was analyzed. In addition to routine follow up, 42 stages I-III CC patients had postoperative PET/CT examinations every 6 months for 2 years. Serological levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), carcinoembryonic antigen, and liberated domain I of urokinase plasminogen activator receptor were analyzed.

RESULTS

Accuracy for tumor, nodal, and metastases staging by PET/CT were 82% (95% confidence interval [CI]: 70; 91), 66% (CI: 51; 78), and 89% (CI: 79; 96); for CT the accuracy was 77% (CI: 64; 87), 60% (CI: 46; 73), and 69% (CI: 57; 80). Cumulative relapse incidences for stages I-III CC at 6, 12, 18, and 24 months were 7.1% (CI: 0; 15); 14.3% (CI: 4; 25); 19% (CI: 7; 31), and 21.4% (CI: 9; 34). PET/CT diagnosed all relapses detected during the first 2 years. High preoperative TIMP-1 levels were associated with significant hazards toward risk of recurrence and shorter overall survival.

CONCLUSIONS

This study indicates PET/CT as a valuable tool for staging and follow up in CC. TIMP-1 provided prognostic information potentially useful in selection of patients for intensive follow up.

Colorectal cancer: Current imaging methods and future perspectives for the diagnosis, staging and therapeutic response evaluation

In the last 10 years the mortality rate of colorectal cancer (CRC) has decreased by more than 20% due to the rising developments in diagnostic techniques and optimization of surgical, neoadjuvant and palliative therapies. Diagnostic methods currently used in the evaluation of CRC are heterogeneous and can vary within the countries and the institutions. This article aims to discuss in depth currently applied imaging modalities such as virtual computed tomography colonoscopy, endorectal ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of CRC. Special focus is put on the potential of recent diagnostic developments as diffusion weighted imaging MRI, MRI biomarkers (dynamic enhanced MRI), positron emission tomography with 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (FDG-PET) combined with computed tomography (PET/CT) and new hepatobiliary MRI contrast agents. The precise role, advantage and disadvantages of these modalities are evaluated controversially in local staging, metastatic spread and treatment monitoring of CRC. Finally, the authors will touch upon the future perspectives in functional imaging evaluating the role of integrated FDG-PET/CT with perfusion CT, MRI spectroscopy of primary CRC and hepatic transit time analysis using contrast enhanced ultrasound and MRI in the detection of liver metastases. Validation of these newer imaging techniques may lead to significant improvements in the management of patients with colorectal cancer.

Indeterminate pulmonary nodules at colorectal cancer staging: a systematic review of predictive parameters for malignancy

BACKGROUND

This study aimed to estimate the prevalence of indeterminate pulmonary nodules and specific radiological and clinical characteristics that predict malignancy of these at initial staging chest computed tomography (CT) in patients with colorectal cancer. A considerable number of indeterminate pulmonary nodules, which cannot readily be classified as either benign or malignant, are detected at initial staging chest CT in colorectal cancer patients.

METHODS

A systematic review based on a search in EMBASE, Medline, the Cochrane library and science citation index, PubMed databases, Google scholar, and relevant conference proceedings was performed in cooperation with the Cochrane Colorectal Cancer Group.

RESULTS

A total of 2,799 studies were identified, of which 12 studies met the inclusion criteria. The studies primarily consisted of case series and included a total of 5,873 patients. Of these patients, 9% (95% confidence interval [95% CI] 8.9-9.2%) had indeterminate pulmonary nodules at chest CT, of which 10.8% (95% CI 10.3-11.2%) turned out to be colorectal cancer metastases at follow-up. Generally, regional lymph node metastasis, and multiple numbers of indeterminate pulmonary nodules were reported to predict malignancy, whereas calcification of the nodules indicated benign lesions.

CONCLUSION

It was found that 1 in 100 colorectal cancer patients subjected to preoperative staging chest CT will have an indeterminate pulmonary nodule that proves to be metastatic disease. Such a low risk suggests that indeterminate pulmonary nodules should not cause further preoperative diagnostic workup or follow-up besides routine regimens.

[Importance of PET/CT for imaging of colorectal cancer]

CLINICAL/METHODICAL ISSUE

Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed.

STANDARD RADIOLOGICAL METHODS

Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer.

METHODICAL INNOVATIONS

Combined FDG-PET/CT.

PERFORMANCE

While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer.

ACHIEVEMENTS

We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance.

PRACTICAL RECOMMENDATIONS

To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma.