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

Imaging in the era of risk-adapted treatment in colon cancer

The treatment landscape for patients with colon cancer is continuously evolving. Risk-adapted treatment strategies, including neoadjuvant chemotherapy and immunotherapy, are slowly finding their way into clinical practice and guidelines. Radiologists are pivotal in guiding clinicians toward the most optimal treatment for each colon cancer patient. This review provides an overview of recent and upcoming advances in the diagnostic management of colon cancer and the radiologist's role in the multidisciplinary approach to treating colon cancer.

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.

Development and validation of an artificial intelligence prediction model and a survival risk stratification for lung metastasis in colorectal cancer from highly imbalanced data: A multicenter retrospective study

BACKGROUND

To assist clinicians with diagnosis and optimal treatment decision-making, we attempted to develop and validate an artificial intelligence prediction model for lung metastasis (LM) in colorectal cancer (CRC) patients.

METHODS

The clinicopathological characteristics of 46037 CRC patients from the Surveillance, Epidemiology, and End Results (SEER) database and 2779 CRC patients from a multi-center external validation set were collected retrospectively. After feature selection by univariate and multivariate analyses, six machine learning (ML) models, including logistic regression, K-nearest neighbor, support vector machine, decision tree, random forest, and balanced random forest (BRF), were developed and validated for the LM prediction. In addition, stratified LM patients by risk score were utilized for survival analysis.

RESULTS

Extremely low rates of LM with 2.59% and 4.50% were present in the development and validation set. As the imbalanced learning strategy, the BRF model with an Area under the receiver operating characteristic curve (AUC) of 0.874 and an average precision (AP) of 0.184 performed best compares with other models and clinical predictor. Patients with LM in the high-risk group had significantly poorer survival (P＜0.001) and failed to benefit from resection (P = 0.125).

CONCLUSIONS

In summary, we have utilized the BRF algorithm to develop an effective, non-invasive, and practical model for predicting LM in CRC patients based on highly imbalanced datasets. In addition, we have implemented a novel approach to stratify the survival risk of CRC patients with LM based the output of the model.

Staging Chest CT in Patients With Early-Stage Colon Cancer: Analysis of Impact on Survival Using Inverse Probability Weighting and Causal Diagram

BACKGROUND. Staging chest CT has been shown to have negligible diagnostic yield for detecting lung metastases in patients with early-stage colon cancer. Nonetheless, staging chest CT may have potential survival benefits, including opportunistic screening of comorbidity and provision of a baseline examination for future comparisons. Evidence is lacking regarding the impact of staging chest CT on survival in patients with early-stage colon cancer. OBJECTIVE. The purpose of this study was to determine whether the performance of staging chest CT affects survival in patients with early-stage colon cancer. METHODS. This retrospective study included patients with early-stage colon cancer (defined as clinical stage 0 or I on staging abdominal CT) at a single tertiary hospital between January 2009 and December 2015. Patients were divided into two groups according to the presence of a staging chest CT examination. To ensure comparability between the two groups, inverse probability weighting was applied to adjust for the confounders derived from a causal diagram. The between-group differences in adjusted restricted mean survival time at 5 years were measured for overall survival, relapse-free survival, and thoracic metastasis-free survival. Sensitivity analyses were performed. RESULTS. A total of 991 patients (618 men and 373 women; median age, 64 years [IQR, 55-71 years]) were included: 606 patients (61.2%) had staging chest CT. For overall survival, the difference between groups in restricted mean survival time at 5 years was not significant (0.4 months [95% CI, -0.8 to 2.1 months]). The differences between groups in restricted mean survival at 5 years were also not significant for relapse-free survival (0.4 months [95% CI, -1.1 to 2.3 months]) and for thoracic metastasis-free survival (0.6 months [95% CI, -0.8 to 2.4 months]). Similar results were observed in sensitivity analyses that tested 3- and 10-year RMST differences, excluded patients who underwent FDG PET/CT during staging workup, and added treatment decision (surgery vs no surgery) to the causal diagram. CONCLUSION. The use of staging chest CT did not affect survival in patients with early-stage colon cancer. CLINICAL IMPACT. Staging chest CT may be omitted from the staging workup for patients with colon cancer of clinical stage 0 or I.

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.

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.

Dealing with indeterminate pulmonary nodules in colorectal cancer patients; a systematic review

INTRODUCTION

Indeterminate pulmonary nodules (IPNs) are frequently encountered on staging computed tomography (CT) in colorectal cancer (CRC) patients and they create diagnostic dilemmas. This systematic review and pooled analysis aims to estimate the incidence and risk of malignancy of IPNs and provide an overview of the existing literature on IPNs in CRC patients.

MATERIALS AND METHODS

EMBASE, Pubmed and the Cochrane database were searched for papers published between January 2005 and April 2020. Studies describing the incidence of IPNs and the risk of malignancy in CRC patients and where the full text was available in the English language were considered for inclusion. Exclusion criteria included studies that used chest X-ray instead of CT, liver metastasis cohorts, studies with less than 60 CRC patients and reviews.

RESULTS

A total of 18 studies met the inclusion criteria, involving 8637 patients. Pooled analysis revealed IPNs on staging chest CT in 1327 (15%) of the CRC patients. IPNs appeared to be metastatic disease during follow up in 16% of these patients. Regional lymph node metastases, liver metastases, location of the primary tumour in the rectum, larger IPN size and multiple IPNs are the five most frequently reported parameters predicting the risk of malignancy of IPNs.

CONCLUSION

A risk stratification model for CRC patients with IPNs is warranted to enable an adequate selection of high risk patients for IPN follow up and to diminish the use of unnecessary repetitive chest CT-scans in the many low risk patients.

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BACKGROUND

Pulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules.

QUESTIONS/PURPOSES

(1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN?

METHODS

Between 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses.

RESULTS

Following re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival.

CONCLUSION

The findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed.

LEVEL OF EVIDENCE

Level III, prognostic study.

Differentiation of primary lung cancer from solitary lung metastasis in patients with colorectal cancer: a retrospective cohort study

Background

This study aimed to evaluate the computed tomography (CT) features of solitary pulmonary nodule (SPN), which can be a non-invasive diagnostic tool to differentiate between primary lung cancer (LC) and solitary lung metastasis (LM) in patients with colorectal cancer (CRC).

Methods

This retrospective study included SPNs resected in CRC patients between January 2011 and December 2019. The diagnosis of primary LC or solitary LM was based on histopathologic report by thoracoscopic wedge resection. Chest CT images were assessed by two thoracic radiologists, and CT features were identified by consensus. Predictive parameters for the discrimination of primary LC from solitary LM were evaluated using multivariate logistic regression analysis.

Results

We analyzed CT data of 199 patients (mean age, 65.95 years; 131 men and 68 women). The clinical characteristic of SPNs suggestive of primary LC rather than solitary LM was clinical stages I–II CRC (P < 0.001, odds ratio [OR] 21.70). The CT features of SPNs indicative of primary LC rather than solitary LM were spiculated margin (quantitative) (P = 0.020, OR 8.34), sub-solid density (quantitative) (P < 0.001, OR 115.56), and presence of an air bronchogram (quantitative) (P = 0.032, OR 5.32).

Conclusions

Quantitative CT features and clinical characteristics of SPNs in patients with CRC could help differentiate between primary LC and solitary LM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02131-7.

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.

Significance of indeterminate pulmonary nodules in resectable pancreatic adenocarcinoma-a review

BACKGROUND

The clinical significance of indeterminate pulmonary nodules (IPN) in patients with resectable pancreatic adenocarcinoma (PDAC) is unknown. The rate of detection on IPN has risen due to enhanced staging investigations to determine resectability. IPNs detected on preoperative imaging represent a clinical dilemma and complicate decision-making. Currently, there are no recommendations on the management of IPN. This review provides a comprehensive overview of the current knowledge on the natural history of IPN detected among patients with resectable PDAC.

METHODS

A systematic review based on a search in Medline and Embase databases was performed. All clinical studies evaluating the significance of IPN in patients with resectable PDAC were included. PRISMA guidelines were followed.

RESULTS

Five studies met the inclusion criteria. The total patient population was 761. The prevalence of IPN reported ranged from 18 to 71%. The median follow-up duration was 17 months. The median overall survival was 19 months. Patients with pre-operative IPN which subsequently progressed to clinically recognizable pulmonary metastases, ranged from 1.5 to 16%. Four studies found that there was no significant difference in median overall survival in patients with or without IPNs.

CONCLUSION

This is a first review on the significance of IPN in patients with resectable PDAC. The preoperative presence of IPN does not demonstrate an association with overall survival after surgery. The identification of IPN is a significant finding however it should not preclude patients with resectable PDAC from undergoing curative resection.

Predictive Role of Biopsy Based Biomarkers for Radiotherapy Treatment in Rectal Cancer

Background and Purpose: Radiation therapy has long been contemplated as an important mode in the treatment of rectal cancer. However, there are few ideal tools available for clinicians to make a radiotherapy decision at the time of diagnosis for rectal cancer. The purpose of this study was to assess whether biomarkers expressed in the biopsy could help to choose the suitable therapy and provide predictive and/or prognostic information. Experimental Design: In total, 30 biomarkers were analyzed in 219 biopsy samples before treatment to discover the possibility of using them as an indicator for radiotherapy selection, diagnosis, survival and recurrence. Results: Twenty-two biomarkers (COX2-RT, COX2-NonRT, etc.; 36.67%) had diagnostic value. For survival, four biomarkers (NFKBP65, p130, PINCH and PPAR) were significant in regulating gene promoter activity and overall survival, while four had a trend (AEG1, LOX, SATB1 and SIRT6). Three biomarkers (COX2, PINCH and WRAP53) correlated with disease-free survival, while eight had a trend (AEG1, COX2, Ki67, LOX, NFKBP65, PPAR and SATB1). Four biomarkers (COX2-RT, NFKBP65cyto-RT, P130cyto-NonRT and PPARcyto-RT) were independent prognostic factors for recurrence. NFKBP65 and SIRT6 were significantly correlated with lymph node metastasis regardless of radiation. Patients with high AEG1, LOX, NFKBP65, PPAR and SATB1 had or showed a positive trend for better survival after radiotherapy, while those with positive PINCH and WRAP53 expression would not benefit from radiotherapy. Conclusions: AEG1, LOX, NFKBP65cyto, PPAR and SATB1 could be used as indicators for choosing radiotherapy. COX2-RT, COX2-NonRT and some other biomarkers may provide additional help for diagnosis.

Factors associated with subcentimeter pulmonary nodule outcomes followed with computed tomography imaging in oncology patients

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PNs with irregular, lobuled or spiculated margins exhibited faster growth than PNs with regular, smooth margins.

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Malignancy was significantly associated with male gender, a colorectal cancer diagnosis and advanced stage disease.

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Oncologic patients should have an individualized CT follow-up strategy, as the rate of malignant pulmonary nodules is higher than in the general population.

Introduction

Technological advancements in computed tomography (CT) have enabled the frequent detection of small pulmonary nodules (PNs), especially in patients with an oncologic history. It is important the malignant versus benign etiology of PNs be determined. The aim of the present study was to evaluate the behavior and clinical/radiological characteristics of subcentimeter PNs detected by CT in oncologic patients.

Methods

An observational, longitudinal, retrospective and single-center study was conducted with a sample of 100 patients with a diagnosis of a primary malignant solid tumor outside of the lungs who developed indeterminate subcentimeter PNs (n = 251) detected on consecutive thoracic CT scans from 2015 to 2017. Follow-up CTs for each patients were examined in each of three periods (0–3 months, 3–6 months, and 6 months to 1 year).

Results

In our study sample, 28 patients (28 %) showed one or more signs suspicious of pulmonary metastasis, including ≥50 % PN growth, nodule growth followed by size reduction in patients undergoing chemotherapy, and the appearance of multiple nodules. The majority (56 %) of the PNs were detected during the 3–6-month follow-up CT scan. PNs with irregular, lobuled, or spiculated margins exhibited faster growth than PNs with regular, smooth margins. Malignancy of PNs was found to be significantly associated with being male, a primary colorectal cancer diagnosis, and advanced stage disease.

Conclusion

Our findings reinforce the necessity of an individualized CT follow-up strategy for patients with an oncologic history, as well as the importance of early nodule screening, with the inter-scan interval being dependent on the primary neoplasm.

Clinical significance of subcentimeter pulmonary nodules in patients undergoing hepatectomy for colorectal liver metastases

BACKGROUND AND OBJECTIVES

The clinical significance of lung metastases regarded as subcentimeter pulmonary nodules (SPN) before hepatectomy for colorectal liver metastases (CLM) has not been assessed well.

METHODS

The data from 569 patients undergoing hepatectomy for CLM from 2010 to 2016 were reviewed. The presence and final diagnosis of SPN were analyzed for their association with overall survival (OS).

RESULTS

A total of 143 patients had SPN (25.1%). SPN were proved to be lung metastases in 43 patients (30.1%). Before hepatectomy, lung metastases were suspected in 25 patients (sensitivity: 58%; specificity: 100%). The 5-year OS of patients with lung metastases (45.4%) was worse than that of those with no pulmonary nodules (60.9%, P = .003). There was no significant difference in the 5-year OS between the patients with lung metastases diagnosed after hepatectomy (48.7%) and before hepatectomy (41.2%, P = .432). The 5-year OS of patients who underwent surgery for lung metastases after hepatectomy (60.5%) was similar to that of those with no pulmonary nodules and benign pulmonary nodules (60.9%, P = .6310; 44.0%, P = .899).

CONCLUSION

Although diagnostic sensitivity for SPN before hepatectomy is low, timing of diagnosis does not affect OS. Conclusive lung resection offers OS similar to that of patients without lung metastases.

CT Morphological Features Integrated With Whole-Lesion Histogram Parameters to Predict Lung Metastasis for Colorectal Cancer Patients With Pulmonary Nodules

Purpose: To retrospectively identify the relationships between both CT morphological features and histogram parameters with pulmonary metastasis in patients with colorectal cancer (CRC) and compare the efficacy of single-slice and whole-lesion histogram analysis. Methods: Our study enrolled 196 CRC patients with pulmonary nodules (136 in the training dataset and 60 in the validation dataset). Twenty morphological features of contrast-enhanced chest CT were evaluated. The regions of interests were delineated in single-slice and whole-tumor lesions, and 22 histogram parameters were extracted. Stepwise logistic regression analyses were applied to choose the independent factors of lung metastasis in the morphological features model, the single-slice histogram model and whole-lesion histogram model. The areas under the curve (AUC) was applied to quantify the predictive accuracy of each model. Finally, we built a morphological-histogram nomogram for pulmonary metastasis prediction. Results: The whole-lesion histogram analysis (AUC of 0.888 and 0.865 in the training and validation datasets, respectively) outperformed the single-slice histogram analysis (AUC of 0.872 and 0.819 in the training and validation datasets, respectively) and the CT morphological features model (AUC of 0.869 and 0.845 in the training and validation datasets, respectively). The morphological-histogram model, developed with significant morphological features and whole-lesion histogram parameters, achieved favorable discrimination in both the training dataset (AUC = 0.919) and validation dataset (AUC = 0.895), and good calibration. Conclusions: CT morphological features in combination with whole-lesion histogram parameters can be used to prognosticate pulmonary metastasis for patients with colorectal cancer.

Expert consensus on multidisciplinary therapy of colorectal cancer with lung metastases (2019 edition)

The lungs are the second most common site of metastasis for colorectal cancer (CRC) after the liver. Rectal cancer is associated with a higher incidence of lung metastases compared to colon cancer. In China, the proportion of rectal cancer cases is around 50%, much higher than that in Western countries (nearly 30%). However, there is no available consensus or guideline focusing on CRC with lung metastases. We conducted an extensive discussion and reached a consensus of management for lung metastases in CRC based on current research reports and the experts' clinical experiences and knowledge. This consensus provided detailed approaches of diagnosis and differential diagnosis and provided general guidelines for multidisciplinary therapy (MDT) of lung metastases. We also focused on recommendations of MDT management of synchronous lung metastases and initial metachronous lung metastases. This consensus might improve clinical practice of CRC with lung metastases in China and will encourage oncologists to conduct more clinical trials to obtain high-level evidences about managing lung metastases.

The clinical significance of indeterminate pulmonary nodules in melanoma patients at baseline and during follow-up chest CT

Objective

This study aims to determine an appropriate timeline to monitor indeterminate pulmonary nodules (IPN) in melanoma patients to confirm metastatic origin.

Materials and Methods

588 clinically non-metastatic melanoma patients underwent curative intent surgery during 3 years. Patients with baseline chest CT and at least one follow-up (FU) CT were retrospectively analyzed to assess for IPN. Patients with definitely benign nodules, metastases and non-melanoma malignancies were excluded. Change in volume from first to FU CT, initial diameter (D1) and volume (V1), distance from pleura, peripheral and perifissural location, density and clinical stage were evaluated. Nodules were volumetrically measured on CTs and were considered metastases if they increased in size between two CTs or if increase was accompanied by multiple new nodules or extrapulmonary metastases.

Results

148 patients were included. Two out of 243 baseline IPN detected in 70 patients, increased significantly in volume in 3 and 5 months and were proven metastases. During FU, 86% of 40 interval IPN detected in 28 patients, were proven metastases. Interval nodule (p < 0.0001, HR:243,CI:[57.32,1033.74]), 3-month volume change (OR:1.023,CI:[1.014,1.033]), V1 (OR:1.006,CI:[1.003,1.009]), D1 (OR:1.424,CI:[1.23,1.648]), distance from pleura (OR:1.03,CI:[1.003,1.059]), and combined stage IIC + III (OR:11.29,CI:[1.514,84.174]), were associated with increased risk for metastasis. 43%, 72% and 94% of patients with IPN were confirmed with metastases in the first FU CT at 3, 6 and 12 months respectively.

Conclusion

Baseline IPN are most likely benign, while interval IPN are high risk for metastasis. Absence of volume increase of IPN within 6 months excluded metastasis in most patients.

Diagnostic Yield and False-Referral Rate of Staging Chest CT in Patients with Colon Cancer

Purpose To measure the diagnostic yield and false-referral rate (FRR) of staging contrast material-enhanced chest CT based on the clinical stage from contrast-enhanced abdominal CT in patients with colon cancer. Materials and Methods This retrospective study included 1743 patients (mean age, 63.4 years; range, 18-96 years) with a diagnosis of colon cancer. The primary outcomes were diagnostic yield and FRR of contrast-enhanced chest CT in the detection of thoracic metastasis. The proportions of patients with occult thoracic metastasis and those undergoing pulmonary metastasectomy for true-positive metastases were key secondary outcomes. The outcomes were stratified according to clinical stage at contrast-enhanced abdominal CT. Results The diagnostic yields in clinical stage 0/I, cII, cIII, and cIV were 0% (95% confidence interval [CI]: 0%, 0.8%), 1.3% (95% CI: 0.4%, 3.3%), 4.4% (95% CI: 3.0%, 6.1%), and 43.3% (95% CI: 36.8%, 49.9%), respectively. The corresponding FRRs were 5.7% (95% CI: 3.8%, 8.2%), 2.9% (95% CI: 1.3%, 5.5%), 6.7% (95% CI: 5.0%, 8.8%), and 6.1% (95% CI: 3.4%, 10.0%), respectively. The proportions of patients with occult metastasis were 0% (95% CI: 0%, 0.8%), 3.3% (95% CI: 1.6%, 5.9%), 1.5% (95% CI: 0.8%, 2.7%), and 6.1% (95% CI: 3.4%, 10.0%), respectively. The proportion of patients who underwent pulmonary metastasectomy was 0% (none of 474; 95% CI: 0%, 0.8%) for clinical stage 0/I tumors. Conclusion In clinical stages 0 and I, the diagnostic yield of staging contrast-enhanced chest CT in detecting thoracic metastasis was zero. For clinical stages II, III, and IV, contrast-enhanced chest CT as a baseline examination was helpful for the detection of thoracic metastasis and allowed for the possibility of a curative metastasectomy. There was no significant association between clinical stage and false-referral rate. © RSNA, 2018 Online supplemental material is available for this article.

Predictive Nomograms for Synchronous Distant Metastasis in Rectal Cancer

BACKGROUND

Nomograms may be used to quantitatively assess the probability of synchronous distant metastasis. The purpose of this study is to develop predictive nomograms for the presence of synchronous distant metastasis in patients with rectal cancer.

METHODS

A retrospective analysis of the Surveillance Epidemiology and End Results database was performed for cases diagnosed between 2010 and 2014.

RESULTS

Overall, 46,785 patients with rectal cancer (27,773 [59.4%] males, mean age 63.9 ± 13.7 years) were identified, of which 6192 (13.2%) had liver metastasis, 2767 (5.9%) had lung metastasis, and 601 (1.3%) had bone metastasis. Age, sex, race, tumor location, tumor grade, primary tumor size, CEA levels, perineural invasion, T stage, N stage, and liver and lung metastasis were found to be associated with the presence of synchronous distant metastasis and were included in the predictive models. The c-indexes of these models were 0.99 for liver metastasis, 0.99 for lung metastasis, and 1 for bone metastasis.

CONCLUSIONS

Predictive nomograms for the presence of synchronous liver, lung, and bone metastasis were developed and may be used to predict the probability of distant disease in rectal cancer patients.

Solitary Pulmonary Lesion in Patients with History of Malignancy: Primary Lung Cancer or Metastatic Cancer?

BACKGROUND

Defining the status of solitary pulmonary lesion (SPL) in patients with history of malignancy is important because primary lung cancer (PLC) or intrapulmonary metastasis might indicate different surgical strategies. The aim of this study is to identify factors related to the status of these lesions and construct a clinical model to estimate the pretest probability of PLC.

METHODS

From January 2005 to January 2016, 104 patients with previous malignancy and suitable for surgery were retrospectively studied. Univariate and multivariate analyses were performed to identify possible factors related to SPLs. A nomogram was constructed to differentiate PLC from intrapulmonary metastasis.

RESULTS

Ninety-seven (93.3%) patients were diagnosed as malignant postoperatively, including 61 patients with intrapulmonary metastasis and 36 patients with PLC. Multivariate analysis showed that site of primary tumor [head and neck squamous cell cancer: odds ratio (OR) = 28.509, P = 0.006; genitourinary cancer: OR = 23.928, P = 0.012], negative lymph node status of primary tumor (OR = 3.154, P = 0.038), spiculation of SPL (OR = 3.972, P = 0.022), and central location of SPL (OR = 4.679, P = 0.026) were four independent factors differentiating PLC from intrapulmonary metastasis. All of these were included in the nomogram. The C-index of the nomogram for predicting probability was 0.82.

CONCLUSIONS

Incidence of malignant SPLs was fairly high in patients with history of malignancy. A nomogram including site and lymph node status of primary tumor, and spiculation and location of SPL might be a good tool for differentiating PLC from intrapulmonary metastasis preoperatively and guiding treatment.

Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Newly Found Suspected Malignant Solitary Pulmonary Lesions in Patients Who Have Received Curative Treatment for Colorectal Cancer

Background. Positron emission tomography/computed tomography (PET/CT) is recommended for colorectal cancer (CRC) patients with suspected malignant pulmonary lesions. This study aims to systematically discuss the ¹⁸F-FDG-PET/CT diagnosis of solitary pulmonary lesions that are strongly suspected to be malignant in CRC patients who have previously undergone curative therapy. Methods. This retrospective study involved 49 consecutive CRC patients who had previously undergone curative therapy and then underwent PET/CT for the investigation of solitary pulmonary lesions that were strongly suspected to be malignant. Results. Pathological examination confirmed the presence of pulmonary metastases (29 patients, 59.2%), primary lung cancer (15 patients, 30.6%), and benign pulmonary disease (5 patients, 10.2%). Small lung lesions, advanced pathological stage, adjuvant chemotherapy after CRC surgery, solitary pulmonary lesions with lower border irregularity, higher carcinoembryonic antigen level, and the lack of concomitant mediastinal lymph node metastasis were more likely to be associated with pulmonary metastasis than with primary lung cancer. None of these factors was independently significant in the multivariate analysis. Conclusion. Clinicopathological characteristics help to differentiate metastasis and primary lung cancer to some extent during the diagnosis of solitary pulmonary lesions suspected to be malignant in this group of patients. This may provide valuable information to clinicians.

Predictive factors for malignancy in incidental pulmonary nodules detected in breast cancer patients at baseline CT

OBJECTIVES

Pulmonary nodules are commonly encountered at staging CTs in patients with extrathoracic malignancies, but their significance on a per-patient basis remains uncertain.

METHODS

We undertook a retrospective analysis of pulmonary nodules identified in patients with a diagnosis of breast cancer from 2010 - 2015, evaluating nodules present at a baseline CT (i.e. prevalent nodules). We reviewed 211 patients with 248 individual nodules.

RESULTS

The rate of malignancy in prevalent nodules is low, approximately 13 %. Variables associated with metastasis include pleural studding, hilar lymphadenopathy and the presence of extrapulmonary metastasis, as well as number of nodules, nodule size and nodule shape. Using a combination of these factors, we have developed an evidence-based multivariate decision tree to predict which nodules are malignant in these patients, which is 91 % accurate and 100 % sensitive for metastasis.

CONCLUSIONS

We propose a simplified clinical prediction algorithm to guide radiologists and oncologists in managing patients with breast cancer and incidental pulmonary nodules.

KEY POINTS

• Incidental pulmonary nodules are common on computed tomography in breast cancer patients. • Nodules present at baseline have a lower malignancy risk than incident nodules. • We present an evidence-based decision algorithm predicting which nodules are likely malignant. • This algorithm can help direct patient management.

Optimizing adjuvant therapy and survivorship care of stage III colon cancer

The MOSAIC trial demonstrated nearly a decade ago that the addition of oxaliplatin to 5-fluorouracil improves outcomes in the adjuvant treatment of colon cancer, but no new agents have been shown to be superior to standard FOLFOX therapy. Oncologists have refined the use of oxaliplatin containing regimens to optimize outcomes, improved patient selection for multi-agent chemotherapy and expanded survivorship care to meet the needs of the growing number of survivors. In this article, we review the historical contexts of current therapy, appropriate staging investigations, the importance of timely initiation of therapy and key survivorship issues. We also discuss exciting opportunities for change, including reduced duration of adjuvant chemotherapy and the use of circulating tumor cells and DNA in surveillance.

Diagnostics and Epidemiology of Colorectal Cancer

Colorectal cancer is one of the leading causes of cancer-related morbidity and mortality. Main risk factors include advanced age, family history, male sex, and lifestyle factors. Screening can reduce incidence and death from colorectal cancer. Therefore, prevention and early detection are crucial in order to detect and remove pre-neoplastic adenomas and to detect cancers at early stages. Colonoscopy, flexible sigmoidoscopy, and fecal occult blood tests are established tools for screening. Newer fecal immunochemical tests reveal higher sensitivities for advanced adenoma and cancer than guaiac-based hemoccult tests. Molecular stool and blood tests as well as virtual colonoscopy and colon capsule endoscopy are promising new developments so far not established as routine instruments for the prevention and early detection of colorectal cancer. Colonoscopy is the method of choice for the diagnosis of colorectal cancer and for adenoma removal. Prognosis is essentially dependent on the tumor stage at the time of the initial diagnosis. Proper staging based on imaging prior to therapy is a prerequisite. In rectal cancer, local staging is an essential requirement for the identification of appropriate candidates for neoadjuvant therapy.

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.

What is the Significance of Indeterminate Pulmonary Nodules in Patients Undergoing Resection for Pancreatic Adenocarcinoma?

OBJECTIVE

The significance of indeterminate pulmonary nodules (IPNs) in patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) is unknown. We sought to define the prevalence and impact of IPN in such patients.

METHODS

We studied all patients who underwent surgical resection of PDAC between 1980 and 2013. IPN was defined as ≥1 well-defined lung nodule(s) less than 3 cm in diameter. Survival was assessed using univariate and multivariate Cox models.

RESULTS

Of the 2306 resected patients, 374 (16.2 %) had a preoperative chest computed tomography (CT) scan. Of these patients, 183 (49 %) had ≥1 IPN. Demographic and clinicopathological characteristics were similar among patients with or without IPN (all P>0.05). Median survival was comparable among patients who did (15.6 months) or did not (18.0 months) have IPN (P=0.66). Of the 183 patients with IPN, 29 (16 %) progressed to clinically recognizable metastatic lung disease compared to 13 % without IPN (P=0.38). The presence of >1 IPN was associated with the development of lung metastasis (relative risk 1.58, 95 % CI 1.03-2.4; P=0.05). However, lung metastasis was not associated with survival (P=0.24).

CONCLUSIONS

An IPN proved to be a lung metastasis in only one of six patients with PDAC undergoing surgical resection in this study. Survival was not impacted, even among patients who developed lung metastasis. Patients with PDAC who have IPN should not be precluded from surgical consideration.

Subcentimeter pulmonary nodules are not associated with disease progression in patients with renal cell carcinoma

PURPOSE

Renal cell carcinoma most commonly metastasizes to the lung. Indeterminate pulmonary nodules develop preoperatively in half of the patients with localized renal cell carcinoma but clinical significance remains poorly defined. We determined whether the presence of indeterminate pulmonary nodules, or nodule size or number is associated with renal cell carcinoma outcomes.

MATERIALS AND METHODS

We reviewed data on 1,102 patients with renal cell carcinoma in whom chest computerized tomography was done within 6 months before nephrectomy from 2002 to 2012. Patients with metastatic disease at presentation, benign tumors, pulmonary nodules greater than 2 cm or concurrent pulmonary disease were excluded, leaving 748 available for analysis. Study outcomes included lung metastasis, any distant metastasis or death from renal cell carcinoma. Cox proportional hazards models were used to assess whether the presence of indeterminate pulmonary nodules, or nodule size or number was associated with outcomes. Models were evaluated by comparing discrimination using the Harrell c-index.

RESULTS

Indeterminate pulmonary nodules were present in 382 of 748 patients (51%). Median followup was 4.1 years (IQR 2.2-6.1). The presence of indeterminate pulmonary nodules was not associated with distant metastasis or death from kidney cancer. However, compared to subcm indeterminate pulmonary nodules the nodules greater than 1 cm were associated with metastatic disease after adjusting for tumor histology, stage and size (HR 2.48, 95% CI 1.08-5.68, p = 0.031). The outcome c-index increased slightly after adding nodule size to a predictive model adjusted for tumor characteristics.

CONCLUSIONS

No evidence in the current study suggested that indeterminate pulmonary nodules less than 1 cm are associated with renal cell carcinoma progression, although large nodules significantly predicted metastatic disease. Patients with subcm indeterminate pulmonary nodules would be unlikely to benefit from extensive postoperative chest imaging surveillance, which should be reserved for patients with nodules greater than 1 cm.

Pulmonary metastasectomy for colorectal cancer: How many nodules, how many times?

Colorectal cancer (CRC) is one of the most common cancers worldwide, with 5%-15% of CRC patients eventually developing lung metastasis (LM). Despite doubts about the role of locoregional therapy in the management of systemic disease, many surgeons have performed pulmonary metastasectomy (PM) for CRC in properly selected patients. However, the use of pulmonary metastasectomy remains controversial due to the lack of randomized controlled studies. This article reviews the results of surgical treatment of pulmonary metastases for CRC, focusing on (1) current treatment guidelines and surgical techniques of PM in patients with LM from CRC; (2) outcomes of PM and its prognostic factors; and (3) controversial issues in PM, focusing on repeated metastasectomy, bilateral multiple metastases, and combined liver and lung metastasectomy.