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.

The value of diffusion kurtosis imaging and intravoxel incoherent motion quantitative parameters in predicting synchronous distant metastasis of rectal cancer

BACKGROUND

The incidence and mortality rate of rectal cancer are still high, the metastasis of rectal cancer are main causes of death. The control of the distant metastasis is one of the main concerns in the treatment of locally advanced rectal cancer, but there are few studies on predicting synchronous distant metastasis (SDM) of rectal cancer.

METHOD

The data of patients with rectal adenocarcinoma confirmed by endoscopic biopsy or postoperative pathology from September 2015 to May 2020 in hospital A (center 1) and hospital B (center 2) were analyzed retrospectively, including age, sex, carcinoembryonic antigen, carbohydrate antigen 19-9, tumor location, tumor length, image staging and characteristics. The average age of the 169 patients consisting of 105 males and 64 females in study is 61.2 years. All patients underwent rectal routine rectal MRI, DKI and IVIM examinations on a 3.0-T scanner. Two radiologists sketched regions of interest (ROIs) on b = 1000 s/mm² DKI and IVIM images to obtain quantitative parameters with FireVoxel manually. We evaluated the difference of histogram analysis, clinical and image data between SDM group and non-SDM group, and evaluated the efficacy of each index in predicting SDM of rectal cancer.

RESULTS

The 90th percentile of f values in the SDM group is lower than that in the non-SDM group (29.4 ± 8.4% vs. 35 ± 17.8%, P = 0.005). CA19-9 in the SDM group is higher than that in the non-SDM group (P = 0.003). Low and high rectal cancer are more likely to develop SDM than middle rectal cancer (P = 0.05 and P = 0.047). The combination of these three indexes has a greater area under the curve (AUC) than any one index (0.801 vs. 0.685 (f (90th percentile)) and 0.627 (CA19-9), P = 0.0075 and 0.0058, respectively), and its specificity and sensitivity are 80.0% and 71.6%, respectively. When this combination is incorporated into the predictive nomogram model, the c-index is 0.801 (95% confidence interval (CI): 0.730-0.871).

CONCLUSIONS

IVIM quantitative parameters combine with CA19-9 and tumor location can better predict the risk of SDM of rectal cancer.

An Exploratory Study on the Stable Radiomics Features of Metastatic Small Pulmonary Nodules in Colorectal Cancer Patients

Objectives

To identify the relatively invariable radiomics features as essential characteristics during the growth process of metastatic pulmonary nodules with a diameter of 1 cm or smaller from colorectal cancer (CRC).

Methods

Three hundred and twenty lung nodules were enrolled in this study (200 CRC metastatic nodules in the training cohort, 60 benign nodules in the verification cohort 1, 60 CRC metastatic nodules in the verification cohort 2). All the nodules were divided into four groups according to the maximum diameter: 0 to 0.25 cm, 0.26 to 0.50 cm, 0.51 to 0.75 cm, 0.76 to 1.0 cm. These pulmonary nodules were manually outlined in computed tomography (CT) images with ITK-SNAP software, and 1724 radiomics features were extracted. Kruskal-Wallis test was performed to compare the four different levels of nodules. Cross-validation was used to verify the results. The Spearman rank correlation coefficient is calculated to evaluate the correlation between features.

Results

In training cohort, 90 features remained stable during the growth process of metastasis nodules. In verification cohort 1, 293 features remained stable during the growth process of benign nodules. In verification cohort 2, 118 features remained stable during the growth process of metastasis nodules. It is concluded that 20 features remained stable in metastatic nodules (training cohort and verification cohort 2) but not stable in benign nodules (verification cohort 1). Through the cross-validation (n=100), 11 features remained stable more than 90 times.

Conclusions

This study suggests that a small number of radiomics features from CRC metastatic pulmonary nodules remain relatively stable from small to large, and they do not remain stable in benign nodules. These stable features may reflect the essential characteristics of metastatic nodules and become a valuable point for identifying metastatic pulmonary nodules from benign nodules.

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.

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.

Predictive Nomograms for Synchronous Liver and Lung Metastasis in Colon Cancer

BACKGROUND

The risk of distant metastasis may be estimated using predictive nomograms. The purpose of this study is to develop nomograms that may assess the risk of synchronous metastasis in patients with colon cancer.

METHODS

A retrospective analysis of the Surveillance Epidemiology and End Results database between 2010 and 2014. Logistic regression was performed to identify factors associated with synchronous liver and lung metastasis.

RESULTS

Overall, 117,934 patients with colon cancer (59,076 [50.1%] males, mean age 68.3 ± 13.7 years) were included, of which 16,135 (13.7%) had liver metastasis and 4601 (3.9%) had lung metastasis at diagnosis. Age, sex, race, tumor location, tumor grade, CEA levels, perineural invasion, and T and N stage were associated with the presence of liver metastasis. Age, sex, race, tumor location, tumor grade, CEA levels, perineural invasion, T stage, N stage, and presence of liver metastasis were associated with the presence of lung metastasis. These variables were used to construct predictive nomograms. The c-indexes for both predictive models were 0.97.

CONCLUSIONS

In this study, we constructed predictive nomograms for the presence of synchronous liver and lung metastasis in patients with colon cancer that may be used to quantitatively assess the risk of synchronous metastatic disease.

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.

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.

Added value of double reading in diagnostic radiology,a systematic review

Objectives

Double reading in diagnostic radiology can find discrepancies in the original report, but a systematic program of double reading is resource consuming. There are conflicting opinions on the value of double reading. The purpose of the current study was to perform a systematic review on the value of double reading.

Methods

A systematic review was performed to find studies calculating the rate of misses and overcalls with the aim of establishing the added value of double reading by human observers.

Results

The literature search resulted in 1610 hits. After abstract and full-text reading, 46 articles were selected for analysis. The rate of discrepancy varied from 0.4 to 22% depending on study setting. Double reading by a sub-specialist, in general, led to high rates of changed reports.

Conclusions

The systematic review found rather low discrepancy rates. The benefit of double reading must be balanced by the considerable number of working hours a systematic double-reading scheme requires. A more profitable scheme might be to use systematic double reading for selected, high-risk examination types. A second conclusion is that there seems to be a value of sub-specialisation for increased report quality. A consequent implementation of this would have far-reaching organisational effects.

Key Points

• In double reading, two or more radiologists read the same images.

• A systematic literature review was performed.

• The discrepancy rates varied from 0.4 to 22% in various studies.

• Double reading by sub-specialists found high discrepancy rates.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0599-0) contains supplementary material, which is available to authorised users.

Mismatch repair status and synchronous metastases in colorectal cancer: A nationwide cohort study

The causality between the metastatic potential, mismatch repair status (MMR) and survival in colorectal cancer (CRC) is complex. This study aimed to investigate the impact of MMR in CRC on the occurrence of synchronous metastases (SCCM) and survival in patients with SCCM on a national basis. A nationwide cohort study of 6,692 patients diagnosed with CRC between 2010 and 2012 was conducted. Data were prospectively entered into the Danish Colorectal Cancer Group's database and merged with data from the Danish Pathology Registry and the National Patient Registry. Multivariable and multinomial logistic- and Cox-regression and proportional excess hazards analyses were used for confounder adjustment and to adjust for the general population mortality. In total, 983 of 6,692 patients (14.7%) had dMMR and 935 (14.0%) had SCCM. dMMR was associated with a decreased risk of SCCM, adjusted Odds Ratio (aOR) = 0.54 (95% confidence interval (CI):0.40-0.70, p < 0.001). The association only applied to confined hepatic metastases (aOR = 0.30, 95%CI: 0.18-0.49, p < 0.001), whereas the presence of confined pulmonary metastases (aOR = 0.71, 95% CI: 0.39-1.29, p = 0.258) or synchronous hepatic and pulmonary metastases (aOR = 0.69, 95% CI:0.26-1.29, p = 0.436) were unaffected by MMR. MMR in patients with SCCM had no impact on survival (Cox: adjusted Hazard Ratio (aHR) = 0.76, 95% CI: 0.54-1.06, p = 0.101; Proportional excess hazards: aHR = 0.73, 95% CI: 0.50-1.07, p = 0.111) when adjusting for other prognostic factors. The metastatic pattern varied according to MMR status. MMR had no impact on survival in patients with UICC Stage IV CRC. These findings may be important for the understanding of the metastatic processes and thus for optimizing staging and treatment in CRC patients.