Routine preoperative chest computed tomography does not influence therapeutic strategy in patients with colorectal cancer

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.

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.

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.

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.

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.

Indeterminate pulmonary nodules in colorectal cancer

AIM: To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer (CRC) patients after lung operation of indeterminate pulmonary nodules (IPNs).

METHODS: From a prospective database of CRC patients, 40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography (CT) were enrolled. The decision to perform a lung operation was made if the patient met the following criteria: (1) completely resected or resectable primary CRC; (2) completely resectable IPNs; (3) controlled or controllable extrapulmonary metastasis; and (4) adequate general condition and pulmonary function to tolerate pulmonary operation. Lung operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic confirmation.

RESULTS: A total of 40 cases of lung resection was performed in 29 patients. Five patients underwent repeated lung resection. The final pathology result showed metastasis from the CRC in 30 cases (75%) and benign pathology in 10 cases (25%). The primary tumor site was the rectum in 26/30 (86.6%) cases with pulmonary metastasis, but only 3/10 (30%) cases in the benign group had a primary rectal cancer (P = 0.001). Positron emission tomography (PET)-CT was performed for 22/30 (73.4%) patients in the lung metastasis group and for 6/10 (60.0%) patients in the benign group. PET-CT revealed hot uptake of ¹⁸fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both groups. The group with pulmonary metastasis had a higher incidence of primary rectal cancer (P = 0.001), a more advanced tumor stage (P = 0.011), and more frequent lymphatic invasion of tumor cells (P = 0.005). Six cases with previous liver metastasectomy were present in the lung metastasis group. Serum carcinoembryonic antigen levels before lung operation were not elevated in any of the patients.

CONCLUSION: The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IPNs in CRC.

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.

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.

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.