Preoperative evaluation of colorectal cancer using CT colonography, MRI, and PET/CT

Clinically Occult Rectal Carcinoma Identified in a Case of Streptococcus bovis Endocarditis on Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Case Report and Review of Literature

Numerous studies over past four decades have implicated a strong association of Streptoccus bovis infection with colorectal carcinomas. Strong is this association that a screening colonoscopy for identifying malignancy is considered mandatory in patients whose blood/fecal cultures show growth of this particular pathogen. Here, we report an interesting case of a 61-year-old female patient who presented with pyrexia of unknown origin for 3 weeks. Positron emission tomography/computed tomography, in addition to helping diagnose mitral valve endocarditis, also identified a clinically occult T2N0 rectal carcinoma.

Laparoscopic surgery for sigmoid colon cancer after multiple operations including urinary diversion with Indiana pouch: A case report

A 73-year-old man with lower abdominal pain was diagnosed at our hospital with sigmoid colon cancer. He had previously undergone radical cystectomy with Indiana pouch construction and gastrectomy to treat bladder cancer and gastric cancer, respectively. We performed a laparoscopic Hartmann's operation with Japanese D3 lymph node dissection. We observed severe adhesion in the abdominal cavity; adhesions between the urostomy and sigmoid colon were particularly severe. The tumor had invaded to the distal rectum, which had adhered to the pubic bone and the previously reconstructed urinary pouch. By performing careful and persistent laparoscopic dissection, we completed the operation without damaging the urostomy and with no remnant tumor tissue (R0). The postoperative course was uneventful, and the patient was doing well with no evidence of cancer recurrence 1 year after surgery.

PET/MRI: Where might it replace PET/CT?

Simultaneous positron emission tomography and MRI (PET/MRI) is a technology that combines the anatomic and quantitative strengths of MR imaging with physiologic information obtained from PET. PET and computed tomography (PET/CT) performed in a single scanning session is an established technology already in widespread and accepted use worldwide. Given the higher cost and complexity of operating and interpreting the studies obtained on a PET/MRI system, there has been question as to which patients would benefit most from imaging with PET/MRI versus PET/CT. In this article, we compare PET/MRI with PET/CT, detail the applications for which PET/MRI has shown promise and discuss impediments to future adoption. It is our hope that future work will prove the benefit of PET/MRI to specific groups of patients, initially those in which PET/CT and MRI are already performed, leveraging simultaneity and allowing for greater degrees of multiparametric evaluation.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2017;46:1247-1262.

Network meta-analysis of the efficacy of first-line chemotherapy regimens in patients with advanced colorectal cancer

This network meta-analysis compared the short-term and long-term efficacies of first-line chemotherapy regimens in patients with advanced colorectal cancer (CRC). The 10 regimens included folinic acid + 5-fluorouracil + oxaliplatin (FOLFOX), folinic acid + 5-fluorouracil + irinotecan (FOLFIRI), folinic acid + 5-fluorouracil + gemcitabine (FFG), folinic acid + 5-fluorouracil + trimetrexate (FFT), folinic acid + 5-fluorouracil (FF), irinotecan + oxaliplatin (IROX), raltitrexed + oxaliplatin (TOMOX), folinic acid + tegafur-uracil (FTU), raltitrexed, and capecitabine. Electronic searches were performed in the Cochrane Library, PubMed and Embase databases from inception to June 2017. Network meta-analysis combined direct and indirect evidence to obtain odds ratios (ORs) and surface under the cumulative ranking curves (SUCRA) of different chemotherapy regimens for advanced CRC. Fourteen randomized controlled trails (RCTs) covering 4,383 patients with advanced CRC were included. The results revealed that FOLFOX, FOLFIRI, IROX, and TOMOX all showed higher overall response rates (ORRs) than FF or raltitrexed. Compared with raltitrexed, the aforementioned four regimens also had higher 1-year progression-free survival (PFS) rates. In addition, FOLFOX and FOLFIRI exhibited higher disease control rates (DCRs) and 1-year PFS rates than FF or raltitrexed. Cluster analysis revealed that FOLFOX, FOLFIRI, and TOMOX had better short-term and long-term efficacies. These findings suggest FOLFOX, FOLFIRI, and TOMOX are superior to other regimens for advanced CRC. These three regimens are therefore recommended for clinical treatment of advanced CRC.

Accuracy of Preoperative Local Staging of Primary Colorectal Cancer by Using Computed Tomography: Reappraisal Based on Data Collected at a Highly Organized Cancer Center

Purpose

In patients with colorectal cancer, preoperative staging using various imaging technologies is important for establishing the treatment plan and predicting the prognosis. Although computed tomography (CT) has been used most widely, the versatility of CT accuracy was primarily because of the lack of specialization. In this study, we aimed to identify whether any advancement in abdominal CT accuracy in the prediction of local staging has occurred.

Methods

Between December 2014 and November 2015, patients with colorectal cancer were retrospectively enrolled. All CT findings were retrospectively reported. A total of 285 patients were included, and their retrospectively collected data were retrospectively reviewed, focusing on a comparison between preoperative and postoperative staging.

Results

The overall prediction accuracy of the T stage was 55.1%, with overstaging occurring in 63 (22.1%) and understaging in 65 patients (22.8%). The sensitivity and specificity were 90.0% and 68.4%, respectively. The overall prediction accuracy of the N stage was 54.7%, with overstaging occurring in 89 (31.2%) and understaging in 40 patients (14.1%). The sensitivity and specificity were 71.9% and 63.2%, respectively. The CT accuracies by pathologic stage were 0%, 62.2%, 25.3%, and 81.2% for stages 0 (Tis N0), I, II, and III, respectively.

Conclusion

CT has good sensitivity for detecting colon cancers with tumor invasion beyond the bowel wall. However, detection of nodal involvement using CT is unreliable. In our opinion, abdominal CT alone has limitations in predicting the local staging of colorectal cancer, and additional technologies, such as CT plus positron emission tomography and/or colonography, will improve its accuracy.

Development and validation of a preoperative prediction model for colorectal cancer T-staging based on MDCT images and clinical information

Objectives

This study aimed to establish and evaluate the efficacy of a prediction model for colorectal cancer T-staging.

Results

T-staging was positively correlated with the level of carcinoembryonic antigen (CEA), expression of carbohydrate antigen 19-9 (CA19-9), wall deformity, blurred outer edges, fat infiltration, infiltration into the surrounding tissue, tumor size and wall thickness. Age, location, enhancement rate and enhancement homogeneity were negatively correlated with T-staging. The predictive results of the model were consistent with the pathological gold standard, and the kappa value was 0.805. The total accuracy of staging improved from 51.04% to 86.98% with the proposed model.

Materials and Methods

The clinical, imaging and pathological data of 611 patients with colorectal cancer (419 patients in the training group and 192 patients in the validation group) were collected. A spearman correlation analysis was used to validate the relationship among these factors and pathological T-staging. A prediction model was trained with the random forest algorithm. T staging of the patients in the validation group was predicted by both prediction model and traditional method. The consistency, accuracy, sensitivity, specificity and area under the curve (AUC) were used to compare the efficacy of the two methods.

Conclusions

The newly established comprehensive model can improve the predictive efficiency of preoperative colorectal cancer T-staging.

Accuracy of Multi-Slice Spiral Computed Tomography for Preoperative Tumor Node Metastasis (TNM) Staging of Colorectal Carcinoma

Background

With the advances in imaging technologies, multi-slice spiral computed tomography (MSCT) has demonstrated superiority in the diagnosis and staging of colorectal carcinoma. In the current study, preoperative TNM staging of colorectal carcinoma by using MSCT was conducted and compared with the corresponding postoperative pathological examination findings, in order to evaluate the accuracy of preoperative MSCT for TNM staging.

Material/Methods

Combinations of biphasic or triphasic enhanced-phase MSCT scans were obtained for 76 patients with colorectal carcinoma, and the TNM stage was determined based on imaging reconstruction from various angles and perspectives to display the size, location, and affected range of tumors. The preoperative TNM stage was compared with the postoperative pathological stage, and the consistency between the 2 methods was tested by the κ test using SPSS 17.0 software.

Results

Among the different combinations of enhanced-phase MSCT scanning, triphasic MSCT imaging, comprising the arterial, portal venous, and delayed phases, showed the highest accuracy rates, at 81.6% (62/76), 82.89% (63/76), and 96.1% (73/76) for T, N, and M staging, respectively, with κ values of 0.72, 0.65, and 0.56, respectively, indicating consistency with the postoperative pathological staging.

Conclusions

Combined MSCT scanning comprising the arterial phase, portal venous phase, and delayed phase showed satisfying consistency with the postoperative pathological analysis results for TNM staging of colorectal carcinoma. Thus, MSCT is an important clinical value for improving the accuracy of TNM staging and for planning the appropriate colorectal cancer treatment.

Accuracy of Whole-Body DWI for Metastases Screening in a Diverse Group of Malignancies: Comparison With Conventional Cross-Sectional Imaging and Nuclear Scintigraphy

OBJECTIVE

The purpose of this study is to assess the role of whole-body (WB) DWI as a screening modality for the detection of metastases and to compare it to conventional cross-sectional imaging modalities or nuclear scintigraphy in a population with various histopathologic malignancies.

SUBJECTS AND METHODS

WB DWI and conventional imaging (CT, MRI, or scintigraphy) were performed for patients with known malignancies for metastatic workup, and these patients were followed up for a period of 1 year. Two radiologists assessed WB DW images separately, and conventional images were assessed by the senior radiologist. The metastatic lesions were classified into four regions: liver, lung, skeletal system, and lymph nodes. The reference standard was considered on the basis of histopathologic confirmation or clinical follow-up of the metastatic lesions.

RESULTS

WB DWI was slightly inferior to conventional imaging modalities for the detection of hepatic metastases (sensitivity, 86.6% vs 93.3%; specificity, 91.6% vs 95.8%; and accuracy, 89.7% vs 94.8%) and skeletal metastases (sensitivity, 81.8% vs 89.4%; specificity, 86.4% vs 94.3%; and accuracy, 85.2% vs 93.0%); however, the differences were not statistically significant (p = 0.625 for hepatic metastases and p = 0.0953 for skeletal metastases, McNemar test). WB DWI was statistically significantly inferior to conventional imaging for the detection of lymph node metastases (sensitivity, 74.0% vs 81.5%; specificity, 87.9% vs 90.1%; accuracy, 81.4% vs 86.0%; p = 0.0389). WB DWI was statistically significantly inferior to conventional imaging for the detection of pulmonary metastases (sensitivity, 33.3% vs 100.0%; specificity, 90.9% vs 100.0%; accuracy, 60.8% vs 100.0%; p = 0.045).

CONCLUSION

WB DWI can be used for screening hepatic and skeletal metastases, but its reliability as the sole imaging sequence for the detection of lymph nodal and pulmonary metastases is poor and, at present, it cannot replace conventional imaging modalities.

Adverse events during CT colonography for screening, diagnosis and preoperative staging of colorectal cancer: a Japanese national survey

OBJECTIVES

To retrospectively evaluate the frequencies and magnitudes of adverse events associated with computed tomographic colonography (CTC) for screening, diagnosis and preoperative staging of colorectal cancer.

METHODS

A Japanese national survey on CTC was administered by use of an online survey tool in the form of a questionnaire. The questions covered mortality, colorectal perforation, vasovagal reaction, total number of examinations, and examination procedures. The survey data was collated and raw frequencies were determined. Fisher's exact test was used to determine differences in event rates between groups.

RESULTS

At 431 institutions, 147,439 CTC examinations were performed. No deaths were reported. Colorectal perforations occurred in 0.014% (21/147,439): 0.003% (1/29,823) in screening, 0.014% (13/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging. The perforation risk was significantly lower in screening than in preoperative staging CTC procedures (p = 0.028). Eighty-one per cent of perforation cases (17/21) did not require emergency surgery. Vasovagal reaction occurred in 0.081% (120/147,439): 0.111% (33/29,823) in screening, 0.088% (80/91,007) in diagnosis and 0.028% (7/25,330) in preoperative staging.

CONCLUSIONS

The risk of colorectal perforation and vasovagal reaction in CTC is low. The frequency of colorectal perforation associated with CTC is least in the screening group and greatest in the preoperative-staging group.

KEY POINTS

• The colorectal perforation rate during preoperative-staging CTC was 0.028 %. • The perforation rates for screening and diagnosis were 0.003 % and 0.014 %, respectively. • The perforation risk is significantly lower in screening than in preoperative staging. • Eighty-one per cent of perforation cases did not require emergency surgery. • Use of an automatic colon insufflator can reduce the risk of bowel perforation.

Utility of the sentinel node concept for detection of lateral pelvic lymph node metastasis in lower rectal cancer

BACKGROUND

There are two lymphatic flows in lower rectal cancer; one along the inferior mesenteric artery and another towards the internal iliac artery. The benefit of dissection of lateral pelvic (LP) lymph nodes (LPLN) remains controversial. This study aimed to clarify the possibility of detecting the sentinel node (SN) of the LP region (LPSN) and examine metastasis, including micrometastasis, using a radio isotope (RI) method.

METHODS

In total, 62 patients with clinical (c)T1-T4 rectal cancer were enrolled in this study (11, 16 and 35 patients had tumor located in the upper, middle and lower rectal third, respectively). LPSNs were detected using a radio-isotope method in which 99 m technetium-tin colloid was endoscopically injected into the submucosa in patients with cT1, and into the muscularis propria in patients with cT2, cT3 and cT4. All patients underwent curative resection with lymphadenectomy. LPSN metastases were diagnosed by HE staining, immunohistochemical staining using AE1/AE3 as a primary antibody and by RT-PCR using CEA as a marker.

RESULTS

Of the lower rectal (c)T2-4 tumors, 38.4% had lateral pelvic lymphatic flow that was significantly greater than that of cT1 tumors in the upper and middle thirds of the rectum (p = 0.0074). HE and immunohistochemical staining did not detect LPSN metastases but RT-PCR detected micrometastasis of three SNs. The remaining half of LPSNs were immunohistochemically re-examined; in all three cases, isolated tumor cells were detected.

CONCLUSION

The SN concept may be useful for detecting lateral pelvic lymphatic flow and LPSN metastases, including micrometastasis in lower rectal cancer.

Diagnostic and prognostic value of preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography for colorectal cancer: comparison with conventional computed tomography

BACKGROUND/AIMS

18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has been used for preoperative staging of colorectal cancer (CRC). However, the diagnostic accuracy of FDG-PET/CT for detection of lymph node or distant metastasis and its prognostic role have not been well established. We therefore evaluated the diagnostic and prognostic value of FDG-PET/CT in comparison with conventional CT for CRC.

METHODS

We investigated 220 patients who underwent preoperative FDG-PET/CT and CT, followed by curative surgery for CRC. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET/CT and CT for detection of lymph node metastasis and distant metastasis were evaluated. In addition, we assessed the findings of FDG-PET/CT and CT according to outcomes, including cancer recurrence and cancer-related death, for evaluation of prognostic value.

RESULTS

For detection of lymph node metastasis, FDG-PET/CT had a sensitivity of 44%, a specificity of 84%, and an accuracy of 67%, compared with 59%, 65%, and 62%, respectively, for CT (P=0.029, P=0.000, and P=0.022). For distant metastasis, FDG-PET/CT had a sensitivity of 79%, a specificity of 94%, and an accuracy of 93%, compared with 79%, 87%, and 86%, respectively, for CT (P=1.000, P=0.004, and P=0.037). In addition, positive findings of lymph node metastasis and distant metastasis on FDG-PET/CT were associated significantly with cancer recurrence or cancer-related death (P=0.009, P=0.001, respectively).

CONCLUSIONS

Preoperative FDG-PET/CT had a higher specificity and accuracy compared to CT for detection of lymph node metastasis and distant metastasis of CRC. In addition, FDG-PET/CT could be a valuable prognostic tool for CRC.

Outcome and Salvage Surgery Following "Watch and Wait" for Rectal Cancer after Neoadjuvant Therapy: A Systematic Review

BACKGROUND

Currently there is no reliable test to predict pathological complete response following neoadjuvant chemoradiotherapy for rectal cancer. However, there is increasing interest in using clinical complete response as a surrogate marker, allowing a subset of patients with locally advanced rectal cancer to be allocated into a "watch and wait" pathway. Little is known about the oncological safety of the "watch and wait" approach or the rate of salvage surgery in cases of tumor regrowth. This information is critical for the implementation of this approach.

OBJECTIVE

The aim of this study is to assess the rate of salvage surgery and associated oncological outcomes for patients who develop a tumor regrowth with the "watch and wait" approach.

DATA SOURCES

Relevant studies were identified through PubMed, Embase, and Google Scholar search.

STUDY SELECTION

A systematic review was undertaken of studies assessing patients selected for the "watch and wait" approach according to PRISMA guidelines.

MAIN OUTCOME MEASURES

The associated tumor regrowth, salvage surgery, and disease-free and overall survival rates were assessed.

RESULTS

Five retrospective and 4 prospective observational studies were included into the analysis, with a total of 370 patients in the "watch and wait" group, of which 256 (69.2%) had persistent clinical complete response. Of those who had tumor regrowth, salvage surgery was possible in 83.8%. There was no difference in overall survival and disease-free survival between patients who received immediate surgery and the "watch and wait" group.

LIMITATIONS

The limitations of this study include its retrospective nature and small sample size. Furthermore, there is significant heterogeneity between study protocols, including the short median follow-up, given that tumor regrowth and distant metastasis may manifest at a later time point.

CONCLUSION

The majority of patients with tumor regrowth can be salvaged with definite surgery after "watch and wait." However, there is insufficient evidence to draw firm conclusions on the oncological safety of this approach; therefore, it is currently not the standard of care for locally advanced rectal cancer.

Evaluation of EphA2 and EphB4 as Targets for Image-Guided Colorectal Cancer Surgery

Targeted image-guided oncologic surgery (IGOS) relies on the recognition of cell surface-associated proteins, which should be abundantly present on tumor cells but preferably absent on cells in surrounding healthy tissue. The transmembrane receptor tyrosine kinase EphA2, a member of the A class of the Eph receptor family, has been reported to be highly overexpressed in several tumor types including breast, lung, brain, prostate, and colon cancer and is considered amongst the most promising cell membrane-associated tumor antigens by the NIH. Another member of the Eph receptor family belonging to the B class, EphB4, has also been found to be upregulated in multiple cancer types. In this study, EphA2 and EphB4 are evaluated as targets for IGOS of colorectal cancer by immunohistochemistry (IHC) using a tissue microarray (TMA) consisting of 168 pairs of tumor and normal tissue. The IHC sections were scored for staining intensity and percentage of cells stained. The results show a significantly enhanced staining intensity and more widespread distribution in tumor tissue compared with adjacent normal tissue for EphA2 as well as EphB4. Based on its more consistently higher score in colorectal tumor tissue compared to normal tissue, EphB4 appears to be a promising candidate for IGOS of colorectal cancer. In vitro experiments using antibodies on human colon cancer cells confirmed the possibility of EphB4 as target for imaging.

Fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography for the detection of proximal synchronous lesions in patients with obstructive colorectal cancer

BACKGROUND AND AIM

We aimed to investigate the ability of fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) to detect synchronous neoplasms, specifically obstructive colorectal cancer (CRC) and CRC in the proximal colon and to suggest a management strategy based on FDG PET/CT findings.

METHODS

From the CRC surgery database of our institution, 518 patients with obstructive CRC whose proximal colon could not be examined by colonoscopy and who underwent preoperative FDG PET/CT were eligible for this study. Of these, final analyses were performed in 345 patients who had reference standards for the proximal colon, which were a surgical colectomy specimen and/or postsurgical colonoscopy. The per-patient and per-lesion performances of FDG PET/CT for synchronous CRC diagnosis were determined.

RESULTS

Of 345 patients, 14 (4.1%) had 14 proximal synchronous CRCs. Thirty-four patients showed 39 areas of abnormal FDG uptake on PET/CT in the colon proximal to the obstructive CRC. PET/CT detected all of the 14 proximal synchronous CRCs. The per-patient PET/CT sensitivity, specificity, positive predictive value, and negative predictive value for proximal synchronous CRC were 100%, 93.9%, 41.2%, and 100%, respectively. Per-lesion values were 100%, 92.6%, 35.9%, and 100%, respectively. The per-lesion sensitivity and negative predictive value of PET/CT for advanced adenoma were 45.5% and 92.7%, respectively.

CONCLUSIONS

The FDG PET/CT shows a high sensitivity and negative predictive value for the detection of proximal synchronous CRC in patients with obstructive CRC, enabling negative findings in the proximal colon on PET/CT to definitively exclude proximal synchronous CRC. Preoperative PET/CT recommended to determine the proper surgical plan in patients with obstructive CRC.

Metabolic Tumor Volume and Total Lesion Glycolysis in PET/CT Correlate With the Pathological Findings of Colorectal Cancer and Allow Its Accurate Staging

INTRODUCTION

PET/CT plays an important role in cancer diagnosis. Recently, novel metabolic parameters in PET/CT such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) have been reported to be diagnostic and prognostic biomarkers of various cancers. We evaluated the diagnostic value of these metabolic parameters in colorectal cancer (CRC).

METHODS

The study included 138 patients who underwent surgical resection of CRCs between August 2012 and March 2014. The MTVs and TLGs of tumors were measured using various SUV thresholds. The diagnostic abilities of the metabolic parameters were analyzed using ROC curves and classification and regression trees.

RESULTS

The AUCs of the MTVs and TLGs for predicting T stage (0.881-0.892) were significantly higher than the AUC of the SUVmax (0.824). In the M stage, the AUCs of MTVs and TLGs (0.688-0.723) were significantly higher than that of the SUVmax (0.606). Recursive partitioning applying classification and regression trees demonstrated that the optimal cutoff values of the most important variables for discriminating T, N, and M stages are MTV2.5 = 9.35 and 63.33 mL, TLG50% = 328.1, and TLG50% = 94.81, respectively.

CONCLUSION

Metabolic tumor volumes and TLGs in PET/CT are reliable diagnostic biomarkers. Using these parameters, more accurate preoperative diagnoses for CRC can be made.

Application of PET/CT in gastrointestinal cancers

Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) is an imaging tool which reflects tumor metabolism. The integration of PET with computed tomography (CT) can provide precise anatomical information along with metabolic data. Here, we review the application and potential role of ¹⁸F-FDG PET/CT imaging in staging, evaluation of chemoradiation therapy, and detection of recurrence in gastrointestinal cancers.

Small colorectal cancer liver metastases: Clinical value of quantitative iodine-based material decomposition images of spectral CT

AIM: To retrospectively assess the diagnostic value of quantitative iodine-based material decomposition images of spectral CT in evaluating small liver metastases (<3 cm) from colorectal cancer.

METHODS: Nine hundred and fifteen consecutive patients with liver lesions were recruited, and 140 of them were confirmed to have metastatic liver cancer. All the patients underwent double-phase [arterial phase (AP) and portal venous phase (PVP)] spectral CT scans and the best single energy images were obtained at the workstation. Fifteen different sources of small metastatic liver lesions (<3 cm) were analyzed, and the diagnosis rate was compared between the best single energy images and traditional images. The final study group included 41 patients with hepatic metastases from colorectal cancer. Iodine concentrations and CT values of normal liver parenchyma and metastatic lesions were derived from iodine-based material-decomposition CT or conventional CT images. The differences in iodine concentration and CT values between the AP and PVP were recorded and the lesion-to-normal liver parenchyma differences were calculated. The paired t-test was employed to compare CT value and iodine concentrations between AP and PVP. Two readers qualitatively assessed lesion types on the basis of conventional CT characteristics. The two-sample t-test was performed to compare the iodine concentrations and CT values changes between AP and PVP in normal liver parenchyma and metastatic lesions (central and marginal).

RESULTS: Compared with traditional CT hybrid energy images, the detection rate of small metastases was much higher by spectral CT images (Wilcoxon sighed-rank test Z = 3.306, P = 0.001). In the AP, comparing the marginal with the central parts of the lesions, the CT values increased by 37.65% while the iodine value increased by 65.95%, and there was a significant difference between them (P < 0.001). Comparing normal liver tissues with the marginal parts of the lesions, the CT values increased by 22.99% while the iodine value increased by 17.96%, and there was no significant difference between them (P = 0.225). In the PVP, comparing the marginal with the central parts of the lesions, the CT values increased by 32.13% while the iodine value increased by 40.01%, and the difference was significant (P < 0.001). Comparing normal liver tissues with the marginal parts of the lesions, the CT values increased by 34.47% while the iodine value increased by 40.92%, and the difference was significant (P = 0.033).

CONCLUSION: Quantitative CT iodine value analysis may be able to improve the detection rate of small lesions, and it can display the enhancement features of colorectal cancer liver metastases. This technique may help to improve the diagnostic accuracy of small metastatic lesions.

Correlation of MRI-detected extramural vascular invasion with regional lymph node metastasis in rectal cancer

AIM

To evaluate the value of magnetic resonance imaging-detected extramural vascular invasion (MR-EMVI) in predicting regional lymph node metastasis (RLNM) in patients with rectal cancer.

METHODS

A total of 183 patients were included. A set of clinical and imaging factors including MR-EMVI were evaluated using univariate and multivariate analyses to determine the risk factors for RLNM.

RESULTS

Among the clinical and imaging factors evaluated, MR-EMVI, pathologic EMVI, nodal size, and diffusion-weighted imaging-detected positive nodes were independent predictors of RLNM.

CONCLUSIONS

MR-EMVI may be an independent predictor of RLNM in patients with rectal cancer.

Circulating cell-free nucleic acids as biomarkers in colorectal cancer screening and diagnosis

Screening methods for the most frequent diagnosed malignant tumor, colorectal cancer (CRC), have limitations. Circulating cell-free DNA (cfDNA) analysis came into focus as a potential screening test for CRC. Detection of epigenetic and genetic alterations of cfDNA as DNA methylation or DNA mutations and related ribonucleic acids may improve cancer detection based on unique, CRC-specific patterns. In this review the authors summarize the CRC-specific nucleic acid biomarkers measured in peripheral blood and their potential as screening markers. Detection of DNA mutation has inadequate sensitivity; however, methylated DNA can be established with higher sensitivity from CRC plasma samples. The ribonucleic acid based miRNA studies represented higher sensitivity for CRC as compared with mRNA studies. Recently, isolation of cfDNA has become automated, highly reproducible and a high throughput method. With automated possible diagnostic tools, a new approach may be available for CRC screening as liquid biopsy.

Colorectal Cancer Staging Using Three Clustering Methods Based on Preoperative Clinical Findings

Determination of the colorectal cancer stage is possible only after surgery based on pathology results. However, sometimes this may prove impossible. The aim of the present study was to determine colorectal cancer stage using three clustering methods based on preoperative clinical findings. All patients referred to the Colorectal Research Center of Shiraz University of Medical Sciences for colorectal cancer surgery during 2006 to 2014 were enrolled in the study. Accordingly, 117 cases participated. Three clustering algorithms were utilized including k-means, hierarchical and fuzzy c-means clustering methods. External validity measures such as sensitivity, specificity and accuracy were used for evaluation of the methods. The results revealed maximum accuracy and sensitivity values for the hierarchical and a maximum specificity value for the fuzzy c-means clustering methods. Furthermore, according to the internal validity measures for the present data set, the optimal number of clusters was two (silhouette coefficient) and the fuzzy c-means algorithm was more appropriate than the k-means clustering approach by increasing the number of clusters.

Colorectal Liver Metastasis, Primary Gallbladder Carcinoma and Myelofibrosis Present Simultaneously in a Liver Resection Specimen

Myelofibrosis and gallbladder carcinoma are both very rare diseases. This case report describes a patient with a history of myelofibrosis and colorectal carcinoma who was diagnosed with colorectal liver metastases. Surgery was performed to remove the metastases, and on site, the gallbladder was removed because of involvement in one of the liver lesions. After pathological examination, a primary gallbladder carcinoma and myelofibrosis were found in addition to the liver metastases. The combination of diseases was not likely to be interconnected but rather an unlucky course of events for the patient.

Influence of extent of lymph node dissection on survival for patients with pT2 colon cancer

PURPOSE

The optimal extent of lymph node dissection for early-stage colon cancer (CC) remains undefined. This study assessed the influence of the extent of lymph node dissection on overall survival (OS) in patients with pT2 CC.

METHODS

We retrospectively examined data from the multi-institutional registry system of the Japanese Society for Cancer of the Colon and Rectum and used a propensity score matching method to balance potential confounders of lymph node dissection. We extracted 463 matched pairs from 1433 patients who underwent major resections for pT2 CC between 1995 and 2004.

RESULTS

Lymph node metastasis was found in 301 (21.0%) of 1433 patients with pT2 CC. In this cohort, significant independent risk factors for lymph node metastasis were lymphatic invasion and venous invasion. Patients who underwent D3 or D2 lymph node dissection did not significantly differ in OS, either among the propensity score-matched cohort (estimated hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.536-1.346, P = 0.484) or in the cohort as a whole (HR 0.720, 95% CI 0.492-1.052, P = 0.089).

CONCLUSIONS

For patients with pT2 CC, D3 lymph node dissection did not add to OS. D2 lymph node dissection may be adequate for pT2 CC.

Anal malignant proliferative trichilemmoma: report of a rare case with review of literature

Trichilemmoma is a rare type of benign cutaneous neoplasm, which derives from outer sheath of hair follicle. It barely develops malignant progression and has rarely been reported in anal cancer. In this article, we report a case of a 73-year-old woman who presented to the outer-patient department with complaints of a ruptured and longstanding anal phyma. All the appearances were atypical. Blood routine examination showed that neutrophilic granulocyte percentage was elevated and suggest it was a simple inflammation response. No evidence of malignancy was detected upon the laboratory examinations. Then we performed an abscess incision drainage for the patient. A few days later, the biopsy pathological report suggested the specimen is a malignant proliferative trichilemmoma. We decided to perform a wide local excision instead of an extended radical operation in order to preserve anus. After the surgery, we chose not to give chemoradio-treatment for fear of side effects and complications. Careful follow-up indicates that peri-anal malignant proliferative trichilemmoma may have a good prognosis and our treatment is a good choice for the patients with this tumor. Because of the low occurrence rate of anal cancer, especially malignant trichilemmoma, any clinical manifestation and experience are valuable. On one hand, our case may help to take the consideration of the diagnosis of malignant trichilemmoma in case of longtime-suffered peri-anal mass, on the other hand it propose a different treatment method from other anal cancers for clinical doctors.