Preoperative evaluation of synchronous colorectal cancer using MR colonography

A novel risk prediction nomogram for early death in patients with resected synchronous multiple primary colorectal cancer based on the SEER database

BACKGROUND

Synchronous multiple primary colorectal cancer (SMPCC) involves the simultaneous occurrence of 2 or more independent primary malignant tumors in the colon or rectum. Although SMPCC is rare, it results in a higher incidence of postoperative complications and mortality compared to patients with single primary colorectal cancer (SPCRC).

METHODS

The clinical factors and survival outcomes of SMPCC patients registered on the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2017 were extracted. The patients were divided into the training and validation cohorts using a ratio of 7:3. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors for early death. The performance of the nomogram was evaluated using the concordance index (C-index), calibration curves, and the area under the curve (AUC) of a receiver operating characteristics curve (ROC). A decision curve analysis (DCA) was used to evaluate the clinical utility of the nomogram and standard TNM system.

RESULTS

A total of 4386 SMPCC patients were enrolled in the study and randomly assigned to the training (n = 3070) and validation (n = 1316) cohorts. The multivariate logistic analysis identified age, chemotherapy, radiotherapy, T stage, N stage, and M stage as independent risk factors for all-cause and cancer-specific early death. The marital status was associated with all-cause early death, and the tumor grade was associated with cancer-specific early death. In the training cohort, the nomogram achieved a C-index of 0.808 (95% CI, 0.784-0.832) and 0.843 (95% CI, 0.816-0.870) for all-cause and cancer-specific early death, respectively. Following validation, the C-index was 0.797 (95% CI, 0.758-0.837) for all-cause early death and 0.832 (95% CI, 0.789-0.875) for cancer-specific early death. The ROC and calibration curves indicated that the model had good stability and reliability. The DCA showed that the nomogram had a better clinical net value than the TNM staging system.

CONCLUSION

Our nomogram can provide a simple and accurate tool for clinicians to predict the risk of early death in SMPCC patients undergoing surgery and could be used to optimize the treatment according to the patient's needs.

Detection methods of synchronous colorectal lesions in proximal colon for patients with obstructive colorectal cancer: a literature review

INTRODUCTION

Colorectal cancer holds a high morbidity and mortality rate. As a common method for colorectal cancer detection, colonoscopy has difficulty in passing through the malignant stenosis in patients with obstructive colorectal cancer, which results in incomplete detection and missed diagnosis. The missed synchronous lesions increase the risk of metachronous cancer. Therefore, detecting proximal synchronous lesions in patients with obstructive colorectal cancer should be appreciated before operation.

AREA COVERED

This review evaluates related literature, aiming at providing clinicians with more ideas and attention for detecting proximal synchronous lesions in patients with obstructive colorectal cancer.

EXPERT OPINION

In patients with obstructive colorectal cancer, missed diagnosis of lesions proximal to the obstruction may lead to metachronous colorectal cancer. Except for preoperative colonoscopy which is difficult to pass through malignant stenosis, other methods that can evaluate proximal colon segment are critical. This article introduced several preoperative, intraoperative and postoperative measures for synchronous lesions detection. The choice of methods should base on patients' conditions, aiming at a high diagnostic yield and low risk. Early detection and resection of synchronous lesions in the proximal section of malignant obstruction are expected to minimize the risk of metachronous colorectal cancer and even effect follow-up treatment strategy, which deserves the attention of clinicians.

Laparoscopic subtotal colectomy for synchronous triple colorectal cancer: A case report

Synchronous colorectal cancers refer to the simultaneous occurrence of multiple colorectal tumors in a single patient, excluding any metastases from other organs. At present, radical surgery is considered the standard curative treatment; however, individualized surgical strategies depend on tumor location, the depth of invasion and the general health of the patient. In the present study, the case of a 52-year-old man who presented with a 2-month history of abdominal pain that was accompanied by intermittent hematochezia and weight loss is reported. The patient had no family history of cancer. Computed tomography (CT) of the abdomen revealed intestinal wall thickness in the transverse colon and volvulus in the hepatic flexure of colon. Colonoscopy identified 3 tumors: The first tumor was located in the descending colon with lumen stenosis ~60 cm from the anal verge, the second tumor was located in the hepatic flexure of the colon, and the third tumor was located in the sigmoid colon, 23 cm from the anal verge. Subsequently, laparoscopic subtotal colectomy was performed and all three tumors were removed, and the diagnosis was confirmed by histopathological examination. The patient did not undergo chemotherapy following surgery, due to personal reasons. Subsequent to 19 months of follow-up examinations using CT and colonoscopy every 6 months, the patient exhibited no signs of recurrence. Thus, laparoscopic subtotal colectomy represents an effective surgical approach for the treatment of synchronous colorectal cancer following imaging and endoscopic diagnosis.

Perioperative Colonic Evaluation in Patients with Rectal Cancer; MR Colonography Versus Standard Care

RATIONALE AND OBJECTIVES

Preoperative colonic evaluation is often inadequate because of cancer stenosis making a full conventional colonoscopy (CC) impossible. In several studies, cancer stenosis has been shown in up to 16%-34% of patients with colorectal cancer. The purpose of this study was to prospectively evaluate the completion rate of preoperative colonic evaluation and the quality of perioperative colonic evaluation using magnetic resonance colonography (MRC) in patients with rectal cancer.

MATERIALS AND METHODS

Patients diagnosed with rectal cancer were randomized to either group A: standard preoperative diagnostic work-up or group B: preoperative MR diagnostic work-up (standard preoperative diagnostic work-up + MRC). A complete and adequate perioperative clean-colon evaluation (PCE) was defined as either a complete preoperative colonic evaluation or a complete colonic evaluation within 3 months postoperatively.

RESULTS

Twenty-eight patients were randomized to group A and 28 to group B. Complete preoperative colonic evaluation with CC was achieved in 39% patients in group A and 93% for group B (Fisher's exact test, P < .001). PCE with CC was achieved in 64% and 93% in groups A and B, respectively (Fisher's exact test, P = .02). In group A, one synchronous cancer was found by CC. However, the location was misjudged as a sigmoid cancer. In group B, two synchronous cancers were found in the same patient who had an insufficient preoperative CC due to an obstructing rectal cancer.

CONCLUSIONS

MRC is a valuable tool and is recommended as part of the standard preoperative evaluation for patients with rectal cancer.

[Newer techniques in diagnostic imaging of colorectal carcinoma]

A wide spectrum of nowadays availible radiological and imaging methods in the diagnostic evaluation of patients with colorectal cancer enabled not only the improvement of primary colorectal malignancy detection, precise staging, regional involvement and metastatic spread assessment, but also the posttherapeutical estimation and follow-up. Having in mind that the exact diagnostic assessment of colorectal carcinoma by use of different imaging modalities still raises a lots of contradictories, in this report we have tried to present the possibilities of newer imaging techniques in the diagnostic evaluation of the patients with colorectal cancer.