Preoperative evaluation of colorectal cancer

Obstructive colon cancers at endoscopy are associated with advanced tumor stage and poor patient outcome. A retrospective study on 398 patients

BACKGROUND

The detection of obstructive colorectal cancer (CRC) masses during endoscopic examination hindering the passage of endoscope and precluding complete examination is not uncommon. The significance and implications of this finding on patients' prognosis and outcomes were not fully investigated and will be addressed in this study.

METHODS

In this retrospective cohort study, we reviewed endoscopy, surgery, pathology and oncology reports of patients diagnosed with CRC over a 10-year period (2007-2016). We compared surgical stages, histologic grades and overall survival between patients with subclinical obstructive tumors at endoscopy to those with nonobstructive tumors. We performed multivariate analysis to identify independent risk factors associated with advanced CRC stage at diagnosis.

RESULTS

A total of 144 patients had obstructive colonic tumors while 254 had nonobstructive tumors and constituted the control group. Obstructive CRC group was significantly associated with advanced tumor stage at diagnosis (69 vs. 42%, OR = 3.018, 95% CI, 1.951-4.670; P < 0.01) and had prominently higher rates of moderate to poorly differentiated tumors (64.5 vs. 38.4%; P < 0.001) when compared to non-obstructive controls. Patients with obstructive tumors were significantly associated with decreased five years overall survival (53.4 vs. 67.3% vs.; P < 0.01). Increased overall mortality was observed in survival curves of patients with obstructive tumors along all follow-up periods.

CONCLUSION

Even in the absence of clinical sequela, obstructive CRC at endoscopic level may be associated with higher stage at diagnosis and reduced overall survival. Further prospective studies are warranted to confirm these findings and address their implication on patients' management.

CT colonography for evaluation of colorectal cancer

AIM: To evaluate the value of computed tomography colonography (CTC) in the evaluation of colorectal cancer by comparing its performance with colonoscopy.

METHODS: Forty-one patients who were diagnosed with colorectal cancer by colonoscopic biopsy and underwent CTC and colonoscopy were included in the study. CTC and colonoscopy were compared for their performance in the evaluation of colorectal cancer.

RESULTS: The locations of tumors revealed by CTC and colonoscopy were consistent. However, colonoscopy had its limitation in determining the size of the tumor, and tumor size was measured by colonoscopy in 54% (23/43) of cases , in contrast to 95% (41/43) of cases by CTC. There was no statistical significance in the pathological type revealed by the two techniques (P = 0.621). Colonoscopy failed to evaluate the condition outside the intestinal tract and the proximal colon in cases with colon obstruction, resulting in incomplete examination. The grade of subjective tolerability was significantly lower for colonoscopy than for CTC (P = 0.000).

CONCLUSION: CTC can evaluate colorectal cancer effectively, although it cannot replace colonoscopy entirely. CTC can be chosen as a preferred means for patients who cannot tolerate colonoscopy as well as patients who have incomplete colonoscopy examination.

Computed tomographic colonography in preoperative evaluation of colorectal tumors: a prospective study

Background

This study aimed to assess the usefulness of computed tomographic colonography (CTC) in preoperative evaluation of colorectal tumors and the entire bowel including endoscopically inaccessible regions.

Methods

Colonoscopy and CTC were performed for 49 patients. The tumor and the entire colon were assessed, and the results were compared with colonoscopy. The extraluminal findings of CTC were compared with contrast-enhanced computed tomography (CT) of the abdomen and the pelvis in 33 patients. All these patients had undergone surgery. A comparison of results for tumor node metastasis classification between CTC, CT, and histopathology was performed.

Results

Exploration of the entire colon was possible for 89.8% of the patients using CTC and 49.0% of the patients using colonoscopy. Bowel cleansing was assessed as worse with CTC. In the evaluation of tumor location and morphologic type, CTC was congruent with colonoscopy. Colonoscopy enabled approximate tumor size and volume to be evaluated for only 59.2% (29/49) and 30.6% (15/49) of patients, respectively, whereas CTC enabled evaluation of all 48 (100.0%) visualized tumors. Wall thickening, outer contour, and suspected infiltration of surrounding tissues and organs are impossible to determine with colonoscopy but can be determined with CTC. Using CTC, two additional tumors were found proximate to occlusive masses in endoscopically inaccessible regions.

Conclusion

Computed tomographic colonography is a useful method for diagnosing colorectal tumors. It allows the clinician to diagnose tumor, determine local tumor progression, and detect synchronous lesions in the large bowel including endoscopically inaccessible regions.

Palliation of colorectal cancer

Patients with advanced incurable colorectal cancer (CRC) face a grim prognosis. The goal of palliative intervention is directed at alleviating disease-related symptoms and improving quality of life. The provision of optimal palliative care for these patients is a compound and demanding process. This dilemma becomes more challenging when patients with advanced metastatic colorectal disease present with an incurable and asymptomatic primary lesion. Treatment options are numerous and include a variety of surgical and nonsurgical interventions. Most data regarding the role of surgery in palliation of CRC are from retrospective, nonrandomized case series. Surgical resection may provide good palliation of symptoms and prevent future tumor-related complications. Metal stents are also able to provide good palliative relief of obstruction and should be used when appropriate. The best palliative care will often require a multidisciplinary approach that involves input from surgical and nonsurgical teams, where treatment plans will be made in accordance with the wishes of the patient and family with a goal of decreasing morbidity and a focus on quality of life.

Surgical approaches to cancer in patients who have inflammatory bowel disease

IBD clearly increases the risk for GI malignancies, especially CRC. The absolute number of patients that develops such malignancies is low compared with the overall cancer rate; however, younger age of onset, higher relative risk, unique clinical presentations, and problems with early diagnosis make this a serious complication of IBD. With the exception of patients with comorbid complications, such as primary sclerosing cholangitis, the prognosis is no worse for CRCs that arise as the result of IBD compared with those that arise sporadically. The prognosis remains poor for small bowel adenocarcinomas in patients who have CD, primarily because of their advanced stage at detection. Diligent surveillance is essential for early detection and treatment of IBD-related CRCs in patients with unresected colons, long-standing or extensive disease, and in those who have early-onset CD, although pundits still question whether it significantly affects prognosis and survival. Better surveillance techniques for small bowel dysplasia or malignancy in patients who have CD is needed, especially given the poor prognosis of these patients when advanced cancers are detected. Depending on the presentation and disease diagnosis, patients have several surgical treatment options and can expect good outcomes for all. When the appropriate surgical technique is used in patients who have colon or rectal cancer, along with adjuvant chemotherapy when appropriate, prognosis and function is good; however, the experience of the surgeon can affect the prognosis for IBD-related GI cancers. Surgical therapy is based not only on general oncologic principles, but also on the surgery that is appropriate for the IBD diagnosis. Resection of the mesentery and lymphadenectomy should be performed according to oncologic principles. Postoperative survival for IBD-related CRC is good, and diligent surveillance and follow-up are critical to the patient's overall prognosis.