| Carcinoid tumor is a fairly rare, well-differentiated endocrine neoplasm that may occur anywhere throughout the gastrointestinal tract and produce a variety of hormones and protein products that are associated with specific clinical symptoms. Biologic behavior of gastrointestinal carcinoids varies by site, but all gastrointestinal carcinoids are considered to have malignant potential.The rectum is one of the most common locations, comprising 27.4% of gastrointestinal carcinoids and second to the small intestine (41.8%). Tumour size correlates well with the potential to metastasise. Theoretically, rectal carcinoid tumors less than 10 mm in diameter and a depth of invasion limited to the submucosal layer can be curatively treated by endoscopic resection. Cap polypectomy is used for small tumors in China, but the procedure seldom had been reported. No ESD or EMR procedure was used for small rectal carcinoid in six hospitals. So this retrospective study assessed conventional polypectomy, cap polypectomy and rectal carcinoid, simple biopsy, conventional polypectomy, modified polypectomy with cap, EMR-C, by the large scale of cases from the six high-volume hopitals in China, and then discusssed the clinical feasibility of cap polypectomy for treatment of small rectal carcinoid.A total of 90 consecutive patients were enrolled in this case-control study. They were definitely diagnosed with rectal carcinoid between January 2001 and October 2009 at 6 high-volume hospitals in China. Forty-seven patients were detected and treated by conventional polypectomy(group A),16 by cap polypectomy (no preinjection) (group B) and 27(29 tumors) by cap polypectomy with preinjection (group C).Between January 2001 and October 2009,90 consecutive patients with 92 rectal carcinoid tumors, which were diagnosed by histopathologic and/or immunohistologic examination at 6 high-volume hospitals in China, were enrolled.The following 6 hospitals participated in the present study:Nanfang Hospital, Guangzhou; Guangdong Province People’s Hospital, Guangzhou; Shanxi Province People’s Hospital, Taiyuan; The Second Affiliated Hospital of Shanxi Medical University, Taiyuan; Meizhou People’s Hospital, Meizhou; The Affiliated Hosptial of Guangdong Medical College, Zhanjiang, China.Inclusion criteria for this multicentre retrospective study were 1) the confirmation of the final diagnosis in all patients by experienced pathologists,2) a tumor less than 10 mm in greatest dimension without muscular layer invasion and metastases to lymph nodes or distal organs.In this study, conventional polypectomy meant simple sanre resection without preinjection or aspiration.The cap polypectomy refered to cap-assisted snare resection without submucosal injection. The procedure was as follows. A transparent cap was attached to the tip of a single-channel endoscope. After the scope had passed the anus, the tumor was found and suctioned into the cap The snare was then passed through the sheath and tightened around the outer circumference of the mucosector. The snare was pushed off and closed. Finally, the tumor and the surrounding mucosa were resected using high-frequency current,and the specimen was aspirated into the cap.EMR-C was performed with the method described by T Nagai et al After the scope had passed the anus, the injection needle was inserted adjacent to the base of the lesion and solution then was injected into the submucosa. The subsequent operations were the same as cap polypectomy.The features of the tumor were determined using endoscopic and histopathologic reports and sections from the six hospitals. Complete resection was deemed when the tumor was removed completely endoscpically with tumor-free lateral and basal margins. They were considered incomplete when tumors were excised with the lateral and basal margins positive for tumor invasion,or when the margins can not be definitely assessed due to artificial burn effects or other causes. After histopathologic and/or immunohistologic examination, additional surgical intervention such as transanal excision, transanal endoscopic microsurgery or radical correction of rectal carcinoma had been performed in the case of tumors with incomplete resection.Early bleeding was defined as either bleeding occurring immediately after polypectomy during the endoscopic procedure or as hematochezia in the first 24 h. Delayed bleeding was defined as bleeding occurring between 24 hours and 30 days after polypectomy presenting as hematochezia. Complications including perforation were diagnosed by endoscopical reports and medical records. Economic health evaluationThe quality of life after procedure were ananlysed by EQ-5D scale.To determine whether there were the recurrence and/or metastsis, the evaluation methods for the patients included 1)endoscopic examinations and, in some cases, images such as abdominal CT, ultrasound sonography, chest X-ray and 2) telephone survey.Continuous variables suitable for analysis by analysis of variance(ANOVA) were summarized by mean (standard deviation). Nominal variables summarized by frequences were analyzed using chi-squared tests. A P-value of less than 0.05 was considered statistically significant. Calculations were made by using the Statistical Package for the Social Sciences (SPSS) program (SPSS 13.0).Ninety patients with rectal carcinoid tumors were included in the study. Eighteen patients were excluded because of insufficient clinical information. The mean patient age at diagnosis was 50.17±12.97 years (range,20-74 years; median,51.00 years). Fifty-eight patients (64.44%) were men, and 32 (35.56%) were women. Seventeen patients principally presented with abdominal or rectal pain,16 with rectal bleeding, 12 with a change in bowel habits,9 with distension. Some patients had multiple symptoms. Alternatively,15 patients were asymptomatic and found on screening colonoscopy. Sixteen patients had a history of colorectal polyps, in which ten were adenoma and the remaining were dysplasia polyps. Fourteen had a history of cystic disease with eighteen located in kidney,5 in liver and 1 in thyroid gland. Two had a history of ulcerative colitis.The mean diameter of the tumors, as assessed on endoscopy or pathologic reports, was 6.30±1.70mm (range,1-9 mm; median,6 mm). With respect to macroscopic appearance,36 were polypoid,56 were nodular. Also, all patients had 1 tumour except 2, who had 2 tumours each. There were 62 rectal tumors (68.89%) located in the Rb,28 (31.11%) located in the Ra and 2 (2.22%) located in the Rs. Pre-procedure EUS were performed in 80 patients. Based on EUS or pathologic reports, all the carcinoid tumors were confined to the mucosal layer or the submucosal layer and had relatively classic histologic architecture of trabecular, insular, ribbon-like cell clusters with minimal cellular pleomorphism and sparse mitoses or immunohistologic features. No lymphovascular invasion was observed in any of the tumors.When three groups were divided according to the method of treatment, there were no significant differences in age, gender, location, tumor diameter and complication. Of 92 lesions, there were 47 polypectomy resections (51.09%),16 cap polypectomy resections(17.39%) and 29(27 patients) EMR-C (31.52%). The total 4 of early bleeding were successfully managed with hemoclips and no blood transfusions or surgery was necessary.Group A included 36 lesions with "positive at the edge" and 11 with "negative at the edge", with the rate of complete resection being 23.40%. Fifteen lesions in Group B were "negative at the edge" and the complete resection rate(93.75%) was significantly higher when compared with that in Group A, but not significantly higher than Group C (93.10%)(p=1.000).Twenty-four patients were unavailable to follow-up assessment for clinical outcomes of recurrence, metastatic disease and survival. The mean follow-up period of the remaining 68 patients was 8.93 months (median,6.00 months; range,1-44 months). Neither local recurrence nor metastases to lymph nodes or distal organs was found in any of the remaining 68 patients. After 1-2 examinations, most patients were no longer recalled by the sutdy hospitals for re-examination. A few patients had been recalled four times at most. However, we have been following up the patients as much as possible by telephones.68 patients are still alive without symptoms related. In conclusion, our data from six hospitals indicate that, for the time being, cap polypectomy proved to be a a safe,effective and relatively simple method for treatment of small rectal carcinoids. Depending on the feasibility of the procedure and the clinicopathological characteristics of the small rectal carcinoid tumors, cap polypectomy has been suggested for treatment of small rectal carcinoids. The follow-up periods were short, in the future, we shall continue to trace these patients and include more cases. |
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