[Skip to Content]
Sign In
Individual Sign In
Create an Account
Institutional Sign In
OpenAthens Shibboleth
[Skip to Content Landing]
Correspondence
February 16, 2009

Local Therapy of Rectal Carcinoids: A Matter of Debate

Arch Surg. 2009;144(2):193-197. doi:10.1001/archsurg.2008.542

Local therapy of small rectal carcinoids (<2 cm) is a matter of debate. The excellent article by Kwaan et al,1 recently published in the Archives, highlights this important issue.

Rectal carcinoids smaller than 2 cm have been and are being managed differently in different parts of the world.1-9 Owing to a lack of controlled prospective studies, our current management of rectal carcinoids is flawed by a low level of evidence. The best we can do for the time being is to base guidelines and recommendations on all the available (retrospective) data from case series, large hospital registries, and national tumor registries. Of course, the individual patient's situation has to be considered too. A 20-mm, well-differentiated rectal carcinoid may well be managed differently in a fit, otherwise healthy 32-year-old woman than in an 85-year-old multimorbid patient.

With respect to carcinoid tumor biology, even very experienced clinicians from different countries appear to favor different concepts.2,4-6 Nevertheless, a great body of evidence shows that rectal carcinoids 1 cm or smaller metastasize in 3% to 10% of patients,1-11 whereas rectal carcinoids 10.1 to 20 mm in diameter spread to regional lymph nodes in 17% to 42% of patients.1-12 The risk of lymph node metastases of rectal carcinoids is not lower than the metastatic risk of rectal adenocarcinoma.3,6-8,12 The prognoses in patients with metastatic rectal carcinoid disease are not better than those in patients with metastatic rectal adenocarcinoma.5-9,12 To stage localized rectal adenocarcinoma, physicians now advise patients to undergo pelvic nuclear magnetic resonance imaging and endoscopic ultrasonography (in nonstenotic cancer). In contrast to the standard of care in rectal adenocarcinoma, we use endoscopic ultrasonography and/or pelvic nuclear magnetic resonance imaging in surprisingly few patients with rectal carcinoids.1 Considering that lymph nodes are involved in as many as 17% to 42% of 1- to 2-cm rectal carcinoids,1,3,6-9,12 we must determine the stage of the carcinoid before deciding on treatment. Staging of localized rectal carcinoids should comprise endoscopic ultrasonography, pelvic nuclear magnetic resonance imaging (or pelvic computed tomography), and somatostatin-receptor scintigraphy.

Long-term Survival Data

Japanese tumor registries3,6 do report more favorable 5-year survival rates in patients with rectal carcinoids than registries from other parts of the world. In Japanese hospitals, rectal carcinoids larger than 10 mm are treated surgically, similar to adenocarcinomas.7 Lymph node dissection is considered standard of care for 10.1- to 20.0-mm rectal carcinoids. Small rectal carcinoids (≤1 cm) that exhibit lymphovascular invasion or infiltration of the muscularis propria or that have spread to locoregional lymph nodes are managed similarly.13 When evaluating different treatment strategies of well-differentiated (neuro)endocrine tumors, we have learned from such diseases as well-differentiated thyroid cancer that 10-, 15-, or even 20-year survival is a much more reliable and valid parameter than 5-year survival. Owing to the low aggressiveness of well-differentiated (neuro)endocrine tumors, even patients who will finally succumb to metastatic rectal carcinoid disease generally survive for the first 5 years.1,9 Kwaan et al1 point out that metastatic disease may not become clinically apparent for as long as 5 to 13 years after local therapy of a small (<10 mm), well-differentiated rectal carcinoid.

Thus, the 10-year survival rates of patients with rectal neuroendocrine tumors from not only the Surveillance, Epidemiology, and End Results registry of the National Cancer Institute but also the Japanese registries (Multi-Institutional Registry of Large Bowel Cancer and the Niigata database) should be published.3,6,11 Similarly, 10-year survival rates from European databases have to be reported. Thanks to Dr Irvin Modlin’s4,5,11 commitment, 10-year survival data of patients with carcinoid disease in the United States will be available this year.

Rectal Carcinoids 1 cm or Smaller

A broad consensus exists for the management of small (≤10 mm), well-differentiated rectal carcinoids that do not show lymphovascular invasion or infiltration of the muscularis propria or lymph node metastases. Such small, well-differentiated neuroendocrine tumors of the rectum can be managed by local excision performed either endoscopically or surgically.2,5,6,13-16 Before embarking on resection, the exact tumor size and in particular the depth of invasion has to be determined by endoscopic ultrasonography. Because more than 75% of rectal carcinoids infiltrate the submucosa, Sakata et al17 modified the ligation device (for esophageal varices) for use in the rectum, whereas Onozato et al18 optimized endoscopic submucosal dissection. By applying the latter techniques, both groups achieved complete resection of small rectal carcinoids in all of their patients.17,18 By omitting endoscopic ultrasonography in tumor staging and using conventional endoscopic techniques, indeterminate or even disease-positive resection margins (on histological examination) were observed in as many as 67% to 83% of patients.1,10 Obviously, endoscopic ultrasonography should precede local resection of rectal carcinoids. A thorough histologic workup of resected rectal carcinoids is important. As Shinohara et al13 and Kwaan et al1 point out, well-differentiated rectal carcinoids exhibiting lymphovascular invasion or infiltration of the muscularis propria can spread to regional lymph nodes despite the primary tumor measuring less than 10 mm in diameter. Lymph node dissection has to be considered in patients with node-positive carcinoid disease.6,12 Local resection of any rectal carcinoid smaller than 2 cm, as stated by Ramage et al,2 may not be adequate in a young, otherwise healthy patient with node-positive disease. Prospective studies, including innovative (neo)adjuvant treatment strategies, should be envisaged for node-positive rectal carcinoids.19

Correspondence: Dr Scherübl, Klinik für Innere Medizin–Gastroenterologie und Gastrointestinale Onkologie Vivantes-Klinikum Am Urban, Dieffenbachstrasse 1, Berlin 10967, Germany (hans.scheruebl@vivantes.de).

Financial Disclosure: None reported.

References
1.
Kwaan  MRGoldberg  JBleday  R Rectal carcinoid tumors: review of results after endoscopic and surgical therapy.  Arch Surg 2008;143 (5) 471- 475PubMedGoogle ScholarCrossref
2.
Ramage  JKGoretzki  PManfredi  R  et al.  Consensus guidelines for the management of patients with digestive neuroendocrine tumours: well-differentiated colon and rectum tumour/carcinoma.  Neuroendocrinology 2008;87 (1) 31- 39PubMedGoogle ScholarCrossref
3.
Soga  J Early-stage carcinoids of the gastrointestinal tract: an analysis of 1914 reported cases.  Cancer 2005;103 (8) 1587- 1595PubMedGoogle ScholarCrossref
4.
Modlin  IMÖberg  KChung  D  et al.  Gastroenteropancreatic neuroendocrine tumours.  Lancet Oncol 2008;9 (1) 61- 72PubMedGoogle ScholarCrossref
5.
Modlin  IDrozdov  IGustafsson  B  et al.  Rectal neuroendocrine tumors: diagnosis and treatment. Modlin  IOberg  K A Century of Advances in Neuroendocrine Tumor Biology and Treatment. Hanover, Germany Felsenstein CCCP2007;124- 133Google Scholar
6.
Konishi  TWatanabe  TKishimoto  JKotake  KMuto  TNagawa  HJapanese Society for Cancer of the Colon and Rectum, Prognosis and risk factors of metastasis in colorectal carcinoids: results of a nationwide registry over 15 years.  Gut 2007;56 (6) 863- 868PubMedGoogle ScholarCrossref
7.
Konishi  TWatanabe  TKishimoto  J  et al.  Prognosis and metastatic potential of colorectal carcinoids compared with adenocarcinomas: results of a nationwide registry over 15 years [ASCO Abstract 4054].  J Clin Oncol 2008;26 (15S) ((suppl)) Google Scholar
8.
Konishi  TWatanabe  TMuto  TKotake  KNagawa  H Risk factors for lymph node and distant metastasis in colorectal carcinoids: an analysis of nationwide registry in Japan over 15 years [ ASCO Abstract 3620].  J Clin Oncol 2006;24 (18S) ((suppl)) Google Scholar
9.
Tsukamoto  SFujita  SYamaguchi  T  et al.  Clinicopathological characteristics and prognosis of rectal carcinoids.  Int J Colorectal Dis (11) PubMedGoogle Scholar
10.
Kaminski  MPolkowski  MRegula  J  et al.  Prevalence and endoscopic features of rectal neuroendocrine tumors (carcinoids) among 50148 participants of the Polish colorectal-cancer screening programme.  Gut 2007;56 ((suppl III)) A310Google ScholarCrossref
11.
Modlin  IMLye  KKidd  M A 5-decade analysis of 13,715 carcinoid tumors.  Cancer 2003;97 (4) 934- 959PubMedGoogle ScholarCrossref
12.
Sauven  PRidge  JQuan  SSigurdson  ER Anorectal carcinoid tumors: is aggressive surgery warranted?  Ann Surg 1990;211 (1) 67- 71PubMedGoogle ScholarCrossref
13.
Shinohara  THotta  TOyama  T Rectal carcinoid tumor, 6 mm in diameter, with lymph node metastases [published online ahead of print February 27, 2008].  Endoscopy 2008;40 ((suppl 2)) E40- E41PubMedGoogle ScholarCrossref
14.
Shim  KNYang  SMyung  S  et al.  Atypical endoscopic features of rectal carcinoids.  Endoscopy 2004;36 (4) 313- 316PubMedGoogle ScholarCrossref
15.
Scherübl  H Options for gastroenteropancreatic neuroendocrine tumours.  Lancet Oncol 2008;9 (3) 203PubMedGoogle ScholarCrossref
16.
Matsui  KIwase  TKitagawa  M Small, polypoid-appearing carcinoid tumors of the rectum: clinicopathologic study of 16 cases and effectiveness of endoscopic treatment.  Am J Gastroenterol 1993;88 (11) 1949- 1953PubMedGoogle Scholar
17.
Sakata  HIwakiri  ROotani  A  et al.  A pilot randomised controlled study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors.  World J Gastroenterol 2006;12 (25) 4026- 4028PubMedGoogle Scholar
18.
Onozato  YKakizaki  SIshihara  H  et al.  Endoscopic submucosal dissection for rectal tumors [published online ahead of print March 13, 2007].  Endoscopy 2007;39 (5) 423- 427PubMedGoogle ScholarCrossref
19.
Höpfner  MSchuppan  DScherübl  H Treatment of gastrointestinal neuroendocrine tumors with inhibitors of growth factor receptors and their signaling pathways: recent advances and future perspectives.  World J Gastroenterol 2008;14 (16) 2461- 2473PubMedGoogle ScholarCrossref
×