Endoscopically identified well-differentiated rectal carcinoid tumors: impact of tumor size on the natural history and outcomes.
BACKGROUND
There is a paucity of data pertaining to the natural history and outcomes of patients with well-differentiated rectal carcinoids.


OBJECTIVE
To correlate endoscopic size with the natural history and outcome.


METHODS
Retrospective study.


METHODS
Single tertiary referral center.


METHODS
Eighty-seven patients with endoscopically identified well-differentiated rectal carcinoid tumors.


METHODS
Colonoscopy.


METHODS
Prevalence of metastasis at diagnosis, disease progression, and survival.


RESULTS
Metastasis was present at diagnosis in 3%, 66%, and 73% of tumors measuring ≤10 mm, 11 to 19 mm, and ≥20 mm, respectively. Metastasis was predicted with 100% sensitivity and 87% specificity using an endoscopic lesion size ≥9 mm. In patients without identified metastasis, 64% were identified during screening colonoscopy. Within this select cohort, subsequent metastasis was discovered only at distant extra pelvic sites, in 1.6%, 50%, and 100% of patients with tumors initially measuring ≤10 mm, 11 to 19 mm, and ≥20 mm, respectively. The carcinoid related 5- and 10-year survival rates for locally confined disease were 96%. The corresponding survival rates for local and advanced metastatic disease were 60% and 35%, respectively.


CONCLUSIONS
Subjective estimation of tumor size, mitotic index or Ki-67 labeling index not reported, and lack of formal and standardized baseline staging algorithm and surveillance program.


CONCLUSIONS
The clinical behavior of 11- to 19-mm tumors appears to mimic that of larger (>20 mm) lesions with respect to the presence of metastasis at diagnosis and disease progression. Therefore, if local therapy is contemplated, we propose to make a distinction between ≤10-mm and 11- to 19-mm tumors, favoring an aggressive staging and management protocol for 11- to 19-mm carcinoid tumors.
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Ferga C
FC
Gleeson
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Michael J
MJ
Levy
Department of Colorectal Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Eric J
EJ
Dozois
Department of Colorectal Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
David W
DW
Larson
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Louis Michel
LM
Wong Kee Song
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Lisa A
LA
Boardman
D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000401:mortality / Q000473:pathology*; D003113:Colonoscopy; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate; D047368:Tumor Burden