Ian W Folkert1, Andrew J Sinnamon1, Seth J Concors1, Bonita J Bennett2, Douglas L Fraker3, Najjia N Mahmoud4, David C Metz2, Kristen M Stashek5, Robert E Roses6. 1. Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. 2. Division of Gastroenterology, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. 3. Division of Endocrine and Oncologic Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. 4. Division of Colon and Rectal Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. 5. Department of Pathology, University of Maryland, Baltimore, MD, USA. 6. Division of Endocrine and Oncologic Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. Robert.Roses@uphs.upenn.edu.
Abstract
BACKGROUND: Small (< 2 cm) and diminutive (< 1 cm) rectal neuroendocrine tumors (RNETs) are often described as indolent lesions. A large single-center experience was reviewed to determine the incidence of metastasis and the risk factors for its occurrence. METHODS: Cases of RNET between 2010 and 2017 at a single institution were retrospectively reviewed. The rate of metastasis was determined, and outcomes were stratified by tumor size and grade. Uni- and multivariable predictors of metastasis were identified, and a classification and regression tree analysis was used to stratify the risk for distant metastasis. RESULTS: The study identified 98 patients with RNET. The median follow-up period was 28 months. Of the 98 patients, 79 had primary tumors smaller than 1 cm, 8 had tumors 1 to 2 cm in size, and 11 had tumors 2 cm in size or larger. In terms of grade, 86 patients had grade 1 (G1) tumors, 8 patients had grade 2 (G2) tumors, and 4 patients had grade 3 (G3) tumors. Twelve patients developed metastatic disease. Both size and grade were associated with distant metastasis in the uni- and multivariable analyses, but when stratified by grade, size was predictive of metastasis only for G1 tumors (p < 0.001). Among the 12 patients with metastatic disease, 3 (25%) had diminutive primary tumors, and 9 (75%) had primary tumors 2 cm in size or larger. Diminutive tumors that metastasized were all G2. CONCLUSIONS: Patients with diminutive and small RNETs are at risk for metastatic disease. Tumor grade is a dominant predictor of dissemination. More rigorous staging, closer surveillance, or more aggressive initial management may be warranted for patients with G2 tumors, irrespective of size.
BACKGROUND: Small (< 2 cm) and diminutive (< 1 cm) rectal neuroendocrine tumors (RNETs) are often described as indolent lesions. A large single-center experience was reviewed to determine the incidence of metastasis and the risk factors for its occurrence. METHODS: Cases of RNET between 2010 and 2017 at a single institution were retrospectively reviewed. The rate of metastasis was determined, and outcomes were stratified by tumor size and grade. Uni- and multivariable predictors of metastasis were identified, and a classification and regression tree analysis was used to stratify the risk for distant metastasis. RESULTS: The study identified 98 patients with RNET. The median follow-up period was 28 months. Of the 98 patients, 79 had primary tumors smaller than 1 cm, 8 had tumors 1 to 2 cm in size, and 11 had tumors 2 cm in size or larger. In terms of grade, 86 patients had grade 1 (G1) tumors, 8 patients had grade 2 (G2) tumors, and 4 patients had grade 3 (G3) tumors. Twelve patients developed metastatic disease. Both size and grade were associated with distant metastasis in the uni- and multivariable analyses, but when stratified by grade, size was predictive of metastasis only for G1 tumors (p < 0.001). Among the 12 patients with metastatic disease, 3 (25%) had diminutive primary tumors, and 9 (75%) had primary tumors 2 cm in size or larger. Diminutive tumors that metastasized were all G2. CONCLUSIONS:Patients with diminutive and small RNETs are at risk for metastatic disease. Tumor grade is a dominant predictor of dissemination. More rigorous staging, closer surveillance, or more aggressive initial management may be warranted for patients with G2 tumors, irrespective of size.
Authors: Jie Cheng; Yao-Jia Lao; Qian Wang; Kai Huang; Juan-Li Mou; Jia-Hui Feng; Fan Hu; Meng-Lu Lin; Jun Lin Journal: Front Oncol Date: 2022-02-24 Impact factor: 6.244
Authors: Camilla Gallo; Roberta Elisa Rossi; Federica Cavalcoli; Federico Barbaro; Ivo Boškoski; Pietro Invernizzi; Sara Massironi Journal: World J Gastroenterol Date: 2022-03-21 Impact factor: 5.742