Risk factor assessment of endoscopically removed malignant colorectal polyps

Abstract

Background-Malignant colorectal polyps are defined as endoscopically removed polyps with cancerous tissue which has invaded the submucosa. Various histological criteria exist for managing these patients. Aims-To determine the significance of histological findings of patients with malignant polyps. Methods-Five pathologists reviewed the specimens of 85 patients initially diagnosed with malignant polyps. High risk malignant polyps were defined as having one of the following: incomplete polypectomy, a margin not clearly cancer-free, lymphatic or venous invasion, or grade III carcinoma. Adverse outcome was defined as residual cancer in a resection specimen and local or metastatic recurrence in the follow up period (mean 67 months). Results-Malignant polyps were confirmed in 70 cases. In the 32 low risk malignant polyps, no adverse outcomes occurred; 16 (42%) of the 38 patients with high risk polyps had adverse outcomes (p<0.001). Independent adverse risk factors were incomplete polypectomy and a resected margin not clearly cancer-free; all other risk factors were only associated with adverse outcome when in combination. Conclusion-As no patients with low risk malignant polyps had adverse outcomes, polypectomy alone seems suYcient for these cases. In the high risk group, surgery is recommended when either of the two independent risk factors, incomplete polypectomy or a resection margin not clearly cancer-free, is present or if there is a combination of other risk factors. As lymphatic or venous invasion or grade III cancer did not have an adverse outcome when the sole risk factor, operations in such cases should be individually assessed on the basis of surgical risk. (Gut 1998;43:669-674)

Histologic Risk Factors and Clinical Outcome in Colorectal Malignant Polyp: A Pooled-Data Analysis

“…In 23 series, [14][15][16][17][18][19][20][21][22][24][25][26][27]29,[31][32][33][34][35]38,[40][41][42] clinical or endoscopic follow-up data were available, ranging from 12 to 90 (median, 60) months, and accounting for 1,535 (80.1 percent) of the included polyps. Regarding endoscopic data, polyp site was clearly specified in 17 series, accounting for 1,461 polyps.…”

“…Polyp morphology was available in 19 series, enrolling 1,145 polyps. 1 [39][40][41][42] Finally, cancerrelated death was reported in 56 (3.6 percent) of those 1,535 patients for whom follow-up data were available, with an interval from the diagnosis ranging from 5 to 101 (median, 32) months. Death because of surgical complications, inferred from 28 studies, was reported in 8 (0.8 percent) of 951 operated patients.…”

“…Death because of surgical complications, inferred from 28 studies, was reported in 8 (0.8 percent) of 951 operated patients. [12][13][14][15][16][17][18][19][20][21][24][25][26][27][28][29][30][31][32][33][34][36][37][38][39][40][41][42] …”

“…[12][13][14][16][17][18][19]21,[27][28][29][30][31][32][33][34]37,[40][41][42] According to our protocol, the resection margin was reported to be positive in 325 (33.2 percent) and negative in the remaining 655 (66.8 percent) cases. In those studies for which polyp morphology also could be inferred, a positive resection margin was significantly more frequent in sessile (25/44) than in pedunculated (34/182) polyps (56.8 vs. 18.7 percent; P < 0.0001).…”

“…[12][13][14]16,[18][19][20][21][22][23]25,26,[28][29][30][31]33,35,39,[40][41][42] This risk factor tended to be more frequent in sessile (30/214) compared with pedunculated (30/327) polyps (14 vs. 9.2 percent, respectively; P = 0.08). 12,20,21,26,28,33,35 Lymph node metastasis was much more common in polyps with such a risk factor than in those without it, whereas no substantial difference in residual disease, hematogenous metastasis, or cancer-related mortality was detected (Table 1).…”