Required Distal Mesorectal Resection Margin in Partial Mesorectal Excision: a Systematic Review on Distal Mesorectal Spread
EAES Academy. Grüter A. 07/05/22; 363192; P256
Mr. Alexander Grüter
Contributions
Contributions
Abstract
Aim:
Partial mesorectal excision (PME) is considered a valid alternative in proximal rectal cancer, but required distal margin is controversial. The systematic review aimed to determine incidence and distance of distal mesorectal spread (DMS).
Method:
A systematic search using PubMed, Embase and Google Scholar databases was performed. For quality assessment, the Agency for Healthcare Research and Quality (AHRQ) methodological checklist was used.
Results:
Out of 2493 articles, 20 studies with a total of 1742 patients were included, of whom 266 underwent neoadjuvant radiotherapy. DMS was reported in 181 (10.4%) specimens, with specified distance of DMS relative to the tumor in 84 (46%) of the cases. The maximum reported DMS was 50 mm in 1 of 84 cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual DMS, respectively, which translates into 1% and 3% overall risk given 10% risk of DMS. In subgroup analysis, for T3 the mean DMS was 18.8 mm (range: 8-40 mm) and 27.2 mm (range: 10-40 mm) for T4 rectal cancer. DMS was mainly determined by lymph node metastases (86.9%).
Conclusion:
DMS occurred in 12.2% after surgery alone and 0.4% after radiotherapy, with a maximum of 50 mm in less than 2% of the cases. This indicates substantial overtreatment if routinely using a distal margin of 5 cm for PME, especially after radiotherapy. Prospective studies evaluating more limited margins based on high quality preoperative MRI and pathological assessment are required.
Partial mesorectal excision (PME) is considered a valid alternative in proximal rectal cancer, but required distal margin is controversial. The systematic review aimed to determine incidence and distance of distal mesorectal spread (DMS).
Method:
A systematic search using PubMed, Embase and Google Scholar databases was performed. For quality assessment, the Agency for Healthcare Research and Quality (AHRQ) methodological checklist was used.
Results:
Out of 2493 articles, 20 studies with a total of 1742 patients were included, of whom 266 underwent neoadjuvant radiotherapy. DMS was reported in 181 (10.4%) specimens, with specified distance of DMS relative to the tumor in 84 (46%) of the cases. The maximum reported DMS was 50 mm in 1 of 84 cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual DMS, respectively, which translates into 1% and 3% overall risk given 10% risk of DMS. In subgroup analysis, for T3 the mean DMS was 18.8 mm (range: 8-40 mm) and 27.2 mm (range: 10-40 mm) for T4 rectal cancer. DMS was mainly determined by lymph node metastases (86.9%).
Conclusion:
DMS occurred in 12.2% after surgery alone and 0.4% after radiotherapy, with a maximum of 50 mm in less than 2% of the cases. This indicates substantial overtreatment if routinely using a distal margin of 5 cm for PME, especially after radiotherapy. Prospective studies evaluating more limited margins based on high quality preoperative MRI and pathological assessment are required.
Aim:
Partial mesorectal excision (PME) is considered a valid alternative in proximal rectal cancer, but required distal margin is controversial. The systematic review aimed to determine incidence and distance of distal mesorectal spread (DMS).
Method:
A systematic search using PubMed, Embase and Google Scholar databases was performed. For quality assessment, the Agency for Healthcare Research and Quality (AHRQ) methodological checklist was used.
Results:
Out of 2493 articles, 20 studies with a total of 1742 patients were included, of whom 266 underwent neoadjuvant radiotherapy. DMS was reported in 181 (10.4%) specimens, with specified distance of DMS relative to the tumor in 84 (46%) of the cases. The maximum reported DMS was 50 mm in 1 of 84 cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual DMS, respectively, which translates into 1% and 3% overall risk given 10% risk of DMS. In subgroup analysis, for T3 the mean DMS was 18.8 mm (range: 8-40 mm) and 27.2 mm (range: 10-40 mm) for T4 rectal cancer. DMS was mainly determined by lymph node metastases (86.9%).
Conclusion:
DMS occurred in 12.2% after surgery alone and 0.4% after radiotherapy, with a maximum of 50 mm in less than 2% of the cases. This indicates substantial overtreatment if routinely using a distal margin of 5 cm for PME, especially after radiotherapy. Prospective studies evaluating more limited margins based on high quality preoperative MRI and pathological assessment are required.
Partial mesorectal excision (PME) is considered a valid alternative in proximal rectal cancer, but required distal margin is controversial. The systematic review aimed to determine incidence and distance of distal mesorectal spread (DMS).
Method:
A systematic search using PubMed, Embase and Google Scholar databases was performed. For quality assessment, the Agency for Healthcare Research and Quality (AHRQ) methodological checklist was used.
Results:
Out of 2493 articles, 20 studies with a total of 1742 patients were included, of whom 266 underwent neoadjuvant radiotherapy. DMS was reported in 181 (10.4%) specimens, with specified distance of DMS relative to the tumor in 84 (46%) of the cases. The maximum reported DMS was 50 mm in 1 of 84 cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual DMS, respectively, which translates into 1% and 3% overall risk given 10% risk of DMS. In subgroup analysis, for T3 the mean DMS was 18.8 mm (range: 8-40 mm) and 27.2 mm (range: 10-40 mm) for T4 rectal cancer. DMS was mainly determined by lymph node metastases (86.9%).
Conclusion:
DMS occurred in 12.2% after surgery alone and 0.4% after radiotherapy, with a maximum of 50 mm in less than 2% of the cases. This indicates substantial overtreatment if routinely using a distal margin of 5 cm for PME, especially after radiotherapy. Prospective studies evaluating more limited margins based on high quality preoperative MRI and pathological assessment are required.
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