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How to get more nodes in laparoscopic colon surgery. John Marks MD Chief Division of Colorectal Surgery Lankenau Hospital and Institute of Medical Research. What factors impact lymph node harvest?. Number of lymph nodes in patient Surgical technique Acquiring the lymph nodes
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How to get more nodes in laparoscopic colon surgery John Marks MD Chief Division of Colorectal Surgery Lankenau Hospital and Institute of Medical Research
What factors impact lymph node harvest? • Number of lymph nodes in patient • Surgical technique • Acquiring the lymph nodes • Pathologists technique • Detecting lymph nodes in specimen
Specimen submitted in formalin • Mesenteric fat dehydrated over 24 hours in Carnoy’s solution • 6 parts ethyl alcohol • 3 parts chloroform • 1 part glacial acetic acid • Manual dissection and lymph node harvest of entire specimen • In cases with few nodes, additional mesenteric fat is submitted Fat-Clearing Technique
Results N = 103 • Colon and rectal specimens fix overnight • The next day, traditional histological blocks taken, LNs counted • Half of each node remains in specimen for reference • The same specimen is then placed in alcohol/xylene for 3-4 weeks • Fully cleared specimen examined, additional lymph nodes recovered are counted
Site of primary tumors and numbers of LNs identified by both techniques
# Nodes - Manual vs. Fat-Clearing • Fat-clearance yielded increases LNs compared to traditional dissection 200% Greater Yield
Lymph node harvest: Lap vs. Open • N=729 (243 lap, 486 open) • All colorectal cancer resections • Mean # LNs per case: 24.8 ± 20.6 • No difference in mean LN with lap vs. open (p=0.4) Laparoscopic resection of colorectal cancer can achieve lymph node retrieval similar to the open approach
Background • Improved survival reported with node-negative colon cancer and # of LNs assessed • Relationship between survival with stage III colon cancer and # LNs is unclear • Prognostic effect of increasing number of positive nodes is a confounding factor J Clin Oncol, 2006; 24(22):3570-5
Methods • Identified patients with stage III colon cancer surgery between January 1988 and December 1997 • SEER cancer registry • Disease-specific survival examined by substage based on no. of negative nodes • Proportional hazards model determined effect of negative nodes on survival J Clin Oncol, 2006; 24(22):3570-5
Results N = 20,702 Stage IIIA n=1,722 • Right sided cancers found in 50% of patients • 74% had well or moderately differentiated tumors • Median no. positive LN = 7 • IIIC > IIIB > IIIA • Median no. negative LN = 2 Stage IIIC n=6,476 Stage IIIB n=12,504 J Clin Oncol, 2006; 24(22):3570-5
Results • Median follow up 5 yrs • For stage IIIB and IIIC, significant decrease in disease-specific mortality as nodes increased (both p<0.001) • No association between no. of negative nodes and survival for stage IIIA (p=0.90) J Clin Oncol, 2006; 24(22):3570-5
Stage IIIB Cancer Relative Reduction of 40% in deaths J Clin Oncol, 2006; 24(22):3570-5
Stage IIIC Cancer Relative Reduction of 35% in deaths J Clin Oncol, 2006; 24(22):3570-5
Disease-Specific survival for Stage III Colon Cancer J Clin Oncol, 2006; 24(22):3570-5
Conclusion • Higher number of negative nodes is independently associated with improved disease-specific survival J Clin Oncol, 2006; 24(22):3570-5
Rectal Cancer LN #s • Effect of radiation on LN count after TME
Less than 12 lymph nodes can be expected in surgical specimen after high dose chemoradiation for rectal cancer LN presentation Marks J H, Valsdottir E B,, Yarandi S, Newman D A, Newze I, DeNittis A, Marks G Lankenau Hospital and Institute of Medical Research Elsa and the crew
Purpose • To determine if harvesting >12 lymph nodes is a useful quality indicator for rectal cancer surgery after neoadjuvant XRT
Methods • Selected patients who underwent TME after neoadjuvant XRT from database • January 1997 – August 2007 • Compared <12 LN to ≥12 LNs relative to multiple patient and treatment factors
Results N=176 • Mean LN harvest = 10.1 (1-38) • No significant difference in LN harvest relative to radiation dose, age, tumor response, or type of surgery • No correlation between LN harvested and # positive nodes
#LN harvested N=176 ≥ 12 Nodes 28% ≥ 6 to < 12 Nodes 40%
Conclusion • With standardized surgical technique and pathological evaluation, # LN present after neoadjuvant chemoradiation and TME for rectal cancer varies greatly • Increased number of nodes does not increase yield of + nodes • Further study necessary to determine if number of nodes correlate with outcome
Conclusion • Due to the high variability of number of lymph nodes after the sterilizing effect of radiation, a target number of nodes that correlates to surgical adequacy is likely unobtainable
Conclusion • Lymph Nodes: More is better • Surgical Technique Optimization • Pathologic Technique Optimization • Variable in rectal cancer after irradiaiton