MICROSCOPIC FAT PROCESSING WITH HARVESTING OF LYMPH NODES IN GASTRIC CANCER IMPROVES NODAL YIELD AND UPSTAGES N STATUS
The current UICC staging system for gastric cancer relies on number of positive nodes to give N stage, up to a maximum of 16 involved nodes. As most nodal harvesting is based on macroscopically detected nodes there is a real danger that involved nodes may be missed and therefore the disease is understaged. We hypothesised that fat processing and microscopic evaluation of gastrectomy specimens would improve nodal yield, detection of nodal metastases and therefore staging of the disease
Methods: 121 consecutive gastrectomy specimens were histologically examined by a consultant gastrointestinal pathologist. All macroscopically enlarged nodes were analysed. In addition fat was processed and microscopic lymph nodes analysed.
Median macroscopic nodal yield was 20 (0-58), fat processing increased this to 43 (1-76, pN1 4 cases, 3.2%, N1->N2 8 cases, 6.5%, N2->N3 5 cases, 4% and N1->N3 in one case 0.8%).
Macroscopic nodal harvesting understages true nodal status for N0, N1 and N2 in 10%, 20% and 25% respectively.
Fat processing for microscopic lymph node analysis improves staging in 15% of cases. This has significant implications for prognosis and possible adjuvant therapy. Further work is being undertaken to improve selection of cases for fat processing.
Program Number: P341