Background/aims: A specific preoperative work-up was used to access a limited number of high-risk lymph nodes with RT-qPCR for micrometastatic sentinel lymph node involvement. We validated our protocol with IHC screening for micrometastases and long-term survival analysis.
Methodology: From the 32 patients included 22 were node-negative patients. With a specific preoperative protocol sentinel lymph nodes (1-2 per patient) were extracted for further RT-qPCR analysis for CEA and CK20 expression. In 10 patients from the study group, the remaining lymph nodes around the extracted sentinel lymph node from the first compartment were additionally screened using IHC for missed micrometastases.
Results: Micrometastases were detected in seven of 22 (31.8%) node-negative patients. RT-qPCR identified micrometastases in four of 10 haematoxylin-eosin-negative lymph nodes (40%), and in three of eight IHC negative lymph nodes (37.5%). The cumulative 3-year survival for the study group was 80.8%. The 3-year survival in the RT-qPCR-negative group was 90%, compared with 66.7% in the RT-qPCR-positive group (p=0.289).
Conclusions: Encouraged by these results, we will include more patients in our focused sentinel lymph node protocol. With a refinement of our method, we believe the focused sentinel lymph node protocol can be implemented for intraoperative tailoring of extent of lymphadenectomy.