Abstract P1-01-11: The health economics of one step nucleic acid amplification for intraoperative sentinel lymph node analysis in breast cancer
Authors: King PM , Simmons F , Philip DJ , Iain BM , Rachel EE , Sheikh A 
Published: August 2014

AIM

Despite the obvious advantages of intraoperative sentinel lymph node (SLN) analysis in the form of One Step Nucleic Acid Amplification (OSNA), this technique has not been widely adopted in the United Kingdom. The aim of this study was to investigate the health economic implication of the technique.

METHODS

Data were collected prospectively on all patients undergoing OSNA at a single institution between September 2011 and February 2013. Initially patients were selected using the Sloan Kettering Nomogram for additional non SLN axillary disease [http://nomograms.mskcc.org] and patients with micrometastases were offered an axillary clearance. From August 2012, all patients undergoing sentinel node biopsy were offered OSNA. A cost analysis was done on the basis of up front purchase costs, OSNA cost per patient minus the cost of standard Haematoxylin and Eosin stain analyses at our institution and HRG4 codes.

RESULTS

Data were collected on 258 patients with a median age of 69. 209 (81%) had invasive ductal carcinoma. 208(80%) were oestrogen receptor positive and approximately 30% had lymphovascular invasion. Table 2 demonstrates the OSNA results.

Table 1 - OSNA results Pre August 2012Post August 2012Total n%n%n%No. of patients169 88 257 Mean no. of nodes2.38 1.98 2.24 OSNA Negative11668.645461.3617066.15OSNA Micrometastases2715.982123.864818.68OSNA Macrometastases2112.431314.773413.23OSNA Inhibited52.960051.95Total no. undergoing Axillary Clearance5130.181820.456926.85Axillary Clearance for Micrometastases2313.6144.552710.51Additional nodes positive overall:      03772.55950.004666.671-3 nodes1121.57738.891826.094-7 nodes11.96211.1134.358-12 nodes11.96  11.45gt]12 nodes[11.96  11.45Additional nodes positive for OSNA Micrometastases:      021  22385.191-3 nodes2   414.81

The capital investment for setting up OSNA in our institution was £40,000. By carrying out OSNA on all patients undergoing sentinel node biopsy we saved a second procedure on 20% of patients. Table 2 outlines the costs saving per year based on the HRG4 code for the cost of second admission and axillary clearance.

Table 2 - Health Economic Analysis  TotalNo. patients undergoing OSNA per year235 Cost of OSNA per patient£286£67,210Cost of H & E analysis based on 2 nodes per patient£101,60£23,876Net costs of OSNA per patient£184,40£43,334No. patients undergoing axillary clearance (20% of 235)47 Cost of axillary clearance (based on HRG4 JA07)£2,030£95,410Total saving per year with OSNA £52,076

CONCLUSION

The use of OSNA as an intraoperative assessment of sentinel lymph nodes in breast cancer is a highly sensitive and efficient way of determining the sentinel node status. It saves patients undergoing a second admission and procedure. By offering OSNA to all patients undergoing SLN, the capital investment will be recouped in less than a year and the local health economy will save over £50,000 per year in subsequent years.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-11.