VALIDATION STUDY OF SENTINEL LYMPH NODE BIOPSY IN
CLINICALLY NODE NEGATIVE EARLY BREAST CANCER
(Ramesh Sarin, Parag Kumar, Deepshika Arora, Uma Ravi Shankar)
SLN biopsy has become the standard of care in detecting axillary nodal metastasis in clinically node negative early breast cancer. There should be either formal mapping instruction with hands on experience or large validation study to get the required 90-95% identification rate and <5% FN rate.
METHODS & RESULTS
- 145 patients with clinically node negative early stage were enrolled for SLNB Followed by axillary dissection.
- SLNs were localized pre operatively by injecting Tc 99m nano colloid Intradermal around the tumor.
- SPECT imaging was performed after 1-2 hours and surgery between 2-18 hrs after injection. 5ml of 1% vital dye was injected periareolar subdermally 8-15 minutes prior to incision.
- Breast surgeon and nuclear medicine consultant co-ordinated in recovering the “hot” sentinel lymph nodes with gamma probe.
- All hot and or blue nodes were removed along with suspicious palpable nodes and sent for frozen section.
- Reporting was according to ASCO-CAP guidelines
|26 Years to||86 Years|
|<35yrs of age||7 (5%)|
|>35yrs of age||138 (95%)|
SLND IN BREAST CANCER
- Avg. no. of Sentinel Nodes dissected 3.33
- Range from-1 to 7
- Increasing the mean no. of sentinel nodes removed improved accuracy (NSABP B- 32 Trial showed that first 2-3 nodes removed predicted the status of axilla in 98% of the cases)
STATUS OF SENTINEL NODE POSITIVITY&TUMOR SIZE
|PT0||Negative Sentinel Node||1|
|PT1||Negative Sentinel Nodes||20 (45.5%)|
|Positive Sentinel Nodes||24 (55.5%)|
|PT2||Negative Sentinel Nodes||51 (53.7%)|
|Positive Sentinel Nodes||44 (46.3%)|
|PT3||Negative Sentinel Nodes||1|
SLND IN BREAST CANCER
42/68 patients with positive sentinel lymph node had positivity only in the sentinel node/nodes while the rest of the non-sentinel lymph nodes were negative. This indicates SLND is a more accurate method of staging the axilla as these sentinel nodes are subjected to a more thorough histopathological examination.
Identification rate with dual technique combined with scintimammography was 97.24%(In four patients sentinel node was not identified, two patients had complete blockade of level III nodes in a deep situated tumor and the other two patient had no apparent reason).
High BMI, age, upper outer quadrant, tumor size, tumor histology, tumor grade and multifocality did not affect identification rate did not affect the identification rate in our series.
TOTAL NUMBER OF PATIENTS-145
- No. of True Negative SLND patients 70
- No. of True Positive SLND patients 68
- False Negative 3*
- No SLN identified 4
- All three patients were reported negative on frozen while in paraffin section of the same nodes, one node was positive (all non-sentinel nodes in this were negative)
SLND IN BREAST CANCER (VALIDATION STUDY)
Sensitivity: True Positivity / (True positivity + false negativity) >> 95.77%
NPV: True Negative / (False negative + True Negative) >> 95.89%
False -ve: >> 3(4.22%)
Accuracy: True positivity + True Negative / Total Number >> 97.87%
- Results of our validation study are at par with the best in the world in identification rate, sensitivity, accuracy and NPV.
- Triple method of lymphatic mapping reduced our failure rate.
- Site of injection of radioactive colloid and the time delay for surgery did not influence the outcome.
- More than 3 SLNs improved the outcome.
- 50%of patients in T1 & T2 tumors had negative SLNs.
- 62% of the patients had lymph node positivity only in SLNs indicating that the correct lymph nodes were picked up.
Grube BJ, Gluliano AE, Adv surg 2004; 38-121-166: Clarke D. San Antanio, Texas, 2001: Zavagno G, DebSalvo GLScalco G et al. Ann Surg 2005; 241:48-54: Goyal A Newcombe R Chhabra A et al. Breast Cancer Res treat 2006; 99:203-208.
APOLLO CANCER INSTITUTE, INDRAPRASTHA APOLLO HOSPITAL, NEW DELHI.
This data was provided by Dr Ramesh Sarin & Ms Janani