VALIDATION OF METHYLENE BLUE IN SENTINEL LYMPH NODE IDENTIFICATION IN BREAST CANCER

ABSTRACT
Background: Sentinel lymph node biopsy (SLNB) is now considered a standard of care in early breast cancers with
N0 axillae; however, its role in locally advanced breast cancer (LABC) after neo-adjuvant chemotherapy (NACT) is still
being    debated.    The    present    study    assessed    the    feasibility,    efficacy    and    accuracy    of    sentinel    lymph    node    biopsy    (SLNB)    
using “dye alone” (methylene blue) method in patients with LABC following NACT.
Objective: To    validate    methylene    blue    dye    in    sentinel    lymph    node    identification    in    breast    cancer.
Methodology: 179, biopsy proven cases of LABC that had received three cycles of neo-adjuvant chemotherapy (cy-
clophosphamide,    adriamycin,    5-fluorouracil)    were    subjected     to    SLNB    (using    methylene    blue    dye)     followed    by    complete    
axillary lymph node dissection (levels I-III). The sentinel node(s) were/were and the axilla were individually assessed
histologically.    The    SLN    accuracy    parameters    were    calculated    employing        standard    definitions.    The    SLN    identification    
rate in the present study were 100%. The sensitivity of SLNB were 86.6% while the accuracy were 93.3%, which were
comparable with other studies done using dual lymphatic mapping method. The SLN were found at level I in all cases
and no untoward reaction to methylene blue dye was observed.
Results:    The    SLN    identification    rate    in    the    present    study    were    100%.    The        sensitivity    of    SLNB    were    86.6%    while    the    
accuracy were 93.3%, which were comparable with other studies done using dual lymphatic mapping method. The
SLN were found at level I in all cases and no untoward reaction to methylene blue dye was observed.
Conclusions: This    study    confirms    that    SLNB    using    methylene    blue    dye    as    a    sole    mapping    agent     is    reasonably    safe    and    
almost as accurate as dual agent mapping method. It is likely that in the near future, SLNB may become the standard
of care and provide a less morbid alternative to routine axillary lymph node dissection even in patients with LABC that
have received NACT.
Key Words: Methylene Blue, Sentinel Lymph Node,  Breast Cancer