- Sentinel lymph node biopsy (SLNB) is an important prognostic factor in breast cancer as it allows detection of cancer spread to axillary lymph nodes.
- SLNB is recommended for early-stage T1-T2 tumors without clinically detectable lymph node involvement but is not recommended for larger T3-T4 tumors or inflammatory breast cancer.
- SLNB accuracy can be improved to over 90% by using blue dye mapping and radioisotope tracing techniques together. A negative SLNB result can spare patients from additional axillary lymph node dissection but a positive result may require further treatment.
2. Diagnosing axillary disease is the most
important prognostic facctor in breast cancer
3. Definition:
It is the first draining lymph node on the direct
lymphatic pathway from the primary tumor site
and so it is the first node to harbour cancer
cells detached from the primary tumour.
4.
5. Studies validating the use of SLNB restricted
its use to T1 or T2 tumors with no clinically
palpable lymph nodes
7. Clinical Circumstance Use of SNB Level of Evidence*
T1 Or T2 tumors Acceptable Good
T3 Or T4 tumors Not recommended Insufficient
Multicentric tumors Acceptable Limited
Inflammatory breast cancer Not recommended Insufficient
DCIS with mastectomy Acceptable Limited
DCIS without mastectomy Not recommended except for
large DCIS (>5cm) on core
biopsy or with suspected or
proven microinvasion
Insufficient
Suspicious, palpable axillary nodes Not recommended Good
Older age Acceptable Limited
Obesity Acceptable Limited
8. Clinical Circumstance Use of SNB Level of Evidence*
Male breast cancer Acceptable Limited
Pregnancy Not recommended Insufficient
Evaluation of internal mammary
lymph nodes
Acceptable Limited
Prior diagnostic or excisional
breast biopsy
Acceptable Limited
Prior axillary surgery Not recommended Insufficient
Prior non oncologic breast surgery
(reduction or augmentation
mammoplasty, breast
reconstruction, etc.)
Not recommended Insufficient
After preoperative systemic
therapy
Not recommended Insufficient
Before preoperative systemic
therapy
Acceptable Limited
9. Mapping using blue dye: 83.1per cent
accuracy.
Mapping using radioisotopes: 89.2 per cent
accuracy.
Combining both techniques: 91.9 per cent
accuracy.
10. Peri-tumoral injection ( which has limited
application in clinically impalpable tumors).
Intra and sub-dermal.
Peri or sub-areolar.
15. NEGATIVE:
SLNB spares many patients the potential
side effects of axillary lymph node dissection
(ALND) such as lymphoedema,
and studies concluded that with a negative
SLNB, SLN surgery alone without ALND is
safe and effective
17. Positive: current
guidelines recommend ALND in breast
cancer patients with positive SLNB.
However recent trials as ACOSOG 0011
which was published recently which provided
convincing evidence that completion (ALND)
was unnecessary in patients with 1 to 2
positive sentinel lymph nodes (SLNs).
18. Although the findings of ACOSOG Z0011 are
impressive, in clinical practice they are
applicable to limited number of cases and
that was because of the limited study
population, old age group, receptor status of
the tumor, and length of follow up.
19. SOUND Trial
Design; Tumor<2cm,any age, negative axilla
Randomized into 2 groups
1. SN biopsy +/- ALND 780 patients
2. Observation 780 patients
20.
21. SLNB has lost much of it's importance, we don't
do ALND when SLN is negative, micro
metastasis and now even when it is positive in 2
nodes.
Advancing imaging technology can identify
increasingly smaller axillary involvement and
may be used for axillary staging
Adjuvant treatment recommendations
increasingly depend on primary tumor biology
and not on axilla status.