Katz et al developed a model for predicting the probability of a woman with breast cancer and a positive sentinel lymph node biopsy having 4 or more positive lymph nodes. This can help guide adjuvant chemotherapy in situations when an axillary node dissection was not performed. The authors are from Massachusetts General Hospital and Brigham and Women's Hospital in Boston.
Patient selection: breast cancer with 1, 2 or 3 positive sentinel lymph nodes
Parameters:
(1) number of positive sentinel lymph nodes
(2) number of negative sentinel lymph nodes
(3) diameter of the primary breast tumor in cm
(4) lymphovascular spread
(5) histology of the primary tumor
(6) extranodal tumor extension
(7) diameter of the largest metastasis in a sentinel lymph node
|
Parameter |
Finding |
Points |
|
lymphovascular spread |
absent |
0 |
|
|
present |
11 |
|
histology of primary tumor |
lobular |
11 |
|
|
non-lobular |
0 |
|
extranodal spread |
absent |
0 |
|
|
present |
11 |
|
diameter of largest metastasis |
<= 0.2 cm |
0 |
|
|
> 0.2 cm |
16 |
|
number of negative lymph nodes |
0 |
0 |
|
|
>= 1 |
- 8.6 |
total score =
= (2.6 * (diameter of primary tumor in cm)) + (9.2 * (number of positive sentinel lymph nodes)) + SUM(points for the other 5 parameters) - 58
Interpretation:
• minimum score: around -57
• maximum score: around 45
• If 4 or more sentinel lymph nodes are positive then the probability of having 4 or more positive lymph nodes is 100%.
|
Total Score |
Percent Probability of Having 4 or More Positive Lymph Nodes |
|
< -53 |
< 0.5% |
|
-53 to -22 |
(0.00041 * ((score)^3)) + (0.059 * ((score)^2)) + (2.904 * (score)) + 49.66 |
|
-22 to 8 |
(0.0314 * ((score)^2)) + (2.481 * (score)) + 48.99 |
|
8 to 45 |
(0.000358 * ((score)^3)) - (0.05471 * ((score)^2)) + (2.807 * (score)) + 50.74 |
|
> 45 |
> 99% |
Specialty: Hematology Oncology, Surgery, general, Obstetrics & Gynecology
