Immunohistochemical staining battery:
(1) GCDFP-15 (gross cystic disease fluid protein)
(2) ER (estrogen receptor)
(3) CEA (carcinoembryonic antigen)
(4) CK7 (cytokeratin 7)
(5) CK20 (cytokeratin 20)
(6) CA-125
|
Intensity of Staining
|
Points
|
|
none
|
0
|
|
mild
|
1
|
|
moderate
|
2
|
|
marked
|
3
|
immunohistochemical score =
= (percent of tumor staining as a whole number from 0 to 100) * (points for staining intensity)
where:
• minimum immunohistochemical score: 0
• maximum immunohistochemical score: 300
metastatic colorectal carcinoma =
= (-0.010 * (immunohistochemical score for GCDFP-15)) + (0.046 * (immunohistochemical score for CEA)) - (0.008 * (immunohistochemical score for ER)) + (0.021 * (immunohistochemical score for CK20)) + (0.019 * (immunohistochemical score for CK7)) + (0.124 * (immunohistochemical score for CA-125)) - 6.907
metastatic breast carcinoma =
= (0.350 * (immunohistochemical score for GCDFP-15)) + (0.016 * (immunohistochemical score for CEA)) + (0.024 * (immunohistochemical score for ER)) + (0.001 * (immunohistochemical score for CK20)) + (0.031 * (immunohistochemical score for CK7)) - (0.013 * (immunohistochemical score for CA-125)) – 6.175
primary ovarian carcinoma =
= (-0.127 * (immunohistochemical score for GCDFP-15)) + (0.008 * (immunohistochemical score for CEA)) + (0.003 * (immunohistochemical score for ER)) + (0.006 * (immunohistochemical score for CK20)) + (0.021 * (immunohistochemical score for CK7)) + (0.031 * (immunohistochemical score for CA-125)) – 3.998
Interpretation (page 286:
• The tumor with the highest score is selected as the probable point of origin.
• Poorly differentiated carcinomas were usually correctly classified.
• In the learning set used, 89% of tumors were correctly classified (98% of colorectal, 88% of ovarian, and 80% of breast). In the test set 82% of tumors were correctly classified.
NOTE: The text of the articles infers that the values from the classification rules can be used to derive the posterior probability for each diagnosis.
