Algorithm of Margel for Predicting Pathologic Stage in a Patient with Organ-Confined Bladder Cancer by Clinical Evaluation

 

Patient selection: bladder cancer that is muscle-invasive and clinically organ confined (cT2N0M0) or less

 

Parameters:

(1) serum CEA (carcinoembryonic antigen, Abbott AxSYM analyzer)

(2) serum CA 19-9 (carbohydrate antigen 19-9, Abbott AxSYM analyzer)

(3) serum CA 125 (cancer antigen 125, Abbott AxSYM analyzer)

(4) clinical stage (CIS, cT1, cT2)

(5) hydronephrosis

(6) concomitant carcinoma in situ (CIS)

(7) initial tumor size

 

Parameter	Finding	Points
clinical stage	CIS	1
	cT1	2
	cT2	3
hydronephrosis	absent	1
	present	2
concomitant CIS	absent	1
	present	2
initial tumor size	<= 3 cm	1
	> 3 cm	2

 

PCA score =

= (0.596 * (CEA value)) + (0.508 * (CA 125 value)) + (0.664 * (CA 19-9 value)) + (0.697 * (points for clinical stage)) - (0.567 * (points for concomitant CIS)) + (0.578 * (points for hydronephrosis)) + (0.590 * (points for tumor size))

 

Interpretation:

• A PCA score > 18.53 was associated with pathologic extravesical disease.

 

Performance:

• The area under the ROC curve was 0.84.

• The positive predictive value was 88% and the negative predictive value was 94%.

• The equation was 95% accurate in predicting non-organ confined disease.

 

Limitations:

• The normal reference ranges for the serum tumor markers were not stated.

• Hydronephrosis and elevated serum markers can be caused by other conditions. The function would work better in patients without these.