Methods for diagnosing benign prostatic diseases and prostatic adenocarcinoma using an algorithm

• US 6,140,065 A
• Filed: 09/05/1997
• Issued: 10/31/2000
• Est. Priority Date: 09/05/1997
• Status: Expired due to Fees

• Current Assignee: Dianon Systems Incorporated (Laboratory Corporation Of America Holdings)
• Original Assignee: Dianon Systems Incorporated (Laboratory Corporation Of America Holdings)
• Inventors: Carlson, Grant D., Cavallo-Calvanese, Christina Beth
• Primary Examiner(s): EYLER, YVONNE L
• Application Number:
  US08/924,667
• Time in Patent Office: 1,152 Days
• Field of Search: 435/7.1, 435/7.23, 436/64, 128/630
• US Class Current: 435/7.23
• CPC Class Codes: G01N 33/57434 of prostate

Abstract

The present invention relates to novel reflex methods for identifying a male human patient as suitable for diagnosis either benign prostatic diseases (BPD), (such as benign prostatic hyperplasia, prostatitis, or glandular atrophy), or prostatic adenocarcinoma (CAP) without requiring a biopsy. The method requires measuring two biochemical markers and knowing the patient age. The total prostate specific antigen (PSA) level in the blood or serum of the patient is measured. If the patient has a total PSA level of between 4.0 ng/mL and 20.0 ng/mL, then the free PSA level in the blood or serum of the patient is measured. The proportion of free PSA to total PSA is calculated. The patient'"'"'s age is noted, rounding down to an integral numbers of years. The two measured values and the age are entered into a particular identifying algorithm which is derived from a logistic regression model. If a value of greater than about 0.18 is generated from entering these values into the algorithm, then the patient is diagnosed as having CAP. If value of less than or equal to about 0.18 is generated from entering these values into the algorithm, then the patient is diagnosed as having BPD.

Claims

1. A method for differentiating a male human patient with either benign prostatic diseases (BPD) or prostatic adenocarcinoma (CAP) comprising:

a) measuring the total prostate specific antigen (PSA) level in the blood or serum of the patient;

b) measuring the free PSA level in the blood or serum of a patient only if the patient has a total PSA level of between about 4.0 ng/mL and about 20.0 ng/mL;

c) calculating an age factor for the patient wherein said age factor is the actual age rounded to the nearest whole integer;

d) calculating a probability value (PV) by entering as variables the total PSA level (PSA_T), the free PSA to total PSA proportion level (F;

T), and the age factor (AGE) into a diagnostic algorithm wherein PV=P₁ /(1+P₁), in which P₁ =e^X, where x=[(-1.8075)+(-0.3297*A₁ P₁)+(-0.3592*A₂ P)+(-0.1242*A₃ P₃)+(0.0591*AGE)+(0.1509*ln (PSA_T))+(-1.1915*ln (F;

T))], and in which F;

T=the free PSA to total PSA proportion;

A₁ P₁ =1 if AGE=61 to 67 and F;

T=16 to 20, otherwise A₁ P₁ =0;

A₂ P=1 if AGE=68 to 72 and PSA_T is greater than 10, otherwise A₂ P=0; and

A₃ P₃ =1 if AGE is equal to or greater than 73 and F;

T is equal to or less than 10, otherwise A₃ P₃ =0; and

wherein * indicates multiplication, and;

e) identifying the patient either as having CAP if the calculated probability value is greater than about 0.18 or as having BPD if the calculated probability value is less than or equal to about 0.18.

2. The method of claim 1 wherein the patient also has a negative prostate biopsy.