Methods for Detecting Nucleic Acids Indicative of Cancer

1 . A method for screening a patient for cancer or precancer, the method comprising the steps of:

detecting in a patient tissue or body fluid sample comprising exfoliated cells and cellular debris, nucleic acid fragments that are greater than 200 base pairs in length;

the presence of said fragments being a positive screen for cancer or precancer.

2 . The method of claim 1 , wherein said detecting step comprises conducting an amplification reaction designed to amplify only nucleic acids in said sample that are greater than 200 base pairs in length.

3 . The method of claim 1 , wherein said sample is selected from the group consisting of stool, pus, and urine.

4 . The method of claim 1 , further comprising the step of enriching said sample for human DNA.

5 . The method of claim 1 , further comprising the step of isolating human DNA from said sample.

6 . A method for screening a patient for cancer or precancer, the method comprising the steps of:

determining in a patient tissue or body fluid sample a first amount of nucleic acid fragments greater than 200 base pairs in length;

determining in said sample a second amount of nucleic acid fragments less than about 200 base pairs in length;

determining a ratio between said first amount and said second amount; and

identifying a positive screen if said ratios exceeds a threshold ratio for patients who do not have cancer or precancer.

7 . A method for screening a patient for cancer or precancer, the method comprising the step of

detecting in a patient tissue or body fluid sample comprising exfoliated cells a nucleic acid fragment of a length that is not expected to be present in said sample in a healthy patient;

the presence of said fragment being a positive screen.