Method to detect prostate cancer in a sample

Abstract

The present invention relates to prostate cancer. More specifically, the present invention relates to a method to detect prostate cancer in a patient sample by detecting the RNA encoded by the gene PCA3. More particularly the present invention relates to a method for determining a predisposition, or presence of prostate cancer in a patient comprising: (a) contacting a biological sample of a patient with at least one oligonucleotide that hybridizes to a PCA3 polynucleotide; (b) detecting in the biological sample an amount of PCA3 and second prostate specific polynucleotides; and (c) comparing the amount of PCA3 polynucleotide that hybridizes to the oligonucleotide to a predetermined cut off value, and therefrom determining the presence or absence of prostate cancer in the biological sample. The present invention further relates to diagnostic kits for the detection of prostate cancer or the risk of developing same in a patient comprising: (a) at least one container means having disposed therein at least one oligonucleotide probe or primer that hybridizes to one a PCA3 nucleic acid or complement thereof; (b) at least one oligonucleotide probe or primer that hybridizes with a second prostate specific nucleic acid or complement thereof; and (c) reagents enabling a detection of PCA3 and of the second prostate specific nucleic acid when PCA3 or second prostate-specific nucleic acid sequence is present.

Description

FIELD OF THE INVENTION [0001] The present invention relates to prostate cancer. More specifically, the present invention relates to a method to detect prostate cancer in a patient sample by detecting an RNA encoded by the prostate cancer antigen PCA3 gene. BACKGROUND OF THE INVENTION [0002] Over the last decade, cancer of the prostate has become the most commonly diagnosed malignancy among men and the second leading cause of male cancer deaths in the western population, following lung cancer. [0003] Early detection and treatment of prostate cancer before it has spread from the prostate gland, reduces the mortality of the disease. This is particularly true for younger men who are at greater risk of dying from this pernicious but slowly growing malignancy. This realization has prompted increasing efforts for early diagnosis and treatment. Indeed, the American Cancer Society and the American Urological Association recommend that male population at large undergo annual screening for pro...

AI Technical Summary

Benefits of technology

[0062] An “immobilized probe” or “immobilized nucleic acid” refers to a nucleic acid that joins, directly or indirectly, a capture oligomer to a solid support. An immobilized probe is an oligomer joined to a solid support that facilitates separation of bound target sequence from unbound material in a sample. Any known solid support may be used, such as matrices and particles free in solution, made of any known material (e.g., nitrocellulose, nylon, glass, polyacrylate, mixed polymers, polystyrene, silane polypropylene and metal particles, preferably paramagnetic particles). Preferred supports are monodisperse paramagnetic spheres (i.e., uniform in size±about 5%), thereby providing consistent results, to which an immobilized probe is stably joined directly (e.g., via a direct covalent linkage, chelation, or ionic interaction), or indirectly (e.g., via one or more linkers), permitting hybridization to another nucleic acid in solution.

Problems solved by technology

A number of conditions can result in leakage of PSA into the blood.

It is therefore not surprising that screening of serum PSA as an indicator of prostate cancer is not absolutely predictive.

However, the sensitivity of such elevated tPSA levels is only 79%; thus leaving 21% of patients with prostate cancer undetected.

The specificity for all tPSA values of 4 ng / ml or greater is very poor.

This low level of specificity results in additional more invasive and costly diagnostic procedures, such as transrectal ultrasounds and prostate biopsies.

Such tests when unnecessary are also very traumatic for the patient.

However, the predictivity of the fPSA test is not as good in people with really low or really high tPSA levels.

The diagnostic usefulness of fPSA is relatively limited as it can be associated with either BPH or prostate cancer.

However, even a biopsy is not always 100% certain.

Despite the improvements in prostate cancer screening over the last ten years, there remains a large unmet need in diagnostic sensitivity and specificity, even when these tools are used in combination.

However, the applicants have shown in a recent patent application that this is not the case (Patent application CA 2,432,365).

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