Use
of Proteomic Patterns in
Serum to Identify Ovarian Cancer
Petricoin EF*, Ardekani AM, Hitt B+, Levine P+, Steinberg
S*, Mills G,
Simone CB#, Fishman D, Kohn E*, Liotta LA.*
Sir – In the year 2002 about 24,000 American women will be diagnosed with ovarian cancer and about 14,000 will die from it. There has been no effective method of early detection of ovarian cancer and consequently the great majority of patients with newly diagnosed ovarian cancer are detected in late stages. New technologies are critically needed.
Certain abnormal
proteins (proteomic) may be secreted in unique patterns into the blood
stream from pathological changes within an organ. To detect these unique
abnormal protein patterns, a bioinformatics tool was developed to distinguish
cancer from non-cancer diseases of the ovary.
First, serum from each patient with an
ovarian problem (cancer or non-cancer), is placed on a special surface that
attracts specific proteins, in this case, hydrophobic proteins. Repeated
washings with special chemicals remove unwanted proteins. Then a laser beam is
used to hurl the remainder proteins from the surface into a chamber separating
the lighter weight proteins from the heavier proteins. Hence, a unique
Proteomic Pattern of different weighted proteins is created after Laser
treatment for each serum specimen: light, moderate, and heavy weight. This
technique is known as Surface Enhanced Laser Desorption and Ionization (SELDI).
Wash Laser
A
large number of unique proteomic patterns may occur. Therefore, a
bioinformatics tool, a special software program, was developed to recognize
patterns and match subsequent test serum samples with known patterns from
either cancer or non-cancer patient proteomic patterns. For example, let's say
that the serum used in the diagram was from a patient with ovarian cancer. Then
proteomic patterns from other patients that are identical or very similar could
suggest a cancer as well.
Findings:
This new technology accurately identified all 50 ovarian cancer cases that
included 18 stage I cases. Of the 66 cases of non-cancer disease, 63 were
recognized as non- cancer. This yielded a sensitivity of 100 percent,
specificity of 95 percent, and a positive predictive value of 94 percent
compared with a positive predictive value of only 34 percent for the blood test
currently used to detect ovarian cancer, the CA-125 test.
Interpretation: Serum proteomic pattern profiling may constitute a
sensitive and specific and specific tool for early ovarian cancer
identification. These findings warrant prospective clinical application of this
technology.
How You Can Help: If you have a newly diagnosed and untreated disease of the ovary (ies), cancer or non-cancer, please call 609- 896-2646.
*National Cancer
Institute, NIH investigators +Correlogic Systems
#Simone Protective
Cancer Institute investigator