WASHINGTON Feb 10 A test that looks for tumor
cells in the blood may make doctors better able to check
whether chemotherapy is helping a prostate cancer patient,
researchers reported on Tuesday.
The CellSearch test, made by Johnson & Johnson (JNJ.N) unit
Veridex, works better than standard tests for men whose
prostate cancer has spread, the researchers said in the journal
The test counts the number of cancer cells that have broken
away from the tumor and are circulating in the blood.
In a study involving 164 men, the researchers found that
CellSearch helped them monitor the response to chemotherapy in
patients who had prostate cancer that had spread and were not
being helped by hormone therapy.
Hormone therapy aims to stop the body's production of
testosterone or block hormones from getting into tumor cells.
They said it worked better than a standard test that looks
at prostate specific antigen, or PSA, levels. PSA is a protein
produced by the prostate, and levels may shoot up when prostate
tumors grow or spread.
"It shows that the CTC (circulating tumor cells) counts can
be used to help determine an individual's prognosis,
particularly when the counts are high," Dr. Howard Scher of
Memorial Sloan Kettering Cancer Center in New York, one of the
researchers, said in a telephone interview.
"And it also helps in terms of understanding if the
treatment is working," Scher added.
Once prostate cancer has advanced to the point that
chemotherapy may be used -- at a late stage, unlike in many
other cancers -- doctors often struggle to determine how well
the treatment is working, said John Neate of the Prostate
Cancer Charity, a London-based advocacy group.
"Measuring circulating tumor cells seems to be more finely
attuned to the effects of the chemotherapy than previously
thought," Neate said in a statement.
"There are, therefore, circumstances where some men will
benefit from further courses of chemotherapy treatment when at
present they may not be offered it," Neate added.
The findings in the study have led to a larger one to
confirm them involving more than 1,100 men, Scher said.
(Editing by Maggie Fox and Xavier Briand)