Last Updated: 2003-02-13 13:11:50 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Detection of survivin, a gene that inhibits apoptosis, in sentinel lymph nodes (SLNs) is an adverse prognostic factor in melanoma patients, according to researchers at the University of Rome.
Dr. Anna Maria Angliano and colleagues studied between outcomes of melanoma patients in relation to sentinel node expression of several apoptosis-related genes: bcl-2, bax, and bcl-X, as well as survivin. They used two reverse transcriptase polymerase chain reaction assays (RT-PCR) to analyze 36 SLNs and reevaluated 17 of them (47%) using immunohistochemistry. The duration of patient follow-up ranged from 19 to 88 months (median 52.9 months).
Of the 26 patients who tested positive for survivin gene expression on RT-PCR, 16 (61.5%) died or showed progression of disease, the research team reports in the Journal of Clinical Oncology for January 15. Conversely, 100% of the 10 patients who tested negative remained disease-free.
On RT-PCR the researchers detected bcl-2 in 86% of patients, bax in 69%, and bcl-X in 80.5%. However, expression of bcl-2 and expression of bcl-X did not correlate with progression of disease, and neither did the ratio of bcl-2 to bax.
"Indeed, this finding may represent a further confirmation of the role of survivin in the progression of disease," Dr. Angliano's group proposes. "The majority of patients (80%) showing both positivity for survivin gene expression and high levels of bcl-2 compared with bax died because of the disease....The expression of survivin and bcl-2 in SLNs may provide two independent mechanisms of apoptosis inhibition."
In 4 of 17 samples (24%), the RT-PCR data regarding survivin did not correlate with immunohistochemical findings. This observation "led us to conclude that the immunohistochemistry is not so sensitive for this purpose," the authors state. "However, we cannot exclude the possibility that the correlation between mRNA and protein expression would be higher on a larger number of samples."
For now, though, they recommend the use of an RT-PCR assay for detection of survivin in sentinel lymph nodes.
J Clin Oncol 2003;21:306-321.