SAN DIEGOA new rapid technique for quantitative reverse transcription-polymerase chain reaction (QRT-PCR) detects nodal micrometastases in esophageal cancer patients intraoperatively and predicts disease recurrence. The technique is quicker and perhaps more accurate than intraoperative histology, making it useful in determining the need for neoadjuvant therapy in some types of cancer.
Investigators from the University of Pittsburgh Cancer Institute presented data at the 81st Annual Meeting of the American Association for Thoracic Surgery describing the new technique and its benefits.
The incidence of esophageal adenocarcinoma is increasing faster than that of any other solid tumor, said Tony E. Godfrey, PhD, assistant professor of surgery. Overall 5-year survival rates for this disease are only 10% to 13%, rising only to 50% to 70% in early-stage, lymph-node-negative patients.
More accurate methods are required to predict disease recurrences and allow appropriate treatment allocation, as there may be a survival benefit for node-positive patients who receive neoadjuvant therapy, Dr. Godfrey said.
RT-PCR successfully detects micro-metastases, but has limitations, including false-positive findings and low specificity. The researchers believed that a quantitative analysis could improve the correlation with disease recurrence.
The research objective was to develop and evaluate a rapid technique for quantitative RT-PCR staging of lymph nodes that could be performed intraoperatively within 30 minutes.The approach utilizes a new quantitative thermocycler (SmartCycler, Cepheid, Sunnyvale, California) capable of fast cycling, combined with rapid RNA isolation, and a sensitive one-tube RT-PCR procedure, developed in the Pittsburgh laboratory (see photograph below).