P1.02-087 Sensitive Detection of Rare Cancer Cells by Preprogrp-Specific RT-PCR and Its Correlation with Clinicopathological Data and Survival

Abstract

Reverse transcription polymerase chain reaction (RT-PCR) based amplification of transcripts expressed in cancer but not in normal non-neoplastic cells is increasingly used for the sensitive detection of rare disseminated or exfoliated cancer cells to improve cancer staging and early detection protocols. This study aimed to detection of Prepro–Gastrin-Releasing Peptide in peripheral blood in lung cancer patients referred to National Cancer Institute, Cairo University, Egypt and to identify its relationship with clinicopathological features, prognosis and survival. Our study group consisted of 62 newly diagnosed lung cancer cases and 30 healthy volunteers, RNA was isolated from peripheral blood and then the samples were assayed by nested RT- PCR. Pearson's chi (X2) test was used to compare categorical variables. Kaplan Meier curves for survival analysis and Median and range for continuous variables were used for statistical analysis. Our study included 62 cases of lung cancer (60 males, median age was 57(34-81) years. For clinicodemographic data (Fig.1). Eleven (17%) cases had pleural effusion (stage IV). Seventeen (27%) cases had extensive SCLC, 7 cases had limited SCLC. Forty-four (70%) cases received chemotherapy, 20 (32%) cases received palliative radiotherapy to bone, brain or mediastinum. Seventeen (27%) had elevated alkaline phosphatase level. Seven (63%) out of the 11 cases with bone metastasis underwent splintage, internal fixation ± bone cement injection to reinforce a bone defect prior to palliative radiotherapy (pRTH). As regard SCLC, 10 (16%) cases received platinum based chemotherapy. One case developed GIII mucositis and one case developed jaundice and PS became III and shifted to best supportive treatment. One case received gamma knife to cerebellar metastasis, one case received palliative RTH to mediastinum and another pRTH to brain before chemotherapy. Twenty-six (41.9%) cases were preprogastrin +ve(53.8% SCLC, 15.4% Squamous cell ca, 15.4%large cell ca, 11.5% adenocarcinoma and 3.8% undifferentiated carcinoma). Median PFS=3.9 months (2.87-4.96). Median PFS among preprogastrin –ve vs. +ve cases was 4 vs. 3 months. There was a statistical significant relationship between preprogastrin and SCLC with higher number of SCLC among +ve preprogastrin cases (P=0.038). Also, there was a statistical significant relationship between preprogastrin and smoking with many smokers among +ve preprogastrin cases (P=0.010). SCLC and smoking are significantly correlated with preprogastrin. Median PFS was longer in preprogastrin -ve cases. So detection of circulating tumor cells might be a suitable parameter to identify patients who might benefit from adjuvant therapy. Smoking cessation is mandatory.