Serum Pro-Gastrin-Releasing Peptide Is a Useful Marker for Treatment Monitoring and Survival in Small-Cell Lung Cancer

Abstract

We investigated the usefulness of serum pro-gastrin-releasing peptide (Pro-GRP) as a tumor marker for diagnosis, treatment monitoring and the prediction of relapse and prognosis in patients with small-cell lung cancer (SCLC). Serum samples were obtained from 127 patients with primary lung cancer (48 patients with small-cell carcinoma, 31 with adenocarcinoma, 36 with squamous cell carcinoma and 11 with large-cell carcinoma). The cutoff levels of serum Pro-GRP and neuron-specific enolase (NSE) were set at 46 pg/ml and 10 ng/ml, respectively. The specificity of Pro-GRP was significantly higher than that of NSE (Pro-GRP: 93.7%, NSE: 65.8%, p < 0.01). According to the histological type of lung cancer, the positive rates of Pro-GRP were 75% (36/48) in the small-cell carcinomas, 9.7% (3/31) in the adenocarcinomas, 5.6% (2/36) in the squamous cell carcinomas and 0% (0/10) in the large cell carcinomas. The median levels of Pro-GRP in limited disease (LD) and extensive disease (ED) patients were 199 and 295.5 pg/ml, whereas those of NSE were 14.8 and 29.3 ng/ml, respectively. The positive rates of Pro-GRP in LD and ED patients were 80.0% (16/20) and 71.4% (20/28), whereas those of NSE were 70.0% (14/20) and 89.3% (25/28), respectively. The positive rate of NSE tended to elevate with the progression of disease, whereas that of Pro-GRP was already high at an early stage. Among the 29 patients with SCLC who could be followed, the serum Pro-GRP levels of 18 responders were significantly decreased after treatment (p < 0.01), whereas those of the 11 nonresponders were not significantly different between before and after treatment (p = 0.72). In the 9 patients with SCLC who relapsed, the serum Pro-GRP levels were again elevated at the time of relapse. Seventeen patients whose ratio of the Pro-GRP level after treatment to the level before treatment was below 50% (taking the levels before treatment as 100%) survived significantly longer than did the patients whose ratio was over 50% (p < 0.01). The results of the present study suggest that serum Pro-GRP has high specificity and could be a useful marker of SCLC for treatment monitoring and prognosis.

Pro‐gastrin–releasing peptide as a factor predicting the incidence of brain metastasis in patients with small cell lung carcinoma with limited disease receiving prophylactic cranial irradiation

“…25 Serum laboratory methods more accurately evaluate the evidence of viable tumor cells, and have a complementary role to the imaging studies when macroscopic tumor disappears or residual scar remains. In SCLC, tumor markers are well correlated to the response and tumor volume, 19,21,22 as was observed with Pro GRP in the current study. Therefore, CR according to the RECIST guidelines might be more appropriate in the evaluation of patients with SCLC for PCI.…”

“…20,21 It is reported that Pro GRP reflects tumor volume and the effect of treatment more sensitively than does NSE, and that it is useful in detecting PD because Pro GRP levels increase before disease recurrence becomes evident. 19,21,22 From the results of the current study, the elevation of Pro GRP before PCI might reflect the existence of residual viable tumor cells after a series of induction treatments, even if CR or good PR is indicated by imaging. A PCI would be recommended for patients with limited and extensive disease SCLC with CR.…”

Definitive Chemoradiotherapy of Limited-disease Small Cell Lung Cancer: Retrospective Analysis of New Predictive Factors Affecting the Treatment Results

“…In these protocols, radiation dose and time factors are crucial. Tumor markers are considered to be associated with outcome (6)(7)(8)(9)(10). In addition to these factors, we proposed that tumor size affected treatment outcome.…”

Treatment of limited disease small cell lung cancer: the multidisciplinary team

“…Next to imaging, smoking cessation should be actively discussed. Although plasma progastrin-releasing peptide with or without neuron-specific enolase measurements may be a useful diagnostic marker to detect early recurrence [112][113][114][115], prospective trials evaluating the benefit are lacking and therefore routine tumour marker assessment is not recommended in this setting.…”