Bone Scan in Gastric Cancer Patients: A Retrospective Review

Abstract

Background: Bone scan has a very highly sensitive role in detection bone metastases. Bone metastasis from stomach cancer occurs only rarely and it is known to have a very poor prognosis. Bone metastases in Gastric cancer are mainly osteolytic, and disruption of bone integrity and resulting in bone pain and pathological fracture. In this study, we aimed to review the incidence, clinical characteristics, and related risk factors for bone metastases in patients with a primarily diagnosis of gastric cancer. Methods: We retrospectively evaluated all patients who diagnosed with primary gastric cancer and underwent initially as staging working up with bone scintigraphy between 2010 and 2014 at Seoul St. Mary’s hospital, The Catholic University of Korea. Total numbers of primary diagnosis of gastric cancer patients were 1589/1721 (92.33%) patients received bone scan as initial staging work up. We further analyzed the patients according to eligibility criteria we created and the incidence of and the risk factors for bone metastases were investigated. Results: Out of 1589 patients analyzed, bone metastases were clearly confirmed only in 15 patients (0.8%). The mean age was 59.0 ± 8.6 years (range 24–90) and a majority of patients were male (60%). Dominant histological type either poorly differentiated type or signet ring cancer type and Bormann’s classification type 3 was the majority. In the distribution of the gastric tumor in correlation to the upper, middle and lower third was not clinically variant. The mean tumor size among this group was 3.6 ± 2.3 cm (range 0.6–20 cm). All patients were advanced gastric cancer type clinically and the median follow-up period was 9 months. The incidence of bone metastases was (20%). In (80%) of patients had bone metastases and another site of metastases. Among these, most of the time associated regional lymph node metastases was found. Most patients had multiple bone metastases instead of a single bone lesion. The whole patients of bone metastases were advanced gastric cancers, and the most common metastatic site was the whole skeleton, followed by combined vertebra, rib and scapula. Bone scintigraphy and PET-CT were mostly used together for diagnosing bone metastasis. The serum alkaline phosphatase at the time of diagnosis had increased in only 5 cases (35.71%) and there were clinical symptoms of bone pain in 8 cases (53.0%). Other variables also were not significantly valued like anemia, tumor markers like carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9).Treatment was given to 14 cases (93.3%) and it was mostly chemo or concomitant chemoradiotherapy. Conclusions: The preoperative bone scan was positive in 0.8% for bone metastasis in patients with gastric cancer. Suggesting that whole-body bone scan should not be performed routinely in patients with gastric cancer. For bone scan to be as cost-effective tool, may be needed for selected group of patients i.e. advanced stages of gastric cancer or clinically symptomatic patients. Serum ALK has poor correlation with early bone metastasis detection.