Objective: To assess the frequency of osteosclerotic changes on CT that appeared after treatment with gefitinib in patients with lung adenocarcinoma and the relationship between the osteosclerotic changes and the response to the therapy.
Materials and methods: Our study included 41 patients with lung adenocarcinoma who underwent chest CT both before (CTpre) and after (CTpost) starting treatment with gefitinib. The presence or absence of bone metastases was assessed on the CTpre, and the interval bony change after the therapy was classified as lytic, sclerotic, or no changes on the CTpost. The relationship between treatment results of primary lung cancer and interval bony changes was evaluated.
Results: Osteosclerotic lesions were identified in 11 patients (27%) on CTpost; in 6 of 11 patients osteosclerotic lesions newly appeared where the CTpre showed no bone metastasis before the gefitinib therapy. There were significant differences in the therapeutic response of the primary cancers (P < 0.001) and in the survival rate (P < 0.01) in patients with osteosclerotic changes versus those without osteosclerotic changes.
Conclusion: Osteosclerotic changes on CT, observed after gefitinib treatment in patients with lung adenocarcinomas, may be an indicator of a good therapeutic response.