Serum amylase is a sensitive tumor marker for amylase-producing small cell lung cancer?

A 68-year-old male smoker was diagnosed as having amylase-producing small-cell lung cancer (SCLC). The serum amylase level was elevated, at 1756 IU/l, and the isozyme pattern was salivary type. Serum levels of "the tumor markers" CEA and NSE were 10.0 ng/ml and 22.6 ng/ml, respectively, but the level of pro-GRP was within the normal range. He was treated with combination chemotherapy of carboplatin and irinotecan. After completion of the chemotherapy, the serum amylase level decreased below the cutoff range and a computed tomography (CT) scan of the chest revealed marked reductions of the tumor in the primary site and in the lymph node metastasis. In November 2003, he was noted to have a slightly raised amylase level, of 168 IU/l, and raised levels of tumor markers. At this time, a CT scan, bone scintigraphy, and magnetic resonance imaging (MRI) of the brain demonstrated no recurrence. However, in December, MRI of the brain showed multiple metastases, and the recurrence of SCLC was thus confirmed. For the treatment of disease progression, the same regimen of chemotherapy as that given initially was administered. CT imaging revealed a partial response in the primary site and lymph node metastasis, and the serum amylase level decreased to 91 IU/l. After the completion of the second chemotherapy regimen, he underwent cranial irradiation and further chemotherapy. However, unfortunately, he died owing to deterioration of lung cancer. In this patient, the serum amylase level was found to be a highly sensitive marker of lung cancer.