2017 Volume 57 Issue 1 Pages 23-28
Background. The recommended primary therapy for ALK-positive lung cancer is crizotinib. While remains effective for a long time for some patients, it eventually becomes ineffective and leads to an enlargement of the tumor in many other patients. Case. The patient was a 71-year-old woman who was diagnosed with pulmonary adenocarcinoma in 2012 (cT2aN3M1b, stage IV, ALK-positive). During chemotherapy, several cystic lesions without contrast enhancement were found on contrast-enhanced cranial MRI and their progress was observed. After chemotherapy became ineffective in May 2013, the treatment was changed to the oral administration of crizotinib, which resulted in the shrinkage of the primary lesion. Nine months from the start of crizotinib treatment, the patient's cerebral lesions were enlarged, while the primary lesion was observed to have shrunk. Craniotomy was therefore performed to conduct a biopsy. The definitive diagnosis of the biopsy specimen was metastasis to the brain from pulmonary adenocarcinoma. After whole brain irradiation, an exacerbation of bone metastasis occurred and the oral administration of alectinib was initiated in September 2014. A significant reduction of the metastatic lesions was observed on contrast-enhanced cranial MRI at one month after the start of alectinib treatment and the tumor reduction effect continues to be effective at 19 months after the start of alectinib treatment. Conclusion. In this case, alectinib was effective for treating brain metastasis for which crizotinib was ineffective. This is partly because there is a difference in the degree of transitivity of both drugs to the central nervous system. Moreover, because metastasis to the brain from mucinous tumors may provide atypical imaging findings--as occurred in this case--sufficient observation and a definitive histology-based diagnosis are vital.
