Successful Alectinib Treatment for Carcinoma of Unknown Primary with EML4-ALK Fusion Gene: A Case Report.

Gene alteration in anaplastic lymphoma kinase (ALK) is rare, and the efficacy of ALK inhibitors in the treatment of carcinoma of unknown primary (CUP) with ALK alteration remains unclear. The patient was a 56-year-old woman who presented with cervical lymph node swelling. Computed tomography revealed paraaortic, perigastric, and cervical lymph node swelling; ascites; a liver lesion; and a left adrenal mass. A cervical lymph node biopsy was performed, and pathological diagnosis of an undifferentiated malignant tumor was conducted. Finally, the patient was diagnosed with CUP and treated with chemotherapy. To evaluate actionable mutations, we performed a multigene analysis, using a next-generation sequencer (FoundationOne® CDx). It revealed that the tumor harbored an echinoderm microtubule-associated protein-like 4 (EML4) and ALK fusion gene. Additionally, immunohistochemistry confirmed ALK protein expression. Alectinib, a potent ALK inhibitor, was recommended for the patient at a molecular oncology conference at our institution. Accordingly, alectinib (600 mg/day) was administered, and the multiple lesions and symptoms rapidly diminished without apparent toxicity. The administration of alectinib continued for a period of 10 months without disease progression. Thus, ALK-tyrosine kinase inhibitors should be considered in patients with CUP harboring the EML4-ALK fusion gene.

Efficacy of trastuzumab deruxtecan in an advanced gastric cancer patient with brain metastasis.

BACKGROUND: There is no clinical evidence supporting the effectiveness of trastuzumab deruxtecan (T-DXd) for treating advanced gastric cancer (AGC) with brain metastasis. CASE REPORT: This is a case of a 65-year-old man with human epidermal growth factor-2 (HER2)-positive AGC. He was initially treated with capecitabine, cisplatin, and trastuzumab, followed by paclitaxel and ramucirumab, nivolumab, trifluridine and tipiracil, and irinotecan regimens in addition to radiation therapy for brain metastasis. The patient exhibited refractoriness to the standard regimen used for AGC and developed relapse of the brain metastasis after radiation accompanied by headache, nausea, and dizziness. In August 2020, following the approval of T-DXd for HER2-positive AGC, he received T-DXd therapy. After 5 cycles of T-DXd, contrast-enhanced computed tomography and magnetic resonance imaging demonstrated significant tumor shrinkage and improvement of symptoms. CONCLUSION: T-DXd demonstrated effectiveness for the treatment of brain metastasis arising from HER2-positive AGC.

Salvage Chemotherapy by FOLFIRI Regimen for Poorly Differentiated Gastrointestinal Neuroendocrine Carcinoma.

PURPOSE: Chemotherapy is the mainstay treatment for advanced poorly differentiated gastrointestinal neuroendocrine carcinoma (GI-NEC), with platinum-containing regimens being the optimal first-line regimen. However, the role and efficacy of second-line chemotherapy for GI-NEC are unclear. This study aimed to evaluate the feasibility and efficacy of fluorouracil, leucovorin, and irinotecan (FOLFIRI) as second-line therapy in patients with relapsed or recurrent GI-NEC after first-line platinum plus etoposide therapy. METHODS: We retrospectively evaluated eight consecutive patients with unresectable GI-NEC treated between 2017 and 2020. The inclusion criteria were pre-treatment with platinum doublet therapy, performance status (PS) 0-2, having measurable lesions, and treatment with FOLFIRI as second-line therapy. The overall response rate, progression-free survival (PFS), overall survival (OS), safety, and relative dose intensity were evaluated. RESULTS: Five patients met the inclusion criteria. Overall, 37 cycles of FOLFIRI were administered. The relative dose intensities for irinotecan, continuous infusion of 5-FU, and a bolus injection of 5-FU were 76%, 72%, and 54%, respectively. Overall, 2 of the 5 patients achieved partial response (40%), and the duration of response (DOR) was 4.0 months. The PFS and OS rates were 5.8 (95% CI, 1.5-NA) and 11 (95% CI, 6.3-NA) months, respectively. Overall, 4 of the 5 patients (80%) proceeded with further chemotherapy. Grade ≥ 3 adverse events except hematological toxicity included febrile neutropenia (n = 2), anorexia (n = 2), and fatigue (n = 1). Treatment discontinuation due to treatment-related adverse events was not observed. CONCLUSIONS: FOLFIRI showed modest efficacy and feasibility for GI-NEC patients and has thus potential for patients who fail the first-line treatment.