Diagnosis and treatment of metachronous multiple primary carcinoma: A case report and review of literature

Table 1 The treatment regimen

Date	Treatment management	Efficacy evaluation
December 2017 to April 2018	In December 2017, modified radical mastectomy for left breast cancer and 4 cycles of EC regimen chemotherapy from December 2017 to March 2018. In April 2018, 4 cycles of chemotherapy were administered using the docetaxel regimen	The therapeutic effect was evaluated as CR
June 2018 to May 2021	Radiotherapy for proliferative lesions with a PTV of 50 Gy/25 fractions for proliferative lesions in the lung posterior right upper lobe in August and tamoxifen endocrine therapy was taken after it. The patient continues to receive treatment with tamoxifen combined with leuprorelin in May 2021	The therapeutic effect was evaluated as CR
August 2023	Diagnosed as DLBCL. R-CHOP regimen chemotherapy was administered, consisting of rituximab 600 mg/day 1, cyclophosphamide 1200 mg/day 1, doxorubicin 80 mg/day 1, vincristine 2 mg/day 1, and prednisone 100 mg/day 1-5	The patient developed neutropenia and fever after chemotherapy and then the dose was adjusted
September 2023 to December 2023	R-CHOP chemotherapy rituximab 600 mg/day 1, cyclophosphamide 1000 mg/day 1, pirarubicin 70 mg/day 1, vincristine 2 mg/day 1, and prednisone 100 mg/day 1-5. After second cycle of R-CHOP chemotherapy, CT showed a significant reduction of lymph nodes in the abdominal aorta, bilateral iliac vessels and abdominal compared to before	The therapeutic effect was evaluated as PR
January 2024 to February 2024	In January 2024, the treatment was changed to rituximab 500 mg/day 0, etoposide 0.15 g/day 1-3, ifosfamide 8 g/day 2, carboplatin 0.5 g/day 2. Bone marrow suppression significantly occurred after chemotherapy. In February 2024, the chemotherapy dosage was adjusted to rituximab 600 mg/day 0, etoposide 0.15 g/day 1-2, 0.1 g/day 3, ifosfamide 65 g/day 2, and carboplatin 0.4 g/day 2	The CT in July showed a reduction in the abdominal tumor, and the therapeutic effect was evaluated as PR
April 2024 to August 2024	From April to June 2024, 4 cycles of chemotherapy using a combination of 600 mg zuberitamab and Gemox regimen. The patient developed grade III bone marrow suppression at last chemotherapy. The fifth round of chemotherapy which included 600 mg of zuberitamab and Gemox regimen and lenalidomide starting from July. Targeted combination chemotherapy was administered in August, specifically consisting of rituximab 600 mg/day, gemcitabine 12 g/day, oxaliplatin 120 mg/day q2w, lenalidomide chemotherapy has been used ever since	The therapeutic effect was evaluated as PR
November 2024 until now	Rituximab 600 mg/day, gemcitabine 1 g/day, oxaliplatin 120 mg/day 1 q2w in November 2024. Targeted therapy with zebitumumab 600 mg was be administered in January 2025	The therapeutic effect was evaluated as CR. Currently, the patient's condition remained stable

EC: Epirubicin + cyclophosphamide regimen chemotherapy; PTV: Planning target volume; CR: Complete response; DLBCL: Diffuse large B-cell lymphoma; R-CHOP: Rituximab, cyclophospha-mide, hydroxydaunorubicin, Oncovin (vincristine) and prednisolone; CT: Computed tomography.