[A Case of Breast Cancer Recurrence Responding to Trastuzumab Deruxtecan for Increased Cervical Lymph Node Metastasis during Anti-HER2 Therapy].

A 65-year-old woman underwent breast-conserving surgery for right breast cancer 12 years ago. The primary lesion was ER-positive, PgR-negative, presenting no amplification of the HER2 gene, and endocrine therapy was continued. After 10 years postoperation, duodenal stenosis due to peritoneal metastasis was noted, and the positive conversion of the HER2 expression was confirmed in peritoneal metastasis. Peritoneal lesions could be reduced by chemotherapies combined with trastuzumab and pertuzumab; however, hoarseness due to cervical lymph node metastasis appeared. Administration of T- DXd was initiated. After 4 cycles of T-DXd, her cervical lymph nodes shrank, and hoarseness improved. Because of its high drug-to-antibody ratio and the bystander effect, T-DXd was considered effective even in metastatic lesions presenting tumor heterogeneity or low HER2 expression.

[Breast Cancer Patient with Bone Metastases Who Was Able to Return Home without Using Opioids after Administration of Strontium-89 Chloride].

A 46-year-old woman underwent mastectomy for right inflammatory breast cancer.Three years later, she was diagnosed with multiple bone metastases and was treated with systemic chemotherapy and zoledronic acid.Six years after the mastectomy, she complained of severe sacral pain, and 40 Gy external radiotherapy was applied to the sacral metastases.Oxycodone was also administered, but dose escalation was difficult because of severe nausea and fatigue.A bone scan showed increased uptake of Tc99m in an area consistent with the painful regions, and an injection of 89SrCl2 was administered.Five weeks after the injection, her severe pain was relieved and she was able to discontinue the use of opioids completely.She successfully lived at home for 100 days without using opioids.In this case, radionuclide therapy with 89SrCl2 led to remarkable pain relief with an improvement in the quality of life of the patient.

[A Case of Drug-Induced Lung Injury Associated with Paclitaxel plus Bevacizumab Therapy].

A 61-year old woman with recurrent breast cancer received combined treatment with paclitaxel (PTX) and bevacizumab (BV) as the third-line chemotherapy. During the administration of PTX in the 3 courses of chemotherapy, she suddenly developed respiratory failure, and both chest X-ray and CT revealed bilateral pulmonary infiltrates. Symptoms and radiographic findings responded dramatically to steroid pulse therapy. The history of onset and laboratory data showed no evidence of infection; therefore, we made a diagnosis of acute lung injury induced by the chemotherapy. It should be noted that lung injury may be induced by both PTX and BV, and is one of the important adverse events despite the low frequency of occurrence.

[Successful Administration of Regorafenib to a Metastatic Colon Cancer Patient with Impaired Performance Status by Reducing the Initial Dose].

A 59-year-old woman had recurrences in the spleen and lung 10 years after radical excision of cecal cancer. After 27 months of treatment with 5-fluorouracil/Leucovorin, oxaliplatin, irinotecan, bevacizumab, and anti-EGFR antibodies, multiple bone metastases and a left adrenal metastasis developed, and the patient's performance status (PS) deteriorated to grade 3. Regorafenib was administered at 80 mg/day. The pain and appetite improved within 2 courses, and her PS improved from grade 3 to 2. Regorafenib was increased to 120 mg/day for the 2nd course, and the patient was treated for 5 months without severe adverse effects. Regorafenib is considered to be a salvage-line treatment only for patients in relatively good condition, because full-dose regorafenib treatment often leads to severe adverse effects. Dose escalation of regorafenib from the low initial dose of 80 mg/day may be a safe and effective way of providing an opportunity of this chemotherapy to patients with impaired PS.

[A case report of recurrent small bowel adenocarcinoma successfully treated with monoclonal antibody against EGFR and S-1].

A man in 30s was admitted to our hospital with a complaint of abdominal and back pain. Abdominal CT scan showed a large mass and double balloon endoscopy detected a tumor of the jejunum. The pathological diagnosis of biopsy samples was poorly differentiated adenocarcinoma. After radical resection, adjuvant chemotherapy with mFOLFOX6 was administered, however, a recurrent lesion developed. Although the lesion was successfully removed again, it did not react to the combination therapy with irinotecan and cisplatin. Because the tumor showed a high percentage of epidermal growth factor receptor (EGFR) expression and also had a wild-type KRAS status, a therapeutic strategy targeting EGFR was selected. The patient started on panitumumab associated with S-1 and obtained a complete response on CT 6 weeks later. Small bowel adenocarcinoma is an aggressive malignancy with a poor prognosis and little information about its definitive chemotherapy. Analysis of molecular characterization, an increase in reported experience, and prospective trials are needed to improve a prognosis.

[Role of palliative chemotherapy and shift from anticancer therapy to palliative care in patients with advanced or recurrent breast cancer].

We examined the role of palliative chemotherapy and the shift from anticancer therapy to palliative care in 30 patients who had died of advanced or recurrent breast cancer. Patients who received more than four chemotherapy regimens had a longer survival and started analgesics later than those who received less than three regimens. In addition, median survival time was prolonged in patients treated with both anthracycline- and taxane-containing regimens. Presence of bone metastases did not influence survival time, but extended the period of last hospitalization. In the average process of advanced or recurrent breast cancer, use of analgesics was started on the 500 th day and the last hospitalization was on the 760 th day from the diagnosis. Last chemotherapy was performed 29 days before death, and the median survival length was 811 days. Patients were treated as outpatients in 94% of the period from their recurrence until death. Therefore, it is especially important to support outpatients physically and mentally from the early stage of recurrence.