[Providing Opportunities for Close Examination of Lynch Syndrome after Microsatellite Instability Testing in a Hospital Setting].

Microsatellite instability(MSI)testing is performed in cancer patients to determine the indication for chemotherapy with immune checkpoint inhibitors. We report on our scheme to ensure that Lynch syndrome patients are offered the opportunity for genetic counseling and genetic testing. Two hundred and eight cancer patients(107 males and 101 females, 20- 87 years, mean 63.3 years)underwent MSI testing at our hospital between February 2019 and November 2021. From February 2019 to December 2020, the MSI testing was performed with a consent document that included a commentary on Lynch syndrome, and the results were explained only by the attending cancer doctors. Eleven(8.6%)of the 136 cases had MSI-high, but none of them led to a visit to the genetic medicine department. The Genome Center in our hospital, which was operational from April 2020, undertook information sharing by multiple professions and established a system to provide appropriate support to cancer doctors. Consecutively, 72 MSI tests were performed between January and November 2021, and 2 patients(2.8%)with MSI-high(1 with endometrial cancer and 1 with colorectal cancer)were referred to the Department of Clinical Genetics for genetic counseling. Through genetic testing, both were diagnosed with Lynch syndrome, and information on future surveillance and health care for blood relatives was provided.

[Administration Period of Olanzapine as an Antiemetic Drug for Patients on FEC Therapy-A Survey].

Olanzapine(OLZ)is a multi-acting receptor-targeted antipsychotic drug approved in Japan in December 2017 for the treatment of anticancer drug-induced nausea and vomiting. However, the recommended doses and administration periods of OLZ in the literature and guidelines are varied. Reports on the efficacy and safety of OLZ combined with perioperative chemotherapy for breast cancer in Japanese patients are few. Moreover, the risk of nausea and vomiting during treatment with anticancer drugs in young and women patients remains to be high. In this study, we conducted an exploratory survey on the optimal duration of OLZ administration(days 1-4: 5 mg, before sleep)during perioperative breast cancer 5-fluorouracil, epirubicin, cyclophosphamide(FEC)therapy. We found that treatment with OLZ showed efficacy in improving nausea grade and maintaining relative dose intensity. Moreover, it could be used safely without interruption due to side effects, such as weight gain, elevation in blood glucose, somnolence, and insomnia. Prophylactic antiemetic therapy with OLZ administration (days 1-4: 5 mg)prior to sleep was effective in patients having FEC therapy-induced nausea and vomiting.

New insights into patterns of first metastatic sites influencing survival of patients with hormone receptor-positive, HER2-negative breast cancer: a multicenter study of 271 patients.

BACKGROUND: The initial therapeutic strategy for hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer is based on the first metastatic site; however, little evidence is available regarding the influence of metastatic distribution patterns of first metastatic sites on prognosis. In this study, we aimed to identify the metastatic distribution patterns of first metastatic sites that significantly correlate with survival after recurrence. METHODS: We performed a retrospective review of records from 271 patients with recurrent metastatic HR+/HER2- breast cancer diagnosed between January 2000 and December 2015. We assessed survival after recurrence according to the metastatic distribution patterns of the first metastatic sites and identified significant prognostic factors among patients with single and multiple metastases. RESULTS: Prognosis was significantly better in patients with a single metastasis than in those with multiple metastases (median overall survival after recurrence: 5.86 years vs. 2.50 years, respectively, p < 0.001). No metastatic organ site with single metastasis was significantly associated with prognostic outcome, although single metastasis with diffuse lesions was an independent risk factor for worse prognosis (HR: 3.641; 95% CI: 1.856-7.141) and more easily progressing to multiple metastases (p = 0.002). Multiple metastases, including liver metastasis (HR: 3.145; 95% CI: 1.802-5.495) or brain metastasis (HR: 3.289; 95% CI: 1.355-7.937), were regarded as significant independent poor prognostic factors; however, multiple metastases not involving liver or brain metastasis were not significantly related to prognosis after recurrence. CONCLUSIONS: Single metastases with diffuse lesions could more easily disseminate systemically and progress to multiple metastases, leading to a poor prognosis similar to multiple metastases. Our findings indicate that the reconsideration of the determinant factors of therapeutic strategies for first recurrence in HR+/HER2- breast cancer may be needed.

Multicenter study of primary systemic therapy with docetaxel, cyclophosphamide and trastuzumab for HER2-positive operable breast cancer: the JBCRG-10 study.

BACKGROUND: The original aim of this study was to evaluate the treatment sequence and anthracycline requirement in docetaxel, cyclophosphamide and trastuzumab therapy. After one death in the anthracycline-containing arm, the protocol was amended to terminate the randomization. The single-docetaxel, cyclophosphamide and trastuzumab arm was continued to examine the efficacy and safety of the anthracycline-free regimen. METHODS: Women with human epidermal growth factor receptor-2-positive, operable and primary breast cancer were randomized to receive 5-fluorouracil, epirubicin and cyclophosphamide (four cycles) followed by docetaxel, cyclophosphamide and trastuzumab (four cycles), or docetaxel, cyclophosphamide and trastuzumab followed by 5-fluorouracil, epirubicin and cyclophosphamide, or docetaxel, cyclophosphamide and trastuzumab (six cycles). After the protocol amendment, patients were allocated to the docetaxel, cyclophosphamide and trastuzumab arm alone. The primary endpoint was a pathological complete response. RESULTS: In total, 103 patients were enrolled between September 2009 and September 2011: 21, 22 and 24 patients in the 5-fluorouracil, epirubicin and cyclophosphamide followed by docetaxel, cyclophosphamide and trastuzumab; docetaxel, cyclophosphamide and trastuzumab followed by 5-fluorouracil, epirubicin and cyclophosphamide and docetaxel, cyclophosphamide and trastuzumab arms, respectively, and 36 patients in the docetaxel, cyclophosphamide and trastuzumab arm after the protocol amendment. In total, 60 patients were allocated to the docetaxel, cyclophosphamide and trastuzumab arm, in which the pathological complete response rate was 45.8%, and disease-free survival at 3 years was 96.6%. Patients with stage I or IIA in the docetaxel, cyclophosphamide and trastuzumab arm showed good disease-free survival (100% at 3 years). The comparison of efficacy among the three arms was statistically underpowered. Left ventricular ejection fraction decreased significantly after 5-fluorouracil, epirubicin and cyclophosphamide followed by docetaxel-docetaxel, cyclophosphamide and trastuzumab (P = 0.017), but not after docetaxel, cyclophosphamide and trastuzumab followed by 5-fluorouracil, epirubicin and cyclophosphamide or docetaxel, cyclophosphamide and trastuzumab. CONCLUSIONS: The pathological complete response rate for docetaxel, cyclophosphamide and trastuzumab was similar to previous reports of anthracycline-containing regimens. Docetaxel, cyclophosphamide and trastuzumab might be an option for primary systemic therapy in human epidermal growth factor receptor-2-positive early breast cancer. A larger confirmatory study is necessary.

Multicentre, phase II study of eribulin in combination with S-1 in patients with advanced breast cancer.

BACKGROUND: We previously reported the synergistic effect of S-1 and eribulin in preclinical models. In addition, our phase I study revealed the recommended dose for the phase II study of the combination therapy in advanced breast cancer (ABC) patients pre-treated with anthracycline and taxane. Our current study reports on the efficacy and safety of the combined use of eribulin and S-1 in patients with ABC and poor prognosis. METHODS: Patients with breast cancer who received prior anthracycline- and/or taxane-based therapy were assigned to receive a combination therapy of eribulin (1.4 mg/m2 on days 1 and 8, every 21 days) and S-1 (65 mg/m2, on days 1 to 14, every 21 days) for advanced/metastatic disease. All patients had at least one clinicopathological factor such as being oestrogen receptor negative, Human Epidermal Growth Factor Receptor 2 (HER2) receptor negative, presence of visceral involvement, presence of three or more metastatic sites, or having a disease-free interval shorter than 2 years. The primary endpoint was the independent-reviewer assessed objective response rate (ORR). Secondary endpoints were clinical benefit rate, disease control rate, progression-free survival (PFS), and overall survival (OS). RESULTS: This study enrolled 33 patients. Confirmed ORR was 33.3% (95% CI: 17.3 to 52.8). Median PFS was 7.5 months (95% CI: 4.0 to 14.3). Median OS time was not reached during the current experimental periods. The most common grade 3/4 adverse event was neutropenia (68.8%). CONCLUSIONS: The combination of eribulin and S-1 is safe and effective for treatment in patients with ABC and poor prognosis. TRIAL REGISTRATION: Current Controlled Trials UMIN000015049 , date of registration: September 5th 2014.

Gemcitabine and Vinorelbine Combination Chemotherapy in Taxane-Pretreated Patients with Metastatic Breast Cancer: A Phase II Study of the Kinki Multidisciplinary Breast Oncology Group (KMBOG) 1015.

BACKGROUND: This phase II study was conducted to evaluate the efficacy and safety of the chemotherapy combination of gemcitabine and vinorelbine in taxane-pretreated Japanese metastatic breast cancer patients. METHODS: In this multicenter, phase II, single-arm study, patients with recurrent or metastatic HER2-negative breast cancer were administered gemcitabine (1,200 mg/m2) and vinorelbine (25 mg/m2) intravenously on days 1 and 8 every 3 weeks. The primary endpoint was the objective response rate, and other endpoints included progression-free survival, overall survival, and safety. RESULTS: A total of 42 patients were enrolled in this study. The objective response rate and clinical benefit rate were 24 and 43%, respectively. The median progression-free survival was 4.0 months. The median overall survival was 11.1 months. Grade 3/4 neutropenia was the most common hematologic toxicity, occurring in 22 patients (54%). Nonhematologic toxicity was moderate and transient, with fatigue (48%) being the most common condition and no severe adverse event reported. CONCLUSION: The combination of gemcitabine and vinorelbine is an effective and tolerable regimen for HER2-negative, taxane-pretreated, metastatic breast cancer patients in Japan.

[A Case of an Elderly Patient with Unresectable Gastric Cancer Treated by Paclitaxel and Ramucirumab].

An 80-year-old man was admitted to our hospital with appetite loss in December 2014. Gastroduodenal scope, abdominal computed tomography(CT), and laparoscopy revealed type 4 advanced gastric cancer(poorly differentiated adenocarcinoma) with multiple lymph node(LN)involvement and multiple peritoneal metastasis. S-1(80mg/body)was administrated between January 2015 and September 2015 in the outpatient clinic. A partial response was obtained, but a gastric tumor, ascites, and LN re-growth were observed. Since October 2015, paclitaxel(PTX)(70mg/m2; day 1, 8, and 15)and ramucir- umab(RAM)(8mg/kg; day 1 and 15)have been administered. After 2 courses, bi-weekly PTX plus RAM were continued for grade 3 neutropenia and grade 2 anorexia. The tumor and LNs partially responded, and the ascites disappeared. With this dosage and administration schedule, the partial response(PR)was maintained for approximately 8 months without any severe adverse reactions. This successful case might indicate that it is important for elderly patients with gastric cancer that progressed with prior chemotherapy regimens to consider appropriate reduction of the PTX dosage, schedule, and continuation of RAM.

[Three Cases of Bleeding from Advanced Gastric Cancer during Chemotherapy Treated with Transcatheter Arterial Embolization(TAE)].

Case 1: An 71-year-old man underwent chemotherapy with S-1 plus trastuzumab to treat type 3 gastric cancer that was diagnosed as Stage IV tubular adenocarcinoma(T4b[Panc], N3, H0, CY1, P0, M1). For anemia and active bleeding from the tumor, transcatheter arterial embolization(TAE)was performed with metallic coils on the splenic artery. Infarction of the spleen and left pleural effusion were observed. Second-line paclitaxel(PTX)chemotherapy was administered 4 weeks after TAE. Case 2: An 76-year-old man underwent chemotherapy with S-1 plus cisplatin to treat type 3 gastric cancer that was diagnosed as Stage IV tubular adenocarcinoma(T4a, N3, H0, P1, M1). For anemia and active bleeding from the tumor, TAE with gelatin sponge(Serescure®)was performed on the left and right gastric artery. Radiotherapy(31 Gy)with S-1 was performed because TAE was not effective for bleeding. After chemoradiotherapy, nab-PTX was administered. Case 3: An 74- year-old man underwent second-line chemotherapy with nab-PTX to treat type 4 advanced gastric cancer that was diagnosed as Stage IV tubular adenocarcinoma(T4a, N3, H1, P0, M1). For progression of anemia due to tumor bleeding, TAE with gelatin sponge(Serescure®)was performed on the left gastric artery. TAE was effective, and he was discharged from the hospital. In 2 of 3 cases, hemostasis was achieved by TAE. Therefore, TAE is effective to decrease bleeding from gastric cancer during chemotherapy.

[Clinical Experience of Ramucirumab for Treating Advanced Gastric Cancer].

BACKGROUND: The REGARD and RAINBOW trials showed that ramucirumab(RAM)alone and RAM plus paclitaxel(PTX) were effective therapies for advanced gastric cancer patients previously treated with chemotherapy. In this retrospective study, we evaluated the safety and efficacy of RAM alone and PTX plus RAM in such patients. METHODS: Patients who were received RAM at 8mg/kg or RAM plus PTX at 80mg/m2(on days 1, 8, and 15 of a 28-day cycle)between June 2015 and March 2016 were enrolled in this study. We compared the clinical outcome of RAM alone(RAM group, n=10)with that of RAM plus PTX(PTX+RAM group, n=13). RESULTS: The RAM group contained many more patients with poor performance status or prior chemotherapy of 2 or more regimens than the PTX+RAM group. All patients in both groups received chemotherapy on an outpatient basis. One case of grade 3 or 4 hematological adverse events was found in the RAM group and 6 cases were found in the PTX+RAM group. The overall response rate was 10% in the RAM group and 30% in the PTX+RAM group. Progression-free survival was 54 days in the RAM group and 187 days in the PTX+RAM group(p=0.0374). Overall survival was 158 days in the RAM group and was not reached in the PTX+RAM group(p=0.1091). CONCLUSIONS: RAM alone and RAM plus PTX can be administered safely on an outpatient basis and are beneficial for advanced gastric cancer patients previously treated with chemotherapy.

[Efficacy and Safety of Pertuzumab for HER2-Positive Metastatic Breast Cancer].

The CLEOPATRA trial showed a significant improvement in the progression-free survival (PFS) and overall survival of patients with HER2-positive first-line metastatic breast cancer (MBC) who were treated with pertuzumab (PER), trastuzumab (TRA), and docetaxel (DTX), compared to those treated with placebo, TRA, and DTX. PER was approved in 2013 for treating HER2-positive MBC in Japan. Herein, we present the retrospective review of data from 10 HER2-positive MBC patients who received PER in our hospital between September 2013 and August 2014.T he median age was 52 years (range, 45-66 years), and 7 patients were positive for ER.Six patients had not received any previous chemotherapy for their metastatic disease, while the others had received comparatively heavy pretreatment doses of chemotherapy.Our patients received the PER, TRA, and DTX regimen, although 2 patients were treated without DTX. Four patients experienced a partial response, 6 patients experienced stable disease (SD), and 3 patients experienced SD for ≥6 months. The response rate was 40%, and the clinical benefit rate was 70%.The median PFS was 7.3 months (range, 2.5-11.5 months). Grade 3 neutropenia and allergic reactions were observed in 1 and 2 patients, respectively; no Grade 4 adverse events were observed, and thus, the regimen was well tolerated. Further clinical research seems to be warranted for developing new treatment strategies involving PER for HER2-positive MBC.

[Examination of the Usefulness of Palliative Self-Expanding Metallic Stents in Patients with Malignant Colorectal Obstruction].

Self-expanding metallic stents (SEMS) are a useful palliative option in malignant colorectal obstruction. The aim of this study was to evaluate the clinical outcomes of SEMS used for palliation. Patients with malignant colorectal obstruction who underwent SEMS insertion in our hospital from April 2014 to March 2015 were enrolled in the study. Clinical outcomes and complications of palliative SEMS insertion were retrospectively analyzed. Nine patients were enrolled in the palliative SEMS group. The success rate was 100%, while the complication rate was 11%. Successful SEMS insertion may enable oral intake in a few days, but 3 patients required up to several weeks to resume oral intake. Palliative SEMS are effective and beneficial for malignant colorectal obstruction.

[A Case of Bone Metastasis from Early Gastric Cancer after a Five-Year Disease-Free Interval Following Gastrectomy].

A woman in her 50s underwent distal gastrectomy and D1+b dissection in December 2005 for early gastric cancer that was diagnosed as a signet-ring-cell carcinoma, fStage Ⅱ (T1a, N2, H0, P0, CY0, M0) with 12 lymph node metastases in the second field. Multiple bone metastases were diagnosed on the basis of CT and bone scintigraphy findings and serum ALP elevation (2,743 IU/L) I n December 2010. Fourteen courses of S-1 plus CDDP and 4 mg of zoledronate were administered from January to September in 2011. Pancytopenia, D-dimmer elevation, myelocytes, and metamyelocytes were observed in October 2012, indicating she had bone marrow metastasis. She was treated with a transfusion, anti-DIC therapy, and paclitaxel. She died from gastric cancer in December 2012. We report a rare case of recurrence with bone metastasis from early gastric cancer. S-1 plus CDDP chemotherapy and zoledronate therapy is an effective treatments for multiple bone metastases from gastric cancer.

[Two Cases of Bleeding Advanced Gastric Cancer Treated with Palliative Radiation Therapy].

Case 1: A man in his 70's was being treated with chemotherapy for unresectable advanced gastric cancer. Blood transfusion, endoscopic intervention including argon plasma coagulation, and transcatheter arterial embolization (TAE) were all used to treat repeated tumor bleeding causing anemia, but controlling the bleeding was difficult. In order to control the hemorrhage, radiation therapy of 31 Gy/10 Fr to the cancer was administered. After receiving radiation therapy, the anemia stopped. Case 2: A man in his 70's considered an operation for advanced gastric cancer, but his cardiac performance was poor and it was impossible to perform an operation. We conducted radiation therapy of 39 Gy/13 Fr for the purpose of preventing bleeding from gastric cancer. After receiving radiation therapy, the anemia stopped. We believe that radiation therapy is effective to stop bleeding from gastric cancer.

[Three Cases of Bleeding from Advanced Gastric Cancer Treated by Transcatheter Arterial Embolization(TAE)and Continued Chemotherapy].

Case 1: A man in his 70s was underwent transcatheter arterial embolization (TAE) because of progressive anemia, and the gastroduodenal artery and left gastric artery were embolized. Two weeks later, he started chemotherapy (S-1, Tmab). Case 2: A man in his 60s was underwent TAE because of anemia. The left gastric artery and right gastroepiploic artery were embolized. Bleeding was controlled and he continued chemotherapy. Case 3: A man in his 70s was who vomited blood during the course of chemotherapy underwent TAE, during which contrast dye extravasated from the anterior gastric artery. The splenic artery was embolized. After TAE, abdominal pain and splenic infarction appeared, but could be treated by conservative therapy. Chemotherapy was started 4 weeks later. TAE is an effective method for controlling bleeding from advanced gastric cancer.

[A Case of Invasive Ductal Carcinoma in the Fat Replacement of the Pancreatic Body and Tail].

A 56 year-old woman with obesity (BMI3 2) and diabetes mellitus was diagnosed with right renal cell carcinoma. She underwent right nephrectomy 1 year ago. Seven months after surgery, CT revealed a rapidly growing mass near the spleen. The mass showed slight accumulation of FDG (SUVmax=2.4) on PET-CT. Since the lesion grew rapidly and was not enhanced in the early phase of enhanced CT, we diagnosed pancreatic cancer. Distal pancreatectomy and splenectomy were performed. The final pathological diagnosis was invasive ductal carcinoma in the fat replacement of the pancreatic body and tail. Postoperatively, the patient had no complications such as pancreatic fistula or aggravation of glucose intolerance. She received postoperative chemotherapy with gemcitabine. Since she developed pulmonary artery thrombosis, postoperative chemotherapy was interrupted after 8 courses. Thirty-two months after the surgery, she was still living without any recurrence. Acinar cells were absent in the fat replacement of the pancreas, but the pancreatic duct cells were still present. There was carcinoma in situ in the main pancreatic duct surrounding chronic inflammation. Fat replacement itself could be potentially precursor of the pancreatic cancer.

[Therapeutic effect of rebamipide for oral mucositis associated with FEC therapy for breast cancer].

No guidelines for supportive drug therapy have been established for oral mucositis occurring during cancer chemotherapy. We retrospectively examined the progression of oral mucositis in 91 patients with breast cancer who received the 5-fluorouracil, epirubicin, and cyclophosphamide (FEC)-100 regimen between September 2007 and August 2008. Daily rebamipide was administered to patients with oral mucositis as per hospital protocol to evaluate the hypothesized preventive and mucosal protective effects of rebamipide(Mucosta®). Oral mucositis was observed in 43 patients (47%)during 4 courses of FEC. The median age of the patients was 55 years(range, 32-76 years). Of the 91 patients, 49 patients who did not receive rebamipide during the 4 FEC courses were classified as group A, 14 patients who received rebamipide before the start of FEC were classified as group B, and 28 patients who received rebamipide after developing oral mucositis were classified as group C. The incidence of oral mucositis at the start of FEC with or without rebamipide administration was observed in 5 patients in group B (36%) and 38 patients in groups A and C (49%) (p=0.3472). The mucositis grade was G1 in 4 patients and G2 in 1 patient in group B, and G1 in 20 patients and G2 plus G3 in 18 patients in groups A and C (p=0.2467). In group C, the grade decreased in 25 patients (89%) and did not occur (G0) in 17 patients (61%) during the next course, and 15 patients (54%) continued to the final course without any occurrence of mucositis. These results suggest that rebamipide is effective for the treatment of oral mucositis. Although significant differences were not observed in the groups, rebamipide has the potential to prevent development of oral mucositis and alleviate its symptoms, and seems promising as a new supportive drug therapy. We hope to verify the preventive and protective effects of rebamipide by conducting a prospective, randomized trial while treating oral mucositis with basic oral care and appropriate interventions provided by a multidisciplinary team.

[Long-term survival of a patient with esophageal metastasis from breast cancer treated with esophagectomy].

Esophageal metastasis from breast cancer is rarely observed. We encountered a case of long-term survival after esophageal metastasis from breast cancer that was treated with esophagectomy. A 79-year-old woman developed dysphagia 26 years after radical mastectomy. Endoscopic examination revealed stenosis at the mid-thoracic esophagus. An esophageal biopsy led to a diagnosis of undifferentiated cancer. A computed tomography (CT) scan revealed a massive tumor in the esophagus, but no distant metastases. Esophagectomy was performed with the suspicion of primary or metastatic esophageal cancer. Histopathologically, the excised tumor was an adenocarcinoma, which had histopathological features similar to that of the breast cancer. Accordingly, the adenocarcinoma was diagnosed as esophageal metastasis of the breast cancer. The patient is still alive 8 years after the esophagectomy.

[Effect of oral dexamethasone given 24 hours previously on docetaxel-induced edema: a retrospective study].

In Europe and the United States, beginning steroid treatment on the day before docetaxel(DTX)administration is recommended to reduce edema and/or hypersensitivity symptoms. In this study, we investigated the usefulness of starting steroid treatment on the day before DTX administration. Patients with breast cancer who received 4 or more cycles of DTX with or without trastuzumab or DTX and cyclophosphamide(TC)with or without trastuzumab as pre- or post-operative chemotherapy in our hospital between January 2010 and May 2012 were analyzed in this retrospective study. Patients were classified as those who started taking steroids on the day of DTX administration(GroupA: 62 patients)and those who started taking steroids on the day before DTX administration(GroupB: 47 patients). The incidence of edema and/or hypersensitivity was retrospectively compared between these groups after the completion of 4 cycles of chemotherapy. The incidence of edema was significantly lower in GroupB (n=12, 25.5%)than in GroupA (n=28, 45.2%; p=0.04). The onset of edema also tended to be later in GroupB. The incidence of hypersensitivity tended to be lower in GroupB(n=3, 6.4%)than in GroupA (n=8, 12.9%), although this difference was not statistically significant. These results suggest the benefit of steroid treatment started on the day before DTX administration in preventing the development of edema. Results also suggest that the onset of edema could be delayed by this administration method. We recommend that steroid premedication, which can lead to a reduction in adverse drug reactions to DTX, be used to help maintain patients' quality of life(QOL)and to support treatment continuation.

[A case of metastatic colorectal cancer that reduced in size after re-challenging with an anti-EGFR monoclonal antibody].

A 58-year-old woman was confirmed as having multiple liver metastases after undergoing a high anterior resection for a sigmoid colon tumor. She was administered bevacizumab+FOLFOX as the first regimen and bevacizumab+FOLFIRI and S-1 and irinotecan (IRIS)therapy as the second regimen. During this treatment she also underwent hepatectomy 3 times and radiofrequency ablation once. She was administered panitumumab+irinotecan as the third regimen and, due to the presence of multiple pulmonary metastases, was subsequently considered to have had a partial response (PR). Because she subsequently developed progressive disease (PD), she received the fourth regimen as part of a clinical trial (TAS102) in another hospital. Cetuximab+irinotecan was administered as the fifth regimen after PD and the tumor was found to have reduced in size by 23%upon computed tomography (CT) 2 months later. Although stable disease (SD) was achieved, she was subsequently administered regorafenib for 8 months as a sixth regimen after the disease progressed a second time. In some cases of KRAS wild type metastatic colorectal cancer, re-challenging with an anti-epidermal growth factor receptor (EGFR) monoclonal antibody seems to be an effective strategy for reducing tumor mass.

[Current status and future perspectives for the treatment of triple-negative breast cancer in Japan].

Triple-negative breast cancer (TNBC) is negative for all three markers, namely the hormone sensitivity receptors: estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2). TNBC accounts for approximately 15% of all primary breast cancer cases. In general, patients with this disease have a higher risk of recurrence and a poorer prognosis compared with those with other subtypes of breast cancer. Patients with TNBC are defined as those for whom endocrine or anti-HER2 therapy are not indicated due to poor response. It is a heterogeneous disease group that shows various characteristics. There is a group that achieves a complete response to chemotherapy and has an excellent prognosis, a group that does not respond to chemotherapy and has a poor prognosis, and a group that has an excellent inherent prognosis and does not need chemotherapy. The subdivision of TNBC cases based on the prognosis and response to therapy is an issue for the future. In addition to classifying TNBC into basal and non-basal types by testing cytokeratin 5/6 (CK5/6) and epidemic growth factor receptors (EGFR) by the immunohistochemical staining method, Ki-67 may predict sensitivity to anticancer agents and a change in Ki-67 before and after therapy may potentially predict prognosis. Patients with a non-pathologic complete response (non-pCR) to preoperative chemotherapy have a high risk of early recurrence, and measures to deal with it are therefore needed. At present, the most commonly used perioperative chemotherapy is sequential combination therapy of an anthracycline drug and a taxane drug; however, it is limited because the pathologic complete response(pCR)rates following preoperative chemotherapy range from 30 to 40%. There is also an urgent need to develop a regimen that will overcome this problem. In association with BRCA gene mutations, sensitivity to DNA-damaging anticancer agents may lead to promising therapies. However, unfortunately, the use of DNA-damaging agents such as cisplatin and carboplatin is not covered by health insurance in Japan. Various new molecular targeted drugs aimed at blocking cell proliferation factors are expected to be developed in the future. Here we have summarized the current status and issues based on the clinical experience with the diagnosis and treatment of TNBC.