The impact of the COVID-19 pandemic on perioperative chemotherapy for breast cancer.

BACKGROUND: Since it was first reported in December 2019, coronavirus disease 2019 (COVID-19) spread rapidly across the globe resulting in a pandemic. As of August 2022, seven outbreak peaks have been confirmed in Tokyo, and the numbers of new cases in the fifth and later outbreak periods have been far greater than in the preceding periods. This retrospective study examined the impact of the COVID-19 pandemic on perioperative chemotherapy for breast cancer. METHODS: Patients with breast cancer who received perioperative chemotherapy at the National Cancer Center Hospital East were divided into 2 groups: 120 and 384 patients who started chemotherapy before and during the pandemic, respectively. The incidence of critical events that had potential detrimental effects on the prognosis, such as start of adjuvant chemotherapy ≥91 days after surgery and relative dose intensity of chemotherapy <85% were compared between groups. RESULTS: No significant difference in the incidence of critical events was found. When stratified by outbreak period, the incidence of critical events was positively correlated with the increasing number of new cases of COVID-19 (r = 0.83, p = 0.04). Moreover, 25/173 patients (14%) who started perioperative chemotherapy during the fifth and sixth outbreak periods developed COVID-19 infection, 80% of whom (20/25) had a delay or interruption to their surgery or other perioperative treatments. CONCLUSIONS: Although the impact of the COVID-19 pandemic on perioperative chemotherapy on whole groups of patients was not evident when comparing periods before and after the pandemic, the impact is becoming prominent in parallel with increasing numbers of new COVID-19 cases.

Clinical features of CDK4/6 inhibitor-related interstitial lung disease in patients with breast cancer: a case series study.

BACKGROUND: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are the standard treatment for advanced hormone receptor-positive breast cancer. Although interstitial lung disease is a rare (1-3.3%) but serious adverse event associated with CDK4/6 inhibitors, the incidence of interstitial lung disease in Japanese patients in the real world and the risk factors of interstitial lung disease are not clear. METHODS: We retrospectively investigated the incidence of interstitial lung disease in 224 patients with advanced breast cancer who received CDK4/6 inhibitors at our hospital between 31 January 2017 and 31 January 2021. The correlation of age (>50 vs ≤50 years), presence or absence of previous history of interstitial lung disease, lung metastasis, smoking history and chest radiation with the development of interstitial lung disease was evaluated. RESULTS: In total, 177 cases received palbociclib, 39 cases received abemaciclib and 8 cases received both palbociclib and abemaciclib, constituting a palbociclib group (n = 185) and an abemaciclib group (n = 47). At a median observation period of 607 days, 8.0% (18/224) cases (13 definite and 5 probable cases) had interstitial lung disease; 6.5% (12/185) of palbociclib-treated and 13% (6/47) of abemaciclib-treated cases. The median time to interstitial lung disease onset was 178 (range, 14-750) days. There was no significant correlation between the background factors studied and the development of interstitial lung disease. CONCLUSION: The frequency of CDK4/6 inhibitor-induced interstitial lung disease was higher than that reported in clinical trials. We did not identify any risk factors for the development of interstitial lung disease in this study, and thus, larger studies that include patient predisposition are required.

[Retropharyngeal abscess with cervical discitis and vertebral osteomyelitis caused by Escherichia coli in a patient with liver cirrhosis].

We describe the case of a 67-year-old male with liver cirrhosis who presented with fever and neck pain. Magnetic resonance imaging of the spine detected cervical vertebral osteomyelitis, and enhanced CT of the neck and spine revealed retropharyngeal abscess. The patient was treated with empirical antimicrobial therapy and surgical drainage due to significant airway involvement. Escherichia coli was cultured from the blood and pus in inferior cervical vertebrae which was a rare pathogen. Haematogenous spread may have resulted in cervical vertebral osteomyelitis and retropharyngeal abscess. With high mortality rates, early diagnosis of retropharyngeal abscess is required to avoid debilitating complications such as airway obstruction.

Renal embolism as a primary manifestation of Streptococcus dysgalactiae subspecies equisimilis endocarditis in a patient with chronic aortic dissection.

We report a case of renal embolism as an initial manifestation of Streptococcus dysgalactiae subspecies equisimilis (SDSE) endocarditis in a patient with chronic aortic dissection. A 37-year-old man who underwent total aortic arch replacement owing to aortic dissection, presented with a 3-h history of fever, chills, and acute right-sided flank pain. The endocarditis affected the native aortic valve and was complicated by a renal embolism. Blood culture results were positive for SDSE. Intravenous penicillin resulted in satisfactory clinical and echocardiographic recovery.

Immunogenicity and toxicity of transferrin receptor-targeted hybrid peptide as a potent anticancer agent.

PURPOSE: Transferrin receptor (TfR) is a cell membrane-associated glycoprotein involved in the cellular uptake of iron and the regulation of cell growth. Recent studies have shown elevated expression levels of TfR on cancer cells compared with normal cells. We previously designed a TfR-lytic hybrid peptide, which combines the TfR-binding peptide and a lytic peptide, and reported that it bound specifically to TfR and selectively killed cancer cells. Furthermore, the intravenous administration of TfR-lytic peptide in an athymic mouse model significantly inhibited tumor progression. To evaluate the immunogenicity of this peptide as a novel and potent anticancer agent, we investigated whether TfR-lytic hybrid peptide elicits cellular and humoral immune responses to produce antibodies. We also examined the toxicity of this peptide in syngeneic mice. METHODS: We performed hematologic and blood chemistry test and histological analysis and assessed hemolytic activity to check toxicity. To evaluate the immunogenicity, measurement of murine interferon-gamma and detection of TfR-lytic-specific antibody by ELISA were demonstrated. RESULTS: No T cell immune response or antibodies were detected in the group treated with TfR-lytic hybrid peptide. No hematologic toxicity, except for a decrease in leukocytes, was observed, and no remarkable influence on metabolic parameters and organs (liver, kidney, and spleen) was noted. CONCLUSIONS: Therefore, TfR-lytic hybrid peptide might provide an alternative therapeutic option for patients with cancer.

HER2-targeted hybrid peptide that blocks HER2 tyrosine kinase disintegrates cancer cell membrane and inhibits tumor growth in vivo.

HER2 is a transmembrane oncoprotein encoded by the HER2/neu gene and is overexpressed in approximately 20% to 30% of breast cancers. We have recently designed a novel class of drug, the hybrid peptide, which is chemically synthesized and is composed of a target-binding peptide and a lytic peptide containing cationic-rich amino acid components that disintegrate the cell membrane, leading to cancer cell death via membrane lysis. In this study, we designed a HER2-binding peptide linked to this novel lytic peptide, which we termed the HER2-lytic hybrid peptide and assessed the cytotoxic activity of this hybrid peptide in vitro and in vivo. The HER2-lytic hybrid peptide showed high cytotoxic activity against all ovarian and breast cancer cell lines, even trastuzumab- and/or lapatinib-resistant cells, but not against normal cells. Competition assays using anti-HER2 antibody and knockdown of this receptor by siRNA confirmed the specificity of the HER2-lytic hybrid peptide. In addition, it was shown that the HER2-lytic hybrid peptide can disintegrate the cancer cell membrane of HER2-overexpressing SK-BR-3 cancer cells in only 5 minutes, but not normal cells, and block HER2 signaling. Intravenous administration of the HER2-lytic peptide in the athymic mouse implanted with BT-474 and MDA-MB-453 cells significantly inhibited tumor progression. The HER2-lytic hybrid peptide was effective even in breast cancer cell lines that are resistant to trastuzumab and/or lapatinib in vitro and in vivo. Therefore, this hybrid peptide may provide a potent treatment option for patients with cancer.

Cytotoxic activity to acute myeloid leukemia cells by Antp-TPR hybrid peptide targeting Hsp90.

We previously reported that Antp-TPR hybrid peptide inhibited the interaction of Hsp90 with TPR2A and had selective cytotoxic activity discriminating between normal and cancer cells to induce cancer cell death. In this study, we investigated the cytotoxic activity of Antp-TPR peptide toward acute myeloid leukemia (AML) cells. It was demonstrated that Antp-TPR peptide induced AML cell death in cell lines such as U937, K562, THP-1, and HL-60 via activation of caspases 3 and 7, and disruption of mitochondrial membrane potential. Conversely, Antp-TPR peptide did not reduce the viability of normal cells including peripheral blood mononuclear cells (PBMCs), although both geldanamycin and 17-AAG, small-molecule inhibitors of Hsp90, mediated cytotoxicity to these normal cells at low concentrations. In addition, mutation analysis of TPR peptide demonstrated that the highly conserved amino acids Lys and Arg were critical to the cytotoxic activity. These results indicated that Antp-TPR hybrid peptide would provide potent and selective therapeutic options in the treatment of AML.

A novel transferrin receptor-targeted hybrid peptide disintegrates cancer cell membrane to induce rapid killing of cancer cells.

BACKGROUND: Transferrin receptor (TfR) is a cell membrane-associated glycoprotein involved in the cellular uptake of iron and the regulation of cell growth. Recent studies have shown the elevated expression levels of TfR on cancer cells compared with normal cells. The elevated expression levels of this receptor in malignancies, which is the accessible extracellular protein, can be a fascinating target for the treatment of cancer. We have recently designed novel type of immunotoxin, termed "hybrid peptide", which is chemically synthesized and is composed of target-binding peptide and lytic peptide containing cationic-rich amino acids components that disintegrates the cell membrane for the cancer cell killing. The lytic peptide is newly designed to induce rapid killing of cancer cells due to conformational change. In this study, we designed TfR binding peptide connected with this novel lytic peptide and assessed the cytotoxic activity in vitro and in vivo. METHODS: In vitro: We assessed the cytotoxicity of TfR-lytic hybrid peptide for 12 cancer and 2 normal cell lines. The specificity for TfR is demonstrated by competitive assay using TfR antibody and siRNA. In addition, we performed analysis of confocal fluorescence microscopy and apoptosis assay by Annexin-V binding, caspase activity, and JC-1 staining to assess the change in mitochondria membrane potential. In vivo: TfR-lytic was administered intravenously in an athymic mice model with MDA-MB-231 cells. After three weeks tumor sections were histologically analyzed. RESULTS: The TfR-lytic hybrid peptide showed cytotoxic activity in 12 cancer cell lines, with IC(50) values as low as 4.0-9.3 µM. Normal cells were less sensitive to this molecule, with IC(50) values > 50 µM. Competition assay using TfR antibody and knockdown of this receptor by siRNA confirmed the specificity of the TfR-lytic hybrid peptide. In addition, it was revealed that this molecule can disintegrate the cell membrane of T47D cancer cells just in 10 min, to effectively kill these cells and induce approximately 80% apoptotic cell death but not in normal cells. The intravenous administration of TfR-lytic peptide in the athymic mice model significantly inhibited tumor progression. CONCLUSIONS: TfR-lytic peptide might provide a potent and selective anticancer therapy for patients.

Identification of HLA-A*0201/-A*2402-restricted CTL epitope-peptides derived from a novel cancer/testis antigen, MCAK, and induction of a specific antitumor immune response.

Cancer immunotherapy is a potential therapeutic strategy, in addition to surgical treatment, radiotherapy, and chemotherapy. Cancer-specific immunotherapy, such as the MAGE peptide vaccine, has been utilized clinically. How-ever, there are inherent limits to the effectiveness of vaccinotherapy using a single antigen because of the expression frequency of cancer-specific antigens on tumor cells. Thus, identification of a new cancer-specific antigen is needed. In this study, we examined the possibility of using cancer-specific immunotherapy based upon mitotic centromere-associated kinesin (MCAK) which was previously identified as a novel cancer/testis antigen. To evaluate the feasibility of developing cancer immunotherapy using MCAK peptides, we studied HLA-A*0201 and *2402 as targets for CTLs in the context of HLA class I molecules. By using a peptide with a sequence of AINPELLQL (amino acid positions 63-71 in MCAK, HLA-A*0201) and FFEIYNGKL (amino acid positions 401-409 in MCAK, HLA-A*2402), CTL responses could be induced from unseparated PBMCs by stimulation of freshly isolated, peptide-pulsed PBMCs as antigen-presenting cells (APCs) and also by using interleukin-7 and keyhole limpet hemocyanin in primary culture. The induced CTLs could lyse HLA-A-*0201/*2402 colon and gastric cancer cells expressing MCAK, as well as the peptide-pulsed target cells, in an HLA class l, and CD8 restricted manner. The identification of the MCAK/HLA-A*0201 and *2402 peptides suggests the possibility of designing peptide-based immunotherapeutic approaches that might prove effective in treating patients with MCAK-positive cancer.