DNAM-1 promotes inflammation-driven tumor development via enhancing IFN-γ production.

DNAM-1 is an activating immunoreceptor on T cells and natural killer (NK) cells. Expression levels of its ligands, CD155 and CD112, are up-regulated on tumor cells. The interaction of DNAM-1 on CD8+ T cells and NK cells with the ligands on tumor cells plays an important role in tumor immunity. We previously reported that mice deficient in DNAM-1 showed accelerated growth of tumors induced by the chemical carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Contrary to those results, we show here that tumor development induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) together with DMBA was suppressed in DNAM-1-deficient mice. In this model, DNAM-1 enhanced IFN-γ secretion from conventional CD4+ T cells to promote inflammation-related tumor development. These findings suggest that, under inflammatory conditions, DNAM-1 contributes to tumor development via conventional CD4+ T cells.

CD155 mutation (Ala67Thr) increases the binding affinity for and the signaling via an inhibitory immunoreceptor TIGIT.

CD155 is a shared ligand for activating and inhibitory immunoreceptors DNAX accessory molecule 1 (DNAM-1), also called CD226, and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), which are expressed on natural killer (NK) cells and T cells, and positively and negatively regulates tumor immune responses, respectively. A recent study showed that the single nucleotide polymorphism rs1058402G>A causing a mutation to Thr from Ala at residue 67 of CD155 is associated with worse overall survival of patients with small cell lung cancer and suggested that this is caused by the decreased affinity of mutant CD155 for DNAM-1 as a result of the 3D structural analysis. Unexpectedly, however, we found that the mutation increased the binding affinity for TIGIT rather than decreased the binding affinity for DNAM-1 and induced a stronger signal than WT CD155. Our results suggest that the mutation suppresses tumor immune responses by generating a stronger inhibitory signal in immune cells in the tumor microenvironment.

Absolute Lymphocyte Count as an Independent Prognostic Factor in Metastatic Breast Cancer: A Retrospective Study.

INTRODUCTION: Recently, absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) have been reported to be prognostic and/or predictive factors in breast cancer. However, most of the investigations on the relationship between systemic inflammatory markers and prognosis have been conducted perioperatively, with few studies reporting on patients with metastatic or recurrent breast cancer (MBC). Here, we investigated the role of ALC and NLR as prognostic factors of MBC. METHODS: This was a retrospective observational study of patients with MBC treated at the University of Tsukuba Hospital between 2013 and 2020. ALC and NLR clinical data were obtained from the patients' charts. Based on the previous reports, the cutoff value of ALC was set at 1,500/µL and that of NLR, at 3. We investigated the prognostic significance of ALC and NLR. RESULTS: About 80% of the 243 included patients were hormone receptor-positive, 20% were HER2-positive, and 10% were triple negative. The patients were grouped as follows: 114 (46.9%) and 129 (53.1%) in the high and low ALC groups and 145 (59.7%) and 98 (40.3%) in the high and low NLR groups, respectively. The group with high ALC at diagnosis of MBC showed significantly better prognosis (p = 0.002), and the median overall survival (OS) was 70.9 months, as compared with 40.2 months for the low ALC group. On multivariate analysis, visceral metastasis, subtype, and ALC were independent variables for OS; the NLR status was not correlated with OS. CONCLUSIONS: Analysis of real-world data suggests that ALC at diagnosis of MBC is an independent prognostic factor.

Two Cases of Distant Metastasis After Mastectomy for Breast Ductal Carcinoma In Situ.

While the prognosis for ductal carcinoma in situ (DCIS) of the breast is generally excellent, distant metastasis after appropriate local treatment is extremely rare. We experienced two cases of distant metastasis after mastectomy for breast ductal carcinoma in situ. In both cases, the surgical margins were negative, the sentinel nodes were negative for metastasis. The first case was a 67-year-old woman who developed lung metastases four years after mastectomy for high-grade DCIS. The second case was a 34-year-old woman with intermediate-grade DCIS who developed intraductal recurrence localized to the nipple two years after the initial nipple-sparing mastectomy and multiple lung and liver metastases six months later. Both cases developed distant metastases despite appropriate local treatment, without preceding or concurrent invasive local recurrence. Although the probability of distant recurrence is low, it is important to inform patients about the risk of recurrence.

Safety and Efficacy of Compression Therapy to Prevent Chemotherapy-Induced Peripheral Neuropathy in Lower Extremities of Breast Cancer Patients: A Pilot Study.

Background Chemotherapy-induced peripheral neuropathy (CIPN) is a problematic adverse event for breast cancer patients receiving taxane antimitotic agents. We evaluated the effectiveness of compression therapy against CIPN in the lower extremities of breast cancer patients receiving taxanes. Methods Eligible patients scheduled for perioperative treatment with taxanes for early-stage breast cancer were enrolled. Each patient wore latex-free surgical gloves and compression socks, putting on two layers of each 15 minutes before the administration of taxanes and removing them 15 minutes after administration. Peripheral neuropathy (PN) was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 and the Patient Neurotoxicity Questionnaire (PNQ). The primary endpoint was the incidence of CTCAE version 4.0 grade 2 or higher CIPN in the lower extremities during the entire period of perioperative chemotherapy with taxanes. Results PN assessment by CTCAE in the lower extremities, the primary outcome, showed that 13.3% developed grade 2 sensory disturbances, and 8.3% developed grade 2 motor disturbances. The incidence of CTCAE grade 2 or higher PN in the hands was 26.7% for sensory disturbances and 13.3% for motor disturbances during the entire study period. No patient had grade 3 or higher PN. No adverse events due to compression therapy were observed. Conclusion Compression of the lower extremities with compression socks tended to reduce the incidence of CIPN compared to the general incidence. Compression therapy may help prevent the development of CIPN.

Recurrent severe hypocalcemia following chemotherapy regimen changes in advanced breast cancer: two case reports.

BACKGROUND: As an oncologic emergency related to abnormalities in calcium metabolism, hypercalcemia associated with paraneoplastic syndrome and bone metastases is well known. Meanwhile, the incidence of hypocalcemia is low, except in cases associated with bone-modifying agents used for bone metastases. Hypocalcemia induced by bone-modifying agents typically occurs early after the initial administration, and its incidence can be significantly reduced by preventive administration of calcium and vitamin D3 supplements. CASE REPORT: We report two cases of recurrent severe hypocalcemia occurring during chemotherapy for metastatic breast cancer with multiple bone metastases. Case 1: A 35-year-old Japanese woman developed metastases in the bone, liver, and ovaries during postoperative endocrine therapy for invasive lobular carcinoma of the breast. She underwent chemotherapy and treatment with denosumab. She experienced recurrent episodes of severe hypocalcemia subsequent to a change in the chemotherapy regimen. Case 2: A 65-year-old Japanese woman encountered multiple bone metastases after postoperative anti-human epidermal growth factor receptor 2 therapy and during endocrine therapy for invasive ductal carcinoma of the breast. She underwent anti-human epidermal growth factor receptor 2 therapy and treatment with denosumab. She experienced recurrent severe hypocalcemia subsequent to a change in the chemotherapy regimen to letrozole + lapatinib, trastuzumab emtansine, and lapatinib + capecitabine. CONCLUSIONS: We observed two cases of recurrent severe hypocalcemia in patients with advanced breast cancer and bone metastases after modifications to their therapy regimens. These cases differed from the typical hypocalcemia induced by bone-modifying agents. It is possible that antitumor drugs affect calcium and bone metabolism associated with bone metastases. While these cases are rare, it is crucial for oncologists to be aware of hypocalcemia not only at the initiation of bone-modifying agents but also throughout the entire antitumor therapy, as hypocalcemia can lead to fatal outcomes.

Local recurrence of breast cancer histologically resembling Paget disease presumably due to needle tract seeding: a case report.

Seeding of cancer cells along the needle tract during core needle biopsy is a well-known phenomenon, with a reported frequency of between 22 and 50% [Hoorntje et al. in Eur J Surg Oncol 30:520-525, 2004;Liebens et al. in Maturitas 62:113-123, 2009;Diaz et al. in AJR Am J Roentgenol 173:1303-1313, 1999;]. Local recurrence due to needle tract seeding is rare because the immune system eliminates the cancer cells in most cases. In addition, most local recurrences due to needle tract seeding occur as invasive carcinoma after diagnosis of invasive ductal carcinoma of the breast or mucinous carcinoma, and needle tract seeding due to noninvasive carcinoma is uncommon. We herein report a rare case of local breast cancer recurrence histologically resembling Paget disease, presumably due to needle tract seeding after core needle biopsy for diagnosis of ductal carcinoma in situ of the breast. After receiving a diagnosis of ductal carcinoma in situ, the patient underwent skin-sparing mastectomy and breast reconstruction with a latissimus dorsi musculocutaneous flap. The pathological study showed ER/PgR-negative ductal carcinoma in situ, and no postoperative radiation therapy or systemic therapy was administered. Six months after the surgery, the patient had a breast cancer recurrence histologically resembling Paget disease, presumably in the scar of her core needle biopsy. The pathological study showed Paget disease localized in the epidermis, no invasive carcinoma, and no lymph node metastasis. It was morphologically similar to the primary lesion and was diagnosed as a local recurrence due to needle tract seeding.

Investigation of the significance of population-based breast cancer screening among women aged under 40 years.

BACKGROUND: Owing to low incidence rates, population-based breast cancer screening is not recommended by many municipalities in Japan for women aged < 40 years. To evaluate the usefulness of screening in women aged < 40 years, we investigated the results of population-based breast cancer screening among young women performed in the Ibaraki Prefecture. METHODS: Data regarding histological characteristics, recall rates, cancer detection rates, positive predictive values, tumor categories, and status of lymph node metastases were obtained from population-based screening data from Ibaraki Health Service Association Institute. The "number needing to be screened" (NNS) was determined; using Pearson's chi-squared test, these data were compared between women aged < 40 years and > 40 years. RESULTS: The data of 428,560 women were evaluated. Cancer detection rates were significantly lower and the NNS and proportion of women with tumor category T2 or higher was significantly increased in women aged < 40 years than in those aged > 40 years (0.06% vs. 0.21%, 1505 vs. 281-439, and 28.9% vs. 6.3%, respectively; all, p < 0.05). The proportion of early-stage cancers was lower in women aged < 40 years than in those > 40 years, but this was not significant. CONCLUSIONS: These results suggest that population-based breast cancer screening should not be recommended for women aged < 40 years. To reduce the breast cancer-related mortality rate in young women and ensure efficient use of limited medical resources in Japan, a more efficient surveillance system, based on genetic propensity and family history, needs to be established.

Four cases of Trousseau syndrome associated with breast cancer that exhibited central nervous system manifestations.

Cancer-associated thrombosis is known as Trousseau syndrome (TS). Here, we report 4 cases of TS associated with advanced breast cancer that caused central nervous system (CNS) vascular events. All 4 patients experienced sudden onset of CNS symptoms. Imaging revealed multiple brain infarctions or intracranial hemorrhage and all 4 patients had leptomeningeal or brain metastasis. Laboratory findings showed hypercoagulability at diagnosis of TS. Of the 4 patients, 2 patients were treated with unfractionated heparin, while 2 patients could not undergo anticoagulant therapy. In all patients, once the TS occurred, the CNS symptoms progressed rapidly and the prognosis was very poor, 3 patients dying within about a month of diagnosis of TS. Therefore, the predictive factors of TS are important and standards and guidelines for administration of anticoagulants are needed.

Tumor-derived soluble CD155 inhibits DNAM-1-mediated antitumor activity of natural killer cells.

CD155 is a ligand for DNAM-1, TIGIT, and CD96 and is involved in tumor immune responses. Unlike mouse cells, human cells express both membranous CD155 and soluble CD155 (sCD155) encoded by splicing isoforms of CD155. However, the role of sCD155 in tumor immunity remains unclear. Here, we show that, after intravenous injection with sCD155-producing B16/BL6 melanoma, the numbers of tumor colonies in wild-type (WT), TIGIT knock-out (KO), or CD96 KO mice, but not DNAM-1 KO mice, were greater than after injection with parental B16/BL6 melanoma. NK cell depletion canceled the difference in the numbers of tumor colonies in WT mice. In vitro assays showed that sCD155 interfered with DNAM-1-mediated NK cell degranulation. In addition, DNAM-1 had greater affinity than TIGIT and CD96 for sCD155, suggesting that sCD155 bound preferentially to DNAM-1. Together, these results demonstrate that sCD155 inhibits DNAM-1-mediated cytotoxic activity of NK cells, thus promoting the lung colonization of B16/BL6 melanoma.

High expression of soluble CD155 in estrogen receptor-negative breast cancer.

BACKGROUND: The poliovirus receptor (CD155) is expressed ubiquitously at low levels on both hematopoietic and nonhematopoietic cells, but its expression is upregulated in various tumor cells. An activating receptor DNAM-1 expressed on cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells binds to CD155 and mediates the cytotoxic activity of CTLs and NK cells against tumors. Unlike mouse tissues, human tissues express a soluble form of CD155 (sCD155), which is a splicing isoform of CD155 lacking the transmembrane region. We previously reported that the serum levels of sCD155 were higher in lung, gastrointestinal, breast, and gynecologic cancer patients than in healthy donors. Here, we focus on breast cancer patients. METHODS: To analyze the association between serum level of sCD155 and clinicopathological parameters of breast cancer, we quantified sCD155 in the sera of 153 breast cancer patients by sandwich ELISA. RESULTS: sCD155 levels in the sera of breast cancer patients were positively correlated with patient age, disease stage, and invasive tumor size. Moreover, they were higher in patients with estrogen receptor (ER)-negative cancers than in those with ER-positive tumors, and higher in those with Ki-67-high cancers than in those with Ki-67-low cancers. CONCLUSIONS: The serum level of sCD155 is correlated with high risk factors in breast cancer.

Preoperative diagnosis of a giant cell tumor of soft tissue arising from the breast by ultrasound-guided core needle biopsy.

Giant cell tumors of soft tissue (GCT-ST) arising in the breast are extremely rare. Herein, we report a case of a 45-year-old woman with a 5-cm mass in her left breast. Ultrasonography revealed a mainly well-circumscribed mass that contained a cystic lesion. Magnetic resonance imaging showed a fibrous capsule-covered mass that contained a high-intensity area, suggesting hemorrhaging. Ultrasound-guided core needle biopsy (CNB) revealed mononuclear histiocytic cells with a round shape or spindled appearance that was mixed with multinucleated giant cells. Immunohistochemical analysis revealed CD68-positive staining in the mononuclear and giant cells but negative staining for pancytokeratin. Preoperatively, the tumor was highly suspected of being GCT-ST. Histopathological results after a left mastectomy showed similar findings to CNB. The final diagnosis was GCT-ST in the breast. To the best of our knowledge, this is the first case report of a GCT-ST arising in the breast diagnosed by ultrasound-guided CNB.

A case of hemorrhagic cystitis caused by nab-paclitaxel.

Nab-paclitaxel (nab-PTX) is a nanoparticle albumin-bound paclitaxel and, as such, is free of solvents like ethanol and polyoxyethylene castor oil. The absence of solvents from this formulation has several practical advantages: it has a shorter infusion time, it negates the need for premedications for hypersensitivity reactions, and it can be administered to patients with alcoholic hypersensitivity. It is thought that nab-paclitaxel will be in widespread use in the near future because of its convenience and efficacy. Here, we report the case of a breast cancer patient who developed hemorrhagic cystitis potentially due to treatment with nab-paclitaxel. The patient was 69-year old lady with stage IIB left breast cancer. She was due to undergo neoadjuvant chemotherapy and started weekly treatment with nab-paclitaxel. On the second day of the first cycle of treatment, she experienced symptoms of cystitis, but was not hemorrhagic and the symptoms were managed with antibiotics. After the third cycle, the symptoms of cystitis became severe, and she was diagnosed with hemorrhagic cystitis and discontinued chemotherapy with nab-paclitaxel. This is the first case report of hemorrhagic cystitis associated with nab-paclitaxel.

Increased Soluble CD155 in the Serum of Cancer Patients.

Emerging evidence suggests that DNAM-1 (CD226) play an important role in the recognition of tumor cells and their lysis by cytotoxic T lymphocytes (CTL) and NK cells. Although the DNAM-1 ligand CD155 is ubiquitously expressed in various tissues, many human tumors significantly upregulate the expression of CD155; DNAM-1 on CTL and NK cells may be involved in tumor immunity. However, unlike those in mice, human tissues also express soluble isoforms of CD155 (sCD155) that lack the transmembrane region. Here, we show that sCD155 levels were significantly higher in the sera of 262 patients with lung, gastrointestinal, breast, and gynecologic cancers than in sera from healthy donors. In addition, the sCD155 levels were significantly higher in patients with early stage (stages 1 and 2) gastric cancer than in healthy donors, and were significantly higher in patients with advanced stage (stages 3 and 4) disease than in patients in those with early stage disease and healthy donors. Moreover, the sCD155 levels were significantly decreased after surgical resection of cancers. Thus, sCD155 level in serum may be potentially useful as a biomarker for cancer development and progression.

Increased CD112 expression in methylcholanthrene-induced tumors in CD155-deficient mice.

Tumor recognition by immune effector cells is mediated by antigen receptors and a variety of adhesion and costimulatory molecules. The evidence accumulated since the identification of CD155 and CD112 as ligands for DNAM-1 in humans and mice has suggested that the interactions between DNAM-1 and its ligands play an important role in T cell- and natural killer (NK) cell-mediated recognition and lysis of tumor cells. We have previously demonstrated that methylcholanthrane (MCA) accelerates tumor development in DNAM-1-deficient mice, and the Cd155 level on MCA-induced tumors is significantly higher in DNAM-1-deficient mice than in wild-type (WT) mice. By contrast, Cd112 expression on the tumors is similar in WT and DNAM-1-deficient mice, suggesting that CD155 plays a major role as a DNAM-1 ligand in activation of T cells and NK cells for tumor immune surveillance. To address this hypothesis, we examined MCA-induced tumor development in CD155-deficient mice. Unexpectedly, we observed no significant difference in tumor development between WT and CD155-deficient mice. Instead, we found that Cd112 expression was significantly higher in the MCA-induced tumors of CD155-deficient mice than in those of WT mice. We also observed higher expression of DNAM-1 and lower expression of an inhibitory receptor, TIGIT, on CD8+ T cells in CD155-deficient mice. These results suggest that modulation of the expression of receptors and CD112 compensates for CD155 deficiency in immune surveillance against MCA-induced tumors.

Accelerated tumor growth in mice deficient in DNAM-1 receptor.

Since the identification of ligands for human and mouse DNAM-1, emerging evidence has suggested that DNAM-1 plays an important role in the T cell- and natural killer (NK) cell-mediated recognition and lysis of tumor cells. However, it remains undetermined whether DNAM-1 is involved in tumor immune surveillance in vivo. We addressed this question by using DNAM-1-deficient mice. DNAM-1-deficient cytotoxic T lymphocyte (CTL) and NK cells showed significantly less cytotoxic activity against DNAM-1 ligand-expressing tumors in vitro than wild-type (WT) cells. The methylcholanthrene (MCA)-induced fibrosarcoma cell line Meth A expressed the DNAM-1 ligand CD155, and DNAM-1-deficient mice showed increased tumor development and mortality after transplantation of Meth A cells. Moreover, the DNAM-1-deficient mice developed significantly more DNAM-1 ligand-expressing fibrosarcoma and papilloma cells in response to the chemical carcinogens MCA and 7,12-dimethylbenz[a]anthracene (DMBA), respectively, than did WT mice. These results indicate that DNAM-1 plays an important role in immune surveillance of tumor development.