Relationship between Volpara Density Grade and Compressed Breast Thickness in Japanese Patients with Breast Cancer.

BACKGROUND: High breast density found using mammographs (MGs) reduces positivity rates and is considered a risk factor for breast cancer. Research on the relationship between Volpara density grade (VDG) and compressed breast thickness (CBT) in the Japanese population is still lacking. Moreover, little attention has been paid to pseudo-dense breasts with CBT < 30 mm among high-density breasts. We investigated VDG, CBT, and apparent high breast density in patients with breast cancer. METHODS: Women who underwent MG and breast cancer surgery at our institution were included. VDG and CBT were measured. VDG was divided into a non-dense group (NDG) and a dense group (DG). RESULTS: This study included 419 patients. VDG was negatively correlated with CBT. The DG included younger patients with lower body mass index (BMI) and thinner CBT. In the DG, patients with CBT < 30 mm had lower BMI and higher VDG; however, no significant difference was noted in the positivity rate of the two groups. CONCLUSIONS: Younger women tend to have higher breast density, resulting in thinner CBT, which may pose challenges in detecting breast cancer on MGs. However, there was no significant difference in the breast cancer detection rate between CBT < 30 mm and CBT ≥ 30 mm.

Number of kinesins engaged in axonal cargo transport: A novel biomarker for neurological disorders.

Kinesin motor proteins play crucial roles in anterograde transport of cargo vesicles in neurons, moving them along axons from the cell body towards the synaptic region. Not only the transport force and velocity of single motor protein, but also the number of kinesin molecules involved in transporting a specific cargo, is pivotal for synapse formation. This collective transport by multiple kinesins ensures stable and efficient cargo transport in neurons. Abnormal increases or decreases in the number of engaged kinesin molecules per cargo could potentially act as biomarkers for neurodegenerative diseases such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), spastic paraplegia, polydactyly syndrome, and virus transport disorders. We review here a model constructed using physical measurements to quantify the number of kinesin molecules associated with their cargo, which could shed light on the molecular mechanisms of neurodegenerative diseases related to axonal transport.

[A Case of Liver Metastasis of Colorectal Cancer Successfully Treated with Hepatic Arterial Infusion Chemotherapy after Systemic Chemotherapy Was Difficult to Administer].

The patient underwent partial sigmoid colon resection for sigmoid colon cancer with hyper CEA blood(1,110.6 ng/mL) and concurrent liver metastases mostly in the right lobe of the liver, followed by systemic chemotherapy(SOX plus BEV). Seven courses of chemotherapy resulted in PR on imaging, and CEA was reduced to 5.0 ng/mL, which was within reference values. As he continued chemotherapy, frequent hematologic toxicities and adverse events forced frequent dose reductions and changes in the chemotherapy schedule. About 2 years after surgery(19 courses of SOX plus BEV), the liver metastases became slightly enlarged on imaging, and the CEA was also increasing. The patient did not wish to undergo systemic chemotherapy and requested hepatic arterial infusion chemotherapy(HAIC), which has relatively few side effects and adverse events. HAIC with pyrimidine fluoride alone is ongoing for 22 courses, and tumor markers have decreased again with PR on imaging. Performance status has been good without hematologic toxicity or adverse events for approximately 1 year during the course of HAIC. HAIC is a weakly recommended therapy in the colorectal cancer treatment guidelines, but it is considered one of the most effective therapies with relatively few side effects.

Deep Learning-Based Image Quality Improvement in Digital Positron Emission Tomography for Breast Cancer.

We investigated whether 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography images restored via deep learning (DL) improved image quality and affected axillary lymph node (ALN) metastasis diagnosis in patients with breast cancer. Using a five-point scale, two readers compared the image quality of DL-PET and conventional PET (cPET) in 53 consecutive patients from September 2020 to October 2021. Visually analyzed ipsilateral ALNs were rated on a three-point scale. The standard uptake values SUVmax and SUVpeak were calculated for breast cancer regions of interest. For "depiction of primary lesion", reader 2 scored DL-PET significantly higher than cPET. For "noise", "clarity of mammary gland", and "overall image quality", both readers scored DL-PET significantly higher than cPET. The SUVmax and SUVpeak for primary lesions and normal breasts were significantly higher in DL-PET than in cPET (p < 0.001). Considering the ALN metastasis scores 1 and 2 as negative and 3 as positive, the McNemar test revealed no significant difference between cPET and DL-PET scores for either reader (p = 0.250, 0.625). DL-PET improved visual image quality for breast cancer compared with cPET. SUVmax and SUVpeak were significantly higher in DL-PET than in cPET. DL-PET and cPET exhibited comparable diagnostic abilities for ALN metastasis.

Spatial and Quantitative Analysis of Tumor-Associated Macrophages: Intratumoral CD163-/PD-L1+ TAMs as a Marker of Favorable Clinical Outcomes in Triple-Negative Breast Cancer.

Tumor-associated macrophages (TAMs) and abnormalities in cancer cells affect cancer progression and response to therapy. TAMs are a major component of the tumor microenvironment (TME) in breast cancer, with their invasion affecting clinical outcomes. Programmed death-ligand 1 (PD-L1), a target of immune checkpoint inhibitors, acts as a suppressive signal for the surrounding immune system; however, its expression and effect on TAMs and the clinical outcome in breast cancer are unknown. In this study, we used high-throughput multiple immunohistochemistry to spatially and quantitatively analyze TAMs. We subjected 81 breast cancer specimens to immunostaining for CD68, CD163, PD-1, PD-L1, CD20, and pan-CK. In both stromal and intratumoral areas, the triple-negative subtype had significantly more CD68/CD163, CD68/PD-L1, and CD163/PD-L1 double-positive cells than the estrogen receptor (ER)/progesterone receptor (PR) subtype. Interestingly, a higher number of CD68+/PD-L1+/CK-/CD163- TAMs in the intratumoral area was correlated with a favorable recurrence rate (p = 0.048). These findings indicated that the specific subpopulation and localization of TAMs in the TME affect clinical outcomes in breast cancer.

Focal Uptake in the Sternum on 18F-FDG-PET/CT Caused by G-CSF Therapy after Chemotherapy Mimicking Bone Metastasis of Breast Cancer.

A woman in her 70s was diagnosed with left breast cancer and left axillary lymph node metastasis by an ultrasound-guided biopsy. 18F-FDG-PET/CT showed strong FDG accumulation in the tumor in the left breast and a left axillary lymph node. Neoadjuvant chemotherapy (NAC) was administered in combination with a G-CSF injection to prevent febrile neutropenia. The post-treatment 18F-FDG-PET/CT showed the disappearance of the left breast tumor and left axillary lymph node and revealed a solitary new area of strong FDG accumulation in the sternum. To rule out the possibility of sternal metastasis, a sternal biopsy was performed at the same time as surgery, which revealed no malignant findings. Although very rare, focal uptake on 18F-FDG-PET/CT performed after anticancer drug therapy with G-CSF may mimic a solitary bone metastasis. A bone biopsy may be a useful technique to avoid an immediate misdiagnosis of bone metastasis.

Comparison of 18F-fluorothymidine Positron Emission Tomography/Computed Tomography and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Breast Cancer.

The uptake of 18F-fluorothymidine (18F-FLT) depends on cells' proliferative rates. We compared the characteristics of 18F-FLT positron emission tomography/computed tomography (PET/CT) with those of 18F-fluorodeoxyglucose (18F-FDG) PET/CT for breast cancer. We prospectively diagnosed patients with breast cancer who underwent 18F-FLT PET/CT and 18F-FDG PET/CT. Subsequently, significant differences and correlation coefficients of the maximum standardized uptake value (SUVmax) in primary breast cancer and axillary lymph nodes were statistically evaluated. We enrolled eight patients with breast cancer. In six treatment-naive patients, the SUVmax for primary lesions showed a significant difference (mean, 2.1 vs. 4.1, p = 0.031) and a strong correlation (r = 0.969) between 18F-FLT and 18F-FDG. Further, although the SUVmax for the axillary lymph nodes did not show a significant difference between 18F-FLT and 18F-FDG (P = 0.246), there was a strong correlation between the two (r = 0.999). In a patient-by-patient study, there were cases in which only 18F-FDG uptake was observed in lymph nodes and normal breasts. Bone metastases demonstrated lower accumulation than bone marrow on the 18F-FLT PET/CT. In conclusion, a strong correlation was observed between the 18F-FLT PET/CT and 18F-FDG PET/CT uptake. Differences in the biochemical characteristics of 18F-FLT and 18F-FDG were reflected in the accumulation differences for breast cancer, metastatic lesions, and normal organs.

Quantitative high-throughput analysis of tumor infiltrating lymphocytes in breast cancer.

In breast cancer (BC), the development of cancer immunotherapy including immune checkpoint inhibitors has progressed. Tumor infiltrating lymphocytes (TILs) is one of the important factors for an immune response between tumor cells and immune cells in the tumor microenvironment, and the presence of TILs has been identified as predictors of response to chemotherapy. However, because complex mechanisms underlies the crosstalk between immune cells and cancer cells, the relationship between immune profiles in the tumor microenvironment and the efficacy of the immune checkpoint blocked has been unclear. Moreover, in many cases of breast cancer, the quantitative analysis of TILs and immuno-modification markers in a single tissue section are not studied. Therefore, we quantified detailed subsets of tumor infiltrating lymphocytes (TILs) from BC tissues and compared among BC subtypes. The TILs of BC tissues from 86 patients were classified using multiplex immunohistochemistry and an artificial intelligence-based analysis system based on T-cell subset markers, immunomodification markers, and the localization of TILs. The levels of CD4/PD1 and CD8/PD1 double-positive stromal TILs were significantly lower in the HER2- BC subtype (p <0.01 and p <0.05, respectively). In triple-negative breast cancer (TNBC), single marker-positive intratumoral TILs did not affect prognosis, however CD4/PDL1, CD8/PD1, and CD8/PDL1 double-positive TILs were significantly associated with TNBC recurrence (p<0.05, p<0.01, and p<0.001, respectively). TIL profiles differed among different BC subtypes, suggesting that the localization of TILs and their tumor-specific subsets influence the BC microenvironment.

De novo mutations in KIF1A-associated neuronal disorder (KAND) dominant-negatively inhibit motor activity and axonal transport of synaptic vesicle precursors.

KIF1A is a kinesin superfamily motor protein that transports synaptic vesicle precursors in axons. Cargo binding stimulates the dimerization of KIF1A molecules to induce processive movement along microtubules. Mutations in human Kif1a lead to a group of neurodegenerative diseases called KIF1A-associated neuronal disorder (KAND). KAND mutations are mostly de novo and autosomal dominant; however, it is unknown if the function of wild-type KIF1A motors is inhibited by heterodimerization with mutated KIF1A. Here, we have established Caenorhabditis elegans models for KAND using CRISPR-Cas9 technology and analyzed the effects of human KIF1A mutation on axonal transport. In our C. elegans models, both heterozygotes and homozygotes exhibited reduced axonal transport. Suppressor screening using the disease model identified a mutation that recovers the motor activity of mutated human KIF1A. In addition, we developed in vitro assays to analyze the motility of heterodimeric motors composed of wild-type and mutant KIF1A. We find that mutant KIF1A significantly impaired the motility of heterodimeric motors. Our data provide insight into the molecular mechanism underlying the dominant nature of de novo KAND mutations.

Bone Marrow Carcinomatosis in a Stage IV Breast Cancer Patient Treated by Letrozole as First-Line Endocrine Therapy.

Bone marrow carcinomatosis (BMC) associated with breast cancer is a rare but often difficult-to-treat condition; we report a case of a female stage IV breast cancer patient in her seventies with BMC that improved with endocrine monotherapy. The patient had hemoglobinopenia and thrombocytopenia at the time of diagnosis. The diagnosis of BMC due to estrogen receptor-positive invasive lobular carcinoma was confirmed. After transfusion of 4 units of concentrated red blood cells, endocrine treatment with letrozole improved the hematopenia. Ten months after the treatment started, bone metastases worsened, so the patient was changed to combination therapy with palbociclib and fulvestrant, after which there was no worsening of the disease.

A special issue of the Australian society for Biophysics.

On behalf of the Australian Society for Biophysics (ASB) and the Editors of this Special Issue, I would like to express our appreciation to Editor-in-Chief, Damien Hall, for arranging the publication of this Special Issue. The ASB is about five times smaller than our sister the Biophysical Society for Japan (BSJ) and tenfold smaller than the US Biophysical Society (USBS), but our meetings are notable because of the encouragement the Society gives to emerging biophysicists. It can be a terrifying experience for a PhD student to have to face a roomful of professors and senior academics, but invariably they appreciate the experience. Another feature of the ASB meetings is the inclusion of contributions from the Asian Pacific region. We now have formal ties with our New Zealand colleagues and our meetings with the BSJ contain joint sessions (see below). In 2020, despite the impact of COVID-19 (see Adam Hill's Commentary), there is a joint session with the University of California Davis. This Special Issue comprises 2 Editorials, 3 Commentaries, and 25 reviews.

The CLIP1-LTK fusion is an oncogenic driver in non-small-cell lung cancer.

Lung cancer is one of the most aggressive tumour types. Targeted therapies stratified by oncogenic drivers have substantially improved therapeutic outcomes in patients with non-small-cell lung cancer (NSCLC)1. However, such oncogenic drivers are not found in 25-40% of cases of lung adenocarcinoma, the most common histological subtype of NSCLC2. Here we identify a novel fusion transcript of CLIP1 and LTK using whole-transcriptome sequencing in a multi-institutional genome screening platform (LC-SCRUM-Asia, UMIN000036871). The CLIP1-LTK fusion was present in 0.4% of NSCLCs and was mutually exclusive with other known oncogenic drivers. We show that kinase activity of the CLIP1-LTK fusion protein is constitutively activated and has transformation potential. Treatment of Ba/F3 cells expressing CLIP1-LTK with lorlatinib, an ALK inhibitor, inhibited CLIP1-LTK kinase activity, suppressed proliferation and induced apoptosis. One patient with NSCLC harbouring the CLIP1-LTK fusion showed a good clinical response to lorlatinib treatment. To our knowledge, this is the first description of LTK alterations with oncogenic activity in cancers. These results identify the CLIP1-LTK fusion as a target in NSCLC that could be treated with lorlatinib.

Laparoscopic Abdominal Surgery after Primary Breast Reconstruction Using an Abdominal Flap.

Background and objectives: Our department has been performing primary breast reconstruction for breast cancer surgery, incorporating a transverse rectus abdominis myocutaneous flap (TRAM)/vertical rectus abdominis myocutaneous flap (VRAM) since 1998 and a deep inferior epigastric artery perforator flap (DIEP) since 2008. Currently, most gastrointestinal operations in abdominal surgery are performed laparoscopically or are robot-assisted. Cases in which abdominal surgery was performed after breast reconstruction using an abdominal flap were reviewed. Method: A total of 119 cases of primary breast reconstruction using an abdominal flap performed in our department were reviewed. Result: The reconstructive techniques were DIEP in 69 cases and TRAM/VRAM in 50 cases. After breast surgery, seven abdominal operations were performed in six cases. In DIEP cases, one robotic surgery was performed for uterine cancer, and one laparoscopic surgery was performed for ovarian tumor. In TRAM/VRAM cases, two laparoscopic cholecystectomies, one laparoscopic total gastrectomy, one laparoscopic ileus reduction, and one open total hysterectomy oophorectomy were performed. Six surgeries were completed by laparoscopy or robotic assistance. Conclusion: The survival rate after breast cancer surgery is improving, and the choice of breast reconstruction procedure should take into account the possibility of performing a prophylactic resection of the ovaries due to the genetic background and possibly postoperative abdominal surgery due to other diseases. However, in cases in which laparoscopic surgery was attempted after breast reconstruction using an abdominal flap, the laparoscopic surgery could be completed in all cases.

Announcing the call for the Special Issue on "The Australian Society for Biophysics (ASB) - 2021 Meeting".

This Commentary describes a call for submissions for the upcoming Special Issue focused on the research topics presented at the Australian Society of Biophysics (ASB) in 2020 and 2021. Submissions from past and present ASB members who could not attend these meetings are also welcome as contributions to this special issue.

Study of the protocol used to evaluate skin-flap perfusion in mastectomy based on the characteristics of indocyanine green.

BACKGROUND: Indocyanine green angiography enables real-time visualization of blood vessels at depths of up to 10 mm beneath the body surface, thereby aiding the evaluation of the viability of skin flaps and predicting necrosis in surgical fields requiring good tissue perfusion. Although skin-flap necrosis also occurs in mastectomy without reconstruction, most studies have focused on reconstructive plastic surgery. Several patients undergoing mastectomy are eligible for postoperative adjuvant therapy, but complications can lead to delays in treatment and thus require prevention. However, a lack of a standard protocol for evaluating skin-flap perfusion using indocyanine green necessitates the study of its characteristics to facilitate comparison of the perfusion rate among individuals. METHODS: This retrospective study focused on the characteristics of indocyanine green and established a protocol for indocyanine green angiography using laser-assisted imaging (SPY system) to predict postoperative skin-flap necrosis from intraoperative images of 30 patients who underwent mastectomy without reconstruction. RESULTS: Our protocol predicted postoperative skin-flap necrosis as follows. First, the intravenous dose and concentration were set at 2.5 mg/mL and 0.05 mg/kg, respectively. Second, the timing of measurement was set to 100 s after the entry of indocyanine green into the skin (plateau phase); the analysis pattern was set to single frame. Third, comparisons among individuals were made using relative values. CONCLUSIONS: We analyzed the area of postoperative flap necrosis using this protocol. We found that the intraoperative images showed decreased perfusion in that area, which was useful in predicting skin-flap necrosis, as reported by previous breast reconstruction studies.

Hydronephrosis Caused by Metastatic Breast Cancer.

Breast cancer metastasizes mainly to organs such as bone, lung, and liver, whereas metastases to the peritoneum and urinary tract are rare. Metastasis to the peritoneum or urinary tract may result in renal dysfunction, infection, and painful hydronephrosis. In our hospital, 1,409 breast cancer surgeries were performed between January 2004 and December 2015, and 7 cases of hydronephrosis associated with recurrence were observed. The median age of patients was 69 years (57-79 years). The median time from surgery to diagnosis of hydronephrosis was 47 months (20-70 months). Histology was invasive ductal carcinoma (IDC) in 6 cases and invasive lobular carcinoma (ILC) in 1 case. There were 6 bilateral cases and 1 unilateral case of hydronephrosis. The causes were retroperitoneal metastasis in 5 cases and lymph node metastasis in 2 cases. The hydronephrosis was untreated in 2 cases, and treated with a ureteral stent in 2 cases, nephrostomy in 1 case, and nephrostomy due to ureteral stent failure in 2 cases. The median survival from the onset of hydronephrosis was 12 months (3-57 months). Although the probability of hydronephrosis in breast cancer recurrence was not high, care must be taken to avoid renal dysfunction, infection, or pain, which may require treatment.

Effects of dynein inhibitor on the number of motor proteins transporting synaptic cargos.

Synaptic cargo transport by kinesin and dynein in hippocampal neurons was investigated by noninvasively measuring the transport force based on nonequilibrium statistical mechanics. Although direct physical measurements such as force measurement using optical tweezers are difficult in an intracellular environment, the noninvasive estimations enabled enumerating force-producing units (FPUs) carrying a cargo comprising the motor proteins generating force. The number of FPUs served as a barometer for stable and long-distance transport by multiple motors, which was then used to quantify the extent of damage to axonal transport by dynarrestin, a dynein inhibitor. We found that dynarrestin decreased the FPU for retrograde transport more than for anterograde transport. This result indicates the applicability of the noninvasive force measurements. In the future, these measurements may be used to quantify damage to axonal transport resulting from neuronal diseases, including Alzheimer's, Parkinson's, and Huntington's diseases.