A case of non-palpating breast cancer with huge lymph node metastasis

We report a case of non-palpating breast cancer with huge lymph node metastasis. The patient was a 58-year-old woman who had a huge tumor at her right armpit. The tumor was 4 cm in diameter. Aspiration biopsy cytology for the tumor was performed. The diagnosis is Class V. Mammography showed an ill-defined mass at her right breast. Ultrasonography revealed a low echoic mass at the C area of her right breast. A core needle biopsy for the breast tumor led to a diagnosis of an invasive ductal carcinoma positive for estrogen receptor and progesterone receptor, and negative for HER2/neu protein expression. She received 4 cycles of CEF (E: 60 mg/tri-weekly) plus 12 cycles of paclitaxe (l80 mg/weekly). After chemotherapy, she received muscle preserving mastectomy plus axillary lymph nodes dissection. In histopathology, there were no carcinoma cells in resected breast tissue and resected lymph nodes. Therefore, the effect of chemotherapy was diagnosed as a pathological complete response. After operation, she was administered aromatase inhibitor. The patient has been well and remained disease-free during a follow-up period of 6 years.     

The combined effect of Paclitaxel and toremifene therapy for estrogen receptor positive and aromatase inhibitor resistant metastatic breast cancer

Multidrug resistance proteins such as P-glycoprotein (P-gp) are potential targets for improving the efficacy of paclitaxel (PTX), a mitotic inhibitor used in cancer chemotherapy. The selective estrogen receptor modulator toremifene (TOR) moderate P-gp was related to a drug resistance in vitro. A comparison of PTX alone with PTX+TOR in hormone-receptor-positive metastatic breast cancer patients (MBC) was conducted to determine the therapeutic value of adding TOR to a PTX regiment. Thirteen MBC patients received 80 mg/m2 PTX weekly (PTX group) and 14 MBC patients received the same weekly dose of PTX plus 120 mg/day TOR daily (PTX+TOR group). All 27 patients were repeatedly treated with a combination of PTX and TOR as long as disease progression or unmanageable severe adverse events were defined. The PTX group was compared with PTX+TOR group with respect to best overall response, response rate, clinical benefit rate, time to progression, adverse events and toxic profile of PTX and TOR. No significant difference in response rate was observed between the PTX group and the PTX+TOR group. However, clinical benefit rate and time to progression improved significantly in the PTX+TOR group in comparison with the PTX group. TOR did not significantly enhance the adverse events of PTX. These results suggested that combined treatment of PTX and TOR for MBC patients improves a patient response over PTX alone.     

Hepatocellular Carcinoma Induction in LEC Rats by a Low Dose of 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline

A food-borne heterocyclic amine, 2-amino-3,8-dimethylimidazo[4,5- f ]qninoxaline (MeIQx), induces hepatocellular carcinomas (HCCs) in F344 male rats at an incidence of 95%, when fed in the diet at 400 ppm for 61 weeks. In this study, the effect of a low dose of MeIQx was examined in Long-Evans with cinnamon-like coat color (LEC) rats, which have a mutation in Atp7b and suffer from hereditary hepatitis and HCCs, with high levels of copper accumulation in the liver. Rats of the LEC and Long-Evans with agouti coat color (LEA) sibling lines were given a diet containing 40 ppm MeIQx from the age of 23 weeks to 63 weeks, for a total administration period of 40 weeks. In LEC rats, HCCs were observed in 8/8 animals administered MeIQx, and 2/8 rats receiving a normal diet. The number of HCCs per rat (mean±SD) was 2.8±2.0 and 0.3±0.5, respectively. In the LEA rats, however, no tumors were induced by administration of MeIQx. These results indicate that damaged liver associated with compensatory cell proliferation is much more susceptible to chemical hepatocarcinogens, including MeIQx, than the normal liver.     

Feeding jejunostomy following esophagectomy may increase the occurrence of postoperative small bowel obstruction

This study aimed to clarify the characteristics and treatment of bowel obstruction associated with feeding jejunostomy in patients who underwent esophagectomy for esophageal cancer. In this single-center retrospective study, 363 patients underwent esophagectomy with mediastinal lymph node dissection for esophageal cancer at the Wakayama Medical University Hospital between January 2014 and June 2021. All patients who underwent esophagectomy routinely underwent feeding jejunostomy or gastrostomy. Feeding jejunostomy was used in the cases of gastric tube reconstruction through the posterior mediastinal route or colon reconstruction, while feeding gastrostomy was used in cases of retrosternal route gastric tube reconstruction. Nasogastric feeding tubes and round ligament technique were not used. Postoperative small bowel obstruction occurred in 19 of 197 cases of posterior mediastinal route reconstruction (9.6%), but in no cases of retrosternal route reconstruction because of the feeding gastrostomy (P < .0001). Of the 19 patients who had bowel obstruction after feeding jejunostomy, 10 patients underwent reoperation (53%) and the remaining 9 patients had conservative treatment (47%). The cumulative incidence of bowel obstruction after feeding jejunostomy was 6.7% at 1 year and 8.7% at 2 years. Feeding jejunostomy following esophagectomy is a risk factor for small bowel obstruction. We recommend feeding gastrostomy inserted from the antrum to the jejunum in the cases of gastric tube reconstruction through the retrosternal route or nasogastric feeding tube in the cases of reconstruction through the posterior mediastinal route.     

The Impact of Antiviral Therapy for Hepatitis C Virus on the Survival of Patients after Hepatocellular Carcinoma Treatment

Objective Owing to advances in direct-acting antiviral (DAA) therapy, a considerable number of patients with hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) are now able to achieve a sustained viral response (SVR) after curative treatment of HCC. However, the beneficial effect of a DAA-SVR on the survival remains unclear. Methods A total of 205 patients with HCC who were HCV-positive with Child-Pugh A at the onset from 2008 to 2018 were categorized into 2 groups: 140 patients untreated for HCV throughout the entire course after HCC development (untreated group) and 65 patients treated for HCV with DAAs following HCC treatment who achieved an SVR (SVR group). After propensity score matching, 63 patients from each group were selected. Using these patients, the survival and maintenance of Child-Pugh A after HCC treatment were compared between the untreated group and SVR group. Results There was a significant difference in the overall survival (p<0.001) and the rate of maintaining Child-Pugh A (p<0.001) between the groups. The 5-year survival rates were 96% (SVR group) and 60% (untreated group), and the proportions of patients with Child-Pugh A at 5 years after HCC treatment were 96% (SVR group) and 38% (untreated group). Conclusion In patients with HCV-positive HCC, achieving a DAA-SVR after HCC treatment significantly improved the overall survival rate compared with HCV-untreated patients. The contribution of DAA-SVR during the course of HCC treatment to a longer survival is mainly due to the prevention of the progression of Child-Pugh A to B/C. Further research is needed to determine whether aggressive antiviral therapy is also effective for HCC patients with Child-Pugh B/C.     

Cetuximab delivery and antitumor effects are enhanced by mild hyperthermia in a xenograft mouse model of pancreatic cancer

Even with current promising antitumor antibodies, their antitumor effects on stroma‐rich solid cancers have been insufficient. We used mild hyperthermia with the intent of improving drug delivery by breaking the stromal barrier. Here, we provide preclinical evidence of cetuximab + mild hyperthermia therapy. We used four in vivo pancreatic cancer xenograft mouse models with different stroma amounts (scarce, MIAPaCa‐2; moderate, BxPC‐3; and abundant, Capan‐1 and Ope‐xeno). Cetuximab (1 mg/kg) was given systemically, and the mouse leg tumors were concurrently heated using a water bath method for 30 min at three different temperatures, 25°C (control), 37°C (intra‐abdominal organ level), or 41°C (mild hyperthermia) (n = 4, each group). The evaluated variables were the antitumor effects, represented by tumor volume, and in vivo cetuximab accumulation, indirectly quantified by the immunohistochemical fluorescence intensity value/cell using antibodies against human IgG Fc. At 25°C, the antitumor effects were sufficient, with a cetuximab accumulation value (florescence intensity/cell) of 1632, in the MIAPaCa‐2 model, moderate (1063) in the BxPC‐3 model, and negative in the Capan‐1 and Ope‐xeno models (760, 461). By applying 37°C or 41°C heat, antitumor effects were enhanced shown in decreased tumor volumes. These enhanced effects were accompanied by boosted cetuximab accumulation, which increased by 2.8‐fold (2980, 3015) in the BxPC‐3 model, 2.5‐ or 4.8‐fold (1881, 3615) in the Capan‐1 model, and 3.2‐ or 4.2‐fold (1469, 1922) in the Ope‐xeno model, respectively. Cetuximab was effective in treating even stroma‐rich and k‐ras mutant pancreatic cancer mouse models when the drug delivery was improved by combination with mild hyperthermia.     

Estimation of the Acoustic Properties of the Random Packing Structures of Granular Materials: Estimation of the Sound Absorption Coefficient Based on Micro-CT Scan Data

In this study, the sound absorption properties of randomly packed granular materials were estimated. Generally, it is difficult to construct a general mathematical model for the arrangement of randomly packed granular materials. Therefore, in this study, an attempt was made to estimate the sound absorption coefficient using a theoretical analysis by introducing data from computed tomography (CT) scans, as the tomographic images of CT scans correspond to the slicing and elemental division of packing structures. In the theoretical analysis, the propagation constants and characteristic impedances in the voids were obtained by approximating each tomographic image as a void between two parallel planes. The derived propagation constants and characteristic impedances were then treated as a one-dimensional transfer matrix in the propagation of sound waves, and the transfer matrix method was used to calculate the normal incident sound absorption coefficient. The theoretical value of the sound absorption coefficient was derived using the effective density to which the measured tortuosity was applied. As a result, for the theoretical values considering the tortuosity, in many cases, the theoretical values were close to the measured values. For the theoretical values, when both the surface area and tortuosity were considered, the peak sound absorption frequency moved to a lower frequency and was in general agreement with the measured values.     

Effectiveness of a new triple-row circular stapler in reducing the risk of colorectal anastomotic leakage: A historical control and propensity score–matched study

Anastomotic leakage (AL) after colorectal surgery is a serious complication. This study aimed to evaluate the effectiveness of the EEA™ circular stapler, a new triple-row circular stapler (TCS), relative to a conventional, double-row circular stapler (DCS).A total of 285 patients who underwent anastomosis with the double stapling technique at the Tokyo Medical University Hospital between 2017 and 2021 were included in this nonrandomized clinical trial with historical controls using a propensity score (PS) analysis. The primary endpoint was the risk of AL.We performed a 1:2 PS matching analysis. Before case matching, AL occurred in 15 (7.4%) and 2 (2.4%) patients in the DCS and TCS groups, respectively, with no significant difference (P = .17). After case matching, AL occurred in 13 patients (11.6%) and 1 patient (1.8%) in the DCS and TCS groups, respectively, revealing a significant difference (P = .04). Cox models were created by applying PS to adjust for group differences via regression adjustment. Odds ratios for AL in the DCS group versus the TCS group were 0.31 (95% confidence interval [CI]: 0.07–1.38) in the entire cohort, 0.15 (95% CI: 0.02–0.64) in the regression adjustment cohort, and 0.14 (95% CI: 0.02–1.09) in the 1:2 PS-matched cohort.PS analysis of clinical data suggested that the use of TCS contributes to a reduced risk of AL after colorectal anastomosis CTwith the double stapling technique.     

Human slow cortical potential in association with voluntary jaw movements

The distribution of a readiness potential (RP), i.e., a negative-going slow cortical potential (SCP) preceding the onset of voluntary movements, was studied in association with self-paced voluntary jaw-closing and jaw-opening movements in 4 healthy human subjects. A negative-going SCP starting at ca.1.5-2.0 s preceding the onset of the self-paced jaw-opening and jaw-closing movements was found at all the recorded sites of Fz, Cz, Pz, F3, F4, F7, F8, C3, C4, T3 and T4. The RP was maximum in amplitude at Cz (ca.8microV), although there was no significant difference between Cz and either C3 or C4; it was smaller at T3 and T4 than at any of Fz, Cz, Pz, C3, and C4. The polarity, amplitude, and time course of the RP in association with jaw movements was virtually the same as those associated with voluntary unilateral extension of the middle finger, except for a contralaterally-dominant side asymmetry between C3 and C4 in the latter. There was neither rapidly increasing negative potential (NS') in the RP recorded from any site, nor bilateral difference in the RPs coinciding with unilateral biting of a gauze pad. It is suggested that the motor cortex would be activated bilaterally in coordination even in the case of unilateral biting.