Inter- and intra-observer variability of qualitative visual breast-composition assessment in mammography among Japanese physicians: a first multi-institutional observer performance study in Japan.

BACKGROUND: Visual assessment of mammographic breast composition remains the most common worldwide, although subjective variability limits its reproducibility. This study aimed to investigate the inter- and intra-observer variability in qualitative visual assessment of mammographic breast composition through a multi-institutional observer performance study for the first time in Japan. METHODS: This study enrolled 10 Japanese physicians from five different institutions. They used the new Japanese breast-composition classification system 4th edition to subjectively evaluate the breast composition in 200 pairs of right and left normal mediolateral oblique mammograms (number determined using precise sample size calculations) twice, with a 1-month interval (median patient age: 59 years [range 40-69 years]). The primary endpoint of this study was the inter-observer variability using kappa (κ) value. RESULTS: Inter-observer variability for the four and two classes of breast-composition assessment revealed moderate agreement (Fleiss' κ: first and second reading = 0.553 and 0.587, respectively) and substantial agreement (Fleiss' κ: first and second reading = 0.689 and 0.70, respectively). Intra-observer variability for the four and two classes of breast-composition assessment demonstrated substantial agreement (Cohen's κ, median = 0.758) and almost perfect agreement (Cohen's κ, median = 0.813). Assessments of consensus between the 10 physicians and the automated software Volpara® revealed slight agreement (Cohen's κ; first and second reading: 0.104 and 0.075, respectively). CONCLUSIONS: Qualitative visual assessment of mammographic breast composition using the new Japanese classification revealed excellent intra-observer reproducibility. However, persistent inter-observer variability, presenting a challenge in establishing it as the gold standard in Japan.

Delayed Diagnosis and Prognostic Impact of Breast Cancer During the COVID-19 Pandemic.

BACKGROUND: Breast screening services were suspended for several months owing to the coronavirus disease 2019 (COVID-19) pandemic. We estimated the potential impact on breast cancer mortality using long-term global observations. However, the magnitude of the impact may vary across countries; therefore, we conducted an analysis and modeling study of this impact in Japan. PATIENTS AND METHODS: We compared the clinicopathological features of breast cancers between the nonpandemicgroup (April 1, 2019 to October 31, 2019) and the pandemic group (April 1, 2020 to October 31, 2020). We also compared the estimated 10-year survival rates between the two groups based on the weighted average of the 10-year survival rate by clinical stage and site (2004-2007). RESULTS: Results...Pandemic-related disruption decreased the number of breast cancer cases from296 to 249 during both 7-month periods. The percentage of patients with stage IIB or higher disease was significantly higher in the pandemic group than in the non-pandemic group (22.0% vs. 31.3%, P = 0.0133). The percentage of cases with a Ki-67 labeling index higher than 20% tended to be higher in the pandemic group than in the non-pandemic group (62.2% vs. 54.4%). The estimated 10-year survival rate was lower in the pandemic group than in the non-pandemic group (83.9% vs. 87.9%, 95% confidence interval of the difference: 0.87-8.8, P > 0.05). CONCLUSION: We found more aggressive and advanced disease afterthe suspension of breast cancer screening services owing to the COVID-19 pandemic. This may have affected the long-term clinical outcomes of patients with breast cancer.

Hereditary breast cancer associated with Cowden syndrome-related PTEN mutation with Lhermitte-Duclos disease.

BACKGROUND: Cowden syndrome is characterized by multiple hamartomas in various tissues, including the skin, brain, breast, thyroid, mucous membrane, and gastrointestinal tract, and is reported to increase the risk of malignant disease. CASE PRESENTATION: We describe the case of a 52-year-old woman in whom a tumor was diagnosed in the left cerebellar hemisphere and treated by surgical resection. Phosphatase and tensin homolog (PTEN) mutation in exon 8 insertion was found in the brain tumor tissue and leukocytes. This finding supported the diagnosis of Cowden syndrome. She consequently developed endometrial cancer and underwent abdominal total hysterectomy with bilateral salpingo-oophorectomy. Four years later, hormone receptor-positive breast cancer was found in the right breast, and breast-conserving surgery with radiation therapy and sentinel lymph node biopsy was performed. CONCLUSIONS: Herein, we describe a patient who was diagnosed as having familial breast cancer associated with PTEN mutation-related Cowden syndrome. We also reviewed reports of this syndrome in the literature for disease appraisal.

Radiation exposure during sentinel lymph node biopsy for breast cancer: effect on pregnant female physicians.

BACKGROUND: The radionuclide (RN) method employed for sentinel lymph node biopsy is generally safe for adult medical care workers. However, the number of pregnant medical care workers who attend surgery has recently been increasing, along with the increasing number of female surgeons. In particular, female surgeons are concerned about the position of a surgeon's lower abdominal region being close to the RN injection site. We measured the exposure dose of the lower abdominal region in medical care workers and investigated the possible exposure effect on fetuses. METHODS: A dose of (99m)Tc-phytic acid (37 MBq) was subcutaneously injected into the areola of the nipple of patients. Scintigraphy and surgery were performed after 1 and 4 h, respectively. At the time of the local injection, a personal dosimeter measured the exposure dose in the surgeon, first and second assistants, anesthesiologist, and scrub nurse. RESULTS: The median exposure doses were 3, 1, 1, 0, and 0 µSv in the surgeon, first and second assistants, anesthesiologist, and scrub nurse, respectively. Protective clothing reduced the mean exposure dose by 66 %. CONCLUSIONS: In surgeons, the exposure dose from daily life activities (1 mSv/year) corresponds to the dose received after performing 333 surgeries (using 3 µSv as the median). However, the maximum value measured was 24 µSv; at this value, the total exposure dose exceeds 1 mSV in the 42nd surgery. Medical care workers can further reduce their exposure dose by paying attention to the surgical procedure and to their posture and position.

Epidermal growth factor-dependent enhancement of invasiveness of squamous cell carcinoma of the breast.

Factors that promote the aggressiveness of squamous cell carcinoma of the breast are not well understood. To examine the involvement of cell motility and the mechanism of this behavior, a squamous cell carcinoma cell line of the breast (HBC9) was established from a metastatic lymph node of a Japanese woman. HBC9 expressed epidermal growth factor receptor (EGFR), but was negative for Her2 or Her3.The invasive ability of HBC9 was compared with that of four breast ductal carcinoma cell lines by Matrigel invasion assay. EGF stimulation induced the formation of surface protrusions and cell migration in HBC9 cells, and significantly increased the number of cells migrating through the Matrigel. The invasive ability of HBC9 was compared with other cell lines of breast carcinoma; it was much greater than that of MCF-7, BT474, or HBC5, but did not differ significantly from that of MDA-MB-231. Observation of the surface protrusions of HBC9 by confocal laser microscopy revealed co-localization of Arp2 and N-WASP with actin polymerization, detected by visualization with phalloidin, indicating that the protrusions induced by EGF were invadopodia. In HBC9 cells, cortactin also co-localized with the N-WASP/Arp2/3 complex in the protrusions. Immunohistochemistry of 12 cases of squamous cell carcinoma of the breast revealed expression of cortactin and EGFR in all of them, and this was confirmed by western blotting in two cases. These results suggest that EGF-dependent enhancement of cell motility by formation of invadopodia associated with cortactin is a cause of the clinical aggressiveness of squamous cell carcinoma of the breast.