A Nationwide Study on HER2-low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols.

Purpose: Notable effectiveness of trastuzumab deruxtecan (T-DXd) in patients with HER2-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. Materials and Methods: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. Results: Total 11,416 patients from twenty-five institutions included in this study. Of these patients, 40.7% (range: 6.0%-76.3%) were classified as HER2-zero, 41.7% (range: 10.5%-69.1%) as HER2-low, and 17.5% (range: 6.7%-34.0%) as HER2-positive. HER2-low tumors were associated with positive ER and PR statuses (p<0.001 and p<0.001, respectively). Antigen retrieval times (≥ 36 min vs. < 36 min) and antibody incubation times (≥ 12 min vs. < 12 min) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy (CNB) and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3259) of the patients. Conclusion: The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Malignant melanoma associated with a plaque-type blue nevus of the cheek: a case report.

Blue nevi, which are characterized by collections of pigment-producing melanocytes in the dermis, have a variety of clinicopathological characteristics. Plaque-type blue nevus (PTBN) is a variant of blue nevi. PTBN presents at birth or arises in early childhood, and it shows a combination of the features found in common blue nevus and cellular blue nevus. It is typically found on the dorsal surface of the hands and feet or on the head and neck, and it is usually benign and stable over time. However, reports have occasionally described malignant melanomas developing in or associated with a PTBN. Malignant blue nevi are most commonly found on the scalp. We report the case of an 88-year-old woman with a malignant melanoma associated with a PTBN of the cheek.

Radiologic-pathologic correlation of interstitial lung abnormalities and predictors for progression and survival.

OBJECTIVES: To evaluate radiologic and histologic correlations for interstitial lung abnormalities (ILAs) and to investigate radiologic or pathologic features contributing to disease progression and mortality. METHODS: From 268 patients who underwent surgical lung biopsy between January 2004 and April 2019, 45 patients with incidentally detected ILA and normal pulmonary function were retrospectively included. CT features were classified as subpleural fibrotic or non-fibrotic, and changes in ILA over at least 2 years of follow-up were evaluated. Histologic findings were categorized as definite, probable, indeterminate, or alternative diagnosis for usual interstitial pneumonia (UIP) patterns. Overall and progression-free survival were calculated using the Kaplan-Meier method, and the Cox proportional hazard method was used to examine predictors for ILA progression and survival. RESULTS: Among 36 subpleural fibrotic ILA subjects, 25 (69%) showed definite or probable UIP patterns, and 89% (8/9) of subpleural non-fibrotic ILA subjects showed an indeterminate or alternative diagnosis for UIP pattern on histopathology. On the radiologic-pathologic correlation, reticular opacity of fibrotic ILA was correlated with patchy involvement of fibrosis, and ground-glass attenuation of non-fibrotic ILA corresponded to diffuse interstitial thickening. The median progression time of ILA was 54 months, and fibrotic ILA increased the likelihood of progression (hazard ratio, 2.42; p = 0.017). The median survival time of ILA subjects was 123 months, and fibrotic ILA was associated with an increased risk of death (hazard ratio, 9.22; p = 0.025). CONCLUSIONS: Subpleural fibrotic ILAs are associated with pathologic UIP patterns, and it is important to recognize subpleural fibrotic ILA on CT to predict disease progression and mortality. KEY POINTS: • In total, 69% of subpleural fibrotic ILA showed definite or probable UIP patterns, while 11% of subpleural non-fibrotic ILA showed definite or probable UIP patterns. • Subpleural fibrotic ILA was associated with an increased rate of progression (hazard ratio, 2.42; p = 0.017), and the median progression-free time was 40 months. • Subpleural fibrotic ILA had an increased risk of death (hazard ratio, 9.22; p = 0.025), and the median survival time was 86 months.

Ectopic Male Breast Cancer in Suprapubic Area That Relapsed with Hematogenous Metastasis.

Tough ectopic male breast cancer is extremely rare, non-axillary ectopic male breast cancer is even rare. To date, the natural course and prognosis of this disease are not fully understood. Consequently, the appropriate treatment for this disease has not been established. We report on a patient with ectopic male breast cancer in the suprapubic area that relapsed with hematogenous metastasis 3 years after complete surgical resection and adjuvant treatment despite an early diagnosis. This unusual case highlights the need for new prognostic factors such as genomic profiling to predict whether ectopic male breast cancer is aggressive and to guide on the duration between follow-ups and the appropriate method for conducting them.

Adenocarcinoma-Papillary Cystic Pattern Arising in a Mixed Squamous and Glandular Papilloma of the Lung.

Mixed squamous and glandular papilloma (mixed papilloma) of the lung has been reported in fewer than 25 cases in the English literature. Although it is known as a benign tumor, malignant transformation has been reported. Papillary cystic carcinoma is characterized by papillary and cystic growth patterns and has been reported as a subtype of adenocarcinoma, mainly in the salivary glands, breast, and pancreas. In this article, we report a case of adenocarcinoma-papillary cystic pattern arising from mixed papilloma of the lung in a 76-year-old male patient. Chest computed tomography scan revealed an endobronchial mass growing at the right medial segmental bronchus. Middle lobe lobectomy was performed, revealing a 4.9 × 1.9 cm-sized mass that protruded into the bronchus. Microscopically, the tumor showed numerous cysts lined by micropapillary projections. The tumor cells had round and vesicular nuclei with prominent nucleoli, and mitosis was frequent. A limited portion of the tumor consisted of benign mixed papilloma. The tumor showed diffuse immunoreactivity for thyroid transcription factor-1 and strong expression of p16. We investigated the mutational status of cancer-related genes using targeted next-generation sequencing and identified a genetic alteration in the BRAF gene. This is the first case report of papillary cystic carcinoma arising in mixed papilloma of the lung.

Association between Expression of 8-OHdG and Cigarette Smoking in Non-small Cell Lung Cancer.

BACKGROUND: Exposure to cigarette smoking (CS) is a major risk factor for the development of lung cancer. CS is known to cause oxidative DNA damage and mutation of tumor-related genes, and these factors are involved in carcinogenesis. 8-Hydroxydeoxyguanosine (8-OHdG) is considered to be a reliable biomarker for oxidative DNA damage. Increased levels of 8-OHdG are associated with a number of pathological conditions, including cancer. There are no reports on the expression of 8-OHdG by immunohistochemistry in non-small cell lung cancer (NSCLC). METHODS: We investigated the expression of 8-OHdG and p53 in 203 NSCLC tissues using immunohistochemistry and correlated it with clinicopathological features including smoking. RESULTS: The expression of 8-OHdG was observed in 83.3% of NSCLC. It was significantly correlated with a low T category, negative lymph node status, never-smoker, and longer overall survival (p < .05) by univariate analysis. But multivariate analysis revealed that 8-OHdG was not an independent prognostic factor for overall survival in NSCLC patients. The aberrant expression of p53 significantly correlated with smoking, male, squamous cell carcinoma, and Ki-67 positivity (p < .05). CONCLUSIONS: The expression of 8-OHdG was associated with good prognostic factors. It was positively correlated with never-smokers in NSCLC, suggesting that oxidative damage of DNA cannot be explained by smoking alone and may depend on complex control mechanisms.

Combined expression of protein disulfide isomerase and endoplasmic reticulum oxidoreductin 1-α is a poor prognostic marker for non-small cell lung cancer.

Protein disulfide isomerase (PDI) is one of the most abundant proteins in the endoplasmic reticulum (ER) and is known as a primary ER resident target of cigarette smoke-induced oxidation. PDI dysfunction triggers unfolded protein response and ER stress. Endoplasmic reticulum oxidoreductin 1-α (ERO1A) is a major regulator of PDI, and recent evidence implicates PDI and ERO1A as tumor prognostic factors. However, the associated role of PDI and ERO1A and their prognostic impact in non-small cell lung cancers (NSCLCs) remains unknown. The present study investigated the expression of PDI and ERO1A using immunohistochemistry and examined its association with smoking status and their prognostic impact in 198 NSCLCs. PDI and ERO1A expression were observed in 71.2 and 69.2% of NSCLCs, respectively, and their expressions were significantly associated with each other (P<0.001). Individual PDI (P=0.001) and ERO1A (P=0.005) expression were significantly associated with shorter overall survival (OS) in univariate analysis. PDI expression was significantly associated with never smoking (P=0.003). PDI expression (P<0.001) and the co-expression of PDI and ERO1A (P<0.001) were independent poor prognostic factors for OS in patients with NSCLC in multivariate analysis. Individual expression and co-expression of PDI and ERO1A may be used as novel prognostic indicators of NSCLC outcome.

Expression of ANO1/DOG1 is associated with shorter survival and progression of breast carcinomas.

The expression of ANO1 is considered to have diagnostic specificity for gastrointestinal stromal tumors. However, its function as a calcium-activated chloride channel suggests that the expression of ANO1 is not restricted to gastrointestinal stromal tumors. Recently, it has been reported that ANO1 has roles in the progression of human malignant tumors. However, the role of ANO1 in breast carcinoma has been controversial. Therefore, we investigated the expression of ANO1 in 139 breast carcinoma patients and the role of ANO1 in vitro. The immunohistochemical expression of ANO1 was significantly associated with the expression of ß-catenin, cyclin D1, MMP9, snail, and E-cadherin. Especially, ANO1 expression was an independent indicator of poor prognosis of shorter overall survival and relapse-free survival of breast carcinoma patients by multivariate analysis. In MCF7 and MDA-MB-231 breast carcinoma cells, inhibition of ANO1 with T16Ainh-A01 or siRNA for ANO1 significantly suppressed the proliferation of cells. Knock-down of ANO1 with siRNA induced G0/G1 cell cycle arrest and significantly inhibited the invasiveness of breast carcinoma cells. Knock-down of ANO1 decreased the expression of ß-catenin, cyclin D1, MMP9, snail, and N-cadherin, and increased the expression of E-cadherin. In conclusion, this study demonstrates that ANO1 expression is an indicator of poor prognosis of breast carcinoma patients and suggests that ANO1 might be a therapeutic target for breast carcinoma patients with ANO1-positive tumors and poor prognosis.