Learning From Noisy Labels With Deep Neural Networks: A Survey.

Deep learning has achieved remarkable success in numerous domains with help from large amounts of big data. However, the quality of data labels is a concern because of the lack of high-quality labels in many real-world scenarios. As noisy labels severely degrade the generalization performance of deep neural networks, learning from noisy labels (robust training) is becoming an important task in modern deep learning applications. In this survey, we first describe the problem of learning with label noise from a supervised learning perspective. Next, we provide a comprehensive review of 62 state-of-the-art robust training methods, all of which are categorized into five groups according to their methodological difference, followed by a systematic comparison of six properties used to evaluate their superiority. Subsequently, we perform an in-depth analysis of noise rate estimation and summarize the typically used evaluation methodology, including public noisy datasets and evaluation metrics. Finally, we present several promising research directions that can serve as a guideline for future studies.

Retention Esophagitis as a Significant Clinical Predictor of Progression to Esophageal Cancer in Achalasia.

BACKGROUND/AIMS: Chronic liquid and/or food stasis caused by retention esophagitis (RE) in achalasia is a notable endoscopic finding because of the presence of a thickened or whitish esophageal mucosa and histologically altered squamous hyperplasia. We aimed to identify the clinical features of RE associated with achalasia and to clarify the clinical definition of RE in achalasia as a precancerous lesion identified by analyzing biomarker expressions. METHODS: From 2006 to 2015, we retrospectively reviewed 37 patients with achalasia without previous treatment. Among them, 21 patients had diagnostic findings of RE (RE+) and 16 patients had no diagnostic findings of RE (RE-). Immunohistochemical staining of p53, p16, and Ki-67 was performed on the endoscopic biopsy tissues from the patients with achalasia and 10 control patients with non-obstructive dysphagia. RESULTS: The symptom duration and transit delay were significantly longer in the RE+ group than in the RE- group. We found particularly high p53 positivity rates in the RE+ group (p<0.001). The rate of p16 expression was also significantly higher in the RE+ group than in the other two groups (p=0.003). CONCLUSIONS: A high p53 expression rate was more frequently found in the RE+ group than in the other two groups. RE could be a meaningful clinical feature of achalasia for predicting esophageal carcinogenesis.

PHH3 as an Ancillary Mitotic Marker in Gastrointestinal Stromal Tumors.

BACKGROUND: Counting mitoses is subjective and time-consuming. The adjunctive diagnostic utility of a recently reported mitotic marker, phosphohistone H3 (PHH3), was investigated in gastrointestinal stromal tumors (GISTs). METHODS: We reviewed 77 GISTs for several proliferative indices. These included the mitotic count per 50 high power fields (HPFs), the immunohistochemical Ki- 67 labeling index and the immunohistochemical PHH3 mitotic index (MI). For comparison, Spearman's rank correlation and interclass correlation coefficient were used. RESULTS: Mitotic counts ranged from 0-138 (mean, 7.57±2.34) and the PHH3 MI ranged from 0-126 per 50 HPFs (mean, 9.61±2.27). We found a positive correlation between mitotic counts and PHH3 MI (r=0.810, p<.001). The inter-observer correlation coefficient for three participants was 0.975 for mitotic counts and 0.940 for the PHH3 MI. When using the PHH3 MI instead of mitotic counts in the Armed Forces Institute of Pathology (AFIP) stratification criteria, 10 cases were reclassified. In one patient with a mitotic count of 2 and a PHH3 MI of 6 per 50 HPFs, distant metastasis occurred. CONCLUSIONS: In GISTs, the PHH3 MI correlated adequately with mitotic counts and can be used as a useful adjunctive to count mitotic figures efficiently.

Gastroenteropancreatic Neuroendocrine Tumors with Liver Metastases in Korea: A Clinicopathological Analysis of 72 Cases in a Single Institute.

PURPOSE: Management of gastroenteropancreatic (GEP) neuroendocrine tumors with liver metastases (NETLM) presents many clinical challenges. Assessment of the extent of disease and primary tumor site is crucial for management. In this study, we investigated the primary tumor sites and prognostic factors in GEP NETLM among Korean patients. MATERIALS AND METHODS: We reviewed the medical records of 72 Korean patients diagnosed with GEP NETLM between January 1999 and May 2013, focusing on their clinical and pathologic characteristics. RESULTS: The most frequently encountered primary tumor sites were the pancreas (n=25, 35%), stomach (n=8, 11%), gall bladder (n=4, 6%) and rectum (n=3, 4%). Twenty-five patients (35%) had occult primary tumor. Twelve patients (17%) had histological grade G1 tumors, 30 patients (42%) had G2 tumors, and 30 patients (42%) had G3 tumors. The mean follow-up period after histological confirmation of hepatic metastases was 11.30±2.44 months for G3 tumors, 19.67±4.09 months for G2 tumors, and 30.67±6.51 months for G1 tumors. Multivariate analyses revealed that an unknown primary tumor site (p=0.001) and higher histological grade (p < 0.001) were independent prognostic indicators for shorter overall survival (OS). Most long-term survivors (OS > 24 months) had received antitumor treatment. CONCLUSION: The primary tumor site most frequently associated with GEP NETLM was the pancreas. Unknown primary tumor and higher histological grade were independent prognostic indicators for shorter OS. Patients identified as being at a risk of shorter OS should be followed up closely.

Cytomorphological identification of advanced pulmonary adenocarcinoma harboring KRAS mutation in lymph node fine-needle aspiration specimens: Comparative investigation of adenocarcinoma with KRAS and EGFR mutations.

BACKGROUND: Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutation in pulmonary adenocarcinoma is clinically important due to its association with resistance to EGFR inhibitors and poor prognosis. To our knowledge, there has not been a comparative study focusing on cytological nuclear features of pulmonary adenocarcinoma harboring KRAS mutation (KRAS-AD). Hence, we compared the cytomorphology of metastatic KRAS-AD and EGFR-positive adenocarcinoma (EGFR-AD) in aspiration specimens from lymph nodes. METHODS: Forty lymph node aspiration specimens from forty KRAS-AD patients were collected at Samsung Medical Center (Seoul, Korea) from 2009 to 2013. As a control group, 40 EBUS-FNA lymph node specimens from 20 EGFR-AD patients were collected. EGFR-AD specimens were evaluated at Samsung Medical Center (Seoul, Korea) from 2012 to 2013. All 80 specimens were histologically confirmed to metastatic adenocarcinoma. Two pathologists performed a blinded review of all specimens. RESULTS: Compared with EGFR-AD, KRAS-AD exhibited more severe nuclear pleomorphism (P < 0.001), coarse chromatin (P = 0.001), cherry-red nucleoli (P < 0.001) and naked tumor cells (P = 0.002) with necrotic (P < 0.001) and neutrophilic (P = 0.008) background. CONCLUSIONS: Our study provides the first demonstration of cytomorphologic differentiation between metastatic KRAS-AD and metastatic EGFR-AD in lymph node aspiration specimens.