Neoplasms

Skin and Connective Tissue Diseases

All Conditions

Breast Neoplasms

Non-proportional stratified sample of women diagnosed with interval or screen-detected breast cancers after participation in BreastScreen Norway. This sample will include under- or overdiagnosed cancers, as well as cancers that were not under- or overdiagnosed.

Women residing in Norway, born between 1927 and 1934 (inclusive). This cohort will include women who have attended screening and who have not attended screening.

Women aged 50-69, and practising family doctors aged 25-75, currently living in Norway.

Diagnosed with a cancer that was visible on prior mammograms

Under- or overdiagnosed cancer

Screening

Solveig Hofvind, PhD

This PhD project will describe tumour characteristics and survival associated with of under- and overdiagnosed breast cancers, the rate of overdiagnosis in BreastScreen Norway, and whether women and family doctors are aware of, and knowledgeable about, under- and overdiagnosis in breast cancer screening.

Mammographic screening among women aged 50-69 reduces breast cancer mortality but also carries some risk. This PhD project will study under- and overdiagnosis, two risks associated with mammographic screening, in BreastScreen Norway. Underdiagnosis can occur when a tumour is present but not detected as a result of screening, while overdiagnosis can occur when a woman is diagnosed with a slow growing cancer that would not become symptomatic during her lifetime.

This project will address the following topics and research questions using observational study methods.

Study 1: To determine whether tumour histopathology and survival differentially associated with potentially under- or overdiagnosed interval and screen-detected breast cancers.

* Do women with potentially underdiagnosed interval cancers have different tumour histopathology and survival than those whose interval cancers showed no signs at the prior screen?
* Do women with potentially overdiagnosed screen-detected cancer have different tumour histopathology and survival than those whose screen-detected cancer showed no signs at the prior screen?

Study 2: To estimate overdiagnosis in the screening program using individual-level data:

* What was the rate of overdiagnosis for women screened in the program during 1996-2003?
* How does adjusting for sociodemographic factors affect estimates of overdiagnosis?

Study 3: To describe awareness and knowledge about under- and overdiagnosis and breast screening in general:

* Are women aware of and knowledgeable about under- and overdiagnosis in breast screening?
* Are family doctors aware of and knowledgeable about breast screening, and under- and overdiagnosis? Are they confident in their ability to relay this information to their patients?

Study 1 is a quality improvement study and has approval from Personvernombudet (PVO 2016-4696). Study 2 has research ethics board (REK) approval (REK 2013/795), while REK approval will be sought for Study 3.

Under- and Overdiagnosis in BreastScreen Norway

Using a self-administered web-based questionnaire designed for this study, the investigators will analyse survey responses to determine whether self-reported age (categorised into 5-year age groups) is associated with awareness and knowledge of overdiagnosis. This will be done separately for women and family doctors.

Using a self-administered web-based questionnaire designed for this study, the investigators will analyse survey responses to determine whether self-reported formal education (none; primary school; high school; up to 4 years postsecondary; more than 4 years of postsecondary education) is associated with awareness and knowledge of overdiagnosis among women.

- Histopathological type (Ductal carcinoma in situ, invasive carcinoma of no special type, invasive lobular carcinoma)

- Crude and adjusted measures of overdiagnosis will be presented to show the amount and direction of confounding resulting from sociodemographic factors.

Agreement between awareness (yes versus no/incomplete) and knowledge (yes versus no/incomplete) of overdiagnosis

Extrastiftelsen

Cancer Registry of Norway

Gland and Hormone Related Diseases

Thyroid Neoplasms

Thyroid Diseases

Endocrine System Diseases

Endocrine Gland Neoplasms

Head and Neck Neoplasms

This article defines cases that preoperative ultrasound indicates no suspicious malignant enlargement of central lymph nodes and postoperative paraffin pathology indicates the presence of metastatic cancer in central lymph nodes as false-negative cases.

The problem of false-negative lymph nodes in the central region (CLN) refers to the inability to detect lymph nodes (LN) metastasis during preoperative ultrasound examination but is confirmed by surgical and postoperative pathological examination. According to this study, the false-negative rate of CLN of patients with TC was relatively high at approximately 71.7%. The high proportion of false-negatives indicates limitations in the sensitivity of ultrasound examination, especially for detecting small LN or small metastases. The presence of false-negative CLN directly affects clinical practice. First, it may lead to insufficient selection of treatment strategies for patients with TC, thereby affecting their prognosis. Second, such false-negative results may lead surgeons to overly trust ultrasound examination during preoperative evaluation, neglecting the importance of comprehensive clinical information, and thus affecting the formulation of treatment plans. This study aimed to explore the factors influencing false-negative CLN through a cohort study and to establish a predictive model.

Setting and Population This study collected 6369 patients admitted to the Breast and Thyroid Surgery Department of Shandong Provincial Hospital between January 2013 and December 2023, who were diagnosed with TC through postoperative pathology. (SDC, Figure 1) All patients included in the study signed a written informed consent form before surgery. Ethical approval for this study (NO.SWYX2024-225) was provided by the Ethical Committee of Shandong Provincial Hospital, Jinan, China on 15 April 2024. According to the relevant literature, the criteria for identifying abnormal cervical LN under ultrasound are: disappearance of the LN hilum structure or abnormalities in the skin and medulla, LN becoming round or having an increased aspect ratio, microcalcifications in the LN, cystic changes present in LN, and abnormal blood flow signals in LN.17 The inclusion and exclusion criteria are: all cases are newly diagnosed TC cases; all cases underwent preoperative thyroid and neck LN examinations by the Ultrasound Department of Shandong Provincial Hospital; all cases underwent thyroid surgery for the first time; all cases were diagnosed with TC through postoperative pathological examination; excluding cases of other combined tumors or major diseases. This study used the postoperative paraffin pathology results as the gold standard for diagnostic testing. All ultrasound examinations were performed by two ultrasound physicians. When two ultrasound physicians had different opinions, a third senior ultrasound physician was requested to assist in the evaluation.

Data Collection After obtaining written consent, we recorded the patient\&#39;s relevant information in detail and followed up on the patient\&#39;s postoperative paraffin pathology results. The collected and organized items included: 1) sex, age, and past medical history; 2) preoperative ultrasound information; 3) preoperative fine-needle biopsy information; 4) surgical information; 5) postoperative pathological information; and 6) immunohistochemical information.

Statistical Analysis This study first analyzed the baseline data of the included patients and obtained descriptive data on the current status of patients with TC. (Table 1) This study also analyzed the efficacy of ultrasound and fine-needle aspiration (FNA) for the evaluation of cervical LN. (Table 2) Subsequently, analysis was conducted on 52 factors that may cause false-negative CLN of TC. (Table 3) A total of 16 statistically significant influencing factors were identified. (Table 4) To construct a predictive model for the occurrence of false-negative CLN of the thyroid gland, we selected five preoperative influencing factors with predictive significance from eight preoperative influencing factors and drew a forest chart for data visualization and outcome prediction.

This study was analyzed using IBM SPSS 29.0 software. Quantitative data are represented by mean ± standard deviation when it follows a normal distribution and homogeneity of variance, and an independent sample t-test is used for comparison between the two groups; the median (P25, P75) is used to represent non-normal distributions, and a non-parametric Mann-Whitney test is used for comparison between the two groups. Qualitative data were expressed as percentages (%), and intergroup comparisons were conducted using the chi-square or Fisher\&#39;s exact test. Variables with statistical significance in the univariate analysis and those professionally considered to have an impact on the outcome were included in the logistic regression model to explore the independent factors influencing the outcome. The test level P was set at 0.05. A forest map was drawn using Graphpad Prism 10.12 software, and a column chart and credibility analysis were drawn using R Studio 4.3 software.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Under- and Overdiagnosis in BreastScreen Norway	NCT03852953	Breast Cancer	Under- or overd... Screening	25 Years - 75 Years	Cancer Registry of Norway
Under- and Overdiagnosis in BreastScreen Norway	NCT03852953	Breast Cancer	Under- or overd... Screening	25 Years - 75 Years	Cancer Registry of Norway
Influencing Factors and Prediction Model of False-negative Central Lymph Nodes in Thyroid Cancer Patients	NCT06423105	Thyroid Cancer		-	Shandong Provincial Hospital

Spots Global Cancer Trial Database for false negative