Data quality at the Cancer Registry of Norway: An overview of comparability, completeness, validity and timeliness

The National Cancer Database Conforms to the Standardized Framework for Registry and Data Quality

BACKGROUND

Standardization of procedures for data abstraction by cancer registries is fundamental for cancer surveillance, clinical and policy decision-making, hospital benchmarking, and research efforts. The objective of the current study was to evaluate adherence to the four components (completeness, comparability, timeliness, and validity) defined by Bray and Parkin that determine registries' ability to carry out these activities to the hospital-based National Cancer Database (NCDB).

METHODS

Tbis study used data from U.S. Cancer Statistics, the official federal cancer statistics and joint effort between the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute (NCI), which includes data from National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) to evaluate NCDB completeness between 2016 and 2020. The study evaluated comparability of case identification and coding procedures. It used Commission on Cancer (CoC) standards from 2022 to assess timeliness and validity.

RESULTS

Completeness was demonstrated with a total of 6,828,507 cases identified within the NCDB, representing 73.7% of all cancer cases nationwide. Comparability was followed using standardized and international guidelines on coding and classification procedures. For timeliness, hospital compliance with timely data submission was 92.7%. Validity criteria for re-abstracting, recording, and reliability procedures across hospitals demonstrated 94.2% compliance. Additionally, data validity was shown by a 99.1% compliance with histologic verification standards, a 93.6% assessment of pathologic synoptic reporting, and a 99.1% internal consistency of staff credentials.

CONCLUSION

The NCDB is characterized by a high level of case completeness and comparability with uniform standards for data collection, and by hospitals with high compliance, timely data submission, and high rates of compliance with validity standards for registry and data quality evaluation.

How do AI markings on screening mammograms correspond to cancer location? An informed review of 270 breast cancer cases in BreastScreen Norway

OBJECTIVES

To compare the location of AI markings on screening mammograms with cancer location on diagnostic mammograms, and to classify interval cancers with high AI score as false negative, minimal sign, or true negative.

METHODS

In a retrospective study from 2022, we compared the performance of an AI system with independent double reading according to cancer detection. We found 93% (880/949) of the screen-detected cancers, and 40% (122/305) of the interval cancers to have the highest AI risk score (AI score of 10). In this study, four breast radiologists reviewed mammograms from 126 randomly selected screen-detected cancers and all 120 interval cancers with an AI score of 10. The location of the AI marking was stated as correct/not correct in craniocaudal and mediolateral oblique view. Interval cancers with an AI score of 10 were classified as false negative, minimal sign significant/non-specific, or true negative.

RESULTS

All screen-detected cancers and 78% (93/120) of the interval cancers with an AI score of 10 were correctly located by the AI system. The AI markings matched in both views for 79% (100/126) of the screen-detected cancers and 22% (26/120) of the interval cancers. For interval cancers with an AI score of 10, 11% (13/120) were correctly located and classified as false negative, 10% (12/120) as minimal sign significant, 26% (31/120) as minimal sign non-specific, and 31% (37/120) as true negative.

CONCLUSION

AI markings corresponded to cancer location for all screen-detected cancers and 78% of the interval cancers with high AI score, indicating a potential for reducing the number of interval cancers. However, it is uncertain whether interval cancers with subtle findings in only one view are actionable for recall in a true screening setting.

CLINICAL RELEVANCE STATEMENT

In this study, AI markings corresponded to the location of the cancer in a high percentage of cases, indicating that the AI system accurately identifies the cancer location in mammograms with a high AI score.

KEY POINTS

• All screen-detected and 78% of the interval cancers with high AI risk score (AI score of 10) had AI markings in one or two views corresponding to the location of the cancer on diagnostic images. • Among all 120 interval cancers with an AI score of 10, 21% (25/120) were classified as a false negative or minimal sign significant and had AI markings matching the cancer location, suggesting they may be visible on prior screening. • Most of the correctly located interval cancers matched only in one view, and the majority were classified as either true negative or minimal sign non-specific, indicating low potential for being detected earlier in a real screening setting.

Increased cancer incidence and mortality among people with opioid use-related disorders: A nation-wide cohort study

BACKGROUND AND AIMS

Studies on cancer incidence and mortality among people with opioid use-related disorders are lacking. We aimed to measure cancer-specific incidence, mortality and survival among people diagnosed with opioid use-related disorders in Norway during 2010-18.

DESIGN AND SETTING

This was a cohort study conducted in Norway during 2010-18.

PARTICIPANTS

Individuals (n = 20 710) diagnosed with opioid use-related disorders.

MEASUREMENTS

We conducted a cohort study utilizing a data-linkage of national health and population registers. Information on opioid use-related disorders was extracted from specialized healthcare, malignancies from the Cancer Registry of Norway and deaths from Cause of Death Registry. Cancer incidence and mortality were compared with the general population by calculating sex-specific age-standardized incidence (SIR) and mortality (SMR) ratios. One-year survival rates were computed.

FINDINGS

Compared with the general population, people with opioid use-related disorders were at an increased risk of developing cancer overall [SIR = 1.2, 95% confidence interval (CI) = 1.1-1.3] with a higher than twofold cancer mortality rate (SMR = 2.3, 95% CI = 2.0-2.7). Excess risk was observed for liver (12.6, 95% CI = 9.1-17.0), larynx (4.7, 95% CI = 1.7-10.2), lung (3.5, 95% CI = 2.8-4.3) and pancreas cancer (2.6, 95% CI = 1.6-4.0), whereas reduced risk was found for melanoma (0.5, 95% CI = 0.3-0.9), breast (0.6, 95% CI = 0.4-0.9) and prostate cancers (0.3, 95% CI = 0.1-0.4). Site-specific SMRs were significantly elevated for liver (12.3, 95% CI = 8.5-17.2), lung (3.9, 95% CI = 3.0-5.0), pancreas (3.0, 95% CI = 1.7-4.8) and colon cancers (1.9, 95% CI = 1.1-3.1). The average 1-year survival rate after a cancer diagnosis was low in liver, pancreas and colon cancer, ranging from 10 to 15% less than that of the general population.

CONCLUSIONS

In Norway, cancer incidence and cancer-related mortality appear to be elevated among individuals with opioid use-related disorders.

Differential levels of circulating RNAs prior to endometrial cancer diagnosis

Endometrial cancer (EC) is one of the most common female cancers and there is currently no routine screening strategy for early detection. An altered abundance of circulating microRNAs (miRNAs) and other RNA classes have the potential as early cancer biomarkers. We analyzed circulating RNA levels using small RNA sequencing, targeting RNAs in the size range of 17-47 nucleotides, in EC patients with samples collected prior to diagnosis compared to cancer-free controls. The analysis included 316 cases with samples collected 1-11 years prior to EC diagnosis, and 316 matched controls, both from the Janus Serum Bank cohort in Norway. We identified differentially abundant (DA) miRNAs, isomiRs, and small nuclear RNAs between EC cases and controls. The top EC DA miRNAs were miR-155-5p, miR-200b-3p, miR-589-5p, miR-151a-5p, miR-543, miR-485-5p, miR-625-p, and miR-671-3p. miR-200b-3p was previously reported to be among one of the top miRNAs with higher abundance in EC cases. We observed 47, 41, and 32 DA miRNAs for EC interacting with BMI, smoking status, and physical activity, respectively, including two miRNAs (miR-223-3p and miR-29b-3p) interacting with all three factors. The circulating RNAs are altered and show temporal dynamics prior to EC diagnosis. Notably, DA miRNAs for EC had the lowest q-value 4.39-6.66 years before diagnosis. Enrichment analysis of miRNAs showed that signaling pathways Fc epsilon RI, prolactin, toll-like receptor, and VEGF had the strongest associations.

Exposure to fibres and risk of pleural mesothelioma in the Norwegian Offshore Petroleum Workers cohort

OBJECTIVES

Pleural mesothelioma is a rare respiratory cancer, mainly caused by inhalation of asbestos fibres. Other inorganic fibres are also suggested risk factors. We aimed to investigate the association between exposure to asbestos or refractory ceramic fibres (RCFs) and pleural mesothelioma among male Norwegian offshore petroleum workers.

METHODS

Among 25 347 men in the Norwegian Offshore Petroleum Workers (NOPW) cohort (1965-1998), 43 pleural mesothelioma cases were identified through the Cancer Registry of Norway (1999-2022). A case-cohort study was conducted with 2095 randomly drawn non-cases from the cohort. Asbestos and RCF exposures were assessed with expert-made job-exposure matrices (JEMs). Weighted Cox regression was used to estimate HRs and 95% CIs, adjusted for age at baseline and pre-offshore employment with likely asbestos exposure.

RESULTS

An increased risk of pleural mesothelioma was indicated for the highest versus lowest tertile of average intensity of asbestos (HR=1.21, 95% CI: 0.57 to 2.54). Pre-offshore asbestos exposure (vs no such exposure) was associated with increased risk of pleural mesothelioma (HR=2.06, 95% CI: 1.11 to 3.81). For offshore workers with no pre-offshore asbestos exposure, an increased risk of pleural mesothelioma was found for the highest tertile of average intensity of asbestos (HR=4.13, 95% CI: 0.93 to 18), versus the lowest tertile. No associations were found between RCF and pleural mesothelioma.

CONCLUSIONS

Associations between JEM-based offshore asbestos exposure and pleural mesothelioma were confirmed in the NOPW cohort. Pleural mesothelioma risk was also associated with asbestos exposure before work in the offshore petroleum industry.

Lifestyle and metabolic factors affect risk for meningioma in women: a prospective population-based study (The Cohort of Norway)

Background

Meningioma is the most common primary brain tumor, with a clear preponderance in women. Obesity is considered a risk factor for the development of meningioma. Obesity is also the clinical hallmark of metabolic syndrome, characterized by glucose intolerance, dyslipidemia, and hypertension. Lifestyle and metabolic factors directly impact overweight and obesity and are therefore potential risk factors for meningioma development. The aim of this study is to assess lifestyle and metabolic factors for meningioma risk in women.

Methods

The Cohort of Norway (CONOR) is a nationwide health survey, conducted between 1994 and 2003, including anthropometric measures, blood tests, and health questionnaires. Linkage to the National Cancer Registry enabled the identification of intracranial meningioma during follow-up until December 2018.

Results

A total of 81,652 women were followed for a combined total of 1.5 million years, and 238 intracranial meningiomas were identified. Increasing levels of physical activity (HR 0.81; 95% CI 0.68-0.96; p trend <0.02) and parity (HR 0.83; 95% CI 0.71-0.97; p trend <0.03) were negatively associated with meningioma risk. Diabetes mellitus or glucose intolerance increased the risk for meningioma (HR 2.54; 95% CI 1.60-4.05). Overweight and obesity were not associated with meningioma risk, nor was metabolic syndrome. However, participants without metabolic dysfunction had a reduced meningioma risk, while participants with all five metabolic factors present had a 4-fold risk increase for meningioma (HR 4.28; 95% CI 1.34-13.68).

Conclusion

Lifestyle factors seem to significantly influence meningioma risk. However, disentangling the complex associations and interactions between factors for meningioma risk will be a challenging task for future studies.

Prevalence of drugs used for chronic conditions after diagnosis of thyroid cancer: a register-based cohort study

OBJECTIVE

Little is known about thyroid cancer survivors' risk of chronic conditions. We, therefore, investigated the prevalence of drugs used for chronic conditions among thyroid cancer patients using population-wide register data.

METHODS

We linked data from the Cancer Registry of Norway to the Norwegian Prescription Database and other databases for a study population of 3.52 million individuals, including 3486 individuals with thyroid cancer diagnosed during 2005-2019. Prevalence ratios (PRs) with 95% CIs of reimbursed prescribed drugs in thyroid cancer patients up to 15 years after thyroid cancer diagnosis were estimated by log-binomial regression, with the cancer-free population as reference.

RESULTS

Individuals (both males and females) with thyroid cancer had higher use of drugs for several chronic conditions in the years after diagnosis; eg, 5 years after thyroid cancer diagnosis, there was elevated use of drugs for hypoparathyroidism (PRmales = 35.4, 95% CI, 25.2-49.7; PRfemales = 42.8, 95% CI, 34.2-53.6), hypertension (PRfemales = 1.20, 95% CI, 1.12-1.28), anxiety and tension (PRmales = 4.01, 95% CI, 1.80-8.92; PRfemales = 2.01, 95% CI, 1.15-3.52), gastric acid disorders (PRmales = 1.52, 95% CI, 1.22-1.91; PRfemales = 1.45, 95% CI, 1.27-1.66), and pain (PRmales = 1.48, 95% CI, 1.11-1.97; PRfemales = 1.24, 95% CI, 1.08-1.42) as compared with the cancer-free population. In addition, males with thyroid cancer had long-term elevated use of drugs for depression (eg, year 10+, PRmales = 1.66, 95% CI, 1.06-2.59). Individuals with thyroid cancer also had higher use of drugs for several conditions prior to the thyroid cancer diagnosis, eg, hypertension, gastric acid disorders, and pain.

CONCLUSIONS

Individuals diagnosed with thyroid cancer had elevated long-term use of drugs for several chronic conditions, as compared with the cancer-free population.

Laryngeal cancer relative survival trends from 1972 to 2021 in the Nordic countries

BACKGROUND AND PURPOSE

Changes in treatment approaches, characterised by the shift from laryngectomy to a focus on organ-preserving methods may have potentially resulted in lower survival. We aim to identify differences in survival trends for laryngeal cancer (LC) in the Nordic countries over a period of 50 years, and discuss the potential impact of factors such as changes in treatment protocols.

MATERIALS AND METHODS

Five-year relative survival (RS) data from 1972 to 2021 were obtained from the NORDCAN database 2.0 which included 33,692 LC cases, of which 85% were diagnosed among men. In the NORDCAN database, the age-standardised RS is calculated using the Pohar Perme estimator with individual International Cancer Survival Standards weights. Joinpoint regression models were used to assess potential shifts in trend over the years in RS.

RESULTS

While Denmark and Norway demonstrated an increasing trend in 5-year RS from 1972 to 2021, in Finland and Sweden, the 5-year RS among men remained static, without any discernible significant trend. Over the 30-year period from 1992-1996 to 2017-2021, RS improved by 9, 4, 13, and 2 percentage points in Denmark, Finland, Norway, and Sweden, respectively. Among women in Sweden, a linear negative trend was observed, noticeable as a 16 percentage-point decline in 5-year RS from the earliest to the latest period.

INTERPRETATION

The underlying causes for the differences in survival trends remain unclear. Besides differences in treatment protocols, several other factors can affect RS making the interpretation of RS trends challenging.

Data quality in Brazilian population-based cancer registries for gastrointestinal cancers

BACKGROUND

Population-based cancer registries (PBCRs) are the primary source of information for cancer surveillance and monitoring. Currently, there are 30 active PBCRs in Brazil. The objective of this study was to analyze the data quality of five gastrointestinal cancers (esophagus, stomach, colorectal, liver, and pancreas) according to the criteria of comparability, validity, completeness, and timeliness in Brazilian cancer registries.

METHODS

This study included data from Brazilian PBCRs with more than ten years of historical data starting in the year 2000, regardless of the type of defined geographical coverage (state, metropolitan region, or capital), totaling 16 registries. Brazilian PBCRs were evaluated based on four international data quality criteria: comparability, validity (accuracy), completeness, and timeliness. All cancer cases were analyzed, except for nonmelanoma skin cancer cases (C44) and five gastrointestinal tumors (esophageal cancer, stomach cancer, colorectal cancer, liver cancer, and pancreatic cancer) per cancer registry and sex, according to the available period.

RESULTS

The 16 Brazilian PBCRs represent 17% of the population (36 million inhabitants in 2021) according to data from 2000 to 2018. There was a variation in the incidence in the historical series ranging from 12 to 19 years. The proportion of morphologically verified (MV%) cases varied from 74.3% (Manaus) to 94.8% (Aracaju), and the proportion of incidentally reported death certificate only (DCO%) cases varied from 3.0% (São Paulo) to 23.9% (Espírito Santo). High-lethality malignant neoplasms, such as liver and pancreas, had DCO percentages greater than 30% in most cancer registries. The sixteen registries have more than a 48-month delay in data release compared to the 2022 calendar year.

CONCLUSION

The studied Brazilian cancer registries met international comparability criteria; however, half of the registries showed indices below the expected levels for validity and completeness criteria for high-lethality tumors such as liver and pancreas tumors, in addition to a long delay in data availability and disclosure. Significant efforts are necessary to ensure the operational and stability of the PBCR in Brazil, which continues to be a tool for monitoring cancer incidence and assessing national cancer control policies.

Menopausal hormone therapy and breast cancer risk: a population-based cohort study of 1.3 million women in Norway

BACKGROUND

It is important to monitor the association between menopausal hormone therapy (HT) use and breast cancer (BC) risk with contemporary estimates, and specifically focus on HT types and new drugs.

METHODS

We estimated hazard ratios (HR) of BC risk according to HT type, administration route and individual drugs, overall and stratified by body mass index (BMI), molecular subtype and detection mode, with non-HT use as reference.

RESULTS

We included 1,275,783 women, 45+ years, followed from 2004, for a median of 12.7 years. Oral oestrogen combined with daily progestin was associated with the highest risk of BC (HR 2.42, 95% confidence interval (CI) 2.31-2.54), with drug-specific HRs ranging from Cliovelle®: 1.63 (95% CI 1.35-1.96) to Kliogest®: 2.67 (2.37-3.00). Vaginal oestradiol was not associated with BC risk. HT use was more strongly associated with luminal A cancer (HR 1.97, 95% CI 1.86-2.09) than other molecular subtypes, and more strongly with interval (HR 2.00, 95% CI: 1.83-2.30) than screen-detected (HR 1.33, 95% CI 1.26-1.41) BC in women 50-71 years. HRs for HT use decreased with increasing BMI.

CONCLUSIONS

The use of oral and transdermal HT was associated with an increased risk of BC. The associations varied according to HT type, individual drugs, molecular subtype, detection mode and BMI.

Small Cell Lung Cancer in Norway: Patterns of Care by Health Region and Survival Trends

INTRODUCTION/BACKGROUND

There has been a marked survival improvement for patients with non-small-cell lung cancer. We describe the national trends in characteristics and survival, and geographical differences in diagnostic workup, treatment, and survival for patients with small-cell lung cancer (SCLC).

MATERIALS AND METHODS

Patients registered with SCLC at the Cancer Registry of Norway in 2002 to 2022 were included. Trends in overall survival were estimated for all SCLC patients, patients with limited stage SCLC, patients undergoing surgery, and by health region. Adjusting for case-mix, a multivariable Cox regression was performed examining the association between health region and death.

RESULTS

The study included 8374 patients. The stage distribution remained unchanged during the study period. The 5-year overall survival increased from 7.7% to 22.8% for patients with limited stage. The use of multidisciplinary team meetings varied from 62.5% to 85.7%, and the use of positron emission tomography-computer tomography varied from 70.4% to 86.2% between the health regions. Treatment patterns differed markedly between the health regions, with the proportion dying without any registered treatment ranging from 1.2% to 10.9%. For limited stage patients in 2018 to 2022, the median overall survival ranged from 16.5 to 25.5 months across health regions, and the 5-year overall survival ranged from 18.7% to 28.7% (P = .019).

CONCLUSION

The survival for patients with SCLC remains poor. The use of diagnostic procedures, treatment modalities, and survival differed between regions, warranting investigations to further explore the reasons.

Low-Dose Aspirin and Prevention of Colorectal Cancer: Evidence From a Nationwide Registry-Based Cohort in Norway

INTRODUCTION

To examine the association between low-dose aspirin use and risk of colorectal cancer (CRC).

METHODS

In this nationwide cohort study, we identified individuals aged 50 years or older residing for 6 months or more in Norway in 2004-2018 and obtained data from national registers on drug prescriptions, cancer occurrence, and sociodemographic factors. Multivariable Cox regression models were used to estimate the association between low-dose aspirin use and CRC risk. In addition, we calculated the number of CRC potentially averted by low-dose aspirin use.

RESULTS

We included 2,186,390 individuals. During the median follow-up of 10.9 years, 579,196 (26.5%) used low-dose aspirin, and 38,577 (1.8%) were diagnosed with CRC. Current use of aspirin vs never use was associated with lower CRC risk (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.84-0.90). The association was more pronounced for metastatic CRC (HR 0.79; 95% CI 0.74-0.84) than regionally advanced (HR 0.89; 95% CI 0.85-0.92) and localized CRC (HR 0.93; 95% CI 0.87-1.00; P heterogeneity = 0.001). A significant trend was found between duration of current use and CRC risk: HR 0.91 (95% CI 0.86-0.95) for <3 years, HR 0.85 (0.80-0.91) for ≥3 and <5 years, and HR 0.84 (0.80-0.88) for ≥5 years of use vs never use ( P trend < 0.001). For past use, HR were 0.89 (95% CI 0.84-0.94) for <3 years, 0.90 (0.83-0.99) for ≥3 and <5 years, and 0.98 (0.91-1.06) for ≥5 years since last use vs never use ( P -trend < 0.001). We estimated that aspirin use averted 1,073 cases of CRC (95% CI 818-1,338) in the study period.

DISCUSSION

In this nationwide cohort, use of low-dose aspirin was associated with a lower risk of CRC.

Validation of miRNA signatures for ovarian cancer earlier detection in the pre-diagnosis setting using machine learning approaches

Introduction

Effective strategies for early detection of epithelial ovarian cancer are lacking. We evaluated whether a panel of 14 previously established circulating microRNAs could discriminate between cases diagnosed <2 years after serum collection and those diagnosed 2-7 years after serum collection. miRNA sequencing data from subsequent ovarian cancer cases were obtained as part of the ongoing multi-cancer JanusRNA project, utilizing pre-diagnostic serum samples from the Janus Serum Bank and linked to the Cancer Registry of Norway for cancer outcomes.

Methods

We included a total of 80 ovarian cancer cases contributing 80 serum samples and compared 40 serum samples from cases with samples collected <2 years prior to diagnosis with 40 serum samples from cases with sample collection ≥2 to 7 years. We employed the extreme gradient boosting (XGBoost) algorithm to train a binary classification model using 70% of the available data, while the model was tested on the remaining 30% of the dataset.

Results

The performance of the model was evaluated using repeated holdout validation. The previously established set of miRNAs achieved a median area under the receiver operating characteristic curve (AUC) of 0.771 in the test sets. Four out of 14 miRNAs (hsa-miR-200a-3p, hsa-miR-1246, hsa-miR-203a-3p, hsa-miR-23b-3p) exhibited higher expression levels closer to diagnosis, consistent with the previously reported upregulation in cancer cases, with statistical significance observed only for hsa-miR-200a-3p (beta=0.14; p=0.04).

Discussion

The discrimination potential of the selected models provides evidence of the robustness of the miRNA signature for ovarian cancer.

Early performance measures following regular versus irregular screening attendance in the population-based screening program for breast cancer in Norway

OBJECTIVE

Irregular attendance in breast cancer screening has been associated with higher breast cancer mortality compared to regular attendance. Early performance measures of a screening program following regular versus irregular screening attendance have been less studied. We aimed to investigate early performance measures following regular versus irregular screening attendance.

METHODS

We used information from 3,302,396 screening examinations from the Cancer Registry of Norway. Examinations were classified as regular or irregular. Regular was defined as an examination 2 years ± 6 months after the prior examination, and irregular examination >2 years and 6 months after prior examination. Performance measures included recall, biopsy, screen-detected and interval cancer, positive predictive values, and histopathological tumor characteristics.

RESULTS

Recall rate was 2.4% (72,429/3,070,068) for regular and 3.5% (8217/232,328) for irregular examinations. The biopsy rate was 1.0% (29,197/3,070,068) for regular and 1.7% (3825/232,328) for irregular examinations, while the rate of screen-detected cancers 0.51% (15,664/3,070,068) versus 0.86% (2003/232,328), respectively. The adjusted odds ratio was 1.53 (95% CI: 1.49-1.56) for recall, 1.73 (95% CI: 1.68-1.80) for biopsy, and 1.68 (95% CI: 1.60-1.76) for screen-detected cancer after irregular examinations compared to regular examinations. The proportion of lymph node-positive tumors was 20.1% (2553/12,719) for regular and 25.6% (426/1662) for irregular examinations.

CONCLUSION

Irregular attendance was linked to higher rates of recall, needle biopsies, and cancer detection. Cancers detected after irregular examinations had less favorable histopathological tumor characteristics compared to cancers detected after regular examinations. Women should be encouraged to attend screening when invited to avoid delays in diagnosis.

Mammographic features and risk of breast cancer death among women with invasive screen-detected cancer in BreastScreen Norway 1996-2020

OBJECTIVES

We explored associations between mammographic features and risk of breast cancer death among women with small (<15 mm) and large (≥15 mm) invasive screen-detected breast cancer.

METHODS

We included data from 17,614 women diagnosed with invasive breast cancer as a result of participation in BreastScreen Norway, 1996-2020. Data on mammographic features (mass, spiculated mass, architectural distortion, asymmetric density, density with calcification and calcification alone), tumour diameter and cause of death was obtained from the Cancer Registry of Norway. Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for breast cancer death by mammographic features using spiculated mass as reference, adjusting for age, tumour diameter and lymph node status. All analyses were dichotomised by tumour diameter (small versus large).

RESULTS

Mean age at diagnosis was 60.8 (standard deviation, SD=5.8) for 10,160 women with small tumours and 60.0 (SD=5.8) years for 7454 women with large tumours. The number of breast cancer deaths was 299 and 634, respectively. Mean time from diagnosis to death was 8.7 (SD=5.0) years for women with small tumours and 7.2 (4.6) years for women with large tumours. Using spiculated mass as reference, adjusted HR for breast cancer death among women with small tumours was 2.48 (95% CI 1.67-3.68) for calcification alone, while HR for women with large tumours was 1.30 (95% CI 1.02-1.66) for density with calcification.

CONCLUSIONS

Small screen-detected invasive cancers presenting as calcification and large screen-detected cancers presenting as density with calcification were associated with the highest risk of breast cancer death.

CLINICAL RELEVANCE STATEMENT

Small tumours (<15 mm) presented as calcification alone and large tumours (≥ 15 mm) presented as density with calcification were associated with the highest risk of breast cancer death among women with screen-detected invasive breast cancer diagnosed 1996-2020.

KEY POINTS

• Women diagnosed with invasive screen-detected breast cancer 1996-2020 were analysed. • Small screen-detected cancers presenting as calcification alone resulted in the highest risk of breast cancer death. • Large screen-detected cancers presenting as density with calcification resulted in the highest risk of breast cancer death.

Performance of an Artificial Intelligence System for Breast Cancer Detection on Screening Mammograms from BreastScreen Norway

Purpose To explore the stand-alone breast cancer detection performance, at different risk score thresholds, of a commercially available artificial intelligence (AI) system. Materials and Methods This retrospective study included information from 661 695 digital mammographic examinations performed among 242 629 female individuals screened as a part of BreastScreen Norway, 2004-2018. The study sample included 3807 screen-detected cancers and 1110 interval breast cancers. A continuous examination-level risk score by the AI system was used to measure performance as the area under the receiver operating characteristic curve (AUC) with 95% CIs and cancer detection at different AI risk score thresholds. Results The AUC of the AI system was 0.93 (95% CI: 0.92, 0.93) for screen-detected cancers and interval breast cancers combined and 0.97 (95% CI: 0.97, 0.97) for screen-detected cancers. In a setting where 10% of the examinations with the highest AI risk scores were defined as positive and 90% with the lowest scores as negative, 92.0% (3502 of 3807) of the screen-detected cancers and 44.6% (495 of 1110) of the interval breast cancers were identified with AI. In this scenario, 68.5% (10 987 of 16 040) of false-positive screening results (negative recall assessment) were considered negative by AI. When 50% was used as the cutoff, 99.3% (3781 of 3807) of the screen-detected cancers and 85.2% (946 of 1110) of the interval breast cancers were identified as positive by AI, whereas 17.0% (2725 of 16 040) of the false-positive results were considered negative. Conclusion The AI system showed high performance in detecting breast cancers within 2 years of screening mammography and a potential for use to triage low-risk mammograms to reduce radiologist workload. Keywords: Mammography, Breast, Screening, Convolutional Neural Network (CNN), Deep Learning Algorithms Supplemental material is available for this article. © RSNA, 2024 See also commentary by Bahl and Do in this issue.

Associations between pregnancy-related factors and birth characteristics with risk of rare uterine cancer subtypes: a Nordic population-based case-control study

PURPOSE

Uterine sarcomas are a rare group of uterine malignancies. Due to the low incidence and changes in uterine sarcoma classification, risk factors are not well characterized. Our objective was to evaluate risk factors for uterine sarcoma and compare risk factors between uterine sarcoma, malignant mixed Mullerian tumors (MMMTs), and type I endometrial carcinomas.

METHODS

This nested case-control study utilized linked data from population-based medical birth and cancer registries in Denmark, Finland, Norway, and Sweden. Up to 10 controls were matched on country and birth year for each uterine cancer case. Using multivariable adjusted multinomial logistic regression, estimates of the associations between pregnancy-related factors and risk of uterine sarcoma, MMMTs, and type I endometrial carcinomas were determined.

RESULTS

Having a very-low-birth-weight infant (< 1500 vs. 2500-3999 g: OR [95% CI] 2.83 [1.61-4.96]) was associated with an increased risk of uterine sarcoma. Whereas, having a more recent pregnancy was associated with reduced risks of MMMT (< 10 vs. ≥ 30 years: 0.66 [0.20-2.23]) and type 1 endometrial carcinomas (0.35 [0.30-0.41]) but not uterine sarcomas (1.33 [0.90-1.98], p-heterogeneity < 0.01).

CONCLUSION

Our study provides evidence that risk factors for uterine sarcoma and MMMT, previously grouped with uterine sarcomas, vary substantially. Additionally, MMMT and type I endometrial carcinomas are more similar than uterine sarcoma in that pregnancy complications like gestational hypertension and preeclampsia were associated with reduced risks of both but not uterine sarcoma, suggesting different etiologies.

Excess weight, weight gain, and prostate cancer risk and prognosis: the PROCA-life study

BACKGROUND

Studies of excess weight and weight changes throughout adult life for prostate cancer (PCa) risk and prognosis have shown inconsistent results.

METHODS

In a population-based cohort, the Prostate Cancer Study throughout life (PROCA-life), 16,960 healthy men from the prospective cohort Tromsø Study (1994-2016) were included. Body mass index (BMI) and weight were measured at all four attendings, and weight change was calculated as the difference between the first and last of either Tromsø4, Tromsø5 or Tromsø6. Overall, 904 men developed PCa during 16 years of follow-up, and Poisson regression with fractional polynomials was used to investigate trends in incidence. Cox proportional hazard and logistic regression models were used to study associations between measurements of BMI and weight change and PCa risk, severity, and mortality.

RESULTS

At study entry, 46% of the participants (median age 44 years) were overweight, and 14% were obese (BMI > 30 kg/m2). We observed a 127% increase in overall age adjusted PCa incidence in the cohort during 1995 through 2019. No overall associations between BMI or weight change and PCa risk were observed. However, in sub-group analysis, weight gain among obese men was associated with a three-fold higher PCa risk (HR 3.03, 95% CI 1.39-6.58) compared with obese men with stable weight. Overweight was associated with lower risk of metastatic cancer (OR 0.48, 95% CI 0.30-0.75) at diagnosis. Men with obesity had higher risk of PCa-specific death (HR 1.72, 95% CI 1.03-2.88), while nonsmoking obese PCa cases had two times higher PCa-specific mortality compared with normal weighted PCa cases (HR 2.10, 95% CI 1.11-3.70).

INTERPRETATION

In our cohort, weight gain among obese men was associated with higher risk of PCa, and obesity was associated with higher PCa-specific mortality, especially among nonsmokers. The relationship between weight and risk for PCa remains complicated, and future studies are needed to determine clinical implications.

Incidence and Factors Associated With Second Primary Invasive Melanoma in Norway

Importance

Patients diagnosed with a primary melanoma are at high risk of subsequent melanomas. Understanding the risk of second primary invasive melanoma and associated factors is crucial to optimize patient follow-up.

Objective

To assess the incidence rate of second primary invasive melanoma and time between the first and second primary invasive melanoma in the Norwegian population.

Design, Setting, and Participants

This population-based cohort study included data from deidentified records of all invasive melanomas diagnosed in Norway in 2008 to 2020, obtained from the Cancer Registry of Norway. Data were from adults aged 18 years or older diagnosed with a first primary melanoma. Data analysis was performed from March to August 2023.

Main Outcomes and Measures

The main outcome was the incidence rate of second primary invasive melanoma at least 30 days after the first. Accelerated failure time models were fitted to examine potential associations with patient and tumor characteristics. Median time between first and second primary melanomas and 95% CIs were calculated. The likelihood of, and median interval for, second primary melanomas on the same or different site as the first primary were calculated.

Results

A total of 19 196 individuals aged 18 years or older were diagnosed with a first primary melanoma. The mean (SD) age at diagnosis of the first primary melanoma was 62 (16) years (range, 18-104 years), and 9763 (51%) were female. The incidence rate in the year following diagnosis was 16.8 (95% CI, 14.9-18.7) per 1000 person-years, which decreased to 7.3 (95% CI, 6.0-8.6) during the second year and stabilized thereafter. Median time between first and second primaries decreased with advancing age and was 37 months (95% CI, 8-49) in patients younger than 40 years, 18 (95% CI, 13-24) in patients aged 50 to 59 years, and 11 (95% CI, 7-18) in patients aged 80 years or older. The second primary was on the same site as their first primary for 47% (359 patients), and on a different site for 53% (407 patients). The median interval until second melanoma on the same site as the initial melanoma was 12 (95% CI, 7-19) months in men and 22 (95% CI, 11-35) months in women.

Conclusions and Relevance

Older age and male sex were associated with an increased risk, suggesting that increased surveillance intensity may be considered for men, especially those older than 50 years, for at least 3 years after their initial diagnosis, regardless of the characteristics of their first invasive melanoma.

Machine Learning-Based Survival Prediction Models for Progression-Free and Overall Survival in Advanced-Stage Hodgkin Lymphoma

PURPOSE

Patients diagnosed with advanced-stage Hodgkin lymphoma (aHL) have historically been risk-stratified using the International Prognostic Score (IPS). This study investigated if a machine learning (ML) approach could outperform existing models when it comes to predicting overall survival (OS) and progression-free survival (PFS).

PATIENTS AND METHODS

This study used patient data from the Danish National Lymphoma Register for model development (development cohort). The ML model was developed using stacking, which combines several predictive survival models (Cox proportional hazard, flexible parametric model, IPS, principal component, penalized regression) into a single model, and was compared with two versions of IPS (IPS-3 and IPS-7) and the newly developed aHL international prognostic index (A-HIPI). Internal model validation was performed using nested cross-validation, and external validation was performed using patient data from the Swedish Lymphoma Register and Cancer Registry of Norway (validation cohort).

RESULTS

In total, 707 and 760 patients with aHL were included in the development and validation cohorts, respectively. Examining model performance for OS in the development cohort, the concordance index (C-index) for the ML model, IPS-7, IPS-3, and A-HIPI was found to be 0.789, 0.608, 0.650, and 0.768, respectively. The corresponding estimates in the validation cohort were 0.749, 0.700, 0.663, and 0.741. For PFS, the ML model achieved the highest C-index in both cohorts (0.665 in the development cohort and 0.691 in the validation cohort). The time-varying AUCs for both the ML model and the A-HIPI were consistently higher in both cohorts compared with the IPS models within the first 5 years after diagnosis.

CONCLUSION

The new prognostic model for aHL on the basis of ML techniques demonstrated a substantial improvement compared with the IPS models, but yielded a limited improvement in predictive performance compared with the A-HIPI.

Work status changes and associated factors in a nationwide sample of Norwegian long-term breast cancer survivors

PURPOSE

The study aims to describe work status at diagnosis and 8 years post-diagnosis in a nationwide sample of breast cancer survivors (BCSs), and investigate associated and self-reported factors of reduced work status.

METHODS

Women aged 20-65 years when diagnosed with stage I-III breast cancer (BC) in 2011 or 2012 were invited to participate in a questionnaire study in 2019 (n = 2803), of whom 49% (n = 1361) responded. For this sub-study, we included 974 BCSs below the legal retirement age in Norway (< 67 years) at survey and with complete work status data. Reduced work status was defined as being in paid work at BC diagnosis and not working at time of survey. Logistic regression analyses were applied to identify factors associated with reduced work status.

RESULTS

Of BCSs who were in paid work at diagnosis (n = 845), 63% maintained their work status to 8 years later. Reduced work status was associated with not living with children (OR .44, 95% CI .24-.82), age (OR 1.16, 95% CI 1.11-1.21), chemotherapy (OR 2.83, 95% CI 1.24-6.61), > 2 comorbid conditions (OR 2.27, 95% CI 1.16-4.32), cognitive function (OR .99, 95% CI .98-.99), fatigue (OR 1.02, 95% CI 1.01-1.03), and neuroticism (OR 1.57, 95% CI 1.00-2.46). BC and late effects were reported as reasons for reduced work status and disability.

CONCLUSIONS

The majority of BCSs who were in paid work at diagnosis were working 8 years later.

IMPLICATIONS FOR CANCER SURVIVORS

Our results suggest a need to focus on fatigue and reduced cognitive function among long-term BCSs, with the ultimate aim of improving work sustainability.

Incidence trends of adult glioma in Norway and its association with occupation and education: A registry-based cohort study

BACKGROUND

Gliomas constitute 75 % of all malignant primary adult brain tumors. Being the most frequent histologic subtype, glioblastomas (GBMs) cause substantial morbidity and mortality worldwide and the Nordic countries have some of the highest incidence rates in the world. Therefore, we investigated the incidence of gliomas in Norway including time trends and associations with education and occupation.

METHODS

We retrieved individual-level data from databases at Statistics Norway containing information on education and occupation and linked them to data on adult glioma patients diagnosed during 2004-21 from the Cancer Registry of Norway. Age-standardized incidence rates (ASIRs) (World Standard Population) were calculated and analyzed with regards to sex and morphology. Poisson regression was used to test for time-trends, and to analyze the associations between education, occupation and glioma incidence, adjusted for age, sex, and calendar year. Estimates were reported as incidence rate ratios (IRRs) with 95 % confidence intervals (CIs).

RESULTS

The overall ASIR of gliomas (per 100,000 person-years) was 7.1 (95 % CI 6.9-7.3), with no specific time trend during the study period. The incidence increased with age. Compared to the other subtypes, GBMs were diagnosed at older ages. The risks of developing glioma overall and GBM were associated with occupation but not with educational level. The relative risk of glioma and GBM were respectively 1.17 (95 % CI 1.05-1.31) and 1.17 (95 % CI 1.02-1.35) among high-skilled white-collar workers compared to blue-collar workers.

CONCLUSIONS

The overall and sex-specific ASIRs of gliomas and GBMs did not show any noticeable time trends. The higher risk of developing glioma overall and GBM in high-skilled white-collar workers compared to blue-collar workers calls for further investigations.

Stable glioma incidence and increased patient survival over the past two decades in Norway: a nationwide registry-based cohort study

BACKGROUND

Surveillance of incidence and survival of central nervous system tumors is essential to monitor disease burden and epidemiological changes, and to allocate health care resources. Here, we describe glioma incidence and survival trends by histopathology group, age, and sex in the Norwegian population.

MATERIAL AND METHODS

We included patients with a histologically verified glioma reported to the Cancer Registry of Norway from 2002 to 2021 (N = 7,048). Population size and expected mortality were obtained from Statistics Norway. Cases were followed from diagnosis until death, emigration, or 31 December 2022, whichever came first. We calculated age-standardized incidence rates (ASIR) per 100,000 person-years and age-standardized relative survival (RS).  Results: The ASIR for histologically verified gliomas was 7.4 (95% CI: 7.3-7.6) and was higher for males (8.8; 95% CI: 8.5-9.1) than females (6.1; 95% CI: 5.9-6.4). Overall incidence was stable over time. Glioblastoma was the most frequent tumor entity (ASIR = 4.2; 95% CI: 4.1-4.4). Overall, glioma patients had a 1-year RS of 63.6% (95% CI: 62.5-64.8%), and a 5-year RS of 32.8% (95% CI: 31.6-33.9%). Females had slightly better survival than males. For most entities, 1- and 5-year RS improved over time (5-year RS for all gliomas 29.0% (2006) and 33.1% (2021), p < 0.001). Across all tumor types, the RS declined with increasing age at diagnosis.

INTERPRETATION

The incidence of gliomas has been stable while patient survival has increased over the past 20 years in Norway. As gliomas represent a heterogeneous group of primary CNS tumors, regular reporting from cancer registries at the histopathology group level is important to monitor disease burden and allocate health care resources in a population.

Distribution and characteristics of malignant tumours by lung lobe

BACKGROUND

The main focus on the characteristics of malignant lung tumours has been the size, position within the lobe, and infiltration into neighbouring structures. The aim of this study was to investigate the distribution and characteristics of malignant tumours between the lung lobes and whether the diagnosis, treatment, and outcome differed based on location.

METHODS

This study is based on 10,849 lung cancer patients diagnosed in 2018-2022 with complete data on the location and characteristics of the tumours. The proportions of tumours in each lobe divided by its volume were termed the relative proportion.

RESULTS

The right upper lobe comprised 31.2% of the tumours and 17.6% of the lung volume. The relative proportion of 1.77 was higher than in the other lobes (p < 0.001). The right middle lobe had a relative proportion of 0.64 but the highest proportion of neuroendocrine tumours (26.1% vs. 15.3 on average). Surgical resection was more often performed in patients with tumours in the lower lobes, and curative radiotherapy was more often performed in the upper lobes. After adjusting for age, sex, stage, and histology, the location of the tumour was found to be a significant independent predictor for resection but not for survival.

CONCLUSION

The main finding of the right upper lobe as a site of predilection for lung cancer is similar to tuberculosis and pneumoconiosis. This may be explained that most of the inhaled air, containing bacilli, inorganic particles or tobacco smoke goes to the upper and right parts of the lung.

Hospital use and cancer treatment by age and socioeconomic status in the last year of life: A Norwegian population-based study of patients dying of cancer

INTRODUCTION

Cancer is the leading cause of death in Norway. In this nationwide study we describe the number and causes of hospital admissions and treatment in the final year of life for patients who died of cancer, as well as the associations to age and socioeconomic status (SES).

MATERIALS AND METHODS

From nationwide registries covering 2010-2014, we identified all patients who were diagnosed with cancer 12-60 months before death and had cancer as their reported cause of death. We examined the number of overnight hospital stays, causes of admission, and treatment (chemotherapy, radiotherapy, surgical procedures) offered during the last year of life by individual (age, sex, comorbidity), cancer (type, stage, months since diagnosis), and socioeconomic variables (co-residential status, income, education).

RESULTS

The analytical sample included 17,669 patients; 8,247 (47%) were female, mean age was 71.7 years (standard deviation 13.7). At diagnosis, 31% had metastatic disease, while 29% had an intermediate or high comorbidity burden. Altogether, 94% were hospitalized during their final year, 82% at least twice, and 33% six times or more. Patients spent a median of 23 days in hospital (interquartile range 11-41), and altogether 38% died there. Younger age, bladder and ovarian cancer, not living alone, and higher income were associated with having ≥6 hospitalizations. Cancer-related diagnoses were the main causes of hospitalizations (65%), followed by infections (11%). Around 51% had ≥1 chemotherapy episode, with large variations according to patient age and SES; patients who were younger, did not live alone, had high education, and high income received more chemotherapy. Radiotherapy was received by 15% and declined with age, and the variation according to SES characteristics was minor. Of the 12,940 patients with a cancer type where surgery is a main treatment modality, only 835 (6%) underwent surgical procedures for their primary tumor in the last year of life.

DISCUSSION

Most patients who die of cancer are hospitalized multiple times during the last year of life. Hospitalizations and treatment decline with advancing age. Living alone and having low income is associated with fewer hospitalizations and less chemotherapy treatment. Whether this indicates over- or undertreatment across various groups warrants further exploration.

Sexual Problems as Late Effects: Awareness and Information Needs Among 1870 Long-term Norwegian Childhood, Adolescent, and Young Adult Cancer Survivors (The NOR-CAYACS Study)

Purpose: Treatment-related sexual problems are common, but understudied, among survivors of Childhood, Adolescent, and Young Adult Cancer Survivors (CAYACS). We investigated awareness of, and information needs regarding, sexual problems as late effects in a nation-wide sample of long-term CAYACS. Methods: Five-year survivors were identified by the Cancer Registry of Norway, diagnosed between 1985 and 2009 with any childhood cancer (0-18 years of age, excluding central nervous system tumors), leukemia, colorectal cancer, breast cancer, non-Hodgkin lymphoma, or malignant melanoma (19-39 years of age). Malignant melanoma survivors treated with local surgery only served as an unmatched reference group. Survivors were mailed a survey, including items on awareness and information needs. Descriptive statistics and logistic regression analyses were used for data analyses. Results: Of 5361 CAYACS invited, 2104 responded (39%), of which 1870 were eligible for inclusion. In all, 62% were aware of sexual problems as late effects (46% aware only, 16% experienced it) and 31% reported information needs. Of all groups, childhood cancer survivors reported the lowest level of awareness (43% aware, 7% experienced it) and the highest information needs (38%). In multivariable models, awareness was associated with higher education, shorter time since treatment, more intense treatments, and experiencing hormonal changes and reduced fertility. Information needs were associated with having experienced sexual problems, female gender, higher treatment intensity, chronic fatigue, and increased depressive symptoms. Conclusions: A substantial proportion of long-term CAYACS report being unaware of, and have information needs regarding sexual problems as late effects decades beyond treatment. Addressing such issues during follow-up care is important.

Body mass index, triglyceride-glucose index, and prostate cancer death: a mediation analysis in eight European cohorts

BACKGROUND

Insulin resistance is a hypothesised biological mechanism linking obesity with prostate cancer (PCa) death. Data in support of this hypothesis is limited.

METHODS

We included 259,884 men from eight European cohorts, with 11,760 incident PCa's and 1784 PCa deaths during follow-up. We used the triglyceride-glucose (TyG) index as indicator of insulin resistance. We analysed PCa cases with follow-up from PCa diagnosis, and the full cohort with follow-up from the baseline cancer-free state, thus incorporating both PCa incidence and death. We calculated hazard ratios (HR) and the proportion of the total effect of body mass index (BMI) on PCa death mediated through TyG index.

RESULTS

In the PCa-case-only analysis, baseline TyG index was positively associated with PCa death (HR per 1-standard deviation: 1.11, 95% confidence interval (CI); 1.01-1.22), and mediated a substantial proportion of the baseline BMI effect on PCa death (HRtotal effect per 5-kg/m2 BMI: 1.24; 1.14-1.35, of which 28%; 4%-52%, mediated). In contrast, in the full cohort, the TyG index was not associated with PCa death (HR: 1.03; 0.94-1.13), hence did not substantially mediate the effect of BMI on PCa death.

CONCLUSIONS

Insulin resistance could be an important pathway through which obesity accelerates PCa progression to death.

Long-term follow-up of complex oncoplastic breast-conserving surgery, standard breast conservation and skin-sparing mastectomy in DCIS - a register-based study

BACKGROUND

Few studies evaluate oncological safety in complex oncoplastic breast-conserving surgery(C-OBCS) for DCIS. It still needs to be defined whether it is equivalent to standard breast conservation(S-BCS) or an alternative to skin-sparing mastectomy(SSM). This study compares local recurrence rates(LR), disease-free survival(DFS) and overall survival (OS) between the three surgical techniques.

METHODS

We conducted a retrospective register-based study on LR, DFS and OS of patients operated with S-BCS(n=1388), C-OBCS (n=106) or skin-sparing mastectomy (n=218) for DCIS diagnosed 2007-2020. Data was extracted from the Norwegian Breast Cancer Registry.

RESULTS

In the S-BCS, C-OBCS and SSM groups, median age was 60, 58 and 51 years (p<0.001), median size 15, 25, and 40 mm (p<0.001) and median follow-up 55, 48 and 76 months. At ten years, the overall LR was 12.7%, 14.3% for S-BCS, 11.2% for C-OBCS and 6.8% for SSM. Overall DFS at ten years was 82.3%, 80.5% for S-BCS, 82.4% for C-OBCS and 90.4% for SSM. At ten years, the OS was 93.8%, 93.0% in S-BCS, 93.3% in C-OBCS and 96.6% in the SSM group. Weighted Kaplan Meier plots showed that SSM had a significantly higher DFS than S-BCS (p=0.003) and C-OBCS (p=0.029). DFS in C-OBCS versus S-BCS and the difference in OS was not significant (p=0.264).

CONCLUSION

SSM had a significantly higher DFS than S-BCS and C-OBCS. The difference in DFS between S-BCS and C-OBCS, and OS between the three groups was not statistically significant. Our study suggests that C-OBCS is a safe alternative to S-BCS and SSM.

Development and quality appraisal of a new English breast screening linked data set as part of the age, test threshold, and frequency of mammography screening (ATHENA-M) study

OBJECTIVES

To build a data set capturing the whole breast cancer screening journey from individual breast cancer screening records to outcomes and assess data quality.

METHODS

Routine screening records (invitation, attendance, test results) from all 79 English NHS breast screening centres between January 1, 1988 and March 31, 2018 were linked to cancer registry (cancer characteristics and treatment) and national mortality data. Data quality was assessed using comparability, validity, timeliness, and completeness.

RESULTS

Screening records were extracted from 76/79 English breast screening centres, 3/79 were not possible due to software issues. Data linkage was successful from 1997 after introduction of a universal identifier for women (NHS number). Prior to 1997 outcome data are incomplete due to linkage issues, reducing validity. Between January 1, 1997 and March 31, 2018, a total of 11 262 730 women were offered screening of whom 9 371 973 attended at least one appointment, with 139 million person-years of follow-up (a median of 12.4 person years for each woman included) with 73 810 breast cancer deaths and 1 111 139 any-cause deaths. Comparability to reference data sets and internal validity were demonstrated. Data completeness was high for core screening variables (>99%) and main cancer outcomes (>95%).

CONCLUSIONS

The ATHENA-M project has created a large high-quality and representative data set of individual women's screening trajectories and outcomes in England from 1997 to 2018, data before 1997 are lower quality.

ADVANCES IN KNOWLEDGE

This is the most complete data set of English breast screening records and outcomes constructed to date, which can be used to evaluate and optimize screening.

Prediction of clinically significant recurrence after partial nephrectomy. Data from the Cancer Registry of Norway with more than five years of follow-up

OBJECTIVE

To determine recurrence incidence after partial nephrectomy (PN) for renal cell carcinoma and identify predictors for local recurrence (LR) and metastasis.

MATERIAL AND METHODS

We retrospectively evaluated a cohort of 524 patients from the Cancer Registry of Norway, who underwent PN between January 2014 and December 2015 and were followed-up for >6 years. Patient demographics and pathological characteristics were correlated with recurrence and progression-free survival using Kaplan-Meier and Cox regression analyses.

RESULTS

Median patient age was 64 years, and the median tumour size was 2.6 cm. A positive surgical margin (PSM) was observed in 11% of the cases, while the LR and metastasis rates were 3.4% and 3.2%, respectively. PSM (hazard ratio [HR], 55.4; 95% confidence interval [CI], 12.55-244.6), tumour number (HR, 45.4; 95% CI, 6.5-316.1) and stage (HR, 33.5; 95% CI, 5.4-205.3) were independent predictors for LR. Undetermined margin status was also a risk factor for LR. Tumour stage (HR, 41.05; 95% CI, 8.52-197.76), tumour necrosis (HR, 1.3; 95% CI, 0.4-4.31) and age (HR, 1.07; 95% CI, 1.01-1.14) were predictors for metastasis.

CONCLUSIONS

Both local and distant recurrences after PN were rare, and the pT stage was a common predictor. PSM or indeterminate surgical margin and tumour number were LR predictors, while age at surgery and the presence of tumour necrosis predicted metastasis.

Burden of late effects in a nationwide sample of long-term breast cancer survivors

BACKGROUND

Long-term breast cancer survivors (BCSs) may experience several late effects (LEs) simultaneously. This study aimed to identify subgroups of 8-year BCSs with higher burden of LEs who could benefit from closer survivorship care, explore variables associated with higher symptom burden, and describe how symptom burden may affect general functioning.

METHODS

All Norwegian women aged 20 to 65 years when diagnosed with stage I-III breast cancer in 2011 and 2012 were invited (n = 2803). The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire/BR23, the Fatigue Questionnaire, Assessment of Survivor Concerns, and Scale for Chemotherapy Induced Long-term Neurotoxicity were used to assess 10 common LEs and general functioning. Using latent class analysis, subgroups of BCSs with similar burden of LEs were identified. Multinominal regression analysis were performed to examine variables associated with higher symptom burden.

RESULTS

The final sample consisted of 1353 BCSs; 46% had low, 37% medium, and 17% high symptom burden. Younger age, short education, axillary dissection, higher systemic treatment burden, higher body mass index, and physical inactivity were associated with higher symptom burden. General functioning scores were lower, and the proportion on disability pension were higher among BCSs in the two most burdened subgroups compared with those in the low burden subgroup.

CONCLUSION

More than half of long-term BCSs suffered from medium or high symptom burden and experienced impaired general functioning compared with BCS with low symptom burden. Younger age and systemic treatment were important risk factors for higher symptom burden. BCSs at risk of higher symptom burdens should be identified and offered closer and extended survivorship care.

Fatal and non-fatal breast cancers in women targeted by BreastScreen Norway: a cohort study

BACKGROUND

Many breast cancer survivors experience anxiety related to dying from their disease even if it is detected at an early stage. We aimed to increase knowledge about fatal and non-fatal breast cancer by describing how histopathological tumour profiles and detection modes were associated with 10-year breast cancer-specific survival.

METHODS

This cohort study included data from women targeted by BreastScreen Norway (aged 50-69) and diagnosed with invasive breast cancer during 1996-2011. Breast cancer was classified as fatal if causing death within 10 years after diagnosis and non-fatal otherwise. We described histopathologic characteristics of fatal and non-fatal cancers, stratified by mode of detection. Recursive partitioning identified subgroups with differing survival profiles.

RESULTS

In total, 6.3% of 9954 screen-detected cancers (SDC) were fatal, as were 17.4% of 3205 interval cancers (IC) and 20.9% of 3237 cancers detected outside BreastScreen Norway. Four to five subgroups with differing survival profiles were identified within each detection mode. Women with lymph node-negative SDC or Grade 1-2, node-negative IC without distant metastases had the highest 10-year survival (95-96%).

CONCLUSIONS

Two subgroups representing 53% of the cohort had excellent (95-96%) 10-year breast cancer-specific survival. Most women with SDC had excellent survival, as did nearly 40% of women diagnosed with IC.

Time trends in human papillomavirus prevalence and genotype distribution in vulvar carcinoma in Norway

INTRODUCTION

Approximately 25%-43% of all vulvar carcinomas are associated with human papillomavirus (HPV). In many countries, vulvar carcinoma incidence rates are increasing, possibly due to greater HPV exposure. However, studies exploring changes in HPV prevalence and genotype distribution in vulvar carcinoma over time are scarce. Our aim was to evaluate time trends in HPV prevalence and genotype distribution in vulvar squamous cell carcinoma in an unselected, nationwide sample of Norwegian women. Further, we explored clinical and histopathological aspects in relation to HPV status and investigated whether HPV status was associated with survival.

MATERIAL AND METHODS

All vulvar squamous cell carcinoma cases from 1970-1975 and 2000-2005 were extracted from the Cancer Registry of Norway and corresponding tissue blocks were retrieved. After detailed histology review, HPV testing was conducted using real-time TaqMan PCR. Overall survival rates were calculated using the Kaplan-Meier method. Multivariable Cox regression analysis was performed to estimate hazard ratios adjusted for age at diagnosis, stage and diagnostic period.

RESULTS

Histological review was performed on 352 vulvar squamous cell carcinoma cases. We were able to obtain valid HPV analysis results for 282 cases, Overall, 29.8% (95% CI 24.5%-35.5%) of cases were high-risk HPV (hrHPV)-positive. When comparing the two periods, we found that the percentage of hrHPV-positive tumors increased significantly from 23% (95% CI 16.0%-31.4%) in 1970-1975 to 35.3% (95% CI 27.8%-43.3%) in 2000-2005 (P = 0.025). The predominant genotypes were HPV 16 (73%), HPV 33 (21%), and HPV 18 (6%), with similar distributions in both periods. In the more recent cohort, several additional genotypes were detected: HPV 6, 11, 39, 45, 52, 58 and 66 were found in smaller percentages, ranging from 1.8% to 3.6%. In univariate analysis, patients with HPV-positive tumors showed improved overall survival compared with patients with HPV-negative tumors (hazard ratio [HR] 0.65, 95% CI 0.48-0.86).

CONCLUSIONS

The prevalence of HPV in vulvar squamous cell carcinomas in Norway was significantly higher in 2000-2005 than in 1970-1975. The three predominant genotypes were HPV 16, 33 and 18 in both time periods. However, several other HPV genotypes have emerged over the last decades. HPV-positivity was associated with better overall survival.

Benzene exposure and risk of lung cancer in the Norwegian Offshore Petroleum Worker cohort: a prospective case-cohort study

OBJECTIVE

The objective of our study was to examine whether occupational exposure to benzene is associated with lung cancer among males in the Norwegian Offshore Petroleum Workers cohort.

METHODS

Among 25 347 male offshore workers employed during 1965-1998, we conducted a case-cohort study with 399 lung cancer cases diagnosed between 1999 and 2021, and 2035 non-cases sampled randomly by 5-year birth cohorts. Individual work histories were coupled to study-specific job-exposure matrices for benzene and other known lung carcinogens. Weighted Cox regression was used to estimate HRs and 95% CIs for the associations between benzene exposure and lung cancer, by major histological subtypes, adjusted for age, smoking and occupational exposure to welding fumes, asbestos and crystalline silica. Missing data were imputed.

RESULTS

For lung cancer (all subtypes combined), HRs (95% CIs) for the highest quartiles of benzene exposure versus unexposed were 1.15 (0.61 to 2.35) for cumulative exposure, 1.43 (0.76 to 2.69) for duration, and 1.22 (0.68 to 2.18) for average intensity (0.280≤P-trend≤0.741). For 152 adenocarcinoma cases, a positive trend was observed for exposure duration (P-trend=0.044).

CONCLUSIONS

In this cohort of offshore petroleum workers generally exposed to low average levels of benzene, we did not find an overall clear support for an association with lung cancer (all subtypes combined), although an association was suggested for duration of benzene exposure and adenocarcinoma. The limited evidence might be due to restricted statistical power.

EGFR-mutation testing, treatment patterns and clinical outcomes in patients with stage IB-IIIA non-small cell lung cancer in Norway-a nationwide cohort study

INTRODUCTION

Testing for mutations of epidermal growth factor receptor (EGFR) is crucial to identify non-small cell lung cancer (NSCLC) patients eligible for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs); This study aims to describe EGFR-mutation testing, treatment patterns, and overall survival (OS) in localized NSCLC patients.

MATERIALS AND METHODS

Patients with localized (Stage IB-IIIA) NSCLC registered in the Norwegian Cancer Registry during 2010-2017 were followed from diagnosis until emigration, death, or end of study in 2018. The cohort was linked to data from the Norwegian Patient Registry, the Prescription Database, and the Cause of Death Registry.

RESULTS

Of 2367 patients identified with localized NSCLC, 52 % were females and median age at diagnosis was 69 years. Most (66 %) were treated with surgery, while 16 % received curatively-intended radiotherapy (RT). EGFR-mutation testing increased significantly from 58 to 84 % during the study period. Testing frequencies varied across regions and comorbidity levels. Nine-percent of tested patients were EGFR-mutation positive (EGFRm+), of whom 27 % were treated with EGFR-TKIs. There was no correlation between initial treatment with either surgery or RT and EGFR-TKI use. The 3-year OS did not vary considerably by EGFR-mutation testing, but EGFRm+ patients had a higher 3-year OS (78.8 %) than wild-type EGFR (EGFRwt) patients (65.9 %).

DISCUSSION

Although EGFR-mutation testing is increasingly being implemented in the early-stage setting in line with national recommendations, some patients are still not being tested for molecular markers as part of their diagnostic workup-a prerequisite for providing equal access to effective targeted treatments, such as EGFR-TKIs, to eligible patients.

Most common health problems in general practice among adolescents, and young adults' survivors of lymphoma: a register-based cohort study in Norway

BACKGROUND

The aim was to investigate the distribution of health problems in general practice (GP) among adolescent and young adult (AYA) survivors of lymphoma and to compare problem rates with the general population.

METHODS

All GP consultations between 2006 and 2020 were identified from the national GP claims register. Diseases and complaints presented 3-10 years after the cancer diagnosis were identified using the International Classification of Primary Care codes (ICPC-2) and compared by applying logistic regression models, presented with odds ratio (OR) and 95%CI.

RESULTS

A total of 2,500,557 AYAs, of whom 1105 were diagnosed with lymphoma, and over 50 million GP consultations were included. The most common causes of consultation among AYA survivors of lymphoma were related to Hodgkin's disease (13%), pregnancy (11%), respiratory diseases (9%), psychological problems (8%), musculoskeletal system (6%) and fatigue (4%). Almost all these problems were significantly higher among AYA lymphoma survivors compared to the general population (OR ranging from 1.1 to 1.5).

CONCLUSION

Compared to the general population, young lymphoma survivors have increased contact with the GP for a considerable number of health problems for up to 10 years post-diagnosis. This emphasizes the importance of robust follow-up and a good flow of information between hospital and primary care.

Cumulative incidence of first recurrence after curative treatment of stage I-III colorectal cancer. Competing risk analyses of temporal and anatomic patterns

BACKGROUND

Updated knowledge about the rates of recurrence and time to recurrence following curative treatment of colorectal cancer is essential to secure better patient information on prognosis, to serve as a premise in the discussion on adjuvant chemotherapy, and help to properly scale the intensity and length of follow-up.

METHODS

This is a population-based study investigating aspects on first recurrence after radical treatment of clinical stages I-III of colorectal cancer in Central-Norway during 2001-2015. To reveal any time-trends, data were stratified by the time periods 2001-2005, 2006-2010 and 2011-2015. The cumulative incidence of first recurrence was calculated, treating death of unrelated causes as a competing event. Multivariable Cox analyses were done to calculate cause specific hazard ratios (HR) for risk of recurrence.

RESULTS

At a minimum follow-up of six years, a first recurrence was detected in 1,113/5,556 patients at risk (20.0%). The recurrence rate was reduced from 23.6% in the first time period, through 20.0% in the second, and to 17.2% in the last, p < 0.001. The reduction applied to all tumor locations, to pathological disease stages II and III, to both gender, across different tumor differentiations, and to both elective and emergency surgery. In multivariable analyses time period, gender, disease stage, and tumor differentiation were significant determinants for risk of recurrence.

CONCLUSIONS

The rate of first recurrence after curative surgery for colorectal cancer was substantially reduced from 2001 to 2015. The reason for the reduction could not be attributed to a single factor only. A combined effect of several incremental improvements, such as an increased use of preoperative radiation for rectal cancers, improved adjuvant chemotherapy for colon cancer, and a reduced proportion of emergency surgery, is suggested.

Initial management and survival of patients with primary metastatic bladder cancer before the immunotherapy era: a population-based study from Norway

Before immunotherapy became part of the management of metastatic bladder cancer (mBC), systemic anti-cancer treatment comprised primarily of platinum-based chemotherapy. The objective of this study was to describe the characteristics, the initial management, overall survival (OS) and hospitalisations of patients with mBC before 2018 when immunotherapy for mBC was introduced in Norway.  Material and methods: It is a nationwide population-based study of primary mBC patients (diagnosed 2008-16). Descriptive statistics were applied and stratified for four initial management options (≤150 days after BC diagnosis): chemotherapy, major local treatment (cystectomy/pelvic radiotherapy), multimodal treatment (chemotherapy and local) and no anti-cancer treatment beyond transurethral resection of bladder tumour (untreated). Group differences were evaluated by Chi-square and Kruskal-Wallis test; OS was estimated with Kaplan-Meier. Results: Of the 305 patients included, 76 (25%) patients had chemotherapy, 46 (15%) patients had major local treatment, 21 (7%) patients had multimodal treatment and 162 (53%) patients were untreated.  Median OS ranged from 2.3 months (untreated) to 9.8 months (chemotherapy). Patients who received treatment had a higher rate of hospitalisation, with a median stay of three to four times that of untreated patients. Conclusion: Before immunotherapy, more than 50% of patients with primary mBC did not receive any initial anti-cancer therapy and had a poor survival. Patients treated with chemotherapy had inferior median OS compared to those treated with comparable systemic strategies in contemporary trials. Our results provide a basis for future research on treatment and survival after the introduction of immunotherapy for mBC, aiming to improve the care and outcome of patients with mBC.

Cancer risk and survival according to body mass index in hepatobiliary malignancies: a nationwide registry-based cohort study

BACKGROUND

The aim of this study was to explore the associations between BMI and cancer of the liver, bile ducts, and gallbladder.

METHODS

A registry-based cohort study was performed by linking data from several national registries in Norway.

RESULTS

The cohort comprised 1 723 692 individuals including 4768 hepatobiliary cancer cases during 55 743 509 person-years of follow-up. In men, we found increased risk of cancer per 5 kg/m2 BMI increase for hepatocellular carcinoma and extrahepatic cholangiocarcinoma. In women there was increased risk of extrahepatic cholangiocarcinoma and gallbladder cancer. Women with high BMI in early adulthood had increased risk of intrahepatic cholangiocarcinoma. Reduced cancer-specific survival was found for all hepatobiliary malignancies in women with overweight and obesity. In men, reduced survival was observed in individuals with obesity for all hepatobiliary cancers, except gallbladder cancer. Increased risk of cancer-death per 5 kg/m2 BMI increase was found for hepatocellular carcinoma, intra-, and extrahepatic cholangiocarcinoma in women. For men, 5 kg/m2 BMI increase was positively associated with cancer-death from intrahepatic cholangiocarcinoma.

DISCUSSION

This study supports the notion of an increased risk of hepatobiliary cancers with increasing BMI, with sex and age variations. The findings also suggest a higher risk of cancer-death with increasing BMI.

Modified study designs to expand treatment options in personalised oncology: a multistakeholder view

Personalised oncology, whereby patients are given therapies based on their molecular tumour profile, is rapidly becoming an essential part of optimal clinical care, at least partly facilitated by recent advances in next-generation sequencing-based technology using liquid- and tissue-based biopsies. Consequently, clinical trials have shifted in approach, from traditional studies evaluating cytotoxic chemotherapy in largely histology-based populations to modified, biomarker-driven studies (e.g. basket, umbrella, platform) of molecularly guided therapies and cancer immunotherapies in selected patient subsets. Such modified study designs may assess, within the same trial structure, multiple cancer types and treatments, and should incorporate a multistakeholder perspective. This is key to generating complementary, fit-for-purpose and timely evidence for molecularly guided therapies that can be used as proof-of-concept to inform further study designs, lead to approval by regulatory authorities and be used as confirmation of clinical benefit for health technology assessment bodies. In general, the future of cancer clinical trials requires a framework for the application of innovative technologies and dynamic design methodologies, in order to efficiently transform scientific discoveries into clinical utility. Next-generation, modified studies that involve the joint efforts of all key stakeholders will offer individualised strategies that ultimately contribute to globalised knowledge and collective learning. In this review, we outline the background and purpose of such modified study designs and detail key aspects from a multistakeholder perspective. We also provide methodological considerations for designing the studies and highlight how insights from already-ongoing studies may address current challenges and opportunities in the era of personalised oncology.

Prediagnostic Hormone Levels and Risk of Testicular Germ Cell Tumors: A Nested Case-Control Study in the Janus Serum Bank

BACKGROUND

It has been hypothesized that poorly functioning Leydig and/or Sertoli cells of the testes, indicated by higher levels of serum gonadotropins and lower levels of androgens, are related to the development of testicular germ cell tumors (TGCT). To investigate this hypothesis, we conducted a nested case-control study within the Janus Serum Bank cohort.

METHODS

Men who developed TGCT (n = 182) were matched to men who did not (n = 364). Sex steroid hormones were measured using LC/MS. Sex hormone binding globulin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were quantified by direct immunoassay. Multivariable logistic regression was used to calculate ORs and 95% confidence intervals (CI) for associations between hormone levels and TGCT risk.

RESULTS

Higher FSH levels [tertile (T) 3 vs. T2: OR = 2.89, 95% CI = 1.83-4.57] were associated with TGCT risk, but higher LH levels were not (OR = 1.26, 95% CI = 0.81-1.96). The only sex steroid hormone associated with risk was androstane-3α, 17β-diol-3G (3α-diol-3G; OR = 2.37, 95% CI = 1.46-3.83). Analysis by histology found that increased FSH levels were related to seminoma (OR = 3.55, 95% CI = 2.12-5.95) but not nonseminoma (OR = 1.19, 95% CI = 0.38-3.13). Increased levels of 3α-diol-3G were related to seminoma (OR = 2.29, 95% CI = 1.35-3.89) and nonsignificantly related to nonseminoma (OR = 2.71, 95% CI = 0.82-8.92).

CONCLUSIONS

Higher FSH levels are consistent with the hypothesis that poorly functioning Sertoli cells are related to the development of TGCT. In contrast, higher levels of 3α-diol-3G do not support the hypothesis that insufficient androgenicity is related to risk of TGCT.

IMPACT

Clarifying the role of sex hormones in the development of TGCT may stimulate new research hypotheses.

Completeness of regional cancer registry data in Northwest Russia 2008-2017

BACKGROUND

A national framework for population-based cancer registration was established in Russia in the late 1990s. Data comparability and validity analyses found substantial differences across ten population-based cancer registries (PBCRs)in Northwest Russia, and only four out of ten met international standards. This study aimed to assess the completeness of the PBCR data of those registries.

METHODS

Qualitative and quantitative methods recommended for completeness and timeliness assessment were applied to the data from ten Russian regional PBCRs in Northwest Russia, covering a population of 13 million. We used historic data methods (using several European PBCRs reference rates), mortality-to-incidence ratios (M:I) comparison, and death certificate methods to calculate the proportion of unregistered cases (Lincoln-Petersen estimator and Ajiki formula).

RESULTS

Incidence rate trends of different cancer types were stable over time (except one region - Leningrad oblast). A slight drop in incidence rates in older age groups for several sites in the Northwestern regions was observed compared to the reference from European countries. Comparing M:I ratios against five-year survival revealed systematic differences in Leningrad oblast and Vologda oblast. Assessment of completeness revealed low or unrealistic estimates in Leningrad oblast and completeness below 90% in St. Petersburg. In other regions, the completeness was above 90%. The national annual report between 2008-2017 did not include about 10% of the cases collected later in the registry database of St. Petersburg. This difference was below 3% for Arkhangelsk oblast, Murmansk oblast, Novgorod oblast, Vologda oblast and the Republic of Karelia.

CONCLUSIONS

Eight out of ten regional PBCRs in Northwest Russia collected data with an acceptable degree of completeness. Mostly populated St. Petersburg and Leningrad oblast did not reach such completeness. PBCR data from several regions in Northwest Russia are suitable for epidemiological research and monitoring cancer control activities.

Oestrogen receptor low positive breast cancer: associations with prognosis

PURPOSE

In this study of oestrogen receptor (ER) Low Positive breast cancers (BC) in three large cohorts of BC patients, we assess associations between levels of ER expression and tumour characteristics and prognosis.

METHODS

Cases were stratified into patients unlikely to have received adjuvant therapy according to treatment guidelines at time of diagnosis (before 1995), and those who could have received adjuvant therapy (diagnosed in 1995 or later). ER status was divided into < 1%; ≥ 1 < 10%; ≥ 10%. Results were correlated with time of diagnosis, histopathological grade, proliferation status, and molecular subtypes, using Pearson's Chi-square test. For prognosis, hazard ratios and cumulative incidence of death from BC were used.

RESULTS

Of the 1955 tumours, 65 (3.3%) were ER Low Positive (ER ≥ 1 < 10%). Overall, the highest proportion of ER Low Positive tumours was observed among Luminal B (HER2 +) subtype (9.4%) and grade 3 tumours (4.3%). The risk of death from BC was lower in ER Low Positive and ER ≥ 10% compared to ER-negative cases. Compared to patients diagnosed before 1995, women diagnosed in 1995 or later showed a higher proportion of ER Low Positive BCs, and their tumours were of smaller size, lower grade, and lower proliferative status. There was no significant difference in prognosis compared to those with ER ≥ 10% tumours.

CONCLUSION

Women with ER Low Positive tumours diagnosed in a time period when adjuvant therapy was available had tumours of smaller size, lower grade, and lower proliferative status, and similar prognosis to those with ER ≥ 10% compared to women diagnosed earlier.

Risk of Cancer in Patients With Crohn's Disease 30 Years After Diagnosis (the IBSEN Study)

Background

Patients with Crohn's disease (CD) are most often diagnosed as young adults; therefore, long-term studies are needed to assess the risk of cancer over their lifetime. Thus, the aims of the present study were to determine the risk of cancer in a Norwegian population-based cohort (the Inflammatory Bowel South Eastern Norway [IBSEN] study), 30 years after diagnosis, and to assess whether patients with CD were at an increased risk of specific cancer types.

Methods

The IBSEN cohort prospectively included all incident patients diagnosed between 1990 and 1993. Data on cancer incidence were obtained from the Cancer Registry of Norway. Overall and cancer-specific hazard ratios (HRs) for CD patients compared with age- and sex-matched controls were modeled using Cox regression. Standardized incidence ratios (SIRs) were estimated compared to the general population.

Results

In total, the cohort included 237 patients with CD, and 36 of them were diagnosed with cancer. Compared to the general Norwegian population, patients with CD had an increased overall risk of cancer (HR = 1.56, 95% CI: 1.06-2.28), particularly male patients (HR = 1.85, 95% CI: 1.08-3.16). The incidence of lung cancer and nonmelanoma skin cancer was increased; however, the difference was not statistically significant (SIR = 2.29, 95% CI: 0.92-4.27 and SIR = 2.45, 95% CI: 0.67-5.37, respectively).

Conclusions

After 30 years of follow-up, the risk of all cancers in patients with CD was increased compared to the general population.

Sexual health in long-term breast cancer survivors: a comparison with female population controls from the HUNT study

PURPOSE

Sexual health is an important aspect of quality of life. Knowledge concerning sexual health in long-term breast cancer survivors (BCSs) is limited. This study compared sexual health in BCSs 8 years after diagnosis with similarly aged controls and examined the impact of menopausal status at diagnosis and systemic breast cancer treatments on sexual health.

METHODS

Women aged 20-65 years when diagnosed with stage I-III breast cancer in 2011-2012 were identified by the Cancer Registry of Norway (n = 2803) and invited to participate in a nationwide survey. Controls were women from the Trøndelag Health Study (HUNT4). Sexual functioning and sexual enjoyment were measured by the EORTC QLQ-BR23 subscales scored from 0 to 100, and sexual discomfort by the Sexual Activity Questionnaire scored from 0 to 6. Linear regression analyses with adjustments for sociodemographic and health-related variables were performed to compare groups. Differences of ≥ 10% of range score were considered clinically significant.

RESULTS

The study samples consisted of 1241 BCSs and 17,751 controls. Sexual enjoyment was poorer (B - 13.1, 95%CI - 15.0, - 11.2) and discomfort higher (B 0.9, 95%CI 0.8, 1.0) among BCSs compared to controls, and larger differences were evident between premenopausal BCSs and controls (B - 17.3, 95%CI - 19.6, - 14.9 and B 1.2, 95%CI 1.0, 1.3, respectively). BCSs treated with both endocrine- and chemotherapy had lower sexual functioning (B - 11.9, 95%CI - 13.8, - 10.1), poorer sexual enjoyment (B - 18.1, 95%CI - 20.7, - 15.5), and more sexual discomfort (B 1.4, 95% 1.3, 1.6) than controls.

CONCLUSION

Sexual health impairments are more common in BCSs 8 years after diagnosis compared to similar aged population controls. During follow-up, attention to such impairments, especially among women diagnosed at premenopausal age and treated with heavy systemic treatment, is warranted.

Pre-diagnostic intake of vitamin D and incidence of colorectal cancer by anatomical subsites: the Norwegian Women and Cancer Cohort Study (NOWAC)

According to the World Cancer Research Fund International, vitamin D might decrease the risk of colorectal cancer (CRC). However, less is known about the association with cancers in different subsites of the colon and in the rectum. The aim of this study was to examine associations between pre-diagnostic intake of vitamin D and risk of CRC by anatomical subsites. Data from 95 416 participants in the Norwegian Women and Cancer Cohort Study was included, and vitamin D intake was estimated from two repeated FFQ. Associations between vitamin D intake and incidence of CRC were assessed using multivariable Cox regression. During follow-up, there were 1774 incident cases of CRC. A small but borderline significant inverse association was found for a 5-µg increase in vitamin D intake and risk of CRC (hazard ratio (HR) = 0·97; 95 % CI 0·93, 1·01) and colon cancer (HR = 0·96; 95 % CI 0·91, 1·01). High (≥ 20 µg) compared with low (< 10 µg) vitamin D intake was associated with 17 % borderline significant reduced risk of CRC (HR = 0·83; 95 % CI 0·68, 1·02). Medium (10-19 µg) v. low intake (< 10 µg) was associated with 27 % reduced risk of proximal colon cancer (HR = 0·73; 95 % CI 0·57, 0·94). No significant associations were observed between vitamin D intake and risk of distal colon or rectal cancer. Our study indicates that vitamin D may be differently associated with subsites of the colon. The association between vitamin D intake and proximal colon cancer is novel.

Lifelong differences in cancer incidence and mortality between subgroups of similar socioeconomic status in the Royal Norwegian Navy

OBJECTIVES

In a previous cohort study of 28 300 Navy servicemen, vessel crews showed higher cancer incidence and mortality than did land-based personnel. We have extended the follow-up to look for changes in cancer risk, and to explore temporal trends in cancer incidence and cancer mortality during more than six decades of follow-up.

METHODS

Cancer incidence and total cancer mortality were compared with the general population by calculating standardised ratios (standardised incidence ratios (SIRs), standardised mortality ratios) for the entire follow-up, with temporal trends through seven consecutive 10-year time spans from individual entry to follow-up. Rates were compared between the subgroups using Poisson regression, expressed as rate ratios (RRs).

RESULTS

Cancer incidence in Navy servicemen suggested a healthy soldier effect limited to the first three decades of follow-up and confined to land-based personnel. Overall, vessel crews showed 13% higher cancer incidence and 36% higher cancer mortality than other Navy servicemen. Some of the differences may be explained by a higher risk in vessel crews of cancers known to have less than 25% 5-year relative survival (RR=1.71), such as cancers of the lung, liver, pancreas and mesothelioma.

CONCLUSION

Through most of the observation time, vessel crews had an overall cancer SIR that was higher than that of land-based personnel. Much of this excess involved cancers with a generally poor prognosis, linked to lifestyle and work environment. The contrasts in cancer incidence and mortality between the two subgroups of Navy servicemen persisted through more than six decades.

Improving communication of cancer survival statistics-feasibility of implementing model-based algorithms in routine publications

BACKGROUND

Routine reporting of cancer patient survival is important, both to monitor the effectiveness of health care and to inform about prognosis following a cancer diagnosis. A range of different survival measures exist, each serving different purposes and targeting different audiences. It is important that routine publications expand on current practice and provide estimates on a wider range of survival measures. We examine the feasibility of automated production of such statistics.

METHODS

We used data on 23 cancer sites obtained from the Cancer Registry of Norway (CRN). We propose an automated way of estimating flexible parametric relative survival models and calculating estimates of net survival, crude probabilities, and loss in life expectancy across many cancer sites and subgroups of patients.

RESULTS

For 21 of 23 cancer sites, we were able to estimate survival models without assuming proportional hazards. Reliable estimates of all desired measures were obtained for all cancer sites.

DISCUSSION

It may be challenging to implement new survival measures in routine publications as it can require the application of modeling techniques. We propose a way of automating the production of such statistics and show that we can obtain reliable estimates across a range of measures and subgroups of patients.

Exposure to benzene and other hydrocarbons and risk of bladder cancer among male offshore petroleum workers

BACKGROUND

Occupational exposures constitute the second leading cause of urinary bladder cancer after tobacco smoking. Increased risks have been found in the petroleum industry, but high-quality exposure data are needed to explain these observations.

METHODS

Using a prospective case-cohort design, we analysed 189 bladder cancer cases (1999-2017) and 2065 randomly drawn non-cases from the Norwegian Offshore Petroleum Workers cohort. Cases were identified in the Cancer Registry of Norway, while work histories (1965-1998) and lifestyle factors were recorded by questionnaire at baseline (1998). Occupational petroleum-related hydrocarbon exposures were assessed by expert-developed job-exposure matrices. Hazard ratios were estimated by weighted Cox-regressions, adjusted for age, tobacco smoking, education, and year of first employment, and with lagged exposures.

RESULTS

Increased risks were found in benzene-exposed workers, either long-term exposure (≥18.8 years, HR = 1.89, 95% CI: 1.14-3.13; p-trend = 0.044) or high-level cumulative benzene exposure (HR = 1.60, 95% CI: 0.97-2.63; p-trend = 0.065), compared with the unexposed. Associations persisted with 20-year exposure lag. No associations were found with skin or inhalation exposure to crude oil, mineral oil (lubrication, hydraulics, turbines, drilling), or diesel exhaust.

CONCLUSIONS

The results suggest that exposures in the benzene fraction of the petroleum stream may be associated with increased bladder cancer risk.