Evaluation of NTRK expression and fusions in a large cohort of early-stage lung cancer.

Tropomyosin receptor kinases (TRK) are attractive targets for cancer therapy. As TRK-inhibitors are approved for all solid cancers with detectable fusions involving the Neurotrophic tyrosine receptor kinase (NTRK)-genes, there has been an increased interest in optimizing testing regimes. In this project, we wanted to find the prevalence of NTRK fusions in a cohort of various histopathological types of early-stage lung cancer in Norway and to investigate the association between TRK protein expression and specific histopathological types, including their molecular and epidemiological characteristics. We used immunohistochemistry (IHC) as a screening tool for TRK expression, and next-generation sequencing (NGS) and fluorescence in situ hybridization (FISH) as confirmatory tests for underlying NTRK-fusion. Among 940 cases, 43 (4.6%) had positive TRK IHC, but in none of these could a NTRK fusion be confirmed by NGS or FISH. IHC-positive cases showed various staining intensities and patterns including cytoplasmatic or nuclear staining. IHC-positivity was more common in squamous cell carcinoma (LUSC) (10.3%) and adenoid cystic carcinoma (40.0%), where the majority showed heterogeneous staining intensity. In comparison, only 1.1% of the adenocarcinomas were positive. IHC-positivity was also more common in men, but this association could be explained by the dominance of LUSC in TRK IHC-positive cases. Protein expression was not associated with differences in time to relapse or overall survival. Our study indicates that NTRK fusion is rare in early-stage lung cancer. Due to the high level of false positive cases with IHC, Pan-TRK IHC is less suited as a screening tool for NTRK-fusions in LUSC and adenoid cystic carcinoma.

Thymoma with pleural metastases. / Tymom med pleurametastaser.

Metastatic thymoma is a rare and serious condition that is treated with cytostatics according to the guidelines. Cytostatics have limited efficacy and are toxic. This case report illustrates how glucocorticoid treatment can have a significant effect.

"Evaluation of ROS1 expression and rearrangements in a large cohort of early-stage lung cancer".

BACKGROUND: ROS1 fusion is an infrequent, but attractive target for therapy in patients with metastatic non- small-cell lung cancer. In studies on mainly late-stage disease, the prevalence of ROS1 fusions is about 1-3%. In early-stage lung cancer ROS1 might also provide a fruitful target for neoadjuvant or adjuvant therapy. In the present study, we investigated the prevalence of ROS1 fusion in a Norwegian cohort of early-stage lung cancer. We also explored whether positive ROS1 immunohistochemical (IHC) stain was associated with certain mutations, clinical characteristics and outcomes. METHODS: The study was performed using biobank material from 921 lung cancer patients including 542 patients with adenocarcinoma surgically resected during 2006-2018. Initially, we screened the samples with two different IHC clones (D4D6 and SP384) targeting ROS1. All samples that showed more than weak or focal staining, as well as a subgroup of negative samples, were analyzed with ROS1 fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) with a comprehensive NGS DNA and RNA panel. Positive ROS1-fusion was defined as those samples positive in at least two of the three methods (IHC, FISH, NGS). RESULTS: Fifty cases were IHC positive. Of these, three samples were both NGS and FISH-positive and considered positive for ROS1 fusion. Two more samples were FISH positive only, and whilst IHC and NGS were negative. These were also negative with Reverse Transcription quantitative real time Polymerase Chain Reaction (RT-qPCR). The prevalence of ROS1 fusion in adenocarcinomas was 0.6%. All cases with ROS1 fusion had TP53 mutations. IHC-positivity was associated with adenocarcinoma. Among SP384-IHC positive cases we also found an association with never smoking status. There was no association between positive IHC and overall survival, time to relapse, age, stage, sex or pack-year of smoking. CONCLUSIONS: ROS1 seems to be less frequent in early-stage disease than in advanced stages. IHC is a sensitive, but less specific method and the results need to be confirmed with another method like FISH or NGS.

Improving public cancer care by implementing precision medicine in Norway: IMPRESS-Norway.

BACKGROUND: Matching treatment based on tumour molecular characteristics has revolutionized the treatment of some cancers and has given hope to many patients. Although personalized cancer care is an old concept, renewed attention has arisen due to recent advancements in cancer diagnostics including access to high-throughput sequencing of tumour tissue. Targeted therapies interfering with cancer specific pathways have been developed and approved for subgroups of patients. These drugs might just as well be efficient in other diagnostic subgroups, not investigated in pharma-led clinical studies, but their potential use on new indications is never explored due to limited number of patients. METHODS: In this national, investigator-initiated, prospective, open-label, non-randomized combined basket- and umbrella-trial, patients are enrolled in multiple parallel cohorts. Each cohort is defined by the patient's tumour type, molecular profile of the tumour, and study drug. Treatment outcome in each cohort is monitored by using a Simon two-stage-like 'admissible' monitoring plan to identify evidence of clinical activity. All drugs available in IMPRESS-Norway have regulatory approval and are funded by pharmaceutical companies. Molecular diagnostics are funded by the public health care system. DISCUSSION: Precision oncology means to stratify treatment based on specific patient characteristics and the molecular profile of the tumor. Use of targeted drugs is currently restricted to specific biomarker-defined subgroups of patients according to their market authorization. However, other cancer patients might also benefit of treatment with these drugs if the same biomarker is present. The emerging technologies in molecular diagnostics are now being implemented in Norway and it is publicly reimbursed, thus more cancer patients will have a more comprehensive genomic profiling of their tumour. Patients with actionable genomic alterations in their tumour may have the possibility to try precision cancer drugs through IMPRESS-Norway, if standard treatment is no longer an option, and the drugs are available in the study. This might benefit some patients. In addition, it is a good example of a public-private collaboration to establish a national infrastructure for precision oncology. Trial registrations EudraCT: 2020-004414-35, registered 02/19/2021; ClinicalTrial.gov: NCT04817956, registered 03/26/2021.

Quality-of-life effects of screening mammography in Norway.

Mammography screening may save women from dying of breast cancer, although it has not been shown to reduce all-cause mortality. Screening also leads to overdiagnosis and many false positive mammograms aggravating women's quality-of-life. Quality adjusted life years (QALY) analyses of mammography screening have so far, calculated life years gained assuming that all prevented breast cancer deaths translate into a reduction in all-cause mortality. We calculated net QALYs in two hypothesized cohorts of 100,000 Norwegian women; one screened biennially from age 50 to 69 years and one not screened. We followed both cohorts to age 85 years. We used EQ-5D and an alternative equity weighted QALY instrument to estimate utility losses. In the screening cohort, we assumed 20% false positive tests during screening, different levels of overdiagnosis (20-75%) and different levels of breast cancer mortality reduction (10-30%). We assumed that reductions in breast cancer mortality only to a limited extent (20, 50 or 80%), resulted in reductions in all-cause mortality. We calculated both undiscounted and discounted (4%) QALYs. Assuming that 50% of the reduction in breast cancer mortality translated to a reduction in all-cause mortality and using estimated levels of benefits and harms in modern screening programs (50-75% overdiagnosis and 10% reduction in breast cancer mortality), undiscounted equity weighted QALY loss varied from 437 to 875 per 100,000 women. Using the levels of benefit and harms as reported in 30-40 years old randomized trials (30% overdiagnosis and 15% reduction in breast cancer mortality), undiscounted equity weighted QALY gain was 535 per 100,000. Net QALY in modern mammography screening in Norway is negative. Results could also be representative for Sweden, Denmark, UK and the US.

Interval and Consecutive Round Breast Cancer after Digital Breast Tomosynthesis and Synthetic 2D Mammography versus Standard 2D Digital Mammography in BreastScreen Norway.

Background Screening that includes digital breast tomosynthesis (DBT) with two-dimensional (2D) synthetic mammography (SM) or standard 2D digital mammography (DM) results in detection of more breast cancers than does screening with DM alone. A decrease in interval breast cancer rates is anticipated but is not reported. Purpose To compare rates and characteristics of (a) interval breast cancer in women screened with DBT and SM versus those screened with DM alone and (b) screen-detected breast cancer at consecutive screenings with DM. Materials and Methods This prospective cohort study from BreastScreen Norway included women screened with DBT and SM (study group) or DM alone (control group) between February 2014 and December 2015 (baseline). All women, except nonattendees, women with breast cancer, and those who exceeded the upper age limit, were consecutively screened with DM after 2 years. Interval breast cancer, sensitivity, and specificity were estimated for women screened at baseline. Recall, screen-detected breast cancer, and positive predictive value were analyzed for consecutively screened women. A χ2 test, t test (P < .001 after Bonferroni correction indicated a significant difference), and binomial regression model were used to analyze differences across groups. Results A total of 92 404 women who underwent baseline screening (mean age, 59 years ± 6 [standard deviation]) were evaluated; 34 641 women in the study group (mean age, 59 years ± 6) were screened with DBT and SM and 57 763 women in the control group (mean age, 59 years ± 6) were screened with DM. A total of 26 474 women in the study group (mean age, 60 years ± 5) and 45 543 women in the control group (mean age, 60 years ± 5) were consecutively screened with DM. Rates of interval breast cancer were 2.0 per 1000 screened women in the study group and 1.5 per 1000 screened women in the control group (P = .12). No differences in histopathologic characteristics of interval breast cancer were observed. In the consecutive screening round, rates of screen-detected breast cancer were 3.9 per 1000 screened women (study group) and 5.6 per 1000 screened women (control group) (P = .001). Rates of histologic grade 1 invasive cancer were 0.5 per 1000 screened women (study group) and 1.3 per 1000 screened women (control group) (P = .001). Conclusion No differences in interval breast cancer rates or tumor characteristics were observed in women screened with DBT and SM compared with women screened with DM. Higher rates of low-grade screen-detected tumors were observed in the control group at consecutive screening. © RSNA, 2019 Online supplemental material is available for this article.

Digital Breast Tomosynthesis and Synthetic 2D Mammography versus Digital Mammography: Evaluation in a Population-based Screening Program.

Purpose To compare the performance of digital breast tomosynthesis (DBT) and two-dimensional synthetic mammography (SM) with that of digital mammography (DM) in a population-based mammographic screening program. Materials and Methods In this prospective cohort study, data from 37 185 women screened with DBT and SM and from 61 742 women screened with DM as part of a population-based screening program in 2014 and 2015 were included. Early performance measures, including recall rate due to abnormal mammographic findings, rate of screen-detected breast cancer, positive predictive value of recall, positive predictive value of needle biopsy, histopathologic type, tumor size, tumor grade, lymph node involvement, hormonal status, Ki-67 level, and human epidermal growth factor receptor 2 status were compared in women who underwent DBT and SM screening and in those who underwent DM screening by using χ2 tests, two-sample unpaired t tests, and tests of proportions. Results Recall rates were 3.4% for DBT and SM screening and 3.3% for DM screening (P = .563). DBT and SM screening showed a significantly higher rate of screen-detected cancer compared with DM screening (9.4 vs 6.1 cancers per 1000 patients screened, respectively; P < .001). The rate of detection of tumors 10 mm or smaller was 3.2 per 1000 patients screened with DBT and SM and 1.8 per 1000 patients screened with DM (P < .001), and the rate of grade 1 tumors was 3.3 per 1000 patients screened with DBT and SM versus 1.4 per 1000 patients screened with DM (P < .001). On the basis of immunohistochemical analyses, rates of lymph node involvement and tumor subtypes did not differ between women who underwent DBT and SM screening and those who underwent DM screening. Conclusion DBT and SM screening increased the detection rate of histologically favorable tumors compared with that attained with DM screening. © RSNA, 2018 Online supplemental material is available for this article.

Accuracy of cervical cytology: comparison of diagnoses of 100 Pap smears read by four pathologists at three hospitals in Norway.

BACKGROUND: Cervical cancer can be prevented by early detection and treatment for precancerous lesions. Since 1995, there has been a national cervical cancer screening program in Norway, where women aged 25-69 years are recommended to take Pap smears every three years. There are 17 cytology laboratories covering a population of 5 million people. The detection rate of cervical abnormalities varies from laboratory to laboratory. We wanted to investigate the accuracy of cytology diagnoses by four different pathologists at three different hospitals in Norway. METHODS: One hundred Pap smears (20 Normal, 20 ASC-US, 20 LSIL, 20 ASC-H and 20 HSIL) screened at UNN in 2015 were evaluated by four pathologists at three hospitals in Norway. All patients were followed up through December 2016. Histologically confirmed high-grade dysplasia (CIN2+) was considered as study endpoint. RESULTS: The number of Pap smears evaluated as abnormal (ASC-US+) by the four pathologists varied from 61 to 85. The number of high-grade cytology (ASC-H+) varied from 26 to 50. There was moderate agreement (weighted kappa 0.45-0.58) between the observers. There were 32 women with high-grade histology (CIN2+) in the follow-up, including 19 CIN2, 12 CIN3 and one squamous cell carcinoma (SCC). Using high-grade cytology (ASC-H+) as cut-off, the sensitivity for CIN2+ varied from 68.8% to 93.8% (mean 77.4%) and specificity from 70.6% to 95.6% (mean 81.3%). The pathologist with the highest sensitivity for CIN2+ had the highest false positive rate and the lowest specificity (p<0.05). The accuracy for CIN2+ varied from 74.1% to 83.8% (mean 79.4%). The Pap smear from the woman with cervical cancer was diagnosed as high-grade (ASC-H+) by one of the four pathologists. CONCLUSIONS: Cervical cancer screening based on cytology has limited accuracy. The study revealed a moderate agreement between the observers, along with a trade-off between sensitivity and specificity. This might indicate that hospitals with high detection rates of cervical cytology have higher sensitivity for CIN2+ but lower specificity.

EGFR mutation testing of lung cancer patients - Experiences from Vestfold Hospital Trust.

BACKGROUND: Patients with advanced stage lung cancer and somatic mutations in the epithelial growth factor receptor (EGFR) gene are currently treated with tyrosine-kinase inhibitors. The Norwegian Lung Cancer Group (NLCG) recommended EGFR testing of all patients with non-small cell lung carcinoma (NSCLC) from June 2010. From March 2013, testing of squamous cell carcinomas was terminated. We have analysed how these recommendation were followed at a medium-sized Norwegian hospital and we present data on mutation frequency, retesting and possible explanations for missing test results. MATERIAL AND METHODS: All pathology reports for patients diagnosed with NSCLC at Vestfold Hospital Trust were examined for the period June 2010 to December 2013. Mutation analyses were done at the Department of Pathology, Oslo University Hospital. RESULTS: Material was sent for EGFR analysis for 256 of the 304 eligible patients diagnosed in the period. Material from 48 patients was never sent for EGFR testing, of which five samples consisted of too few tumour cells. For the rest, no obvious reason for omitting EGFR mutation analyses was identified. During the first six months of our study period, material from 25 of 66 NSCLC patients (38%) was not tested, whereas only six of the 118 patients (5%) in 2013 were not tested. For 34 patients, the first tissue specimen contained too few tumour cells and a new sample was sent for EGFR analyses for 11 of these. EGFR mutation was detected in 7.1% of the analysed NSCLC and in 9.4% of adenocarcinomas. DISCUSSION: Especially for patients with advanced stages of NSCLC, EGFR mutation status is necessary for treatment stratification. Our results show that the guidelines were followed increasingly over time for patients diagnosed with NSCLC at the Vestfold Hospital Trust. The establishment of interdisciplinary meetings has improved the diagnostic routines.

Breast cancer incidence and menopausal hormone therapy in Norway from 2004 to 2009: a register-based cohort study.

In Norway, the breast cancer incidence increased by 50% in the 1990 s, during a period with initiation of mammography screening as well as a fourfold increase in use of menopausal hormone therapy (HT). After 2002, the HT use has dropped substantially; however, the breast cancer incidence has declined only marginally. How much mammography screening contributed to the breast cancer incidence increase in the 1990 s compared with HT use and specifically different types of HT use, has thus been discussed. Whether HT affects the incidence of subtypes of breast cancer differently has also been questioned. We have linked individual data from several national registries from 2004 to 2009 on 449,717 women aged 50-65 years. 4597 cases of invasive cancer and 681 cases of ductal carcinoma in situ (DCIS) were included in the analysis. We used Cox regression to estimate hazard ratio (HR) as a measure of the relative risk of breast cancer associated with use of HT. The HRs associated with prescriptions of HT for more than 1 year were 2.06 (1.90-2.24) for estrogen and progesterone combinations, 1.03 (0.85-1.25) for systemic estrogens, and 1.23 (1.01-1.51) for tibolone. Invasive lobular carcinoma was more strongly associated with use of estrogen and progesterone combinations, HR = 3.10 (2.51-3.81), than nonlobular carcinoma, HR = 1.94 (1.78-2.12). The corresponding value for DCIS was 1.61 (1.28-2.02). We estimated the population attributable fraction to 8.2%, corresponding to 90 breast cancer cases in 2006 indicating that HT use still caused a major number of breast cancer cases.

Expression of thyroid transcription factor-1 is associated with a basal-like phenotype in breast carcinomas.

BACKGROUND: The differential diagnosis between primary and secondary breast cancers might be difficult, especially in poorly differentiated tumors. Thyroid Transcription Factor-1 (TTF-1) has been regarded as a reliable marker for lung or thyroid origin, with only occasional positive staining in other tumors. However, positive cases have recently been reported among primary breast carcinomas. METHODS AND RESULTS: Here, we analyzed expression of TTF-1 protein (clone SPT24) by immunohistochemical staining of sections from paraffin embedded tumor samples in 247 primary breast cancers from the population-based Norwegian Breast Cancer Screening Program. Positive staining (weak or strong) was observed in 7 cases (2,8%). As novel observations, positivity was demonstrated more frequently in estrogen receptor negative cases (14,0% vs. 1,4%; p = 0,004), highly proliferative tumors (8,8% vs. 1,1%; p = 0,008), tumors with a basal-like phenotype by showing expression of CK5/6 and/or P-cadherin (11,1% vs. 1,4%; p = 0,01), and tumors with blood vessel invasion (9,7% vs. 1,9%; p = 0,04). Also, TTF-1 was associated with histological grade 3 tumors compared with grade 1 or 2 tumors (7,7% vs. 1,5%; p = 0,04) as well as lymph node positive cases (5,2% vs. 1,8%; p = 0,03). CONCLUSIONS: Our population-based findings indicate that TTF-1 may be positive in approximately 3% of primary breast cancers, and positivity indicates an association with adverse prognostic factors. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8313753509421182.

Hormone therapy use and breast cancer incidence by histological subtypes in Sweden and Norway.

Mammography screening and postmenopausal hormone therapy (HT) both influence breast cancer incidence. While breast cancer incidence increased by around 50% during the introduction of screening, a smaller decline in incidence has been reported in several countries after 2002 when the sales of HT started to decline. Data suggest that HT increases the risk of the second most common type of breast cancer, invasive lobular carcinoma (ILC) but not the most common, invasive ductal carcinoma (IDC). Breast cancer incidences stratified on histological subtypes were obtained from the national cancer registries. HT sales data from drug consumption statistics and information on the county-level introduction of mammography screening were combined, and breast cancer incidence trends were estimated using Poisson regression models, focusing on the period after 2002. From 2002 to 2007 the annual decrease in breast cancer incidence rates for women aged 50-69 was 1.5% (95% CI -2.3% to -0.7%) in Sweden and 0.8% (95% CI -2.8% to 1.2%) in the part of Norway not confounded by prevalence screening. Most of the decline was in the rates of ILC which dropped by 4.7% (95% CI -6.6% to -2.7%) and 7.0% (95% CI -12.8% to -0.9%) per year, respectively. The rates of IDC were stable in this period. Breast cancer incidence has declined in Sweden and Norway since 2002, but the reduction is moderate compared with the large increase that occurred during the introduction of mammography screening. Declining rates of ILC, but not of IDC, support the hypothesis that the drop in breast cancer incidence is associated with reduced HT use.

Effect of mammography screening on surgical treatment for breast cancer in Norway: comparative analysis of cancer registry data.

OBJECTIVE: To determine the effect of mammography screening on surgical treatment for breast cancer. DESIGN: Comparative analysis of data from Norwegian cancer registry. SETTING: Mammography screening, Norway (screening of women aged 50-69 was introduced sequentially from 1996 to 2004). PARTICIPANTS: 35,408 women aged 40-79 with invasive breast cancer or ductal carcinoma in situ treated surgically from 1993 to 2008. MAIN OUTCOME MEASURES: Rates of breast surgery (mastectomy plus breast conserving treatment) and rates of mastectomy for three age groups of women: 40-49, 50-69, and 70-79. Changes in rates from pre-screening period (1993-5) to introduction of screening phase (1996-2004) and then to screening period (2005-8) are presented as hazard ratios in invited and non-invited women. RESULTS: The annual rate for breast surgery from the pre-screening period (1993-5) to screening period (2005-8) in Norway increased by 70% (hazard ratio 1.70, 95% confidence interval 1.62 to 1.78), from 180 to 305 per 100,000 women in the invited age group (50-69 years). In the younger, non-invited age group (40-49 years), however, the increase was only 8% (1.08, 1.00 to 1.16), from 133 to 144 per 100,000 women per year, whereas in the older, non-invited age group (70-79 years) the rate decreased by 8% (0.92, 0.86 to 1.00), from 227 to 214 per 100,000 women per year. The rates for mastectomy decreased similarly from the pre-screening period to screening period in invited and non-invited women. From the pre-screening period to the introduction phase of screening (1996-2004), however, the annual mastectomy rate in women aged 50-69 invited to screening increased by 9% (1.09, 1.03 to 1.14), from 156 to 167 per 100,000 women, and in the younger non-invited women declined by 17% (0.83, 0.78 to 0.90), from 109 to 91 per 100,000 women. In consequence, the mastectomy rate was 31% (1.31, 1.20 to 1.43) higher in the invited than in the non-invited younger age group. CONCLUSIONS: Mammography screening in Norway was associated with a noticeable increase in rates for breast cancer surgery in women aged 50-69 (the age group invited to screening) and also an increase in mastectomy rates. Although over-diagnosis is likely to have caused the initial increase in mastectomy rates and the overall increase in surgery rates in the age group screened, the more recent decline in mastectomy rates has affected all age groups and is likely to have resulted from changes in surgical policy.