"It was an important part of my treatment": a qualitative study of Norwegian breast Cancer patients' experiences with mainstreamed genetic testing.

BACKGROUND: In South-Eastern Norway, genetic testing for BRCA1 and BRCA2 is offered to breast cancer patients by their treating surgeon or oncologist. Genetic counselling from a geneticist or a genetic counsellor is offered only to those who test positive for a pathogenic variant or have a family history of cancer. This practice is termed "mainstreamed genetic testing". The aim of this study was to learn about patients' experience of this healthcare service. METHODS: Qualitative in-depth interviews were conducted with 22 breast cancer patients who had been diagnosed during the first half of 2016 or 2017 at one regional and one university hospital and who had been offered testing by their treating physician. A six-phase thematic approach was used to analyse the data. RESULTS: The participants had varied experiences of how and when testing was offered. Three main themes emerged from the analysis: 1. informational and communicational needs and challenges during a chaotic time, 2. the value of genetic testing and 3. the importance of standardised routines for mainstreamed genetic testing. CONCLUSIONS: Despite the shock of their diagnosis and the varying experiences they had in respect of how and when testing was offered, all of the participants emphasised that genetic testing had been an important part of their diagnosis and treatment. Our results indicate that there is a need for continuous collaboration between geneticists, surgeons, oncologists and laboratory specialists in order to establish simple and robust routines so as to ensure that all eligible breast cancer patients are offered testing at a point when the test result can have an impact on treatment.

Mainstreamed genetic testing of breast cancer patients in two hospitals in South Eastern Norway.

Studies have shown that a significant number of eligible breast cancer patients are not offered genetic testing or referral to genetic counseling. To increase access to genetic testing in South Eastern Norway, testing has since 2014 been offered directly to breast cancer patients by surgeons and oncologists. This practice is termed "mainstreamed genetic testing". The aim of this study was to investigate to what extent patients in South Eastern Norway are offered testing. Three hundred and sixty one patients diagnosed in 2016 and 2017 at one regional and one university hospital in South Eastern Norway were included. Data on whether the patients fulfilled the criteria, whether they had been offered testing and if they were tested were collected. In total, 26.6% (96/361) fulfilled the criteria for testing. Seventy five percent (69/92) of these were offered testing, and 71.7% (66/92) were tested. At the university hospital, 90.2% (37/41) of eligible patients were offered testing, and at the regional hospital 62.7% (32/51). Fifty two percent (12/23) of eligible patient not offered testing were younger than 50 years at time of diagnosis. As many as 95.4% (125/131) of all patients who were offered testing, wanted to be tested. The majority of patients who fulfilled the criteria were offered testing, supporting the practice of mainstreamed genetic testing. There were nevertheless differences in rates of testing between the hospitals that affected all groups of patients, indicating that genetic testing may not be equally accessible to all patients. We suggest that efforts should be made to increase awareness and improve routines for genetic testing of breast cancer patients in Norway.

The intronic BRCA1 c.5407-25T>A variant causing partly skipping of exon 23-a likely pathogenic variant with reduced penetrance?

Rare sequence variants in the non-coding part of the BRCA genes are often reported as variants of uncertain significance (VUS), which leave patients and doctors in a challenging position. The aim of this study was to determine the pathogenicity of the BRCA1 c.5407-25T>A variant found in 20 families from Norway, France and United States with suspected hereditary breast and ovarian cancer. This was done by combining clinical and family information with allele frequency data, and assessment of the variant's effect on mRNA splicing. Mean age at breast (n = 12) and ovarian (n = 11) cancer diagnosis in female carriers was 49.9 and 60.4 years, respectively. The mean Manchester score in the 20 families was 16.4. The allele frequency of BRCA1 c.5407-25T>A was 1/64,566 in non-Finnish Europeans (gnomAD database v2.1.1). We found the variant in 1/400 anonymous Norwegian blood donors and 0/784 in-house exomes. Sequencing of patient-derived cDNA from blood, normal breast and ovarian tissue showed that BRCA1 c.5407-25T>A leads to skipping of exon 23, resulting in frameshift and protein truncation: p.(Gly1803GlnfsTer11). Western blot analysis of transiently expressed BRCA1 proteins in HeLa cells showed a reduced amount of the truncated protein compared with wild type. Noteworthily, we found that a small amount of full-length transcript was also generated from the c.5407-25T>A allele, potentially explaining the intermediate cancer burden in families carrying this variant. In summary, our results show that BRCA1 c.5407-25T>A leads to partial skipping of exon 23, and could represent a likely pathogenic variant with reduced penetrance.

Extra-tumoral breast tissue in breast cancer patients: variations with steroid contraceptive use.

The association between oral contraceptive (OC) use and benign breast changes in extra-tumoral breast tissue was studied histologically in 1,503 breast cancer patients from The WHO Collaborative Study of Neoplasia and Steroid Contraceptives. The occurrence of ductal hyperplasia, ductal atypia, sclerosing adenosis, cysts, apocrine metaplasia, apocrine hyperplasia, apocrine atypia, adenosis, lobular atypia, duct ectasia, calcifications, inflammatory reaction, lactational metaplasia and a high epithelial-stromal ratio was graded semi-quantitatively. Prevalence odds ratio (POR) for each histologic variable was calculated by logistic regression analyses. Patients who had ever used OC had lower occurrence of ductal hyperplasia than never users (POR 0.72 (95% CI 0.52-0.99)). Current use and more than 8 years of use was also associated with a lower prevalence of ductal hyperplasia (POR 0.40 (0.20-0.81) and POR 0.33 (0.17-0.64), respectively). Age > 35 years at first use was associated with increased prevalence of ductal carcinoma in situ (POR 2.15 (1.05-4.40)), but not of atypical ductal hyperplasia. Our results show that the effects of OC use on ductal hyperplasia in non-neoplastic breast tissue of breast cancer patients are similar to what others have found in patients with benign breast disease only. The increased prevalence of extra-tumoral ductal carcinoma in situ in breast cancer patients who started OC use at high age may possibly be explained by a longer preinvasive phase in these patients.