Comprehensive Inherited Risk Estimation for Risk-Based Breast Cancer Screening in Women

PURPOSE

Family history (FH) and pathogenic variants (PVs) are used for guiding risk surveillance in selected high-risk women but little is known about their impact for breast cancer screening on population level. In addition, polygenic risk scores (PRSs) have been shown to efficiently stratify breast cancer risk through combining information about common genetic factors into one measure.

METHODS

In longitudinal real-life data, we evaluate PRS, FH, and PVs for stratified screening. Using FinnGen (N = 117,252), linked to the Mass Screening Registry for breast cancer (1992-2019; nationwide organized biennial screening for age 50-69 years), we assessed the screening performance of a breast cancer PRS and compared its performance with FH of breast cancer and PVs in moderate- (CHEK2)- to high-risk (PALB2) susceptibility genes.

RESULTS

Effect sizes for FH, PVs, and high PRS (>90th percentile) were comparable in screening-aged women, with similar implications for shifting age at screening onset. A high PRS identified women more likely to be diagnosed with breast cancer after a positive screening finding (positive predictive value [PPV], 39.5% [95% CI, 37.6 to 41.5]). Combinations of risk factors increased the PPVs up to 45% to 50%. A high PRS conferred an elevated risk of interval breast cancer (hazard ratio [HR], 2.78 [95% CI, 2.00 to 3.86] at age 50 years; HR, 2.48 [95% CI, 1.67 to 3.70] at age 60 years), and women with a low PRS (<10th percentile) had a low risk for both interval- and screen-detected breast cancers.

CONCLUSION

Using real-life screening data, this study demonstrates the effectiveness of a breast cancer PRS for risk stratification, alone and combined with FH and PVs. Further research is required to evaluate their impact in a prospective risk-stratified screening program, including cost-effectiveness.

Abstract 4122: TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell activation

Globally, breast cancer is among the most diagnosed cancer types for women. Current and upcoming breast cancer therapies are being investigated in combination with compounds that stimulate an immune response, but whether the therapeutic agents themselves have unexpected immunomodulatory effects is often overlooked. Here, we have developed a method to grow 3D cultures of intact fragments of patient-derived tissue (Patient-Derived Explant Cultures; PDECs) to assess the preclinical potential of studying human tumor cells and immune cells simultaneously ex vivo

Single cell sequencing, flow cytometry, gene expression profiling and cytokine profiling data show that the tumor immunocontexture is conserved in PDECs and that these resident immune cells respond to distinct immune stimulus

We performed gene expression profiling, flow cytometry, and cytokine profiling of drug-treated human explants and found that metformin has antitumor potential through the activation of antigen presenting cells. We further validated in vitro that metformin-mediated APC activation is largely through mitochondrial respiration inhibition irrespective of the presence of tumor cells. Our PDEC platform highlights the preclinical potential of ex vivo explants by simultaneously offering information of tumor and immune cell toxicity and mechanism.

Citation Format: Rita J. Turpin, Ruixian Liu, Pauliina Munne, Aino Peura, Jenna Rannikko, Gino Philips, Natasha Salmelin, Elina Hurskainen, Ilida Suleymanova, Minna Mutka, Tuomo Meretoja, Johanna Mattson, Satu Mustjoki, Päivi Saavalainen, Diether Lambrechts, Jeroen Pouwels, Maija Hollmén, Juha Klefström. TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell activation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4122.

FinnGen provides genetic insights from a well-phenotyped isolated population

Population isolates such as those in Finland benefit genetic research because deleterious alleles are often concentrated on a small number of low-frequency variants (0.1% ≤ minor allele frequency < 5%). These variants survived the founding bottleneck rather than being distributed over a large number of ultrarare variants. Although this effect is well established in Mendelian genetics, its value in common disease genetics is less explored^1,2. FinnGen aims to study the genome and national health register data of 500,000 Finnish individuals. Given the relatively high median age of participants (63 years) and the substantial fraction of hospital-based recruitment, FinnGen is enriched for disease end points. Here we analyse data from 224,737 participants from FinnGen and study 15 diseases that have previously been investigated in large genome-wide association studies (GWASs). We also include meta-analyses of biobank data from Estonia and the United Kingdom. We identified 30 new associations, primarily low-frequency variants, enriched in the Finnish population. A GWAS of 1,932 diseases also identified 2,733 genome-wide significant associations (893 phenome-wide significant (PWS), P < 2.6 × 10^-11) at 2,496 (771 PWS) independent loci with 807 (247 PWS) end points. Among these, fine-mapping implicated 148 (73 PWS) coding variants associated with 83 (42 PWS) end points. Moreover, 91 (47 PWS) had an allele frequency of <5% in non-Finnish European individuals, of which 62 (32 PWS) were enriched by more than twofold in Finland. These findings demonstrate the power of bottlenecked populations to find entry points into the biology of common diseases through low-frequency, high impact variants.

Delay in the initiation of adjuvant chemotherapy in patients with breast cancer with mastectomy with or without immediate breast reconstruction

Background

Patients with breast cancer undergoing mastectomy should be offered the option of immediate breast reconstruction (IBR). The aim of this retrospective study was to assess whether there is a delay in the initiation of adjuvant chemotherapy in patients undergoing mastectomy with or without IBR.

Method

The study included patients aged 70 years or younger with clinically node-negative breast cancer who underwent unilateral mastectomy with IBR (IBR group) or mastectomy alone (no-IBR group) followed by adjuvant chemotherapy at the Helsinki University Hospital between January 2012 to July 2018.

Results

A total of 645 patients were included; 186 in the IBR group and 459 in the no-IBR group. Sixty-six (35.5 per cent) patients in the IBR group and 102 (22.2 per cent) patients in the no-IBR group received their first chemotherapy cycle later than 6 weeks after surgery (P &lt; 0.001). The respective numbers for later than 8 weeks were 17 (9.1 per cent) and 14 (3.1 per cent) (P = 0.001). Among all 645 patients, postoperative complications were a significant risk factor for a delay in the initiation of chemotherapy. Sixty-seven (39.9 per cent) patients with and 101 (21.2 per cent) patients without complications had a delay in chemotherapy (P &lt; 0.001). The delay in chemotherapy was due to complications in 39 (59.1 per cent) in the IBR group and in 28 (27.5 per cent) in the no-IBR group (P &lt; 0.001).

Conclusion

Patients undergoing mastectomy alone were more likely to receive adjuvant chemotherapy within 6 weeks after surgery compared with the IBR patients. IBR significantly increased the risk of postoperative complications in comparison with mastectomy alone. The complications, in turn, were a significant risk factor for delay in adjuvant chemotherapy.

Oncological Safety of Skin-Sparing Mastectomy and Immediate Breast Reconstruction in Extensive Ductal Carcinoma In Situ

INTRODUCTION

Skin-sparing mastectomy (SSM) with immediate breast reconstruction is the ideal treatment for interested and suitable patients with extensive ductal carcinoma in situ (DCIS). There is no guideline to indicate on how large DCIS the procedure can be performed safely. The primary target of this study was to define the oncological safety of SSM in extensive pure DCIS. The secondary target was to find predictive factors for DCIS upstaging to invasive disease.

MATERIALS AND METHODS

A total of 71 consecutive patients with extensive pure DCIS and undergoing SSM with immediate latissimus dorsi (LD) breast reconstruction were retrospectively evaluated.

RESULTS

The median size of DCIS lesion in preoperative imaging was 60 mm, the median weight of mastectomy specimen was 350 g, and the median resection margin (RM) was 2.0 mm. A total of 20 patients (28%) had an RM less than 0.5 mm and nine patients (13%) had ink positive margins. Six patients having positive RM underwent reoperation. A total of 29 patients (41%) presented invasive cancer foci in final histopathological assessment and nine patients (13%) had an axillary metastasis. Adjuvant therapy was given to 23 patients presenting invasive cancer. There were no local recurrences or distant metastases (0%, 95% confidence interval 0-0.051) during the mean follow-up of 71 mo. None of the factors evaluated predicted upstaging to invasive disease.

CONCLUSIONS

SSM with immediate breast reconstruction in patients with extensive DCIS is oncologically safe even when the margins are close or positive. Additional invasive foci and solitary axillary lymph node metastases are frequent but do not worsen the outcome.

Same‐day mastectomy and axillary lymph node dissection is safe for most patients with breast cancer

Background and Objective

The aim of this study was to evaluate the safety of same‐day mastectomy, with or without a sentinel node biopsy (SNB) and/or axillary lymph node dissection (ALND).

Methods

In this retrospective study, we reviewed 913 consecutive women who underwent a simple mastectomy for breast cancer between the years 2014 and 2019 and were treated either with same‐day surgery (SDS) or an overnight stay (OS) regime. We reviewed all surgical complications, any unplanned return to care (RTC) and the rehospitalization rate for 30 postoperative days.

Results

A total of 259 patients (28%) were treated with SDS and 654 patients (72%) with an OS regime. There was no difference in RTC (odds ratio: 0.79 [95% confidence interval: 0.53–1.18], p = 0.26) or any major complications between the groups. None of the investigated subgroups, such as patients with previous neoadjuvant therapy, diabetes, obesity (up to a body mass index of 40 kg/m²), the American Society of Anaesthesiologist Class of 3, or elderly patients aged 75–84 years, showed an increased complication rate when treated with the SDS regime.

Conclusion

A same‐day simple mastectomy is safe with SNB and/or ALND. It can be performed safely for most patients with stable co‐morbidities.

Compressive stress-mediated p38 activation required for ERα + phenotype in breast cancer

Breast cancer is now globally the most frequent cancer and leading cause of women's death. Two thirds of breast cancers express the luminal estrogen receptor-positive (ERα + ) phenotype that is initially responsive to antihormonal therapies, but drug resistance emerges. A major barrier to the understanding of the ERα-pathway biology and therapeutic discoveries is the restricted repertoire of luminal ERα + breast cancer models. The ERα + phenotype is not stable in cultured cells for reasons not fully understood. We examine 400 patient-derived breast epithelial and breast cancer explant cultures (PDECs) grown in various three-dimensional matrix scaffolds, finding that ERα is primarily regulated by the matrix stiffness. Matrix stiffness upregulates the ERα signaling via stress-mediated p38 activation and H3K27me3-mediated epigenetic regulation. The finding that the matrix stiffness is a central cue to the ERα phenotype reveals a mechanobiological component in breast tissue hormonal signaling and enables the development of novel therapeutic interventions. Subject terms: ER-positive (ER + ), breast cancer, ex vivo model, preclinical model, PDEC, stiffness, p38 SAPK.

Abstract 2966: Novel ex vivo model for ERα positive breast cancer

Three-dimensional ex vivo cultures from patient-derived tumor tissue offer new opportunities for drug development and personalized treatment of cancer. However, one of the main challenges in establishing a tumor type faithful ex vivo tissue culture system is in optimization of biochemical and physical microenvironment to preserve desired phenotypic features. A collaboration with the Helsinki University Hospital enables us to receive live patient-derived breast cancer tissue samples from most breast cancer surgeries performed in the Southern Finland, typically samples arriving twice a week. Together with a group of materials scientists from Aalto Technical University we have explored seven different 3D culture matrices and defined their biomechanical properties and stiffness values with rheological measurements. Four investigated matrices preserved the luminal CK8+ cell phenotype of the luminal cancers they derived from, whereas rest of the matrices that included commonly used Matrigel and collagen scaffolds promoted a switch in the cell identity from luminal CK8+ to basal CK14+ phenotype. Furthermore, the genetic expression profiles examined with NGS corresponded to observed phenotypic switch. We noticed significant species-specific differences between mouse mammary and human breast samples in their morphology, phenotypic responses and ERα+ preservation to microenvironmental matrix stiffness. Furthermore, a combination of scaffold stiffness and composition of biochemical matrix constituency is required for long-term maintenance of ERα+ luminal tumour phenotype. Therefore, both physical properties and composition of the microenvironment need to be optimized for maintenance of breast tumor type specific phenotype and genetic profiles of ex vivo tumor explant cultures.

Citation Format: Pauliina M. Munne, Lahja Martikainen, Iiris Räty, Kia Bertula, Nonappa Nonappa, Aino Peura, Minna Mutka, Marjut Leidenius, Tuomo Meretoja, Panu Kovanen, Johanna Mattson, Paivi Heikkila, Heikki Joensuu, Olli Ikkala, Juha T. Klefstrom. Novel ex vivo model for ERα positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2966.

Breast reconstruction after breast cancer surgery - persistent pain and quality of life 1-8 years after breast reconstruction

OBJECTIVES

To assess the long-term outcome of breast reconstructions with special focus on chronic postsurgical pain (CPSP) in a larger cohort of breast cancer survivors.

METHODS

A cross-sectional study on 121 women with mastectomy and breast reconstruction after mean 2 years 4 months follow up. The mean time from breast reconstruction to the follow-up visit was 4 years 2 months. We studied surveys on pain (Brief Pain Inventory, BPI and Douleur Neuropathique 4, DN4), quality of life (RAND-36 health survey), sleep (insomnia severity questionnaire, ISI), mood (Beck's Depression Index, BDI; Hospital Anxiety and Depression Scale, HADS), and a detailed clinical sensory status. Patients were divided into three groups: abdominal flap (Deep inferior epigastric perforator flap, DIEP; Free transverse rectus abdominis flap, fTRAM, and Pedicled transverse rectus abdominis flap, pTRAM), dorsal flap (Latissimus dorsi flap, LD and Thoracodorsal artery perforator flap, TDAP), and other (Transverse myocutaneous gracilis flap, TMG; implant). Clinically meaningful pain was defined ≥ 4/10 on a numeric rating scale (NRS). We used patients' pain drawings to localize the pain. We assessed preoperative pain NRS from previous data.

RESULTS

106 (87.6%) of the patients did not have clinically meaningful persistent pain. We found no statistically significant difference between different reconstruction types with regards to persistent pain (p=0.40), mood (BDI-II, p=0.41 and HADS A, p=0.54) or sleep (p=0.14), respectively. Preoperative pain prior to breast reconstruction surgery correlated strongly with moderate or severe CPSP.

CONCLUSIONS

Moderate to severe CPSP intensity was present in 14% of patients. We found no significant difference in the prevalence of pain across different reconstruction types. Preoperative pain associated significantly with postoperative persistent pain.

The role of polygenic risk and susceptibility genes in breast cancer over the course of life

Polygenic risk scores (PRS) for breast cancer have potential to improve risk prediction, but there is limited information on their utility in various clinical situations. Here we show that among 122,978 women in the FinnGen study with 8401 breast cancer cases, the PRS modifies the breast cancer risk of two high-impact frameshift risk variants. Similarly, we show that after the breast cancer diagnosis, individuals with elevated PRS have an elevated risk of developing contralateral breast cancer, and that the PRS can considerably improve risk assessment among their female first-degree relatives. In more detail, women with the c.1592delT variant in PALB2 (242-fold enrichment in Finland, 336 carriers) and an average PRS (10–90^th percentile) have a lifetime risk of breast cancer at 55% (95% CI 49–61%), which increases to 84% (71–97%) with a high PRS ( > 90^th percentile), and decreases to 49% (30–68%) with a low PRS ( < 10^th percentile). Similarly, for c.1100delC in CHEK2 (3.7–fold enrichment; 1648 carriers), the respective lifetime risks are 29% (27–32%), 59% (52–66%), and 9% (5–14%). The PRS also refines the risk assessment of women with first-degree relatives diagnosed with breast cancer, particularly among women with positive family history of early-onset breast cancer. Here we demonstrate the opportunities for a comprehensive way of assessing genetic risk in the general population, in breast cancer patients, and in unaffected family members.

Identifying women at high risk of breast cancer has important implications for screening. Here, the authors demonstrate that polygenic risk scores improve breast cancer risk prediction in the population, in women with mutations in high-risk genes and in women with close relatives with the disease.

[Inflammations of the mammary gland]

Breast inflammation, i.e. mastitis is an entity with a variable etiology and severity, typically affecting women of fertile age. In most cases, anamnesis reveals the etiology of the disease, bacterial puerperal mastitis associated with breastfeeding being the most common. Periductal mastitis is a breast inflammation typically associated with smoking in women of 40 to 50 years of age, localized to the region of the areola. Granulomatous mastitis and other rare breast inflammations usually require specialized care. Regardless of etiology, treatment of acute inflammation depends on the clinical picture and, with the exception of puerperal mastitis, emergency ultrasound imaging is often necessary in order to detect an abscess and drain it. In all cases of mastitis, the possibility of underlying malignancy as well as inflammatory breast cancer should be kept in mind. If specialized care is required, breast inflammation is treated in a breast, general or plastic surgery unit.

Breast cancer prognosis and isolated tumor cell findings in axillary lymph nodes after core needle biopsy and fine needle aspiration cytology: Biopsy method and breast cancer outcome

BACKGROUND

It is unknown whether performing a core needle biopsy (CNB) to diagnose breast cancer increases the incidence of isolated tumor cells (ITC) in the axillary sentinel lymph nodes.

METHODS

Patients diagnosed with unilateral invasive pT1 breast cancer (≤2 cm in diameter, n = 1525) at a single center between February 2001 and August 2005 were included in this prospective observational cohort study. The patients were categorized into two groups according to the type of the preoperative breast needle biopsy performed, the CNB and the fine needle aspiration cytology (FNAC) groups, and followed up for a median of 9.5 years after breast surgery.

RESULTS

868 (56.9%) patients had FNAC and 657 (43.2%) CNB. In the subset of patients with no axillary metastases (pN0, n = 1005) 70 patients had ITC, 37 (4.3%) out of the 546 patients in FNAC group and 33 (5.0%) out of the 459 patients in the CNB group (p = 0.798). The type of tumor biopsy did not influence breast cancer-specific survival (p = 0.461) or local recurrence-free survival (p = 0.814) in univariable survival analyses. Overall, survival favored the CNB group in a univariable analysis, but no difference in survival emerged in a multivariable analysis (p = 0.718).

CONCLUSIONS

CNB was not associated with a greater incidence of ITC in axillary lymph nodes as compared with FNAC, and did not have an adverse effect on survival outcomes in a patient population treated with modern adjuvant therapies.

[Breast lump in a young woman]

While a breast lump in a young woman is almost always benign, the lump may also be caused by breast cancer and rare malignant tumors. Factors increasing the risk of breast cancer, and especially the family history in respect of breast cancer and ovarian cancer should be mapped out from the anamnesis. Clinical examination of both breasts and lymph node regions is carried out in a systematic manner. Benignity of the lump must in all cases be confirmed by imaging and when necessary, by taking a core needle biopsy. Among the benign tumors of the breast, only a small symptomless fibroadenoma confirmed by core needle biopsy does not require an assessment by a surgeon.

Demand for plastic surgical operations after primary breast cancer surgery

BACKGROUND AND AIMS

The aim of this study is to evaluate the demand for plastic operations after primary breast cancer surgery. In addition, this study aims to increase knowledge on factors affecting the wish of women for breast reconstruction.

MATERIAL AND METHODS

A questionnaire was sent to some 111 patients who had undergone either mastectomy or breast conserving surgery. The response rate was 76%. The questionnaire consisted of 20 structured questions. The data was analysed statistically using the t test and the chi-square test.

RESULTS

28% of the mastectomized patients wanted a breast reconstruction. Factors found to affect the patient's wish for reconstruction were age (p < 0.001) and whether the patient had received radio- (p < 0.05) or chemotherapy (p < 0.05). A difference was found between the mastectomy group and the breast conserving surgery group as to satisfaction in the general (p < 0.05) and the cosmetic (p < 0.05) outcome of the surgery, as well as patient's expectations regarding the outcome (p < 0.01).

CONCLUSIONS

Rather fewer mastectomized patients wanted a reconstruction. The proportion, however, grew significantly larger in the younger age groups. This study also shows that receiving radio- or chemotherapy seems to predict a woman's choice against a reconstruction. Patients who receive radio- or chemotherapy may consider their illness more severe and life-threatening than those not receiving such treatments.

Cytogenetic effects of styrene and styrene oxide

Styrene and styrene oxide induce various cytogenetic effects, similar in both human lymphocytes in vitro and onion root-tip cells in vivo. Styrene appears to cause chromosome breakage in both systems, and in Allium it shows a strong c-mitotic effect. Styrene oxide, on the other hand, seems to destroy the tertiary folding of the chromatin. Cytotoxicity of styrene oxide is very high (complete mitotic inhibition occurs on 0.03% v/v) in human lymphocytes, whereas, in Allium, styrene is slightly more toxic than styrene oxide. Styrene glycol, a further metabolite of styrene oxide, does not cause mitotic inhibition.

Partial characterization of amyloid proteins in inherited amyloidosis with lattice corneal dystrophy and in secondary amyloidosis

Amyloid fibrils isolated from two patients, one with inherited systemic amyloidosis and lattice corneal dystrophy, and the other with secondary amyloidosis due to chronic glomerulonephritis, were studied using immunologic, electrophoretic and chromatographic techniques. Amino acid hydrolysates of both amyloid types showed a high proportion of acidic and aliphatic amino acid residues but were non-identical in the overall amino acid composition. The preparations also contained 12--16% lipids. Guanidine hydrochloride denaturated amyloid fibrils of both types were resolved into four fractions in Sepharose 6B chromatography with molecular weights of ca. 160 000, 45 000, 20 000 and 8 000. The 160 000 mol. wt. fraction predominated in the chromatograms of inherited amyloid protein and was further resolved into two main fractions of 17 000 and 15 000 mol. wt. in sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. None of these fractions from inherited amyloid protein showed immunologic identity with tissue-derived amyloid protein A (AA) whereas all four fractions from secondary amyloid reacted against anti-AA antiserum. The three major Sepharose 6B fractions of secondary amyloid fibrils were resolved into a 25 000 mol. wt. fraction in SDS-polyacrylamide gel electrophoresis without urea but into a 12 000 mol. wt. fraction in gels containing 8M urea after more drastic dissolving conditions of the fibrils.

Mutagenicity and toxicity of amitrole. II. Human lymphocyte culture tests

Effects of amitrole (3-amino-1,2,4-triazole) on human leucocytes in culture were investigated. Amitrole interfered with lymphoblast transformation and inhibited cell growth in concentrations of 0.2% w/v and higher. Selected metaphases were examined for the presence of chromosome and chromatid aberrations. No clastogenic effects were observed.

Mutangenicity and toxicity of amitrole. I. Drosophila tests

Amitrole was highly toxic at early larval stages of Drosophila (LD50 is 40 ppm in medium). Toxicity of amitrole was also revealed by prolongation of development time even at 10 ppm. However, no mutagenic effects of amitrole were observed either in the sex chromosome non-disjunction test (females reared on medium containing amitrole at 10 ppm) or in the sex-linked recessive lethal test (males reared on medium containing amitrole at 10 ppm).

Mutagenicity and toxicity of amitrole. III. Microbial tests

Amitrole (3-amino-1,2,4-triazole) inhibits bacterial growth both in Escherichia coli and Salmonella typhimurium at a concentration of 0.5% in minimal medium. Repression of growth already occurs at a concentration of 0.1% of amitrole in this medium. In complete medium the bacteria tolerate concentrations of amitrole as high as 1.7-2.4% before growth ceases. Mutagenicity was tested by differential growth comparisons on E. coli strains W 3110 thy pol A1, defective in DNA polymerase I, and its revertant pol A+. Known mutagens (MMS, NTG, mitomycin C) were used as positive controls. Analogous negative results were also obtained in a revertant test when several trp mutant strains of Salmonella were used.