Gastric Cancer in BRCA1 Germline Mutation Carriers: Results of Endoscopic Screening and Molecular Analysis of Tumor Tissues

INTRODUCTION

There is some evidence suggesting a link between BRCA1/2 germline mutations and increased risk of gastric cancer.

METHODS

Endoscopic screening for stomach malignancies was performed in 120 BRCA1 mutation carriers in order to evaluate the probability of detecting the tumor disease.

RESULTS

No instances of gastric cancer were revealed at the first visit. The analysis of atrophic changes performed by OLGA (Operative Link for Gastritis Assessment) criteria revealed that OLGA stages I-IV alterations were observed in 26 of 41 (63%) subjects aged >50 years as compared to 29 of 79 (37%) in younger subjects (p = 0.007, χ2 test). One BRCA1 mutation carrier developed gastric cancer 4 years after the first visit for endoscopic examination. We performed next-generation sequencing analysis for this tumor and additional 4 archival gastric cancers obtained from BRCA1/2 mutation carriers. Somatic loss of the remaining BRCA1/2 allele was observed in 3 out of 5 tumors analyzed; all of these carcinomas, but none of the malignancies with the retained BRCA1/2 copy, showed chromosomal instability.

CONCLUSION

Taken together, these data justify further studies on the relationships between the BRCA1/2 and gastric cancer.

Frequency and spectrum of founder and non-founder BRCA1 and BRCA2 mutations in a large series of Russian breast cancer and ovarian cancer patients

BACKGROUND

The spectrum of BRCA1 and BRCA2 mutations in Slavic countries is characterized by a high prevalence of founder alleles.

METHODS

We analyzed a large data set of Russian breast cancer (BC) and ovarian cancer (OC) patients, who were subjected to founder mutation tests or full-length BRCA1 and BRCA2 analysis.

RESULTS

The most commonly applied test, which included four founder mutations (BRCA1: 5382insC, 4153delA, 185delAG; BRCA2: 6174delT), identified BRCA1 or BRCA2 heterozygosity in 399/8533 (4.7%) consecutive BC patients, 230/2317 (9.9%) OC patients, and 30/118 (25.4%) women with a combination of BC and OC. The addition of another four recurrent BRCA1 mutations to the test (BRCA1 C61G, 2080delA, 3819del5, 3875del4) resulted in evident increase in the number of identified mutation carriers (BC: 16/993 (1.6%); OC: 34/1289 (2.6%); BC + OC: 2/39 (5.1%)). Full-length sequencing of the entire BRCA1 and BRCA2 coding region was applied to 785 women, very most of whom demonstrated clinical signs of BRCA-driven disease, but turned out negative for all described above founder alleles. This analysis revealed additional BRCA1 or BRCA2 mutation carriers in 54/282 (19.1%) BC, 50/472 (10.6%) OC, and 13/31 (42%) BC + OC patients. The analysis of frequencies of founder and "rare" BRCA1 and BRCA2 pathogenic alleles across various clinical subgroups (BC vs. OC vs. BC + OC; family history positive vs. negative; young vs. late-onset; none vs. single vs. multiple clinical indicators of BRCA1- or BRCA2-associated disease) revealed that comprehensive BRCA1 and BRCA2 analysis increased more than twice the number of identified mutation carriers in all categories of the examined women.

CONCLUSION

Full-length BRCA1 and BRCA2 sequencing is strongly advised to Slavic subjects, who have medical indications for BRCA1 and BRCA2 testing but are negative for recurrent BRCA1 and BRCA2 mutations.

[Difficulties and mistakes in the diagnosis of abdominal tuberculosis in the practice of the general practitioner]

The relevance of the research is determined by the growth of cases of abdominal tuberculosis (AT), which is difficult to diagnose.

AIM

Identify clinical features and possibilities of timely AT diagnosis.

MATERIALS AND METHODS

Medical reports of 116 AT patients. The results of clinical, microbiological, immunological, radiological, endoscopic and morphological studies were analyzed.

THE RESULTS

AT proceeded under the mask of ulcerative colitis and Crohn's disease (26.3%), alcoholic and biliary hepatitis (11.8%), lymphoproliferative and oncological diseases (61.8%), often generalized against the background of HIV-infection. The duration of the diagnostic search for disease verification exceeded 3 months due to incorrect (erroneous) interpretation of intoxication (26.3%) and radiological pattern in the lungs (23.7%), non - application and late application of laparoscopy (39.5%).

CONCLUSION

When diagnosing AT, it is necessary to consider the peculiarities of its clinic and to conduct timely laparoscopy.

Abstract P3-01-18: Determining the need for axillar lymph node dissection based on pre-neoadjuvant chemotherapy sentinel lymph node biopsy results

An open-label single institution study of sentinel lymph node biopsy prior to neoadjuvant chemotherapy is conducted in the N.N. Petrov research institute of oncology. So far 30 patients with locally advanced breast carcinoma (T2-4N0) were included. Mammography, breast US and SPECT are performed prior to hospitalization so as core biopsy with subsequent IHC staining to determine the levels of ER, PR, KI67 and HER2. Sentinel lymph node biopsy with the use of radiocompound is performed prior to the first cycle of neoadjuvant chemotherapy. Patients receive 4 to 6 cycles with response evaluation after cycles 2, 4 and 6 (same evaluations as at the baseline). Axillary lymph node dissection is later performed along with the definitive surgery of the primary.

Interim analysis showed: 3 of 30 patients with cN0 were node positive after sentinel lymph node biopsy, 27 were node-negative (sn)pN0. All patients with (sn)pN0 completed neoadjuvant chemotherapy with clinical response. No cases of upfront progression were detected. All patients (sn)pN0 underwent axillary dissection upon completion of the neoadjuvant therapy. No cases of nodal involvement were detected (ypN0). All of the patients considered node-positive after sentinel biopsy also underwent lymph node dissection after completion of the neoadjuvant therapy. 2 of them were pN1 and one was pN2.

Conclusion: sentinel lymph node biopsy in cN0 patients prior to neoadjuvant chemotherapy allows to determine a category of patients ((sn)pN0) in whom axillary dissection can be avoided, provided they remain clinically node-negative at the time of definitive surgery.

Citation Format: Semiglazov VF, Krivorotko PV, Zhiltsova EK, Dashayan GA, Zernov KU, Bessonov AA, Trufanova ES, Tabagua TT, Ivanova OA, Kanaev SV, Novikov SN, Krzivickiyi PI, Brayanceva ZV, Komayachov AV, Nikolaev KS, Gigolaeva LP. Determining the need for axillar lymph node dissection based on pre-neoadjuvant chemotherapy sentinel lymph node biopsy results [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-18.

[CHEK2-associated hereditary breast cancer]

CHEK2 is classified as a moderate-penetrance gene for hereditary breast cancer (BC). In Russia, CHEK2 mutations hold second position in the list of BC-predisposing gene defects after BRCAl, and include CHEK2 1100deIC, de15395, and IVS2+lG>A gene-inactivating alleles. CHEK2-driven breast carcinomas are generally characterized by poor prognosis and low sensitivity to the conventional therapeutic regimens. CHEK2 testing needs to be incorporated into routine clinical practice owing its overt clinical significance.

Development of breast tumors in CHEK2, NBN/NBS1 and BLM mutation carriers does not commonly involve somatic inactivation of the wild-type allele

Somatic inactivation of the remaining allele is a characteristic feature of cancers arising in BRCA1 and BRCA2 mutation carriers, which determines their unprecedented sensitivity to some DNA-damaging agents. Data on tumor-specific status of the involved gene in novel varieties of hereditary breast cancer (BC) remain incomplete. We analyzed 32 tumors obtained from 30 patients with non-BRCA1/2 BC-associated germ-line mutations: 25 women were single mutation carriers (7 BLM, 15 CHEK2 and 3 NBN/NBS1) and 5 were double mutation carriers (2 BLM/BRCA1, 1 CHEK2/BLM, 1 CHEK2/BRCA1 and 1 NBN/BLM). Losses of heterozygosity affecting the wild-type allele were detected in none of the tumors from BLM mutation carriers, 3/18 (17 %) CHEK2-associated BC and 1/4 (25 %) NBN/NBS1-driven tumors. The remaining 28 BC were subjected to the sequence analysis of entire coding region of the involved gene; no somatic mutations were identified. We conclude that the tumor-specific loss of the wild-type allele is not characteristic for BC arising in CHEK2, NBN/NBS1 and BLM mutation carriers. Rarity of "second-hit" inactivation of the involved gene in CHEK2-, NBN/NBS1- and BLM-associated BC demonstrates their substantial biological difference from BRCA1/2-driven cancers and makes them poorly suitable for the clinical trials with cisplatin and PARP inhibitors.

[HER2-positive breast cancer: standard and double targeted therapy]

Neoadjuvant systemic therapy is frequently used option for the systemic treatment for breast cancer. Inclusion in the regimen of targeted drugs as trastuzumab (Herceptin) and pertuzumab significantly improves outcomes in HER2-positive breast cancer patients. A certain part of HER2-positive patients can be cured by using only targeted drugs without chemotherapy.

[The role of nanotechnology in creating novel antitumor agents]

Nanobiotechnology, defined as an arm of a nano-system is a rapidly developing area of medicine. Nanomaterials ranging from 1 to 1000 nm in size offer unique advantages of interaction with biological systems on the molecular level. Nanobiotechnologies can be used in definition, diagnosis and treatment of cancer thus leading to the new development of a new discipline--nanooncology. The potential of nanoparticles to be used in in-vivo tumor visualization, biomolecular profiling of tumor growth factors and targeted drug delivery is being studied. These methods stemming from nanotechnology may soon find a broad application in oncology.