Uptake and Effectiveness of Risk-Reducing Surgeries in Unaffected Female BRCA1 and BRCA2 Carriers: A Single Institution Experience in the Czech Republic.

Unnafected female carriers of BRCA1 and BRCA2 pathogenic/likely pathogenic variants (P/LPVs) are at higher risk of breast cancer (BC) and ovarian cancer (OC). In the retrospective single-institution study in the Czech Republic, we analyzed the rate, longitudinal trends, and effectiveness of prophylactic risk-reducing mastectomy (RRM) and risk-reducing salpingo-oophorectomy (RRSO) on the incidence of BC and OC in BRCA1/2 carriers diagnosed between years (y) 2000 to 2020. The study included 496 healthy female BRCA1/2 carriers. The median follow-up was 6.0 years. RRM was performed in 156 (31.5%, mean age 39.3 y, range 22-61 y) and RRSO in 234 (47.2%, mean age 43.2 y, range 28-64 y) BRCA1/2 carriers. A statistically significant increase of RRM (from 12% to 29%) and RRSO (from 31% to 42%) was observed when comparing periods 2005-2012 and 2013-2020 (p < 0.001). BC developed in 15.9% of BRCA1/2 carriers without RRM vs. 0.6% of BRCA1/2 carriers after RRM (HR 20.18, 95% CI 2.78- 146.02; p < 0.001). OC was diagnosed in 4.3% vs. 0% of BRCA1/2 carriers without vs. after RRSO (HR not defined due to 0% occurrence in the RRSO group, p < 0.001). Study results demonstrate a significant increase in the rate of prophylactic surgeries in BRCA1/2 healthy carriers after 2013 and the effectiveness of RRM and RRSO on the incidence of BC and OC in these populations.

Ex Vivo Vibration Spectroscopic Analysis of Colorectal Polyps for the Early Diagnosis of Colorectal Carcinoma.

Colorectal cancer is one of the most common and often fatal cancers in humans, but it has the highest chance of a cure if detected at an early precancerous stage. Carcinogenesis in the colon begins as an uncontrolled growth forming polyps. Some of these polyps can finally be converted to colon cancer. Early diagnosis of adenomatous polyps is the main approach for screening and preventing colorectal cancer, and vibration spectroscopy can be used for this purpose. This work is focused on evaluating FTIR and Raman spectroscopy as a tool in the ex vivo analysis of colorectal polyps, which could be important for the early diagnosis of colorectal carcinoma. Multivariate analyses (PCA and LDA) were used to assist the spectroscopic discrimination of normal colon tissue, as well as benign and malignant colon polyps. The spectra demonstrated evident differences in the characteristic bands of the main tissue constituents, i.e., proteins, nucleic acids, lipids, polysaccharides, etc. Suitable models for discriminating the three mentioned diagnostic groups were proposed based on multivariate analyses of the spectroscopic data. LDA classification was especially successful in the case of a combined set of 55 variables from the FTIR, FT Raman and dispersion Raman spectra. This model can be proposed for ex vivo colorectal cancer diagnostics in combination with the colonoscopic extraction of colon polyps for further testing. This pilot study is a precursor for the further evaluation of the diagnostic potential for the simultaneous in vivo application of colonoscopic Raman probes.

The potential of chiroptical and vibrational spectroscopy of blood plasma for the discrimination between colon cancer patients and the control group.

Colorectal cancer is one of the most abundant causes of cancer deaths in the world. At an early stage, the established clinical procedures have low reliability and sensitivity. Therefore, we tested a novel approach based on chiroptical methods such as electronic circular dichroism (ECD) and Raman optical activity (ROA). These methods are suitable for detecting slight changes in the 3D structure of chiral biomolecules, some of which may be caused by pathological processes occurring during cancer growth. Fifty-five blood plasma samples were analyzed using the combination of ECD and ROA supplemented by conventional Raman and FT-IR spectroscopy. All obtained spectra were evaluated together by linear discriminant analysis. The accuracy of sample discrimination reached 100% and the subsequent leave-one-out cross-validation resulted in 93% sensitivity and 81% specificity. The achieved results indicate that chiroptical methods supplemented by Raman and FT-IR spectroscopy might be new supporting and minimally invasive tools in the clinical diagnosis of colon cancer.

The minimizing of fluorescence background in Raman optical activity and Raman spectra of human blood plasma.

Raman optical activity (ROA) is inherently sensitive to the secondary structure of biomolecules, which makes it a method of interest for finding new approaches to clinical applications based on blood plasma analysis, for instance the diagnostics of several protein-misfolding diseases. Unfortunately, real blood plasma exhibits strong background fluorescence when excited at 532 nm; hence, measuring the ROA spectra appears to be impossible. Therefore, we established a suitable method using a combination of kinetic quenchers, filtering, photobleaching, and a mathematical correction of residual fluorescence. Our method reduced the background fluorescence approximately by 90%, which allowed speedup for each measurement by an average of 50%. In addition, the signal-to-noise ratio was significantly increased, while the baseline distortion remained low. We assume that our method is suitable for the investigation of human blood plasma by ROA and may lead to the development of a new tool for clinical diagnostics.

Analysis of human blood plasma and hen egg white by chiroptical spectroscopic methods (ECD, VCD, ROA).

Chiroptical methods are widely used in structural and conformational analyses of biopolymers. The application of these methods to investigations of biofluids would provide new avenues for the molecular diagnosis of protein-misfolding diseases. In this work, samples of human blood plasma and hen egg white were analyzed using a combination of conventional and chiroptical methods: ultraviolet absorption/electronic circular dichroism (UV/ECD), Fourier transform infrared absorption/vibrational circular dichroism (FTIR/VCD), and Raman scattering/Raman optical activity (Raman/ROA). For comparison, the main components of these substances--human serum albumin (HSA) and ovalbumin (Ova)--were also analyzed by these methods. The ultraviolet region of the ECD spectrum was analyzed using the CDNN CD software package to evaluate the secondary structures of the proteins. The UV/ECD, FTIR/VCD, and Raman/ROA spectra of the substances were quite similar to those of the corresponding major proteins, while some differences were also detected and explained. The conclusions drawn from the FTIR/VCD and Raman/ROA data were in good agreement with the secondary structures calculated from ECD. The results obtained in this work demonstrate that the chiroptical methods used here can be applied to analyze not only pure protein solutions but also more complex systems, such as biological fluids.