Diagnosing molecular subtypes of breast cancer by means of Raman spectroscopy

OBJECTIVES

Raman spectroscopy has been used to discriminate human breast cancer and its different tumor molecular subtypes (luminal A, luminal B, HER2, and triple-negative) from normal tissue in surgical specimens.

MATERIALS AND METHODS

Breast cancer and normal tissue samples from 31 patients were obtained by surgical resection and submitted for histopathology. Before anatomopathological processing, the samples had been submitted to Raman spectroscopy (830 nm, 25 mW excitation laser parameters). In total, 424 Raman spectra were obtained. Principal component analysis (PCA) was used in an exploratory analysis to unveil the compositional differences between the tumors and normal tissues. Discriminant models were developed to distinguish the different cancer subtypes by means of partial least squares (PLS) regression.

RESULTS

PCA vectors showed spectral features referred to the biochemical constitution of breast tissues, such as lipids, proteins, amino acids, and carotenoids, where lipids were decreased and proteins were increased in breast tumors. Despite the small spectral differences between the different subtypes of tumor and normal tissues, the discriminant model based on PLS was able to discriminate the spectra of the breast tumors from normal tissues with an accuracy of 97.3%, between luminal and nonluminal subtypes with an accuracy of 89.9%, between nontriple-negative and triple-negative with an accuracy of 94.7%, and each molecular subtype with an accuracy of 73.0%.

CONCLUSION

PCA could reveal the compositional difference between tumors and normal tissues, and PLS could discriminate the Raman spectra of breast tissues regarding the molecular subtypes of cancer, being a useful tool for cancer diagnosis.

Substantial Reduction in Adjuvant Chemotherapy With the Use of the 21-Gene Test to Manage Early Breast Cancer in a Public Hospital in Brazil

We evaluated the impact of 21-gene test results on treatment decisions for patients with early-stage breast cancer treated under the public health care system in Brazil, Sistema Único de Saúde.

Abstract P4-03-04: Stereotactic vaccum-assisted breast biopsy: A cost effective diagnostic method for suspicious calcifications investigation in Brazil

Background: Mammographic screening carried out in Brazil's Public Health System (SUS) is opportunistic and restricted to large cities mainly in the South and Southeast regions. However, only 30% of the suspicious calcifications are confirmed to be malignancy after the biopsy. The surgical procedure to investigate is still the routine in most centers in Brazil. A vacuum assisted stereotactic biopsy (VASB) is expensive and it is not available in most centers in the developing countries. Objective: To estimate saved values in SUS by performing VASB instead of performing classic surgical procedure in the investigation of suspicious calcifications. Methods: We’ve performed a retrospective and descriptive study from July, 2012 to June, 2019, in which 1,809 patients diagnosed with suspicious calcifications on mammography (BIRADS 4 and 5) had VASB performed at Hospital Estadual Pérola Byington. The device used was Surus Pearl (Hologic, Malbolrough, Massachusetts, USA) with probe gauge 9. The biopsy`s costs were calculated and estimated in terms of American Dollars (US$) in 2019. No direct medical and nonmedical or indirect costs have been evaluated. Results: the histopathological study of the lesions revealed benign alterations in 1,179 (65.1%) The findings were positive for malignancy in 533 (29.5%) and the precursor lesions were diagnosed in 97 (5.4%) VASB is an outpatient procedure; a single biopsy has an average cost of US$ 36. Instead, the classic surgical procedure is a procedure that requires hospitalization and general anesthesia with estimated cost of US$ 97 for every single procedure. The saved values in that time by SUS were US$ 29,077. Conclusion: we found a high economic impact of VASB in the SUS scenario. Lower costs than surgical procedures and being an outpatient procedure may indirectly increase hospital beds` supply for cancer treatment. Studies focusing on other direct and indirect costs are desirable, especially in developing countries.

Keywords: calcifications; vacuum-assisted stereotactic biopsy; breast cancer.

Citation Format: Andressa Amorim, Marcellus N. M. Ramos, Maria Isabela B. A. C. Sawada, André Mattar, Jorge Y. Shida, Luiz H. Gebrim. Stereotactic vaccum-assisted breast biopsy: A cost effective diagnostic method for suspicious calcifications investigation in Brazil [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-03-04.

Abstract P4-03-03: Accuracy of stereotactic vacuum-assisted breast biopsy for investigating suspicious calcifications in 1,809 patients a public hospital in Brazil

Background: The gold standard for breast biopsy procedures is currently an open excision of the suspected lesion. However, an excisional biopsy inevitably makes a scar. The cost and morbidity associated with this procedure has prompted many physicians to evaluate less invasive, alternative procedures. Stereotactic vacuum assisted breast biopsy (VASB) can provide a more accurate diagnosis and completely remove the lesion under real-time ultrasonic guidance. The advantage of complete lesion removal with VASB is to reduce or eliminate sampling error, to decrease the likelihood of a histological underestimation, to decrease imaging-histological discordance, to decrease the re-biopsy rate, and to diminish the likelihood of subsequent growth on follow-up, especially when stereotactic VASB is used to investigate microcalcifications. This method is expensive but cost effective when used to investigate microcalcifications classified as BI-RADS 4 and 5. Objectives: To evaluate the accuracy of VASB in the investigation of suspicious calcifications. Methods: We’ve performed a retrospective study from July, 2012 to June, 2019, in which 1,809 women with suspicious calcifications detected on mammography (BI-RADS 4 and 5) had VASB performed at Hospital Estadual Pérola Byington, a public Hospital in São Paulo, Brazil. The device used was Surus Pearl (Hologic, Malbolrough, Massachusetts, USA), with probe gauge 9. Fragments were obtained and sent to anatomopathological study; a metal clip was placed on the biopsy site. Four groups were analyzed, based on the biopsy results: benign, precursor lesions, Ductal Carcinoma In Situ (DCIS) and malignant. Most patients with positive or discordant cases underwent surgical treatment and the previous biopsy results were compared to surgery results. Results: patients median age was 55y (49-63). Pathology results on VASB and surgery were classified respectively as benign n=1,179 (65.1%), precursor lesions n=97 (5.4%), DCIS n=414 (22.9%) and malignant n=119 (6.6%). Benign and lesion precursor lesions results were clustered to form a new group (lower risk lesions) and so DCIS and malignant lesions (higher risk lesions). ROC curve and AUC were calculated to compare the results of lower and higher risk lesions groups according to VASB and surgery results (AUC=0,642). The X2 test was performed between the groups (p<0,05). The sensitivity of the method was 84.4 %, specificity was 96.1%, false negative rate was 4.5%, positive predictive value (PPV) was 89.8%, negative predictive value (NPV) was 93.8%. Conclusion: the VASB method has a good accuracy to distinguish lower and higher risk lesions groups comparing to the gold standard. It has high predictive value in both benign and malignant lesions, guiding therapeutic planning.

Keywords: Calcifications; Vacuum-assisted stereotactic biopsy; Breast cancer; Diagnosis

Citation Format: Andressa Amorim, Marcellus N. M. Ramos, André Mattar, Maria Isabela B. A. C. Sawada, Jorge Y. Shida, Luiz H. Gebrim. Accuracy of stereotactic vacuum-assisted breast biopsy for investigating suspicious calcifications in 1,809 patients a public hospital in Brazil [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-03-03.

Abstract P3-04-01: The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital

Background: The gold standard for breast biopsy procedures is currently an open excision of the suspected lesion. However, an excisional biopsy inevitably makes a scar. The cost and morbidity associated with this procedure has prompted many physicians to evaluate less invasive, alternative procedures. More recently, image-guided percutaneous core-needle biopsy has become a frequently used method for diagnosing palpable and non-palpable breast lesions. Although sensitivity rates for core-needle biopsy are high, it has the disadvantage of histological underestimation, which renders the management of atypical ductal hyperplasia, papillary lesions, and fibroepithelial lesions somewhat difficult. Stereotactic vacuum assisted breast biopsy (VABB) was developed to overcome some of these negative aspects of core-needle biopsy. VABB allows for a sufficient specimen to be obtained with a single insertion and can provide a more accurate diagnosis and completely remove the lesion under real-time ultrasonic guidance. The advantage of complete lesion removal with VABB is to reduce or eliminate sampling error, to decrease the likelihood of a histological underestimation, to decrease imaging-histological discordance, to decrease the re-biopsy rate, and to diminish the likelihood of subsequent growth on follow-up, especially when stereotactic VABB is used to investigate microcalcifications. This method is expensive but cost effective when used to investigate microcalcifications classified as BI-RADS 4 and 5.

Methodology: We performed a review in 1,354 patients with suspicious mammography microcalcifications, classified as BI-RADS 4 or 5 that were seen in Perola Byington Hospital from July 2012 to July 2017 in São Paulo-Brazil. We have used aHologic Lorad Multicare Platinum Stereotactic Prone Breast Biopsy and a Surus Pearl (Hologic, Malbolrough, Massachusetts, USA), with gauge 9 probe. Four to eight fragments (median of 6) were obtained with the placement of a metal clip in the bed that the biopsy was performed, and histopathological analysis was made.

Results:The histopathological study of the lesions revealed benign alterations in 956 (68%) of our patients. The findings were positive for malignancy in 358 patients (29%) and the precursor lesions were diagnosed in 40 (3%). In 81 cases (5.9%) the findings were discordant. The sensitivity of the method was 84.4%, specificity was 96.1%, false negative rate was 4.5%, positive predictive value (PPV) was 89.8%, negative predictive value (NPV) was 93.8%. In literature review the sensitivity varies 91.5-100%, specificity 81.9-110%, false negative rate 0-3.3%, PPV 92.2-100% and NPV 80.5-99.5%. All patients with positive or discordant cases underwent surgical treatment to increase the margin or complete removal of the lesion. Conclusions: The VABB is an outpatient procedure that avoids hospital admissions for diagnostic elucidation in most of cases suspected of malignancy. It has high predictive value in both benign and malignant lesions, guiding therapeutic planning. In addition to presenting the cost lower than the surgical biopsy it indirect increases the supply of hospital beds for cancer treatment.

Citation Format: Mattar A, Amorim AG, Ramos MdNM, Shida JY, Fonseca GR, Hegg R, Gebrim LH. The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-04-01.

Abstract P2-06-05: p27 Expression in Hormone Sensitive Breast Carcinomas, Prior and after Short Term Hormone Treatment: A Prospective Placebo Double-Blind Study

Background: Mutations in genes that regulate the cell cycle are found in most human cancers. In addition, there are other cell cycle genes, including those encoding p27, that contribute to tumor progression but are rarely mutated. p27 is a member of the Cip/Kip family of cyclin-dependent kinase inhibitors and it is present in high levels in quiescent cells, but its levels decline when cells proliferate in response to mitogenic signals. Various functions have been attributed to p27, including promotion of apoptosis and regulation of drug resistance. p27 is functionally inactivated in most of human cancers through enhanced p27 proteolysis, sequestration by cyclin D/cdk complexes, and by cytoplasmic mislocalization. There is evidence from preclinical studies that p27 is essential for cell cycle arrest by tamoxifen and other antiestrogenic drugs.

Objectives: To compare the expression of nuclear and cytoplasmic p27, cyclin D1, Ki-67, p53, HER2/ErbB2, ER and PR in hormone sensitive invasive ductal carcinomas (IDC) in postmenopausal women, prior and after tamoxifen and anastrozole in a short term treatment. Methods: Seventy one patients were enrolled in this study and fifty-eight were elegible for analyses. All patients had palpable ER-positive IDC (stage II and III) and were double-blind randomized in a prospective placebo controlled study with short term hormone treatment (HT) groups for twenty-six days prior to surgical treatment: Anastrozole 1mg/day (n= 18), Placebo (n=25) and Tamoxifen 20mg/day (n= 15). Pre and post HT samples were disposed in tissue micro array blocks and submitted to immunohistochemical assay. Biomarkers status (nuclear and cytoplasmic p27, cyclin D1, Ki-67, p53, HER2/ErbB2, ER and PR) were obtained comparing each immunohistochemical evaluation of pre and post-surgery samples using semi-quantitative Allred's method for nuclear biomarkers, and scored based on a four-point intensity based system: negative (no stain), weakly positive (1+), mild positive (2+) and strongly positive (3+). Statistical analysis were performed using the GEE (General Estimation Equations) and ANOVA tests with significant p ≥0.05. Results: The patients mean age was 66.25 ± 9.95 years. The mean tumor size was 4.0 ± 1.06 cm. There was no statistically significant correlation between nuclear p27 expression and tumor size or histologic grade. Before HT, 38 (62.5%) patients had positive nuclear p27 expression, 5 (8.6%) patients had positive cytoplasmic p27 expression, and after treatment their expression was increased in all groups. There was a positive correlation between Ki-67, cyclin D1, p53 and nuclear p27 prior to HT. After HT, there was a positive correlation between Ki-67, cyclin D1, p53, HER2/ErbB2, ER, and nuclear p27.

Conclusions: There was an increment of nuclear and cytoplasmic p27 after short term treatment, regardless of the drug used. The positive correlation between nuclear p27 and poor prognostic markers was unexpected.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-05.

Effects of low dose tamoxifen on normal breast tissue from premenopausal women

The aim of this study was to determine the effects of low doses of tamoxifen (5 and 10mg/day) for 50 days compared with the standard dose (20 mg/day) on breast biomarkers measured in normal breast tissue from premenopausal patients. A randomised double-blind study was performed using tissue from 56 premenopausal women with a diagnosis of fibroadenoma of the breast. Excisional biopsy was performed on the 50th day of therapy. Normal breast tissue samples were collected during surgery. The patients were divided in groups: A (placebo, n=11); group B (5 mg, n=16), group C (10 mg, n=14) and group D (20 mg, n=15). In this cross-sectional study, differences in the expression of Oestrogen Receptor alpha (ERalpha), Progesterone Receptor (PR), Ki-67, apoptotic bodies and mitotic index between the different groups after treatment can be seen on the normal breast tissue. We believe that a lower dose of tamoxifen could reduce the side-effects associated with treatment without affecting its chemopreventive activity in the breast.