Rubens Silveira de Lima

Oncoplastic principles in breast conserving surgery.

Oncoplastic surgery (OP) represents a major advance in breast cancer surgery. It is based on three principles: ideal oncology surgery with free margins and adequate local control of disease, immediate breast reconstruction and symmetry, with the transposition of plastic surgery techniques into breast cancer surgery. Its original focus was to improve the quality of life of patients undergoing oncological treatments that can be more effective from the aesthetic-functional point of view than the traditional breast conserving techniques. As it happens with all changes of paradigms, it brings new challenges for the traversal formation of all involved in the treatment of breast cancer. Besides that, it opens to new perspectives of surgical research related to the aesthetic results, quality of life and local control, as well as optimization of operative timing and reduction of both adverse effects and costs. The aim of this review was to present the principles of this approach and the main techniques applied, evaluating its indications and limits in conservative breast cancer surgery.

Genetic and epigenetic alterations in sentinel lymph nodes metastatic lesions compared to their corresponding primary breast tumors

The accumulation of genetic and epigenetic changes plays a pivotal role in tumor development and progression. In this study, we investigated these changes using comparative genomic hybridization and bisulfite polymerase chain reaction analysis for CpG island hypermethylation of the following genes: TP16, THBS2, E-Cadherin (ECAD), RARbeta2, MINT1, MINT2, and MINT31 in six paired primary breast tumors and their matched sentinel lymph nodes (SLN). The most frequent chromosomal alterations observed were the following: losses of 6q13 approximately q23 and 13q13 approximately q32 and gains of 9q31 approximately qter, 11p15 approximately q21, 12q23 approximately qter, and 20q12 approximately qter. Gain of 6p21 approximately pter was observed in the SLN but in none of the primary tumors. Overall, 71% (30/42) of the methylation measurements were identical between the primary tumors and the SLN. Of the six cases, two showed no differences between the primary tumors and SLN, one tumor with 4 of 7 genes hypermethylated in the primary tumor showed loss of all four hypermethylation events in the SLN, and the remaining three tumors showed loss of one methylation event and simultaneous gain of one to two methylation changes in the SLN. This is the first study reporting genetic and epigenetic alterations in breast sentinel lymph nodes compared to their corresponding primary tumors. Characterization of such alterations may lead to identification of initial events associated with the metastatic dissemination process.

Genetic polymorphisms in oestrogen metabolic pathway and breast cancer: a positive association with combined CYP/GST genotypes.

The cytochrome P450 family (CYPs) and the glutathione S-transferase (GSTs) enzymes play an important role in the metabolism of environmental carcinogens and of oestrogen and can affect breast cancer risk. In this study we examine the role of the genes CYP1A1, CYP17, CYP2D6, GSTM1, GSTP1 and GSTT1 in breast cancer risk in Brazilian women. The study population consisted of 102 incident breast cancer cases and 102 healthy controls. Genotyping analyses were performed by PCR-based methods. A significant finding was observed between GSTP1 Ile-Val polymorphism and breast cancer risk (OR = 1.81; CI 95% = 1.04–3.16). A significant association was observed between women with 0–2 risk genotypes and those with 4 or more risk genotypes (OR = 2.42; CI 95% = 1.13–5.18) when the potential combined effects of the risk genotypes were examined. No significant differences between cases and controls were found correlating the genotypes and the clinical-histopathological parameters. In conclusion, in our population only GSTP1 was associated with breast cancer risk. However, when the genes were tested in combination, a significant association in the breast cancer risk was observed.

Amplification of the BP1 homeobox gene in breast cancer

The homeobox gene BP1 is expressed in over 80% of breast cancers and is associated with tumor progression and invasion. However, the mechanism of BP1 activation in these tumors remains unknown. Therefore our aim in this study is to assess the amplification status of the BP1 gene in breast cancer and to determine whether BP1 protein expression is caused by gene amplification in these tumors. BP1 amplification and expression were assessed in 36 samples. Twenty primary breast tumors (PBT) and 14 sentinel lymph node (SLN) metastases were analyzed using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Because of the close proximity of BP1 and HER2/NEU genes on 17q, correlation between their amplification/expression was also investigated. Increased BP1 copy number was observed in 33% of the cases, with a frequency of 36% and 29% in the PBT and SLN metastasis, respectively. BP1 protein was expressed in 91% of the samples: in all of the PBT with increased BP1 copy number and 65% of PBT with normal copy number. HER2/NEU amplification was detected in 22% of the cases. Concordance between BP1 and HER2/NEU copy numbers was found in 68% of the PBT and 90% of the SLN metastasis. In conclusion, we demonstrated that the BP1 homeobox gene is amplified in breast cancer, both in PBT and SLN metastasis, with a significant correlation with HER2/NEU amplification. Considering that BP1 expression was observed in cases with both increased and normal BP1 copy number, we conclude that other mechanisms in addition to gene amplification play a role in BP1 protein expression.

Comprehensive cytogenetic evaluation of a mature ovarian teratoma case

Mature ovarian teratomas are benign ovarian germ cell tumors that usually present with a normal karyotype. There are very few reports describing chromosomal abnormalities in these tumors, none of which are recurrent. In this study we report on a mature teratoma case with clonal chromosomal alterations which include monosomies of chromosomes 6, 14, 16, and 21; trisomies of chromosomes 14 and 21; and deletions of Xq, 5p, 16p, and 17p. Comparative genomic hybridization evaluation of the sample revealed a normal profile. These findings are discussed together with the cytogenetic reports on other cases of ovarian teratomas described in the literature.

Clonal chromosomal alterations in fibroadenomas of the breast.

A cytogenetic study on short-term cell cultures from 10 fibroadenomas of the breast is reported. Clonal chromosomal alterations were observed in all cases analyzed, involving preferentially chromosomes X, 12, 14, 20, and 22. Normal karyotypes were found in 34.9% of the cells. The present findings are discussed together with the reports on fibroadenomas and other benign lesions of the breast described in the literature. Although no specific chromosome abnormality to date can be attributed to a particular type of benign breast pathology, some recurrent alterations are starting to emerge and may characterize these benign breast lesions, differentiating them from their malignant counterparts.

Copy number variation in ACHE/EPHB4 (7q22) and in BCHE/MME (3q26) genes in sporadic breast cancer

Gene amplifications and deletions are common changes in human cancer cells. Previous studies indicate that the regions, where the ACHE (7q22) and BCHE (3q26.1-q26.2) genes are localized, are suffering such structural modifications in breast cancer. Therefore, the products of these genes, acetylcholinesterase and butyrylcholinesterase, respectively, are related to the process of cell differentiation and proliferation, as well as apoptosis. This study also included two other genes involved in tumorigenesis, the EPHB4 (7q22.1) and MME (3q21-27). The aim of this study was to verify amplification and/or deletion in the ACHE, BCHE, EPHB4 and MME genes in 32 samples of sporadic breast cancer. The gene alterations were detected using real-time PCR and determined by relative quantification with the standard curve method. All samples presented genetic alterations, showing a higher tendency for amplification of the ACHE (62.5% vs. 37.5%; p>0.1) and EPHB4 (53.13% vs. 46.88%; p>0.5) genes, and for deletions of the BCHE and MME genes (56.25% vs. 43.75% for both; p>0.5). A positive correlation was found between alterations in ACHE-EPHB4 and BCHE-MME pairs (r(s) = 0.5948; p = 0.0004; r(s) = 0.3581; p = 0.0478, respectively) indicating that these changes comprise a wide region. In conclusion, the results suggest that these genomic regions may contain important genes for this pathology, such as the oncogenes MET (7q31) and PIK3CA (3q26), and thus being interesting targets for future studies in breast cancer research.

Increased copy number of the DLX4 homeobox gene in breast axillary lymph node metastasis.

DLX4 is a homeobox gene strongly implicated in breast tumor progression and invasion. Our main objective was to determine the DLX4 copy number status in sentinel lymph node (SLN) metastasis to assess its involvement in the initial stages of the axillary metastatic process. A total of 37 paired samples of SLN metastasis and primary breast tumors (PBT) were evaluated by fluorescence in situ hybridization, quantitative polymerase chain reaction and array comparative genomic hybridization assays. DLX4 increased copy number was observed in 21.6% of the PBT and 24.3% of the SLN metastasis; regression analysis demonstrated that the DLX4 alterations observed in the SLN metastasis were dependent on the ones in the PBT, indicating that they occur in the primary tumor cell populations and are maintained in the early axillary metastatic site. In addition, regression analysis demonstrated that DLX4 alterations (and other DLX and HOXB family members) occurred independently of the ones in the HER2/NEU gene, the main amplification driver on the 17q region. Additional studies evaluating DLX4 copy number in non-SLN axillary lymph nodes and/or distant breast cancer metastasis are necessary to determine if these alterations are carried on and maintained during more advanced stages of tumor progression and if could be used as a predictive marker for axillary involvement.

Clonal Karyotypic Abnormalities in Gynecomastia

Gynecomastia is a benign condition that frequently occurs in the male breast gland; however, the cytogenetic data on this entity are very limited. To our knowledge, three cases have been reported in the literature, and the only one with an abnormal karyotype had a concomitant breast carcinoma. In this study we report clonal chromosomal alterations in a gynecomastia sample without any signs of adjacent malignant tissue. The nonrandom abnormalities observed were a deletion of 12p, monosomies of chromosomes 9, 17, 19, and 20, and the presence of a marker chromosome. Most of these alterations have been previously described in the literature in other breast lesions, including benign and malignant (male and female) tumors, indicating their recurrence and nonrandomness in abnormal processes of the mammary gland.

Lack of association between LOH in the 9p region and clinicopathologic parameters in primary breast cancer

Previous studies have suggested the involvement of the 9p region in the genesis and progression of several types of cancer. To perform a more in-depth investigation of the 9p region in samples from breast carcinomas, we analyzed loss of heterozygosity (LOH) in 230 patients with primary breast cancer using five microsatellite markers spanning a genomic region of approximately 16.2 megabases. Genomic DNA was obtained from frozen tumor tissue, and peripheral blood was used as a normal reference. Among all samples, 171 (74%) were informative for at least 1 marker and 44 (25.73%) showed LOH. The LOH rates detected for all markers ranged from 10.29% (D9S169) to 15.97% (D9S1749). Among the informative cases for intragenic markers D9S1748 (CDKN2A) and D9S1749 (MTAP), we noticed a concordant loss of 90% (9/10). Associations between LOH frequencies and clinicopathologic parameters were found between marker D9S200 and tumor grade (P < 0.05), and between marker D9S1748 and estrogen receptor (ER) status (P < 0.05). In conclusion, our results agree with other data from the literature that point to LOH as a secondary mechanism of tumor suppressor inactivation on 9p in breast cancer, showing lower frequencies than those observed in other types of cancer. On the other hand, our results point to an interesting association between the concordant loss of genes CDKN2A and MTAP, which was not sufficiently explored in primary breast cancer.