A working model for the time sequence of genetic changes in breast tumorigenesis

The prognostic significance of co-existence ductal carcinoma in situ in invasive ductal breast cancer: a large population-based study and a matched case-control analysis

Background

To evaluate the prognostic significance of co-existence ductal carcinoma in situ (DCIS) in invasive ductal breast cancer (IDC) compared with pure IDC.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was searched to identify unilateral IDC cases between 2004 and 2015, which were grouped into pure IDC and IDC with DCIS component (IDC-DCIS). Comparisons of the distribution of clinical-pathological characteristics the two groups were performed using Pearson's chi-square. Breast cancer-specific survival (BCSS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared across RS groups using the log-rank statistic. Cox models were fitted to assess the factors independently associated with survival. A 1:1 matched case-control analysis was conducted with each clinical-pathological characteristic matched completely.

Results

A total of 98,097 pure IDC cases (39.6%) and 149,477 IDC-DCIS cases (60.4%) were enrolled. IDC-DCIS patients were presented with less aggressive characteristics such as lower proportion of histologic grade III (34.2% vs. 42.2%, P<0.001), ER negative (16.8% vs. 26.1%, P<0.001) and PR negative (26.5% vs. 35.7%, P<0.001) disease and higher proportion of T1 cases (68.7% vs. 58.2%, P<0.001) compared with pure IDC patients. Co-existence DCIS was an independent prognostic factor for BCSS and OS in the whole cohort. According to the multivariate analysis, it was an independent favorable prognostic factor among ER positive cases, but an independent negative prognostic factor among ER negative cases based on the matched cohort.

Conclusions

Co-existence DCIS showed quite different prognostic significance among ER positive and negative disease.

Accompanying DCIS in breast cancer patients with invasive ductal carcinoma is predictive of improved local recurrence-free survival

BACKGROUND

Ductal carcinoma in situ (DCIS) often accompanies invasive ductal carcinoma (IDC). The presence of co-existing DCIS is postulated to present as a less aggressive phenotype than IDC alone.

PATIENTS AND METHODS

Patients diagnosed with hormone receptor-positive breast cancer receiving mastectomy were evaluated. Only patients without adjuvant radio- and chemotherapy were included to decrease treatment bias on local recurrence (LR).

RESULTS

Of 2239 breast cancer patients, 198 fulfilled the inclusion criteria. The overall LR rate was 11.6%. Tumor stage (p = 0.002), nodal status (pN2 vs. pN0, p = 0.023) and pure IDC compared with IDC-DCIS (p = 0.029) were multivariate independent factors for increased LR risk. Patients with IDC-DCIS were significantly younger (p < 0.001), had smaller tumors (p = 0.001), less lymph node involvement (p = 0.012). The LR rate was significantly increased in patients with pure IDC (p = 0.012). The time to distant metastases was decreased in patients with pure IDC compared with that observed in patients with IDC-DCIS (log rank = 0.030).

CONCLUSION

Invasive ductal carcinoma accompanied by DCIS is associated with lower LR. The prognostic value of co-existing DCIS in the adjuvant decision-making process may be considered a new independent prognostic marker. This finding needs further studies to evaluate its usefulness in premenopausal women.

Gene amplification in ductal carcinoma in situ of the breast

Multiple different biologically and clinically relevant genes are often amplified in invasive breast cancer, including HER2, ESR1, CCND1, and MYC. So far, little is known about their role in tumor progression. To investigate their significance for tumor invasion, we compared pure ductal carcinoma in situ (DCIS) and DCIS associated with invasive cancer with regard to the amplification of these genes. Fluorescence in situ hybridization (FISH) was performed on a tissue microarray containing samples from 130 pure DCIS and 159 DCIS associated with invasive breast cancer. Of the latter patients, we analyzed the intraductal and invasive components separately. In addition, lymph node metastases of 23 patients with invasive carcinoma were included. Amplification rates of pure DCIS and DCIS associated with invasive cancer did not differ significantly (pure DCIS vs. DCIS associated with invasive cancer: HER2 22.7 vs. 24.2%, ESR1 19.0 vs. 24.1%, CCND1 10.0 vs. 14.8%, MYC 11.8 vs. 6.5%; P > 0.05). Furthermore, we observed a high concordance of the amplification status for all genes if in situ and invasive carcinoma of individual patients were compared. This applied also to the corresponding lymph node metastases. Our results indicate no significant differences between the gene amplification status of DCIS and invasive breast cancer concerning HER2, ESR1, CCND1, and MYC. Therefore, our data suggest an early role of all analyzed gene amplifications in breast cancer development but not in the initiation of invasive tumor growth.

Predictors of contralateral breast cancer in patients with unilateral breast cancer undergoing contralateral prophylactic mastectomy

BACKGROUND

Although contralateral prophylactic mastectomy (CPM) reduced the risk of contralateral breast cancer in unilateral breast cancer patients, it was difficult to predict which patients were most likely to benefit from the procedure. The objective of this study was to identify the clinicopathologic factors that predict contralateral breast cancer and thereby inform decisions regarding performing CPM in unilateral breast cancer patients.

METHODS

A total of 542 unilateral breast cancer patients who underwent CPM at The University of Texas M. D. Anderson Cancer Center from January 2000 to April 2007 were included in the current study. A logistic regression analysis was used to identify clinicopathologic factors that predict contralateral breast cancer.

RESULTS

Of the 542 patients included in this study, 25 (5%) had an occult malignancy in the contralateral breast. Eighty-two patients (15%) had moderate-risk to high-risk histologic findings identified at final pathologic evaluation of the contralateral breast. Multivariate analysis revealed that 3 independent factors predicted malignancy in the contralateral breast: an ipsilateral invasive lobular histology, an ipsilateral multicentric tumor, and a 5-year Gail risk >or=1.67%. Multivariate analysis also revealed that an age >or=50 years at the time of the initial cancer diagnosis and an additional ipsilateral moderate-risk to high-risk pathology were independent predictors of moderate-risk to high-risk histologic findings in the contralateral breast.

CONCLUSIONS

The findings indicated that CPM may be a rational choice for breast cancer patients who have a 5-year Gail risk >or=1.67%, an additional ipsilateral moderate-risk to high-risk pathology, an ipsilateral multicentric tumor, or an ipsilateral tumor of invasive lobular histology.

Antimetastatic gene expression profiles mediated by retinoic acid receptor beta 2 in MDA-MB-435 breast cancer cells

Background

The retinoic acid receptor beta 2 (RARβ2) gene modulates proliferation and survival of cultured human breast cancer cells. Previously we showed that ectopic expression of RARβ2 in a mouse xenograft model prevented metastasis, even in the absence of the ligand, all-trans retinoic acid. We investigated both cultured cells and xenograft tumors in order to delineate the gene expression profiles responsible for an antimetastatic phenotype.

Methods

RNA from MDA-MB-435 human breast cancer cells transduced with RARβ2 or empty retroviral vector (LXSN) was analyzed using Agilent Human 1A Oligo microarrays. The one hundred probes with the greatest differential intensity (p < 0.004, jointly) were determined by selecting the top median log ratios from eight-paired microarrays. Validation of differences in expression was done using Northern blot analysis and quantitative RT-PCR (qRT-PCR). We determined expression of selected genes in xenograft tumors.

Results

RARβ2 cells exhibit gene profiles with overrepresentation of genes from Xq28 (p = 2 × 10^-8), a cytogenetic region that contains a large portion of the cancer/testis antigen gene family. Other functions or factors impacted by the presence of exogenous RARβ2 include mediators of the immune response and transcriptional regulatory mechanisms. Thirteen of fifteen (87%) of the genes evaluated in xenograft tumors were consistent with differences we found in the cell cultures (p = 0.007).

Conclusion

Antimetastatic RARβ2 signalling, direct or indirect, results in an elevation of expression for genes such as tumor-cell antigens (CTAG1 and CTAG2), those involved in innate immune response (e.g., RIG-I/DDX58), and tumor suppressor functions (e.g., TYRP1). Genes whose expression is diminished by RARβ2 signalling include cell adhesion functions (e.g, CD164) nutritional or metabolic processes (e.g., FABP6), and the transcription factor, JUN.

Ductal lavage for breast cancer risk assessment

Ductal lavage is a minimally-invasive procedure that permits sampling of breast ductal fluids for cytopathologic analysis. The technique is performed with topical anesthesia and involves cannulation of any fluid-yielding nipple orifice with a specially-designed catheter for lavage and aspiration of the ductal system. The procedure is used for women who have clinical evidence of increased breast cancer risk; if atypia is detected, it may strengthen a woman's interest in committing to a risk-reducing strategy or a chemoprevention trial. The technology also is being used as a tool in ongoing translational research studies.

Contralateral prophylactic mastectomy

BACKGROUND

Women with unilateral breast carcinoma are at increased risk for developing contralateral breast carcinoma (CBC). The authors sought to identify predictors of malignant or moderate to high-risk histologic findings in contralateral prophylactic mastectomy (CPM) specimens, and to determine the efficacy of CPM.

METHODS

The authors performed a retrospective review of 239 patients with unilateral early-stage breast carcinoma who underwent CPM. The number of CBCs expected if the contralateral breast had been left intact was calculated based on CBC rates observed in the Surveillance, Epidemiology, and End Results (SEER) database and on life-table analysis by family history.

RESULTS

In the current study, 11 patients (4.6%) had occult contralateral malignancies (4 invasive carcinomas and 7 ductal carcinomas in situ) and 44 (18.4%) patients had moderate to high-risk pathology (8 lobular carcinoma in situ, 11 atypical lobular hyperplasia, 25 atypical ductal hyperplasia). At 1846 patient-years of follow-up, only 1 patient (0.4%) developed a new CBC compared with 11 expected cancers based on SEER data. One CBC was observed among 140 patients with a family history of breast carcinoma, compared with 16 expected cancers based on life-table analysis adjusted for adjuvant therapy. The determinants of significant findings at CPM were invasive lobular histology, estrogen and progesterone receptor positivity, additional ipsilateral moderate to high-risk pathology, and age > 40 years at cancer diagnosis.

CONCLUSIONS

CPM was associated with a low risk of subsequent development of breast carcinoma. Evaluation of histologic findings in the ipsilateral breast may help to predict the likelihood of significant disease in the contralateral breast and assist in risk stratification.

Current comprehensive assessment and management of women at increased risk for breast cancer

The potential for reducing the risk of breast cancer through selective estrogen receptor modulators, aromatase inhibitors, and surgery has generated interest in the use of quantitative models of risk assessment. With the addition of ductal lavage cytology to traditional epidemiologic risk factors, a discovery of cellular atypia can result in refinement of assigned risk values, while simultaneously optimizing patient selection for selective estrogen receptor modulators utilization. In view of increasing complexity in this arena, a Risk Assessment Working Group was formed to outline management strategies for the patient at an elevated risk for the development of breast cancer. No longer a statistical exercise, quantitative risk assessment is part of basic breast care and comprehensive management includes a discussion of the following: ductal lavage for improved risk stratification, multiple options for risk reduction, and high risk surveillance strategies that might incorporate investigational imaging protocols.

Biopsy Needle Technique and the Accuracy of Diagnosis of Atypical Ductal Hyperplasia for Mammographic Abnormalities

The evaluation of mammographic abnormalities has become a substantial effort for surgeons and radiologists. The vacuum-assisted core biopsy (VACB) has been touted as a more accurate tool for the evaluation of mammographic lesions. Diagnosis of atypical ductal hyperplasia (ADH) from a percutaneous needle biopsy of the breast is associated with a significant risk of missing a significant breast lesion. We compared 2 methods of sampling with stereotactic-guided breast biopsy, 14-gauge automated gun core biopsy (AGCB) and VACB, on the accuracy of diagnosis of ADH at a single institution. All cases of ADH, without associated malignancy, found via image-guided breast biopsy of nonpalpable lesions between March 1996 and April 2002 were evaluated. VACB biopsy needles were utilized between July 1998 to April 2002 (686 patients) and 14-gauge AGCB from March 1996 to June 1998 (350 patients). The results of these biopsies were reviewed and compared to surgical biopsy and pathological records. ADH alone was found in 53 cases (5.1% of biopsies; mean age 57.9 years). Of these, 39 patients with ADH subsequently underwent wire-localized excisional biopsy. The other 14 patients were observed. VACB biopsy understaged 7 of 29 (24%) patients with ADH (all of which were DCIS), AGCB understaged 4 of 10 cases (40%) with one being invasive. Of the patients in the core biopsy group who were initially followed, 2 developed significant lesions within 3 years of follow-up in the same quadrant of the breast. If these cases are added to the AGCB group, then 50 per cent were understaged and significantly more invasive lesions were understaged than with VACB (17% vs. 0%; P = 0.018). The VACB resulted in less understaging of ADH than AGCB. However, there remains a significant risk of missing DCIS in this setting even with the VACB. Furthermore, the risk of understaging an invasive lesion is significantly lower in this setting with a VACB than an AGCB. Although the risk of understaging ADH is lower with the VACB, we continue to recommend excisional biopsy in a good-risk patient when a diagnosis of ADH is rendered via VACB biopsy.

Rating the risk factors for breast cancer

OBJECTIVE

To update and summarize evidence of risk factors for breast cancer.

SUMMARY BACKGROUND DATA

Women who are at high risk for breast cancer have a variety of options available to them, including watchful waiting, prophylactic surgery, and chemoprevention. It is increasingly important to accurately assess a patient's risk profile to ensure that the cost/benefit ratio of the selected treatment is favorable.

METHODS

Estimates of relative risk for documented risk factors were obtained from seminal papers identified in previous reviews. These estimates were updated where appropriate with data from more recent reports using large sample sizes or presenting meta-analyses of previous studies. These reports were identified from a review of the Medline database from 1992 to 2002.

RESULTS

Risk factors that have received a great deal of publicity (hormone use, alcohol consumption, obesity, nulliparity) present a relatively modest relative risk for breast cancer (<2). Factors associated with a prior history of neoplastic disease or atypical hyperplasia and factors associated with a genetic predisposition significantly affect the risk of breast cancer, with relative risks ranging from 3 (for some cases of positive family history) to 200 (for premenopausal women positive for a BRCA mutation).

CONCLUSIONS

More precise tools, based on techniques of molecular biology such as microarray analysis, will be needed to assess individual risk for breast cancer.

Ductal lavage for breast cancer risk assessment

BACKGROUND

Effective chemoprevention is available for breast cancer, but it is associated with the potential for life-threatening adverse events. Accurate identification of women facing increased risk of breast cancer is therefore essential. Atypical hyperplasia is a histopathologic pattern that has been consistently associated with an elevated future risk of breast cancer.

METHODS

The literature was reviewed to assess the strength of the association between atypical hyperplasia and breast cancer. The rationale for developing a nonsurgical modality to document the presence of atypia is discussed.

RESULTS

Ductal lavage identifies atypical hyperplasia by retrieving epithelial cells shed into the ductal system with a specially designed catheter. Women with clinical evidence of increased breast cancer risk may consider ductal lavage as a means of determining whether abnormal proliferative activity is occurring in their breasts at a given point in time from ducts yielding fluid.

CONCLUSIONS

Ductal lavage is a minimally invasive procedure that facilitates the detection of atypia via retrieval of breast ductal fluid that can be evaluated cytologically. It can facilitate the selection of women who may benefit from breast cancer risk reduction intervention.

A new model for ductal carcinoma in situ suggests strategies for treatment

Human ductal carcinoma in situ (DCIS) of the breast is now diagnosed quite frequently, due largely to the introduction of mammographic screening. It has been shown in a cell culture system that activation of c-erbB-2, but not the epidermal growth factor receptor, results in a DCIS-like phenotype. Since overexpression of c-erbB-2 occurs in 60% of DCIS, this suggests that it could be a target for treatment in this disease.