Marta Santisteban

Immune-induced epithelial to mesenchymal transition in vivo generates breast cancer stem cells

The breast cancer stem cell (BCSC) hypotheses suggest that breast cancer is derived from a single tumor-initiating cell with stem-like properties, but the source of these cells is unclear. We previously observed that induction of an immune response against an epithelial breast cancer led in vivo to the T-cell-dependent outgrowth of a tumor, the cells of which had undergone epithelial to mesenchymal transition (EMT). The resulting mesenchymal tumor cells had a CD24(-/lo)CD44(+) phenotype, consistent with BCSCs. In the present study, we found that EMT was induced by CD8 T cells and the resulting tumors had characteristics of BCSCs, including potent tumorigenicity, ability to reestablish an epithelial tumor, and enhanced resistance to drugs and radiation. In contrast to the hierarchal cancer stem cell hypothesis, which suggests that breast cancer arises from the transformation of a resident tissue stem cell, our results show that EMT can produce the BCSC phenotype. These findings have several important implications related to disease progression and relapse.

Association Between Cyclooxygenase-2 Expression in Atypical Hyperplasia and Risk of Breast Cancer

BACKGROUND The cyclooxygenase-2 (COX-2) enzyme, which is induced by inflammatory and mitogenic stimuli, plays a protumorigenic role in several human cancers. COX-2 is overexpressed in invasive and in situ breast cancers. Atypical hyperplasia in breast tissue, although benign, is associated with a high risk of breast cancer. We investigated whether COX-2 overexpression in atypical hyperplasia is associated with the risk of subsequent breast cancer. METHODS COX-2 expression was assessed immunohistochemically in archival sections from 235 women with atypia whose biopsy specimens were obtained at the Mayo Clinic from January 1, 1967, through December 31, 1991. COX-2 expression was scored as 0 (negative), 1+ (weak), 2+ (moderate), or 3+ (strong). Risk factor information and follow-up for breast cancer events were obtained via a study questionnaire and the medical records. All statistical tests were two-sided. RESULTS Forty-one (17%) of the 235 women developed breast cancer during a median follow-up of 15 years. Moderate (category 2+) or strong (category 3+) COX-2 expression was identified in 71 (30%) and 34 (14%) of the 235 samples, respectively. The risk for developing breast cancer, relative to a control population (the Iowa Surveillance, Epidemiology, and End Results registry), increased with increasing COX-2 expression (relative risk [RR] = 2.63, 95% confidence interval [CI] = 1.56 to 4.15, for those with negative or weak COX-2 expression; RR = 3.56, 95% CI = 1.94 to 5.97, for those with moderate expression; and RR = 5.66, 95% CI = 2.59 to 10.75, for those with strong expression; P = .07). Overexpression of COX-2 was statistically significantly associated with the type of atypia (lobular vs ductal, P < .001), number of foci of atypia in the biopsy (P = .02), and older age at time of biopsy (>45 years, P = .01). CONCLUSIONS COX-2 appears to be a biomarker that further stratifies breast cancer risk among women with atypia and may be a relevant target for chemoprevention strategies.

p16(INK4a) expression and breast cancer risk in women with atypical hyperplasia.

p16, a nuclear protein encoded by the p16INK4a gene, is a regulator of cell-cycle regulation. Previous studies have shown that expression of p16 in tissue biopsies of patients with ductal carcinoma in situ (DCIS) is associated with increased risk of breast cancer, particularly when considered in combination with other markers such as Ki-67 and COX-2. Here, we evaluated how expression of p16 in breast tissue biopsies of women with atypical hyperplasia (AH), a putative precursor lesion to DCIS, is associated with subsequent development of cancer. p16 expression was assessed by immunohistochemistry in archival sections from 233 women with AH diagnosed at the Mayo Clinic. p16 expression in the atypical lesions was scored by percentage of positive cells and intensity of staining. We also studied coexpression of p16, with Ki-67 and COX-2, biomarkers of progression in AH. Risk factor and follow-up data were obtained via study questionnaire and medical records. Forty-seven patients (20%) developed breast cancer with a median follow-up of 14.5 years. Staining of p16 was increased in older patients relative to younger patients (P = 0.0025). Although risk of developing breast cancer was not associated with increased p16 expression, joint overexpression of Ki-67 and COX-2 was found to convey stronger risk of breast cancer in the first 10 years after diagnosis as compared with one negative marker (P < 0.01). However, the addition of p16 levels did not strengthen this association. p16 overexpression, either alone or in combination with COX-2 and Ki-67, does not significantly stratify breast cancer risk in women with AH. Cancer Prev Res; 4(12); 1953–60. ©2011 AACR.

Docetaxel Plus Vinorelbine as Salvage Chemotherapy in Advanced Breast Cancer: A Phase II Study

AbstractPrécis Administration of a combined regimen of docetaxel plus vinorelbine every 4 weeks is feasible and shows activity in heavily pretreated patients with advanced breast cancer. Purpose. To determine the activity and tolerance of docetaxel plus vinorelbine in heavily pretreated patients with advanced breast cancer. Methods. Thirty-five metastatic breast cancer patients with ECOG performance status of 0–2 received docetaxel (80 mg/m2 given intravenously) on day 1 and vinorelbine (30 mg/m2 given intravenously) on days 1 and 14, every 4 weeks. The median number of prior chemotherapy regimens was 2 (range: 1–4). Twenty-five patients (71.4%) had been treated previously using intensive therapy approaches with peripheral blood-derived stem cell (PBSC) support, including high-dose chemotherapy (11 patients), multicyclic dose-intensive chemotherapy supported with repeated PBSC infusions (seven patients), or both (seven patients). Twenty-eight patients (80%) received previous chemotherapy for metastatic disease. Adjuvant therapy in the remaining seven patients consisted of high-dose chemotherapy and PBSC support or an anthracycline-containing regimen. Results. The total number of courses was 229, and the median number of courses per patient was 6 (range: 1–16). There was one toxic death (2.8%). Grade 3–4 toxicities included mucositis (17.1%), neutropenia (37.1%), anemia (5.7%), vomiting (2.9%), and asthenia (14.3%). Eighteen patients (58%; 95% CI: 40.6–75.4%) achieved an objective response, including four complete responses (12.9%) and 14 partial responses (45.1%). Overall response rate was 51.4% (95% CI: 34.8–67.9%). After a median follow-up of 20 months (range: 2–42), overall survival was 20 months (95% CI: 16–24), and median time to progression was 13 months (95% CI: 7–19). Conclusion. This combination shows activity and an acceptable toxicity profile in patients with advanced breast cancer.

Ki67: A Time-Varying Biomarker of Risk of Breast Cancer in Atypical Hyperplasia.

Background: Uncontrolled proliferation is a defining feature of the malignant phenotype. Ki67 is a marker for proliferating cells and is overexpressed in many breast cancers. Atypical hyperplasia is a premalignant lesion of the breast (relative risk ∼ 4.0). Here we asked if Ki67 expression could stratify risk in women with atypia.Methods: Ki67 expression was assessed immunohistochemically by digital image analysis in archival sections from 192 women with atypia diagnosed at the Mayo Clinic 1/1/67-12/31/91. Risk factor and follow-up data were obtained via study questionnaire and medical records. Observed breast cancer events were compared to population expected rates (Iowa SEER) using standarized incidence ratios (SIRs). We examined both short-term (within 10 years) and long-term (after 10 years) risk of breast cancer (BC) following atypia biopsy.Results: The median value for percent positive cells for Ki67 was 1.0%; the 75 th percentile value was 2.3%. Based on the empirical distribution of staining values in our cohort, we selected a cutoff of 2% cells positive to separate high from low staining. There were no differences in Ki67 levels by age at biopsy, type of atypia (ADH, ALH, or both), number of foci of atypia, or family history. 32 women developed BC over a median of 14.6 years. Among them, those with ≥2% Ki67 expression had a shorter time to breast cancer (median 5.5 years, IQR=3.2-7.2) than those with Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 909.

Combination of pegylated liposomal doxorubicin plus gemcitabine in heavily pretreated metastatic breast cancer patients: Long-term results from a single institution experience

The combination of Pegylated Liposomal Doxorubicin (PLD) plus Gemcitabine (GEM) has been previously investigated in the treatment of metastatic breast cancer (MBC). PLD is a doxorubicin formulation with prolonged circulation time and better tissue distribution. GEM is a nucleoside analog with nonoverlapping toxicity compared to PLD. The aim of our study was to assess efficacy, toxicity, and long‐term outcome of this combination. Patients with heavily treated MBC were retrospectively analyzed. Chemotherapy consisted of PLD 25 mg/m2 and GEM 800 mg/m2 day 1, on a three‐week schedule. Cardiac function was evaluated baseline and during treatment. Radiological response was graded according to RECIST criteria v1.1. Toxicity was scored according to CTCAE v4.0. Progression‐free survival (PFS) and overall survival (OS) were evaluated. From 2001 to 2014, 122 pts were included. Median age was 55 (range: 28‐84). Median previous treatment schedules in the metastatic scenario were 3 (range: 1‐15). Most patients received prior anthracyclines (85%). Median number of metastatic sites was 2 (range: 1‐7). Median number of cycles delivered was 5 (range: 1‐36). Overall response rate was 31% (5% complete responses; 26% partial responses). Stable and progressive diseases were observed in 32% and 26% of patients. Grade ≥3 neutropenia was observed in 29 patients (24%). Grade ≥3 hand‐foot syndrome was detected in 17 patients (14%), mostly since cycle 3 (88%). Median cumulative PLD dose was 125 mg/m2. At a median follow‐up of 101 months, median PFS and OS were 7 and 22 months, respectively. PLD‐GEM combination achieves remarkable long‐term outcomes with an acceptable toxicity profile in patients with MBC.