Genome-wide association study of susceptibility loci for breast cancer in Sardinian population.

BACKGROUND: Despite progress in identifying genes associated with breast cancer, many more risk loci exist. Genome-wide association analyses in genetically-homogeneous populations, such as that of Sardinia (Italy), could represent an additional approach to detect low penetrance alleles. METHODS: We performed a genome-wide association study comparing 1431 Sardinian patients with non-familial, BRCA1/2-mutation-negative breast cancer to 2171 healthy Sardinian blood donors. DNA was genotyped using GeneChip Human Mapping 500 K Arrays or Genome-Wide Human SNP Arrays 6.0. To increase genomic coverage, genotypes of additional SNPs were imputed using data from HapMap Phase II. After quality control filtering of genotype data, 1367 cases (9 men) and 1658 controls (1156 men) were analyzed on a total of 2,067,645 SNPs. RESULTS: Overall, 33 genomic regions (67 candidate SNPs) were associated with breast cancer risk at the p < 0(-6) level. Twenty of these regions contained defined genes, including one already associated with breast cancer risk: TOX3. With a lower threshold for preliminary significance to p < 10(-5), we identified 11 additional SNPs in FGFR2, a well-established breast cancer-associated gene. Ten candidate SNPs were selected, excluding those already associated with breast cancer, for technical validation as well as replication in 1668 samples from the same population. Only SNP rs345299, located in intron 1 of VAV3, remained suggestively associated (p-value, 1.16 x 10(-5)), but it did not associate with breast cancer risk in pooled data from two large, mixed-population cohorts. CONCLUSIONS: This study indicated the role of TOX3 and FGFR2 as breast cancer susceptibility genes in BRCA1/2-wild-type breast cancer patients from Sardinian population.

Dose-dense FEC followed by dose-dense ixabepilone as neoadjuvant treatment for breast cancer patients: a feasibility study.

BACKGROUND: Ixabepilone is an effective chemotherapy in metastatic breast cancer that has been pretreated with anthracyclines and is resistant or refractory to taxanes. Adjuvant dose-dense (DD) chemotherapy is more effective than regimens administered every 3 weeks, especially in hormonal receptor (HR)-negative tumors. METHODS: A feasibility study of neoadjuvant DD ixabepilone was conducted in breast cancer patients with tumors measuring at least 2 cm. Patients received 5-fluorouracil 600 mg/m(2), epirubicin 90 mg/m(2), and cyclophosphamide 600 mg/m(2) ("FEC" in combination) administered intravenously on day 1 every 14 days with granulocyte-colony stimulating factor (filgrastim) followed by ixabepilone 40 mg/m(2) administered intravenously on day 1 every 14 days with granulocyte-colony stimulating factor. The study's primary endpoint was feasibility, and the secondary endpoint was pathologic complete response. A two-stage Simon's design was adopted. RESULTS: Forty-seven patients were enrolled, and 42 were evaluable. For 10 of 42 patients, DD ixabepilone was not feasible. Six (14%) required ixabepilone interruption, and four (9.5%) required ixabepilone dose reduction of 25%. One toxic death occurred. Hematologic grade 3-4 toxicities included anemia (9.5%), grade 4 neutropenia (2.4%), febrile neutropenia (4.8%), and thrombocytopenia (2.4%). Nonhematologic grade 3-4 toxicities consisted of fatigue (14.3%), mucositis (14.3%), sensory neuropathy (7.1%), onychopathy (7.1%), and liver toxicity (4.8%). Grade 2 sensory neuropathy lasting longer than 7 days was recorded in 11.9% of patients. Pathologic complete response was observed in 16 of 42 patients (38.1%), including 11 of 23 (47.8%) with HR-negative tumors and 5 of 19 (26.3%) with HR-positive tumors. CONCLUSION: Despite high activity, DD ixabepilone after DD FEC is poorly tolerated.

Prevalence of KRAS, BRAF, and PIK3CA somatic mutations in patients with colorectal carcinoma may vary in the same population: clues from Sardinia.

BACKGROUND: Role of KRAS, BRAF and PIK3CA mutations in pathogenesis of colorectal cancer (CRC) has been recently investigated worldwide. In this population-based study, we evaluated the incidence rates and distribution of such somatic mutations in genetically isolated population from Sardinia. METHODS: From April 2009 to July 2011, formalin-fixed paraffin-embedded tissues (N = 478) were prospectively collected from Sardinian CRC patients at clinics across the entire island. Genomic DNA was isolated from tissue sections and screened for mutations in KRAS, BRAF, and PIK3CA genes by automated DNA sequencing. RESULTS: Overall, KRAS tumour mutation rate was 30% (145/478 positive cases). Distribution of mutation carriers was surprisingly different within the island: 87/204 (43%) in North Sardinia vs. 58/274 (21%) in Middle-South Sardinia (p<0.001). Among 384 CRC cases whose DNA was available, only one (0.3%) patient carried a mutation in BRAF gene; PIK3CA was found mutated in 67 (17%) patients. A significant inverse distribution of PIK3CA mutation rates was observed within Sardinian population: 19/183 (10%) cases from northern vs. 48/201 (24%) cases from central-southern island (p<0.001). This heterogeneity in frequencies of KRAS/PIK3CA somatic mutations is consistent with already-reported discrepancies in distribution of germline mutations for other malignancies within Sardinian population. Preliminary clinical evaluation of 118 KRAS wild-type patients undergoing anti-EGFR-based treatment indicated lack of role for PIK3CA in predicting response to therapy. CONCLUSIONS: Our findings support the hypothesis that differences in patients' origins and related genetic backgrounds may contribute to even determine the incidence rate of somatic mutations in candidate cancer genes.

Effect of the gonadotropin-releasing hormone analogue triptorelin on the occurrence of chemotherapy-induced early menopause in premenopausal women with breast cancer: a randomized trial.

CONTEXT: Premenopausal patients with breast cancer are at high risk of premature ovarian failure induced by systemic treatments, but no standard strategies for preventing this adverse effect are yet available. OBJECTIVE: To determine the effect of the temporary ovarian suppression obtained by administering the gonadotropin-releasing hormone analogue triptorelin during chemotherapy on the incidence of early menopause in young patients with breast cancer undergoing adjuvant or neoadjuvant chemotherapy. DESIGN, SETTING, AND PATIENTS: The PROMISE-GIM6 (Prevention of Menopause Induced by Chemotherapy: A Study in Early Breast Cancer Patients-Gruppo Italiano Mammella 6) study, a parallel, randomized, open-label, phase 3 superiority trial, was conducted at 16 sites in Italy and enrolled 281 patients between October 2003 and January 2008. The patients were premenopausal women with stage I through III breast cancer who were candidates for adjuvant or neoadjuvant chemotherapy. Assuming a 60% rate of early menopause in the group treated with chemotherapy alone, it was estimated that 280 patients had to be enrolled to detect a 20% absolute reduction in early menopause in the group treated with chemotherapy plus triptorelin. The intention-to-treat analysis was performed by including all randomized patients and using imputed values for missing data. INTERVENTIONS: Before beginning chemotherapy, patients were randomly allocated to receive chemotherapy alone or combined with triptorelin. Triptorelin was administered intramuscularly at a dose of 3.75 mg at least 1 week before the start of chemotherapy and then every 4 weeks for the duration of chemotherapy. MAIN OUTCOME MEASURE: Incidence of early menopause (defined as no resumption of menstrual activity and postmenopausal levels of follicle-stimulating hormone and estradiol 1 year after the last cycle of chemotherapy). RESULTS: The clinical and tumor characteristics of the 133 patients randomized to chemotherapy alone and the 148 patients randomized to chemotherapy plus triptorelin were similar. Twelve months after the last cycle of chemotherapy (last follow-up, August 18, 2009), the rate of early menopause was 25.9% in the chemotherapy-alone group and 8.9% in the chemotherapy plus triptorelin group, an absolute difference of -17% (95% confidence interval, -26% to -7.9%; P < .001). The odds ratio for treatment-related early menopause was 0.28 (95% confidence interval, 0.14 to 0.59; P < .001). CONCLUSION: The use of triptorelin-induced temporary ovarian suppression during chemotherapy in premenopausal patients with early-stage breast cancer reduced the occurrence of chemotherapy-induced early menopause. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00311636.

Triple-negative breast cancer frequency and type of BRCA mutation: Clues from Sardinia.

Germline mutations in BRCA1 or BRCA2 genes have been demonstrated to increase the risk of developing breast cancer. Among the prognostic factors currently used in clinical practice, the disease stage and the receptor status play a crucial role in the management of breast carcinoma. Triple-negative breast cancer (TNBC) has been classified as a disease subgroup that is negative for oestrogen, progesterone and HER2 receptor expression, and presents a poor prognosis. The present study investigated the correlation between BRCA1/2 mutations and TNBC status in a large series (n=726) of breast cancer patients from Sardinia. The BRCA mutation screening was performed on genomic DNA from peripheral blood samples by denaturing high-performance liquid chromatography analysis and automated DNA sequencing. Overall, 21/726 (2.9%) patients carried a germline mutation in BRCA1 or BRCA2. The TNBC phenotype was significantly associated with the BRCA1 mutations (P<0.001), whereas no association was found with the BRCA2 mutations (P=0.837). With respect to patient origin within Sardinia, a significant inverse distribution of mutations was found; BRCA1 and BRCA2 mutations represented 86 and 93% of the mutated cases in Southern and Middle-Northern Sardinia, respectively (P<0.001). Patients from the geographical area with BRCA1 mutation prevalence presented a TNBC incidence much higher than that observed in cases from the area with BRCA2 mutation prevalence (12 vs. 4%, respectively; P=0.037). These findings further confirmed that the occurrence of TNBC is significantly associated with the BRCA1 mutation carrier status and that a different 'genetic background' may have a phenotypic impact in the onset of breast cancer.