Parity and breastfeeding are protective against breast cancer in Nigerian women

As the relation between reproductive factors and breast cancer risk has not been systematically studied in indigenous women of sub-Saharan Africa, we examined this in a case–control study in Nigeria. In-person interviews were conducted using structured questionnaires to collect detailed reproductive history in 819 breast cancer cases and 569 community controls between 1998 and 2006. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). Compared with women with menarcheal age <17 years, the adjusted OR for women with menarcheal age ⩾17 years was 0.72 (95% CI: 0.54–0.95, P=0.02). Parity was negatively associated with risk (P-trend=0.02) but age at first live birth was not significant (P=0.16). Importantly, breast cancer risk decreased by 7% for every 12 months of breastfeeding (P-trend=0.005). It is worth noting that the distribution of reproductive risk factors changed significantly from early to late birth cohorts in the direction of increasing breast cancer incidence. Our findings also highlight the heterogeneity of breast cancer aetiology across populations, and indicate the need for further studies among indigenous sub-Saharan women.

Outcomes of patients with AML and MDS who relapse or progress after reduced intensity allogeneic hematopoietic cell transplantation

We describe treatment, outcomes and prognostic factors for patients who relapse following transplantation with a reduced intensity conditioning regimen. Seventy consecutive patients with high-risk myeloid malignancies underwent transplant and 25 (36%) relapsed, a median of 120 days later. The median percentage of bone marrow blasts at relapse was 24, the median donor chimerism was 73% and new karyotypic abnormalities occurred in 8 out of 20 (40%) evaluable patients. Twenty-one patients (84%) received aggressive treatment for relapse, including chemotherapy (60%), second hematopoietic cell transplantation (HCT; 52%) and/or donor lymphocyte infusion (DLI; 12%). Thirteen achieved a complete response (CR) and four remain in CR. Median overall survival (OS) after relapse was 6 months (95% confidence interval=2.7-9.9 months), and actuarial 1 year OS was 24%. Most deaths were due to disease progression (17/20, 85%). We did not observe an advantage for cellular therapy (DLI or second transplant) compared to chemotherapy. Salvage therapy for relapse after reduced intensity HCT is feasible, associated with low treatment-related mortality, and may result in prolonged survival in select patients. Studies exploring the optimal treatment for relapse following reduced intensity HCT are warranted.

BRCA1 and BRCA2 mutation carrier predictions using the BRCAPRO model in clinic-based minority families enrolled in the Breast Cancer Family Registry (B-CFR)

21037

Background: BRCA mutation prediction models, such as BRCAPRO, are used in cancer risk clinics, but they were developed based on mutation rates and penetrance observed in individuals of Ashkenazi Jewish and European ancestry. Furthermore, in clinical counseling it is not always clear whether to test additional family members for BRCA mutations after the proband tests negative. The aim of this study is to evaluate the performance of the BRCAPRO model among clinic-based minority families and to evaluate the clinical utility of testing additional family members in high risk families. Methods: A total of 314 families with at least one member having been tested for BRCA mutations were enrolled through the B-CFR. Families of Ashkenazi Jewish ancestry were excluded. Using the BRCAPRO model with default penetrance and allele frequency for non-Ashkenazi Jewish populations, the predicted likelihood of carrying either a BRCA1 or BRCA2 mutations was generated. Sensitivity, specificity, and area under the receiver operating characteristic curves (AUC) were calculated. Results: There were 55 African American, 181 Hispanic, 42 Asian American and 36 other minority families. The AUC was 0.771 (95% confidence interval, CI: 0.720–0.816) for all minorities combined. At a predicted probability of 10%, the sensitivity for identifying mutation carriers was 65% and the specificity was 76%. The performance was marginally significantly better for Hispanic families than the other minority groups (p=0.07). In 228 families (73%), multiple individuals were tested for BRCA mutations. After taking into account the mutation status of family members, the performance of the BRCAPRO model was improved: the AUC increased to 0.862 (95% CI: 0.820–0.899) and the specificity at the 10% threshold increased to 83%, while the sensitivity remained the same. Conclusions: The data support the use of BRCAPRO in pretest prediction of BRCA1/2 mutations for minority families in high risk clinic settings. Mutation status of family members provides additional predictive value, which may help counselors decide whether to offer other family members the test when one member has already tested negative, given a positive family history of breast and ovarian cancer.

No significant financial relationships to disclose.

Relationship between BRCA1 promoter methylation and sensitivity of breast cancer cell lines to cisplatin and paclitaxel

21083

Background: While BRCA1 germline mutations are uncommon, and contribute to fewer than 5% of breast cancer cases, epigenetic alterations in BRCA1 occur more frequently. BRCA1 promoter methylation has been detected in 10–30% of breast tumors. Given the role of BRCA1 in DNA repair and cell cycle regulation, we hypothesize that cells with decreased expression of BRCA1 secondary to promoter methylation will be sensitive to DNA damaging agents and resistant to microtubule inhibitors, as has previously been shown for cells deficient in BRCA1 secondary to mutation. Methods: BRCA1 methylation was determined using methylation specific PCR (MSP) as previously described (Wei et al, Cancer Research 2005). The relative sensitivities of BRCA1 methylated, mutated and competent cells to cisplatin and paclitaxel were determined in five representative breast cancer cell lines using the AlamarBlue cytotoxicity assay. Exponentially growing cells were treated with increasing concentrations of cisplatin and paclitaxel for 96 hours. IC50 values and 95% confidence intervals (CI) were calculated from sigmoidal dose response curves fitted with SAS 9.1 Proc NLIN. Western blot analysis for BRCA1 was performed on each cell line. Results: Conclusions: Only one of the two BRCA1 methylated cell lines studied (UACC3199) was sensitive to cisplatin and resistant to paclitaxel, as hypothesized. While both cell lines are methylated, western blot analysis revealed that both express BRCA1, but to a lesser degree than unmethylated cells. BRCA1 methylation, as assessed by non-quantitative MSP, does not correlate with sensitivity to cisplatin and resistance to paclitaxel. Quantification of BRCA1 promoter methylation may better predict chemosensitivity. Identification of the degree of BRCA1 methylation which does correlates with sensitivity to cisplatin and resistance to paclitaxel could improve treatment selection for patients with breast cancer. This work was supported by the US Army Grant W81XWH-04–1-0545.

[Table: see text]

No significant financial relationships to disclose.

Outcomes after breast cancer in an ethnically diverse cohort of high-risk patients: Differences in survival based on BRCA1/BRCA2 mutation status

21116

Background: Most studies of hereditary breast cancer report that BRCA1 associated tumors are characterized by high grade and hormone receptor negativity, while those associated with BRCA2 are more similar to sporadic cases. Several groups have demonstrated that BRCA1 mutations, but not BRCA2 mutations, are associated with reduced survival in women with breast cancer. These studies have primarily included women of European and Ashkenazi Jewish heritage. No study to date has assessed outcomes in an ethnically diverse cohort of high-risk individuals. Methods: High-risk individuals were identified through the University of Chicago Cancer Risk Clinic (UCCRC). Clinicopathologic data was collected on all patients with breast cancer who had undergone genetic testing and consented to inclusion in research protocols. Recurrence-free survival (RFS) and overall survival (OS) for BRCA1, BRCA2 and non-carriers was compared using the log-rank test. Hazard ratios (HR) and 95% Confidence Intervals (95% CI) were calculated from Cox proportional hazard models. Results: 280 patients from 258 families were studied. 67 were BRCA1 mutation positive, 36 were BRCA2 positive and 177 were non-carriers. 65% of patients were non-Hispanic non-Jewish whites, 15% African American, 15% Ashkanazi Jewish, 3% Hispanic and 2% Asian. At a median follow up of 5 years, 40 patients had relapsed and 22 had died. HRs (95% CI) for RFS of the BRCA1 and BRCA2 carriers relative to non-carriers were 1.6 (0.77–3.33) and 1.3 (0.55–3.09) respectively, when adjusted for year at diagnosis. The adjusted HRs (95% CI) for OS for the BRCA1 and BRCA2 carriers relative to non-carriers were 1.82 (0.48–3.02) and 0.67 (0.15–3.04), respectively. Conclusions: In this study of an ethnically diverse cohort of high-risk individuals, BRCA1 mutation carriers had a poorer outcome as compared to those with BRCA2 mutations or those without identifiable mutations in either gene, although this difference was not statistically significant. This observation is consistent with previous studies of women of predominantly Ashkenzi Jewish and European ancestry. This study was funded by the Falk Medical Research Trust, the Breast Cancer Research Foundation and the Entertainment Industry Fund.

No significant financial relationships to disclose.

Phase II trial of decitabine in myelofibrosis with myeloid metaplasia

7088

Background: DNA hypermethylation of promoter-specific CpG islands has been implicated in the pathogenesis and progression of disease in MMM. We are evaluating Decitabine, a DNA methyltransferase inhibitor in patients (pts) with MMM. Methods: This is a single stage Phase II trial: planned accrual of 20 pts. Pts had to have MMM with anemia and/or splenomegaly. Decitabine is given subcutaneously (SQ) at a dose of 0.3 mg/kg/d on days 1–5, and days 8–12; cycles are repeated every 6 weeks, in the absence of dose limiting toxicities. Response is determined every 12 weeks as an improvement in cytopenias and/or splenomegaly. CD34+ cells are measured by flow cytometry in peripheral blood at baseline, and at days 5 and 12 of therapy; elevated levels are associated with advanced stage and evolution to blast phase in MMM. Results: Pt characteristics: M/F: 6/4, median age 67 (range 42–89), median absolute CD34+ cell count 116 × 106/L (11–4,959), Dupriez score of 2, 1 and 0 in 50%, 30% and 20% respectively. Median number of cycles administered: 3 (range 1- 9). Median WBC and platelet (plt) count: 5.2 K/uL (1.5–29), and 171 K/uL (47–465 K/uL); 5 pts were red cell transfusion dependent. Grade 4 neutropenia (ANC) occurred in all pts, and grade 3/4 plts in 6 pts. 7 pts have developed febrile neutropenia. Grade 3–4 non-hematologic toxicities include a variceal bleed in a patient with baseline portal hypertension and a splenic infarct occurring in another pt. 7 pts are evaluable for response: 3 pts have responded including 1 pt with a CR (normalization of blood counts and transfusion independence), and 1 pt with a PR (Hb increase of > 2 g/dL). A third pt in the blast phase of the disease had a hematological improvement as evidenced by a normalization in plts (from 62 K/uL to 219 K/uL) associated with a significant decrease (from 2.58 K/uL to 0.03 K/uL) in circulating blasts. The other 4 pts have had stable disease. There was a reduction in CD34+ levels: mean decrease of approximately 75% at day 12 of therapy (p<0.0001). Conclusions: Low dose SQ decitabine is feasible in MMM and is associated with a significant decrease in CD34+ cells. There is preliminary evidence of clinical activity. Myelosupression is significant, though reversible and requires close monitoring. These findings must be validated in a larger group of pts. Sponsored by NCI grant NO1-CM-62201

No significant financial relationships to disclose.

Up-regulation of MKK4, MKK6 and MKK7 during prostate cancer progression: an important role for SAPK signalling in prostatic neoplasia

Identification of the signalling cascades that are differentially activated during prostatic tumourigenesis is a crucial step in the search for future molecular targets in this disease. The stress-activated protein kinase (SAPK) signalling cascade culminates in the phosphorylation of the JNK and p38 mitogen-activated protein kinases (MAPKs). Recently, the upstream activators of these proteins, the MAPK kinases (MKKs), have been implicated as inhibitors of tumour progression in a variety of clinical and experimental tumour models. This study evaluates MKK4, MKK6 and MKK7 expression during prostate cancer progression in humans and in the transgenic adenocarcinoma of a mouse prostate (TRAMP) model of prostate tumourigenesis. Benign prostate, prostatic intraepithelial neoplasia (PIN) lesions and tumour tissues were collected from 37 TRAMP mice. Additionally, six tissue microarrays were constructed with tumours from a matched group of 102 men who underwent radical prostatectomy. Tissues from 20 patients with extensive high-grade prostatic intraepithelial neoplasia (HGPIN) were also analysed. For all samples, immunohistochemical staining for MKK4, MKK6 and MKK7 was scored in normal and neoplastic glands. Staining intensities of MKK4, MKK6 and MKK7 were significantly increased in HGPIN and prostate cancer compared to surrounding normal glands in both the TRAMP and human samples (p < 0.0001 for all markers). Increased levels of MKK4 or MKK7 correlated with higher pathological stage at prostatectomy (p = 0.01 and p = 0.04). Using multivariate analysis, there was no association between protein levels and time to biochemical recurrence in the human samples. The up-regulation of MKK4, MKK6 and MKK7 during prostate cancer progression in both TRAMP and human tissues highlights an important role for the SAPK signalling cascade in prostatic neoplasia. The finding that higher MKK4 and MKK7 expression is associated with higher-stage prostatic tumours underscores the dynamic regulation of these proteins during prostatic tumourigenesis.

Prognostic significance of WT-1 levels in patients with myelodysplastic syndrome and leukemia after reduced-intensity allogeneic transplantation

6524

Background: Expression of WT-1, a zinc-finger transcription factor, is elevated at diagnosis in many kinds of leukemia. The prognostic significance of the WT-1 transcript level before and after stem cell transplant is controversial. We performed real-time quantitative PCR (RQ-PCR) on samples from pts with leukemia and MDS undergoing allo stem-cell transplant (SCT) to determine if WT-1 expression correlates with survival (OS) and/or disease-free survival (DFS). Methods: Pts were conditioned with fludarabine, melphalan and alemtuzumab. cDNA was synthesized for RQ-PCR, which was performed on bone marrow (BM) and peripheral blood (PB) samples drawn prior to transplant admission and at day 28 (D28) post transplantation. All samples were analyzed using LightCycler technology and reported as a normalized ratio of WT-1 copy number to ABL copy number. Results: Data on 48 patients who underwent allo SCT are reported here. During a median follow up of 17 months, 24 patients died and the OS rate at one year was 52%. The DFS rate at one year was 34%. There was a statistically significant association between pretransplant WT-1 levels measured in PB and OS, with increase in risk of death by 36% for every 10 fold increase in WT-1 levels (p=0.048). Pretransplant WT-1 levels in both PB and BM also predicted DFS: the risk of relapse or death was increased by 44% (PB) and 71% (BM) for every 10 fold increase in WT-1 levels (p=0.012; p=0.048). However, after controlling for disease status at transplantation using a Cox model, pretransplant WT-1 levels were no longer a significant predictor because these levels were highly correlated with disease status at transplantation. We did not find any significant correlation between WT-1 levels 28 days post-transplantation and outcome. Conclusions: Our preliminary results differ from several published studies demonstrating prognostic significance of WT-1 RQ-PCR after allo SCT. Although elevated WT-1 levels prior to transplantation correlate with higher risk of post-transplant relapse and death from any cause, these preliminary data fail to establish an independent prognostic role for WT-1 RQ-PCR in the setting of reduced intensity allo SCT. Analysis of additional post-transplant time points is proceeding.

No significant financial relationships to disclose.

Injection-related risk behaviors in young urban and suburban injection drug users in Chicago (1997-1999)

We compared injection-related risk practices between urban and suburban injection drug users (IDUs) in a large cross-sectional sample of young IDUs. From 1997 to 1999, we recruited 700 active IDUs aged 18 to 30 years in Chicago and its suburbs. A suburban residence was reported by 38% of participants. Participants were interviewed at four urban locations and screened for HIV and hepatitis C virus antibodies. Receptive sharing of syringes and other paraphernalia by urban and suburban IDUs in the preceding 6 months was compared using univariable and multivariable models. Sharing injection paraphernalia in the total sample was high, with 50% of participants reporting receptive syringe sharing and 70% reporting sharing cotton, cookers, and/or rinse water. After adjusting for demographic characteristics, injection settings, frequency, and duration of injection as well as ease of acquiring new syringes, suburban IDUs were significantly more likely than urban IDUs to share syringes (adjusted odds ratio = 1.7; 95% confidence interval: 1.1-2.5); however, the likelihood of sharing cotton, cookers, or rinse water was roughly equal. Despite overall higher risk profiles among suburban IDUs, HIV and hepatitis C prevalence levels were significantly lower than among urban participants. Current high levels of injection risk behaviors in suburban groups represent a potential for rapid dissemination of infection.

Prevalence and incidence of HIV among out-of-treatment injecting drug users, Chicago 1994-1996

OBJECTIVES

To assess HIV prevalence, incidence, and associated risk factors among IDUs in Chicago.

METHODS

Seven hundred ninety-four street-recruited IDUs ranging in age from 18 to 50 years, who were not in drug treatment at study enrollment, were interviewed and tested for HIV at baseline and at two follow-ups scheduled 6 and 12 months after baseline. Questionnaires assessed respondents' demographic characteristics, medical and drug treatment histories, drug use, and sexual practices.

RESULTS

HIV seroprevalence at baseline was 18%. Logistic regression identified the following determinants of prevalent HIV infection: Puerto Rican ethnicity, homosexual or bisexual self-identification, injecting for 4 or more years, and having smoked crack cocaine in the past 6 months. Follow-up data were collected from 584 (73.6%) participants. Mean duration of follow-up was 16.5 months, indicating that most subjects had follow-up intervals longer than the scheduled 6 and 12 months. Seven HIV seroconversions were observed in 632 person years of risk, yielding an incidence rate of 1.1 per 100 person years of risk. Injection for 3 or less years was positively associated with HIV seroconversion.

CONCLUSIONS

The findings provide evidence of a decline in HIV incidence among IDUs, though newer injectors remain at elevated risk for infection.

[A case - control study on risk factors for hip fracture in the middle - aged and elderly in Beijing]

OBJECTIVE

To investigate the risk factors for hip fracture in women and men aged 50 years and older.

METHODS

A matched case - control study was carried out in the urban area of Beijing from Jan. 1994 to May 1996. A total number of 201 cases having had hip fracture were identified by X - ray films in four hospitals of Beijing. Four hundred and two neighbourhood controls were individually matched with these cases by age and sex. Data were analyzed by statistical technique of Chi-square test and conditional logistic regression.

RESULTS

In a multiple conditional logistic regression model, low dietary calcium intake, previous history of more sedantary position, lack of calcium supplement, low body mass index, current low physical exercise, never living in rural, sedentary position at work, previous fractures of any type after the age of 50, history of family hip fracture and diabetes mellitus were significantly associated with increased risk of hip fracture. In addition, hip fracture was related to the age of menopause and duration of breastfeeding in women, as well as body height in men.

CONCLUSION

Hip fracture is a disease with multiple risk factors which are different with sex.

[Analysis of isoenzymes in six kinds of caulis drug by means of polyacrylamide gel slab electrophoresis]

OBJECTIVE

To probe into the possibility of application of electrophoresis in the identification of caulis drugs.

METHOD

The isoenzymes of peroxidase, esterase and amylase in six kinds of caulis drug with similar characteristics were analyzed by means of polyacrylamide gel slab electrophoresis.

RESULT

The bands of isoenzymogram of peroxidase are the clearest of all, and band number and mobility rates of the six drugs differ from one another, showing a remarkable interspecific distinction.

CONCLUSION

Electrophoresis of isoenzymes of peroxidase can be employed as one of the effective means in differentiating caulis drugs.

Conformational study of sequential Lys and Leu based polymers and oligomers using vibrational and electronic CD spectra

Vibrational CD (VCD) and electronic CD (ECD) spectra of some sequential Lys and Leu based oligo- and polypeptides were studied as a function of added salt and (for ECD) as a function of concentration in aqueous solution. For these samples, the VCD spectra can only be measured at relatively high concentrations under which the well-known salt-induced transition to a beta-sheet form can be observed for the KL based species, but only the end-state alpha-helical conformation is obvious for the LKKL based samples. ECD concentration dependence demonstrates that, at high concentration with no added or with added salt, LKKL based oligomers and polymers give alpha-helical spectra. These data provide evidence of aggregation induced secondary structure formation in an exceptionally simple peptide system. Similarly, the KL based oligomers and polymers give beta-sheet like spectra at high concentration or at high salt. These systems further provide model systems under "normal" aqueous conditions that yield VCD band shapes that correlate to the major secondary structural types of polypeptides. They are in substantial agreement with those spectra obtained on homopolypeptides and on proteins, confirming the relative independence of the VCD technique from side-chain and solvent effects.