Electron imaging of pyrrhotite superstructures

Natural pyrrhotites, when studied by high resolution electron microscopy, yield crystallographic information on a unit cell scale. Structural heterogeneity is prominent. The many reported superstructures are interpretable through an antiphase model. The 5C pyrrhotite superstructure results from an ordered sequence of antiphase domains while the higher temperature NC type results from a disordered sequence.

Local Therapy in BRCA1/2 Carriers with Operable Breast Cancer: Comparison of Breast Conservation and Mastectomy

Background: Women with inherited germline BRCA1/2 mutations have a 55-85% cumulative risk of breast cancer (BC) by age 70. Thus, knowledge of expected outcomes following various treatments is needed to advise these patients should they be diagnosed with BC. It is unclear whether breast conservation (BCT) offers similar rates of tumor control as mastectomy (M) in BRCA1/2 carriers and it is doubtful whether a randomized trial comparing these options could be performed. Thus, this analysis compares the outcomes between similarly staged women with BRCA1/2 mutations treated with BCT vs. M.Methods: Women with deleterious BRCA1/2 mutations diagnosed with operable BC and who consented to longitudinal studies were identified at 10 institutions in the US, Australia, Spain and Israel. Patient, clinical and treatment characteristics were compared between those receiving BCT and those receiving M +/- RT. Time-to-event endpoints included first failure of treatment, diagnosis of contralateral breast cancer (CBC), and overall and BC-specific survival. Cox regression models were constructed to detect significant associations between patient and clinical characteristics and time-to-event endpoints.Results: Clinical characteristics and outcomes for 302 BCT and 353 M patients were compared. With a median F/U of 8.2 years for BCT patients and 8.9 years following M, 15-year local failure as first failure was significantly higher with BCT vs. M (23.5% vs. 5.5%, p<0.0001). Multivariate analysis indicted choice of local therapy as the only factor significantly predicting local recurrence, with a 4.5-fold risk of local failure with BCT compared to M (p<0.0001). Local failure analyses by cohort revealed the presence of a BRCA2 mutation (HR 2.8; p=0.024) and no use of adjuvant chemotherapy (HR 5.4; p=0.0001) as significant predictors within the BCT group; presence of invasive lobular cancer (HR 9.9; p=0.004) was the only significant predictor within the M cohort. No significant differences were seen in distant failure, BC-specific or overall survival by local therapy. 15-year estimates of CBC were 52.1% with BCT; 41.4% with M; and 37.9% with M+RT (p=0.44). Analyses of BCT vs. M +/- RT and surgery +/- RT did not reveal significant differences in CBC by cohort.Conclusions: The higher risk of local failure in BRCA1/2-associated BC treated with BCT compared to M did not translate into an increased risk of distant failure or mortality. RT did not result in a detectable increase in CBC at 15 years above baseline elevated rates. These results at both the involved and contralateral breasts should be discussed when patients with BRCA1/2-associated BC are considering local treatment options.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 959.

Workshop on Partial Breast Irradiation: State of the Art and the Science, Bethesda, MD, December 8-10, 2002

Breast conserving surgery followed by radiation therapy has been accepted as an alternative to mastectomy in the management of patients with early-stage breast cancer. Over the past decade there has been increasing interest in a variety of radiation techniques designed to treat only the portion of the breast deemed to be at high risk for local recurrence (partial-breast irradiation [PBI]) and to shorten the duration of treatment (accelerated partial-breast irradiation [APBI]). To consider issues regarding the equivalency of the various radiation therapy approaches and to address future needs for research, quality assurance, and training, the National Cancer Institute, Division of Cancer Treatment and Diagnosis, Radiation Research Program, hosted a Workshop on PBI in December 2002. Although 5- to 7-year outcome data on patients treated with PBI and APBI are now becoming available, many issues remain unresolved, including clinical and pathologic selection criteria, radiation dose and fractionation and how they relate to the standard fractionation for whole breast irradiation, appropriate target volume, local control within the untreated ipsilateral breast tissue, and overall survival. This Workshop report defines the issues in relation to PBI and APBI, recommends parameters for consideration in clinical trials and for reporting of results, serves to enhance dialogue among the advocates of the various radiation techniques, and emphasizes the importance of education and training in regard to results of PBI and APBI as they become emerging clinical treatments.

Protection of mice against challenge with homologous and heterologous serovars of Actinobacillus pleuropneumoniae after live vaccination

Protective immune responses and the virulence of Actinobacillus pleuropneumoniae (APP) have been attributed, in part, to toxins (Apx) produced by the bacterium. A mutant of the serovar 7 strain HS93 (HS93Tox-), lacking the genes encoding the structural toxin ApxA and the post-translational activating protein ApxC, but retaining the genes required for secretion ApxB and ApxD, was isolated and shown to be attenuated in a mouse model. A plasmid vector system was developed and used to express the ApxA gene from within the HS93Tox- strain. The resulting strain, HS93Tox-/pIG-T1K, expresses the Apx structural protein in a non-activated form. HS93Tox-/pIG-T1K was shown to be attenuated in a mouse model and to be capable of inducing Apx-specific antibodies, which were boosted on re-inoculation. Live vaccination of mice with HS93Tox-/pIG-T1K offered protection against homologous wild-type serovar 7 challenge, and also heterologous challenge with a serovar 1 strain. This is in contrast to vaccination with the HS93Tox- strain, which failed to protect mice against a heterologous challenge.

Associations of CYP1A1, GSTM1, and CYP2E1 polymorphisms with lung cancer suggest cell type specificities to tobacco carcinogens

The dramatic shift in the pathological presentation of lung cancer [the proportional decrease in squamous cell carcinoma (SCC) and increase in adenocarcinoma (AC)] observed in the United States after the 1950s may have taken place as the result of the reduction in polycyclic aromatic hydrocarbons (PAHs) and the increase in N-nitrosamines in inhaled smoke from filtered low-yield cigarettes. The predominant mutation patterns of these tumors also suggest differences in their etiology. We tested the hypothesis that genetic susceptibility to PAHs, as determined by polymorphisms in CYP1A1 and GSTM1, predominantly causes lung SCCs, and susceptibility to nitrosamines, as determined by polymorphisms in CYP2E1, predominantly causes lung ACs. CYP1A1 and GSTM1 play a major role in the metabolic activation and detoxification of PAHs, respectively, and CYP2E1 plays a major role in the metabolic activation of nitrosamines. We conducted a population-based case-control study among 341 incident lung cancer cases and 456 controls of Caucasian, Japanese, or Hawaiian origin. In-person interviews collected detailed information on lifestyle risk factors, and DNA extracted from peripheral leukocytes was used in PCR-based genotyping assays. Logistic regression analyses were used to compute odds ratios and 95% confidence intervals (CIs) for each cell type, adjusting for smoking and dietary variables. The presence of at least one copy of the CYP1A1 MspI variant allele was found to be associated with a 2.4-fold (95% CI, 1.2-4.7) increase in the risk of SCC when this gene was considered singly and a 3.1-fold (95% CI, 1.2-7.9) increase in the risk of SCC when combined with a GSTM1 deletion. No significant association was found between MspI and all lung cancers or other cell types or with the CYP1A1 exon 7 polymorphism. In contrast, the CYP2E1 RsaI and DraI polymorphisms were not clearly related to SCC risk, but these homozygous variant genotypes were associated with a 10-fold (95% CI, 0.0-0.5) decrease in the risk of overall lung cancer (RsaI variant) and AC (DraI variant) compared to the homozygous wild-type genotypes. Inverse associations with these two closely linked CYP2E1 polymorphisms were also suggested for small cell carcinoma. In agreement with past experimental and epidemiological data, the associations found in this study between CYP1A1 and lung SCC and between CYP2E1 and lung AC suggest a certain specificity of tobacco smoke PAHs for lung SCC and tobacco-specific nitrosamines for lung ACs.

The lived experience of aloneness for older women currently being treated for depression

A phenomenological study was conducted to answer the following question: What is the lived experience of aloneness for older women currently being treated for depression? Eight women from Northern Ohio composed the purposively selected sample. Transcriptions of each 1-hr interview were reviewed by use of Colaizzi's (1978) method of data analysis. The analysis identified two major experiences of self for all participants: aloneness in depression and aloneness in recovery. Five paired, and somewhat dichotomous, themes defined the essence of aloneness: (a) vulnerability versus self-reliance, (b) fear versus hope, (c) helplessness versus resourcefulness, (d) loss of self-control versus self-determination, and (e) identity confusion versus self-reflection. All the participants expressed profound feelings of moving between the five paired themes as they gained clarity of insight into their experiences of depression and recovery. Results of this study make a valuable contribution by providing important insights into the lived experience of aloneness among older women currently being treated for depression, offer direction in the assessment and treatment of these women, and serve as an impetus for further research.

The use of mammography in breast preservation in locally advanced breast cancer

PURPOSE

As the feasibility of breast preservation in locally advanced breast cancer is currently under evaluation, little information is available correlating mammographic changes to chemotherapy with local outcome. To evaluate the role of mammography in selecting candidates with locally advanced breast cancer for conservative local therapy, we analyzed mammographic changes in the breast to induction chemotherapy and correlated the radiologic appearance with pathologic outcome.

METHODS AND MATERIALS

From 1985 through 1993, 91 patients with Stage III breast cancer were enrolled on a multimodality clinical trial using chemohormonal therapy followed by local treatment and maintenance therapy. Induction therapy consisted of cyclophosphamide, doxorubicin, methotrexate,and 5-fluorouracil with hormonal synchronization using tamoxifen and conjugated estrogens. After nine cycles, surgical biopsies of the breast were performed. Through 1988, clinical examination alone directed the site for postinduction biopsy; for patients treated after 1988, mammography, in addition to physical examination, determined the biopsy location. Local treatment was determined by biopsy result. Patients with a pathologic complete response received radiation only to the breast adn regional nodes, while those with pathologically proven residual disease underwent mastectomy and postoperative radiotherapy. Nine additional cycles of maintenance chemotherapy were administered.

RESULTS

Fifty-five of 91 patients (58%) obtained a clinical complete response (CR) to induction chemotherapy. Twenty-eight of the 53 women with a clinical CR had both pre- and postinduction mammograms. Of these 28 women, 9 obtained a pathologic CR and 19 obtained a pathologic partial response (PR). Fifty-five percent of the pathologic complete responders had resolution of mammographic abnormalities on the postinduction mammograms. Sixty-eight percent (13) of the pathologic partial responders had abnormal mammographic findings. The positive predictive value for residual cancer using physical examination was 92%, while the negative predictive value was only 36%. Among patients with a clinical complete response, the positive and negative predictive values for residual cancer using postinduction mammography were 79% and 56%, respectively. Limitations of mammography included uncertain significance of residual microcalcifications and residual masses on postinduction chemotherapy mammograms.

CONCLUSIONS

Although mammography improved the accuracy of noninvasive evaluations in patients with a clinical complete response, pathologic assessment was still required to determine appropriate local therapy. More sensitive imaging modalities or modifications of film-screen mammography may improve noninvasive detection of residual disease following induction chemotherapy.