dylglycerol phosphate ( 3 ). For each of these lipids, there can exist several molecular species arising from the different lengths, unsaturation, and/or cyclopropane analogs of the acyl chains ( 4 ). The complexity of the E. coli lipidome, however, is even greater than can be explained by acyl chain heterogeneity. Numerous additional minor lipids are present in wild-type cells, as judged by isotopic labeling experiments and two-dimensional TLC ( 3 ). Many of these species cannot be identifi ed by their migration with standards of known lipids or biosynthetic precursors.Electrospray ionization-mass spectrometry (ESI-MS) is well suited to the analysis of intact lipids ( 5 ). Fragmentation during ionization is minimized and the sensitivity is high ( 6, 7 ). In addition, collision-induced dissociation mass spectrometry (MS/MS) allows for the structural analysis of the lipid ion of interest and, when combined with the high mass accuracy of time-of-fl ight mass spectrometers, can be used to propose a molecular formula for a particular ion.Current applications of mass spectrometry to lipid analysis have focused mainly on the quantifi cation of known lipid species, often coupling liquid chromatography directly to the mass spectrometer ( 8-10 ). These analyses compare levels of known lipid species present under various growth conditions or disease states. However, important changes in levels of unknown or minor lipids are diffi cult to analyze without knowledge of their structures and the availability of appropriate standards. Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) are the major membrane glycerophospholipids of Escherichia coli , constituting about 10% of the dry weight of the cell ( 1, 2 ). Important minor lipids include the precursors phosphatidic acid, CDP-diacylglycerol, phosphatidylserine, and phosphati-

Electrospray ionization mass spectrometry is a powerful technique to analyze lipid extracts especially for the identification of new lipid metabolites. A hurdle to lipid identification is the presence of solvent contaminants that hinder the identification of low abundance species or covalently modify abundant lipid species. We have identified several non-enzymatically derived minor lipid species in lipid extracts of Escherichia coli, phosphatidylmethanol, ethyl and methyl carbamates of PE and N-succinyl PE were identified in lipid extracts of Escherichia coli. Phosphatidylmethanol (PM) was identified by exact mass measurement and collision induced dissociation tandem mass spectrometry (MS/MS). Extraction in the presence of deuterated methanol leads to a 3 atomic mass unit shift in the [M-H]- ions of PM indicating its formation during extraction. Ethyl and methyl carbamates of PE, also identified by exact mass measurement and MS/MS, are likely to be formed by phosgene, a breakdown product of chloroform. Addition of phosgene to extractions containing synthetic PE significantly increases the levels of PE-MC detected in the lipid extracts by ESI-MS. Extraction in the presence of methylene chloride significantly reduced the levels of these lipid species. N-succinyl PE is formed from reaction of succinyl-CoA with PE during extraction. Interestingly N-succinyl PE can be formed in an aqueous reaction mixture in the absence of added E. coli proteins. This work highlights the reactivity of the amine of PE and emphasizes that careful extraction controls are required to ensure that new minor lipid species identified using mass spectrometry are indeed endogenous lipid metabolites.

Hidradenitis suppurativa (HS) is a chronic, debilitating disease with definitive treatment consisting of wide surgical excision of all affected tissue. Originally described in burns, Marjolin's ulcer (MU) has been described in a variety of wound types, including hidradenitis. HS patients often have long delays to diagnosis and management of their chronic wounds, leading to increased risk of MU. A retrospective review of our burn database was performed from 2008 to 2014. Seventy-two consecutive patients taken to the operating room for HS were retrospectively evaluated for demographic data, number of excisions, total area of excised skin, need for skin grafting, pathology results, and outcome. Fifty-eight percent of patients were male. Mean age was 36.88 ± 13.52 years. Mean size of excision was 743.71 ± 774.75 cm. Total number of operative procedures was 187, averaging 2.612 per patient, with 52% of patients undergoing skin grafting. Two patients had confirmed pathology of squamous cell carcinoma. Both were women with perineal HS and had metastatic disease on further workup. Both patients underwent chemotherapy and radiation with progression of their disease. The incidence of MU of 2.78% in this study is similar to the 2% incidence described historically in the burn population. All practitioners who treat HS patients should be aware of the devastating complication of MU arising in the chronic wound bed. We recommend that all excised tissue be sent to pathology for evaluation, and to consider early wide local excision of any chronically inflamed tissues to alleviate the risk of MU for this patient population.

There has been a tremendous evolution in our thinking about cancer since the 1880s. Breast cancer is a particularly good example to evaluate the progress that has been made and the new challenges that have arisen due to screening that inadvertently identifies indolent lesions. The degree to which overdiagnosis is a problem depends on the reservoir of indolent disease, the disease heterogeneity, and the fraction of the tumors that have aggressive biology. Cancers span the spectrum of biological behavior, and population-wide screening increases the detection of tumors that may not cause harm within the patient's lifetime or may never metastasize or result in death. Our approach to early detection will be vastly improved if we understand, address, and adjust to tumor heterogeneity. In this article, we use breast cancer as a case study to demonstrate how the approach to biological characterization, diagnostics, and therapeutics can inform our approach to screening, early detection, and prevention. Overdiagnosis can be mitigated by developing diagnostics to identify indolent disease, incorporating biology and risk assessment in screening strategies, changing the pathology rules for tumor classification, and refining the way we classify precancerous lesions. The more the patterns of cancers can be seen across other cancers, the more it is clear that our approach should transcend organ of origin. This will be particularly helpful in advancing the field by changing both our terminology for what is cancer and also by helping us to learn how best to mitigate the risk of the most aggressive cancers.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

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Neoadjuvant chemotherapy (NAC) increases rates of successful breast-conserving surgery (BCS) in patients with breast cancer. However, some studies suggest that BCS after NAC may confer an increased risk of locoregional recurrence (LRR). We assessed LRR rates and locoregional recurrence-free survival (LRFS) in patients enrolled on I-SPY2 (NCT01042379), a prospective NAC trial for patients with clinical stage II to III, molecularly high-risk breast cancer. Cox proportional hazards models were used to evaluate associations between surgical procedure (BCS vs mastectomy) and LRFS adjusted for age, tumor receptor subtype, clinical T category, clinical nodal status, and residual cancer burden (RCB). In 1462 patients, surgical procedure was not associated with LRR or LRFS on either univariate or multivariate analysis. The unadjusted incidence of LRR was 5.4% after BCS and 7.0% after mastectomy, at a median follow-up time of 3.5 years. The strongest predictor of LRR was RCB class, with each increasing RCB class having a significantly higher hazard ratio for LRR compared with RCB 0 on multivariate analysis. Triple-negative receptor subtype was also associated with an increased risk of LRR (hazard ratio: 2.91, 95% CI: 1.8–4.6, P < 0.0001), regardless of the type of operation. In this large multi-institutional prospective trial of patients completing NAC, we found no increased risk of LRR or differences in LRFS after BCS compared with mastectomy. Tumor receptor subtype and extent of residual disease after NAC were significantly associated with recurrence. These data demonstrate that BCS can be an excellent surgical option after NAC for appropriately selected patients.

Background: Surgical treatment of invasive lobular carcinoma (ILC) is challenging due to its diffuse growth pattern, and the positive margin rate after mastectomy is poorly described. Methods: We retrospectively determined the positive margin rate in those with stage I-III ILC undergoing mastectomy. We evaluated the relationship between management strategy and recurrence free survival (RFS). Results: In 357 patients, the positive margin rate was 10.6% overall and 18.7% in those with T3 tumors. Having a positive margin was associated with significantly shorter RFS on multivariate analysis (p ¼ 0.01). Undergoing additional local treatment (radiation or re-excision) for a positive margin was significantly associated with improved RFS (p ¼ 0.004). Older women with positive margins were significantly less likely to undergo additional local therapy. Conclusions: Even mastectomy fails to clear margins in a high proportion of patients with large ILC tumors, a finding which may warrant testing neoadjuvant strategies even prior to planned mastectomy.

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