Abstract PD06-03: Predictors of Local Recurrence in High Risk Patients Undergoing Neoadjuvant Chemotherapy in the I-SPY1 Trial (CALGB 150007/12 ACRIN 6657)

Background: Given that many patients with more locally advanced breast cancer are receiving neoadjuvant therapy, predictors of local recurrence will be important for learning how to optimize the use of local regional therapy. We investigated the local regional recurrence (LRR) rates in patients treated with neoadjuvant chemotherapy in the I SPY1 trial. Methods: Data were analyzed from 221 women that were enrolled in I-SPY1 and completed treatment. Final surgical procedure was not randomized. Multiple clinicopathologic factors were investigated in both the lumpectomy (BCS) and mastectomy cohorts. Logistical regression was applied to identify factors predicting LRR although this was not a specified endpoint for the I-SPY parent trial.

Results: At 3.9 years median followup, 123 patients (56%) had mastectomy, 93 patients (42%) had breast conservation and 5 did not have a surgical procedure. The majority of patients in both groups received radiation with 77% and 94% in the mastectomy and breast conservation (BC) group respectively. Within the mastectomy group, there was no correlation between whether pts received PMRT and predictors of high LRR risk: LVI, grade, stage and nodal disease following neoadjuvant chemotherapy. Rates of PMRT in each residual cancer burden (RCB) category were 78%(RCB0), 80%(RCB 1), 81%(RCB2) and 66%(RCB3, highest residual burden of disease) for the mastectomy group. Median tumor size before chemotherapy was 6.0 cm and 5.0 cm mastectomy and BC groups, respectively. Fewer patients had pCR in the mastectomy group, compared to the BC group. LRR rates were very low for both the mastectomy and BC groups, with 9 (7.5%) and 7 (7.3%) total recurrences, respectively. Only 2 patients in each group had LLR without distant recurrence (2% total). For the mastectomy and BC groups, 4/7 and 3/5 patients had synchronous presentation of their local and distant disease. For patients with distant recurrence 44% and 29% had a local recurrence in the BC and mastectomy groups respectively.

In a logistical regression model, patients with local progression in the BC group were 17 times more likely to develop distant progression (p=0.005) while in the mastectomy group, those with LLR were 10.5 times more likely to develop distant progression (p=0.001). Individual factors that appeared to be predictive of local recurrence included clinical size of tumor at presentation (p=0.032) for the BC group, and final pathologic tumor size in the mastectomy group (p=0.002). Patients with low risk molecular features (wound healing quiescent, luminal A, NKI low, and ROR-S low) did not have any local recurrences.

Conclusion: Although the sample size was small, and the ability to discriminate between the two surgical groups was limited, in this high risk group of locally advanced breast cancer pts, BC does not appear to lead to an increased rate of LRR. In fact tumor biology that predicts for high risk of distant progression might be able to be applied to risk stratification for LRR. Patients with low risk of distant recurrence (e.g. those with pCR, RCB1or low-risk molecular markers) may be those that we can consider testing PMRT vs not in future neoadjuvant trials.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD06-03.

Beta-lactams and beta-lactamase-inhibitors in current- or potential-clinical practice: a comprehensive update

The use of successive generations of beta-lactams has selected successive generations of beta-lactamases including CTX-M ESBLs, AmpC beta-lactamases, and KPC carbapenamases in Enterobacteriaceae. Moreover, this cephalosporin resistance, along with rising resistance to fluoroquinolones, is now driving the use of carbapenems and unfortunately the carbapenem resistance has emerged markedly, especially in Acinetobacter spp. due to OXA- and metallo-carbapenemases. The industry responded to the challenge of rising resistance and recently developed some novel beta-lactams such as ceftobiprole, ceftaroline etc. and many beta-lactam compounds, including beta-lactamase-inhibitors, such as BMS-247243, S-3578, RWJ-54428, CS-023, SMP-601, NXL 104, BAL 30376, LK 157, and so on are under trials. This review provides the comprehensive accounts of the developments in penicillins, cephalosporins, carbapenems, and beta-lactamase-inhibitors, and the insight about medicinal chemistry, mechanism(s) of action and resistance, potential strategies to overcome resistance due to beta-lactamases, and also the recent advancements in the development of newer beta-lactam compounds; some of which are still under trials and yet to be classified. This review will fill the gap since previously published reviews and will serve as a comprehensive update on the current topic.

Characterization of germanium linear kinoform lenses at Diamond Light Source

The unprecedented brilliance achieved by third-generation synchrotron sources and the availability of improved optics have opened up new opportunities for the study of materials at the micrometre and nanometre scale. Focusing the synchrotron radiation to smaller and smaller beams is having a huge impact on a wide research area at synchrotrons. The key to the exploitation of the improved sources is the development of novel optics that deliver narrow beams without loss of brilliance and coherence. Several types of synchrotron focusing optics are successfully fabricated using advanced miniaturization techniques. Kinoform refractive lenses are being developed for hard X-ray beamlines, and the first test results at Diamond are discussed in this paper.

Lipoxygenase inhibitory tetraketones: potential remedial source for inflammation and asthma

OBJECTIVE

A series of tetraketones has been synthesized by way of a one pot synthesis and screened for inhibitory activity against the enzyme lipoxygenase.

METHOD

An efficient and high yielding one pot synthesis to tetraketones [2-22] has been developed by way of tetraethyl ammonium bromide (Et4N+Br-) mediated condensation of cyclohexane-1, 3-dione [1] with a variety of aldehydes. Lipoxygenase enzyme solution was prepared so that enzyme concentration in reaction mixture was adjusted to give rates of 0.05 absorbance/minute. The test compounds were prepared in methanol of concentrations 50, 25, 12.5, 6.25 and 3.125 microM. The reaction mixture contained 160 microL (100 mM) sodium phosphate buffer (pH 8.0), 10 microL of test-compound solution and 20 microL of lipoxygenase solution. The contents were mixed and incubated for 10 minutes at 25 degrees C. The reaction was then initiated by the addition of 10 microL substrate solution (linoleic acid, 0.5 mM, 0.12% w/v tween 20 in the ratio of 1:2), with the formation of (9Z, 11E)-(13S)-13-hydroperoxyoctadeca-9,11-dienoate, the change of absorbance at 234 nm was followed for 6 minutes. The concentrations of the test compounds that inhibited the lipoxygenase activity by 50% (IC50) were determined by monitoring the effect of increasing concentrations of these compounds in the assays on the degree of inhibition. The IC50 values were calculated by means of the EZ-Fit Enzyme-Kinetics Program (Perrella Scientific Inc., Amherst, U.S.A.).

RESULT

The tetraketones [2-22] were synthesized in high yields (91-98%) using mild reaction conditions. Most of these compounds showed significant inhibitory activity against the enzyme lipoxygenase. It was found that the presence of substituents which increase delocalization of electrons enhances the inhibitory activity.

CONCLUSION

It is concluded that the study is likely to lead to the discovery of therapeutically efficient agents against important disorders such as inflammation and asthma.

The Prevalence of Self-Reported Halitosis and Oral Hygiene Practices among Libyan Students and Office Workers

AIMS

The aims of this study were to assess the prevalence of self-reported halitosis, oral hygiene practices and related diseases among Libyan students and employees.

METHODS

Six hundred self-administered structured questionnaires were used to investigate self-perception of halitosis and oral hygiene practices among a group of Libyan volunteers. Chi square test was used to detect significant differences between frequencies and to test correlation between self-perception of halitosis and measures of oral hygiene.

RESULTS

Forty three percent of the subjects were males and 57% were females. Forty four percent of the males and 54% of the females revealed self-perception malodour. Malodour was reported with the highest frequency (68%) during wake up time. Malodour was perceived by 31.7% of the females and 23.4% of the males during the hand-on-mouth test (p=0.04). Significantly more females (89.9%) than males (75.7%) practiced brushing (p<0.001). Fifty one percent of the males and 49.6% of females had dental caries. Smoking was significantly (p<0.001) more prevalent among males (17%) than among females (1%). Brushing was practiced by 85% of non-smokers and 68% of smokers (p=0.004). About 71% of the subjects who practiced brushing reported malodour during wake up time in comparison to subjects who did not practice brushing (p=0.041).

CONCLUSIONS

The prevalence of self-perceived malodour among the Libyan volunteers in this study is within the range of other studies. There is a great demand to reduce the incidence of dental caries and periodontal diseases.

Laparoscopic resection for colorectal cancer

BACKGROUND

This study examined one surgeon's practice to determine the place of laparoscopic colorectal cancer surgery.

METHODS

Some 365 patients undergoing elective colorectal cancer resection (219 colonic, 146 rectal) were studied prospectively. Early (1994-1997; 104 patients), middle (1998-2001; 112) and late (2002-2005; 149) cohorts were analysed with respect to suitability for laparoscopic surgery, conversion and outcome.

RESULTS

Forty-six of 135 patients undergoing open resection were suitable for laparoscopic surgery but randomized to open surgery. The proportion of attempted laparoscopic resections (35.6, 65.2 and 80.6 per cent in early, middle and late cohorts) and patients thought suitable for laparoscopic resection (37.5, 87.5 and 94.0 per cent respectively; P = 0.001) increased over time. Independent predictors of conversion were rectal cancer surgery (odds ratio (OR) 3.12 versus colonic surgery) and body mass index 28 kg/m(2) or more (OR 3.87). Conversion was necessary in all five patients with a threatened margin predicted by preoperative magnetic resonance imaging. After exclusion of these patients the conversion rate in the late cohort was 8.7 per cent. During the same period, inclusion of 20 patients who were suitable for laparoscopic surgery but underwent open resection meant that 135 (90.6 per cent) of 149 patients were actually suitable for laparoscopic resection.

CONCLUSION

With experience, laparoscopic surgery is feasible in around 90 per cent of elective colorectal cancer resections.

Conjugative plasmids in multi-resistant bacterial isolates from Indian soil

AIMS

Determination of heavy metal and antibiotic resistance and presence of conjugative plasmids in bacteria isolated from soil irrigated with wastewater.

METHODS AND RESULTS

Composite soil samples were collected from Ghaziabad, Uttar Pradesh, India. Forty different bacteria were selected from nutrient agar and characterized by morphological, cultural and biochemical tests. All the isolates were tested for their resistance to different heavy metals and antibiotics. The DNA derived from multiple metal and antibiotic-resistant bacterial isolates was PCR amplified and plasmid-specific sequences (IncP, IncN, IncW, IncQ and pMV158-type) were analysed by dot blot hybridization. All isolates gave PCR products with trfA2 and oriT primers of the IncP group. These PCR products also hybridized with the RP4-derived probes. However, the samples were negative for all the other investigated plasmids as proved by PCR and dot blots.

CONCLUSIONS

The presence of conjugative/mobilizable IncP plasmids in the isolates indicates that these bacteria have gene-mobilizing capacity with implications for potential dissemination of introduced recombinant DNA.

SIGNIFICANCE AND IMPACT OF THE STUDY

The detection of IncP plasmids in all the bacterial isolates is another proof for the prevalence of these plasmids. We propose that IncP plasmids are mainly responsible for the spread of multi-resistant bacteria in these soils.

Comparative features and outcomes of malaria at a tertiary care hospital in Karachi, Pakistan

OBJECTIVES

A comparison of clinical and laboratory features, diagnostic methods, drug treatment, and outcomes for patients hospitalized with malaria by Plasmodium species.

METHODS

Records of 521 patients hospitalized during the four and half-year study period were analyzed.

RESULTS

Infections were caused by Plasmodium vivax (51.8%), Plasmodium falciparum (46.5%), P. vivax plus P. falciparum (1.3%), and Plasmodium malariae (0.4%). Vomiting (odds ratio (OR)=1.86, p=0.001) and abdominal pain (OR=1.60, p=0.024) occurred more frequently in patients infected with P. falciparum compared to P. vivax; this was also the case for hepatomegaly, splenomegaly and jaundice. Low hemoglobin levels were common but were significantly lower with P. falciparum, and creatinine levels were significantly higher with P. falciparum. Treatment regimens consisted of single drug therapy (61.5%), appropriate combination therapy (15.8%), and inappropriate combination therapy (22.7%). Antimalarials given alone included chloroquine (38.7%), quinine (19%) and doxycycline (1.5%). The overall mortality was 1.7% (n=9) and nearly 56% of patients developed disease complications, most commonly thrombocytopenia (36.4%), anemia (23.4%), and thrombocytopenia plus anemia (32.7%).

CONCLUSIONS

Despite resistance, chloroquine was prescribed in patients with malaria requiring hospitalization. We found a high proportion of single antimalarial drug use as well as inappropriate combination therapy (22.7%), and inadequate use of primaquine terminal prophylaxis. Physicians need to be acquainted with malaria treatment guidelines in an endemic zone.