Combined effects of flow condition and parasitism on shoaling behaviour of female guppies Poecilia reticulata

Group living in fish can provide benefits of protection from predators and some parasites, more efficient foraging for food, increased mating opportunities and enhanced energetic benefit when swimming. For riverine species, shoaling behaviour can be influenced by various environmental stressors, yet little is known how flow rate might influence the shoaling of diseased fish shoals. In view of the increasingly unpredictable flow rates in streams and rivers, this study aimed to assess the combined effect of flow condition and parasitism on the shoaling behaviour of a model fish species. Shoal size, shoal cohesion and time spent shoaling of female guppies Poecilia reticulata were compared when infected with the directly transmitted ectoparasite Gyrodactylus turnbulli under flow and static conditions. Flow condition was an important factor in influencing shoaling behaviour of guppies with the fish forming larger shoals in the absence of flow. When a shoal member was infected with G. turnbulli, shoal cohesion was reduced, but the magnitude of this effect was dependent on flow condition. In both flow and static conditions, bigger fish formed larger shoals than smaller counterparts. Future changes to stream hydrology with more frequent flooding and drought events will affect the shoaling tendency of fish. During high-flow events, diseased fish may not be able to keep up with shoal mates and therefore have a higher risk of predation. Additionally, these findings may be important for aquaria and farmed species where an increase in flow rate may reduce aggregation in fish.

Ottawa Cardiac Oncology Program wins 2013 Cancer Quality Council of Ontario Innovation Award

The Ottawa Cardiac Oncology Program (ocop) has won the 2013 Innovation award from the Cancer Quality Council of Ontario [...]

Treatment outcomes for male breast cancer: a single-centre retrospective case-control study

BACKGROUND

Male breast cancer (bc) is a rare disease, and the availability of information on treatment outcomes is limited compared with that for female bc. The objective of the present study was to compare disease-free (dfs) and overall survival (os) for men compared with women having early-stage bc.

METHODS

This retrospective case-control study compared men and women treated for stage 0-iiib bc at a single institution between 1981 and 2009. Matching was based on age at diagnosis, year of diagnosis, and stage. Treatment, recurrence, and survival data were collected. Kaplan-Meier analysis was used to calculate os and dfs.

RESULTS

For the 144 eligible patients (72 men, 72 women), median age at diagnosis was 66.5 years. Treatments included mastectomy (72 men, 38 women), radiation (29 men, 44 women), chemotherapy (23 men, 20 women), and endocrine therapy (57 men, 57 women). Mean dfs was 127 months for women compared with 93 months for men (p = 0.62). Mean os was 117 months for women compared with 124 months for men (p = 0.35). In multivariate analysis, the only parameter that affected both dfs and os was stage at diagnosis.

CONCLUSIONS

This case-control study is one of the largest to report treatment outcomes in early-stage male bc patients treated in a non-trial setting. Male patients received systemic therapy that was comparable to that received by their female counterparts, and they had similar os and dfs. These results add to current evidence from population studies that male sex is not a poor prognostic factor in early-stage breast cancer.

Comparative cervical profiles of adult and under-18 front-row rugby players: implications for playing policy

OBJECTIVE

To compare the cervical isometric strength, fatigue endurance and range of motion of adult and under-18 age-grade front-row rugby players to inform the development of a safe age group policy with particular reference to scrummaging.

DESIGN

Cross-sectional cohort study.

SETTING

'Field testing' at Murrayfield stadium.

PARTICIPANTS

30 high-performance under-18 players and 22 adult front-row rugby players.

OUTCOME MEASURES

Isometric neck strength, height, weight and grip strength.

RESULTS

Youth players demonstrated the same height and grip strength as the adult players; however, the adults were significantly heavier and demonstrated substantially greater isometric strength (p<0.001). Only two of the 'elite' younger players could match the adult mean cervical isometric strength value. In contrast to school age players in general, grip strength was poorly associated with neck strength (r=0.2) in front-row players; instead, player weight (r=0.4) and the number of years' experience of playing in the front row (r=0.5) were the only relevant factors in multivariate modelling of cervical strength (R(2)=0.3).

CONCLUSIONS

Extreme forces are generated between opposing front rows in the scrum and avoidance of mismatch is important if the risk of injury is to be minimised. Although elite youth front-row rugby players demonstrate the same peripheral strength as their adult counterparts on grip testing, the adults demonstrate significantly greater cervical strength. If older youths and adults are to play together, such findings have to be noted in the development of age group policies with particular reference to the scrum.

Clinical outcomes of women with metastatic breast cancer treated with nab-paclitaxel: experience from a single academic cancer centre

BACKGROUND

Nab-paclitaxel is a solvent-free, taxane-based chemotherapy approved for the treatment of metastatic breast cancer (mbc). This study reports clinical benefit and toxicities experienced by women with mbc treated with nab-paclitaxel at the Ottawa Hospital Cancer Centre.

METHODS

Women with mbc treated with single-agent nab-paclitaxel between June 2006 and December 2010 were included in this analysis. Retrospective data obtained included demographics, disease characteristics, prior chemotherapy, nab-paclitaxel treatment, toxicity, and survival. Clinical benefit was defined as partial or complete response or stable disease (by clinical or radiologic evaluation, or both) at 6 months or more.

RESULTS

Of 43 women (mean age: 57.0 years; range: 34-74 years), most had disease positive for estrogen or progesterone receptor (72.1%, 58.1%), or both. Nab-paclitaxel was administered weekly (qw: 44.2%), every 3 weeks (q3w: 46.5%), q3w switched to qw (7.0%), or qw switched to q3w (2.3%). Median duration of therapy was 5.1 months (qw) and 3.0 months (q3w). Sensory neuropathy was the primary toxicity (45.4% qw, 38.1% q3w; p = 0.62). Clinical benefit was observed in most women (76.2% qw, 57.1% q3w; p = 0.20). Women receiving nab-paclitaxel had a median overall survival of 13.6 months qw (range: 8.1-28.3 months) and 10.8 months q3w (range: 5.9-17.9 months; p = 0.03). Regardless of dosing schedule, women experiencing clinical benefit lived significantly longer than those not experiencing a benefit (17.3 months vs. 7.7 months; hazard ratio: 0.14; 95% confidence interval: 0.06 to 0.33).

CONCLUSIONS

Our clinical experience demonstrates that most women treated with nab-paclitaxel experienced some clinical benefit. Patients achieving clinical benefit lived significantly longer than those who did not. Nab-paclitaxel was well tolerated, with the primary toxicity being mild sensory neuropathy. Nab-paclitaxel represents another treatment option, with a favourable toxicity profile, for women with mbc.

Abstract P3-04-11: Systemic treatment decision making for patients with stage I and II, hormone receptor positive, her2/neu negative breast cancer

Background: Oncotype DX is a clinically validated risk stratification tool that can predict the risk of recurrence and the benefit of adjuvant chemotherapy in women with hormone receptor positive (HR+), HER2/neu negative early stage breast cancer (EBC). This tool has been available to oncologists in Ontario since April 2010 at significant cost, yet no guidelines exist regarding their use. This retrospective chart review examined the factors that were associated with use of Oncotype DX at a tertiary care cancer centre.

Materials and methods: One hundred patients (pts) diagnosed with HR+, HER2/neu negative EBC (stage I-II), who underwent Oncotype DX testing between April 1, 2010, and June 30, 2011 were included in the study. A second control group of 100 patients with similar disease characteristics but who did not receive Oncotype DX testing were randomly selected. Data collection included demographics, tumor grade and stage, and Adjuvant! Online recurrence risk scores. The distribution of patients in each category was compared using the chi-square test to detect statistically significant differences between distributions.

Results: Median age in the Oncotype DX group was 58 years (r: 26–77) and 63 years (r: 30–81) in the control group. 20 patients in the Oncotype DX group were aged 35–49, 57 patients were aged 50–64, and 23 patients were aged 65 or older, while the control group had 16, 43, and 41 patients, respectively (p = 0.02). The Oncotype DX group had 72 pre- and perimenopausal pts and 28 postmenopausal patients, while the control group had 81 and 19 patients, respectively (p = 0.13). 20, 56, and 24 pts in the Oncotype DX group had grade 1, 2, and 3 histology, respectively, vs. 44, 44, and 12, respectively in the control group (p &lt; 0.01). The Oncotype DX group had 7 patients with tumors between 1–10 mm, 55 between 10.1–20 mm, 34 between 20.1–50 mm, and 4 greater than 50 mm, vs. 29, 42, 23, and 1, respectively in the control group (p &lt; 0.01). When 10-year Adjuvant Online recurrence scores were calculated using tamoxifen, 17, 67, and 16 patients in the Oncotype DX group had risk scores of &lt;15, 15–25, and &gt;25, respectively, vs. 62, 33, and 5 in the control group (p &lt; 0.01). When the scores were calculated using tamoxifen plus an aromatase inhibitor, 49, 42, and 9 patients in the Oncotype DX group, and 75, 24, and 1 patients in the control group fell into these categories, respectively (p &lt; 0.01). Median Oncotype DX recurrence score was 17 (r: 0–70), with 10-year recurrence risk of 11% (r:3–34%).

Conclusions: This single-centre series is aimed at identifying potential clinical and pathological factors which can influence physicians' decision to request Oncotype DX testing for pts with EBC. Physicians were more likely to request Oncotype DX testing for patients that were younger, had larger and higher grade tumors, and higher Adjuvant! Online recurrence risk scores. These results will be used to design a prospective study evaluating these factors and how Oncotype DX testing may influence treatment decision making.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-04-11.

Abstract P3-11-03: Treatment outcomes for early stage male breast cancer: a single centre retrospective case-control study

Background: Male breast cancer (BC) is a rare disease with a reported incidence of 1%, and treatment strategies are therefore driven by studies conducted in the female BC population. There is also limited information with regards to treatment outcomes for men with early stage BC, particularly when compared with their female counterparts. The objective of this study is to compare the disease free survival (DFS) and overall survival (OS) of males with early stage BC compared to age and stage matched females in a single institution.

Methods: A retrospective matched case-control study was conducted to compare male and female pts treated for stage 0 to IIIB BC, at the Ottawa Hospital Cancer Centre, between 1981 and 2009. Matching of male and female pts was done based on age at diagnosis (+/− 2 years), year of diagnosis (+/− 1 year), and disease stage. Data regarding surgery, adjuvant radiation, chemotherapy, and endocrine therapy was collected. Overall survival and disease-free survival were calculated using Kaplan-Meir analysis.

Results: A total of 144 pts (72 female; 72 male) were eligible for this study; median age at diagnosis for both groups was 74 years (r: 30–85). Median follow-up was 54 months (r: 2–204) for males and 54 months (r: 4–241) for females. All 72 men underwent mastectomy compared to 38 females (53%). Forty-four (61%) females received adjuvant radiation therapy compared to 29 (40%) males. Twenty (28%) females received adjuvant chemotherapy, compared to 23 (31%) males. All female pts had estrogen receptor positive (ER+) disease, while 59 males (13 unknown) had ER+ disease. An equal number of males and females (79%) received endocrine treatment. The mean DFS for females was 127 months (25th percentile 33 months; median 104 months; 75th percentile 174 months), compared to 93 months (25th percentile 46 months; median 88 months; 75th percentile 112 months) for males (p = 0.62). Mean OS for females was 117 months (25th percentile 40 months; median 107 months; 75th percentile 136 months), and 124 months (25th percentile 48 months; median 90 months; 75th percentile 128 months) for males (p = 0.35). In multivariate analysis, the only parameter that affected both DFS and OS was stage at diagnosis (hazard ratio 0.42, 95% CI 0.18–1.00; hazard ratio 0.25, 96% CI 0.09–0.68).

Conclusions: This is one of the largest case-cohort studies to report on treatment outcomes of early stage male BC pts treated in a non-trial setting. Male pts received comparable systemic therapy (chemotherapy/endocrine) as their female counterparts and DFS and OS were similar. These results add to current evidence from population studies that male sex is not a poor prognostic factor for treatment outcomes in early stage BC. The development of a national male breast cancer registry would facilitate the evaluation of modern treatment strategies and patient outcomes in this population.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-03.

PD04-04: Sexual Dysfunction in Women with Early Stage Breast Cancer on Endocrine Therapy: Encouraging Results from a Prospective Study

Background: While the side effects of endocrine therapy (ET) for early stage breast cancer (EBC) have been extensively studied, the link between ET and sexual dysfunction (SD) remains a contentious issue. Most studies have focused on documenting only the presence of problems in specific domains of endocrine symptoms (ES) (e.g. hot flushes, vaginal dryness) and sexual functioning (SF) (interest, satisfaction, arousal, lubrication) without also taking sexual distress into account. To our knowledge, there have been no prospective longitudinal studies evaluating SF and SD before the onset of ET and after treatment initiation. We report the initial 6 month results of this study of SD in women initiating ET for EBC.

Methods: Hormone receptor positive EBC post-menopausal women were approached for a larger study of SF aimed at comparing the prevalence of SD across endocrine agents (tamoxifen vs aromatase inhibitor) and at evaluating the impact of anxious predisposition and ES on SD. Here we report on changes in ES, SF and SD after 6 months of ET. SF was evaluated with the Female Sexual Function Index (FSFI) while sexual distress was assessed with the Female Sexual Distress Scale. ES were measured with FACT-B ES subscale. Participants completed questionnaires prior to initiation (T0) of ET and at 6 months (T1). SD was assessed using the APA classification.

Results: Between January 2009 and May 2011, 118 EBC patients entered the study and 83 have completed both assessments (mean age 62; 30% received chemotherapy). Over time, the levels of ES increased (p &lt;0.001). Despite the worsening of ES at T1, no decline in SF was observed, this for each FSFI domain (desire, arousal, lubrication, discomfort during intercourse and satisfaction). There was no change in the percentage of women reporting 1 or more sexual problems over time (85% vs 87%, ns) nor in the percentage who were sexually distressed (32% vs 34%, ns). The prevalence of SD did not increase after 6 months of ET (T0=28% vs T1=33%, ns). There were no differences in the percentage of women who worsened (i.e., no SD at T0 but SD at T1, 12%) and those who improved (SD at T0 but no SD at T1, 7%) over time (McNemar X2, p &gt;.5) Importantly, women classified as experiencing SD at T0 were more likely to also experience SD at T1 (OR=4.5, 95% CI=2.162 to 9.366) than women who had no SD at T0.

Discussion: This is the first prospective case cohort study evaluating ES, SF and SD in women with EBC on ET. The good news for women is that although ES increased during ET (p &lt; 0.001), this did not have a negative impact on sexual problems (85% vs 87%, ns) or SD (32% vs 34%, ns). This is encouraging news but longer follow-up of these women will provide further insight into the impact of ET on ES and SD over time (&gt; 6 months). The impact of specific types of ET on ES, and SD will also be evaluated. Of interest, the high uptake and high completion rate (&gt;80%) of questionnaires, indicate this is a matter of relevance and importance to women taking adjuvant ET and merits acknowledgement and sensitive discussion.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD04-04.

OT3-02-01: A 1-Year Prospective Longitudinal Study of the Role of Psychosocial Factors in Adherence to Adjuvant Endocrine Therapy in Early Breast Cancer

Background: Extensive evidence suggests that endocrine therapy (ET) and adherence to adjuvant ET directly impacts on disease-free and overall survival in women with hormone receptor positive (HR+) early stage breast cancer (EBC). Despite this, adherence to ET is suboptimal, with 35%-50% of patients discontinuing therapy earlier than recommended. Interventions to improve adherence are lacking, due in part to a poor understanding of the modifiable risk factors influencing adherence. Virtually all authors have focused on educational needs of patients and side effect management of ET but there remains a paucity of data on how potentially modifiable psychosocial factors present at outset of treatment initiation influence adherence. We believe that a better understanding of these factors may lead to interventions which enable women to adhere to long term life-saving therapies. This study aims to identify such factors guided by the Common-Sense Model of Self-Regulation which proposes that cognitive, emotional, coping and interpersonal factors are modifiable determinants of adherence.

Study Design: The study is a single centre prospective longitudinal quantitative study. Women diagnosed with HR+ EBC for which endocrine therapy is intended will be enrolled. Participants will complete questionnaires prior to initiating ET, then at 3, 6 and 12 months. The predictor variables are: 1) modifiable factors including illness and treatment cognitions, self-efficacy in coping with side effects anticipated or experienced, fear of breast cancer recurrence, trait anxiety, patient-physician interaction, 2) treatment-induced toxicities and 3) clinical factors including ET, chemotherapy, radiation, cancer stage and menopausal status. The outcome variable is adherence measured at each assessment post-treatment initiation with pill counts and participants'self-report.

Inclusion criteria: 1.Histologically proven Stage I, II, IIIa EBC; 2. Treatment with ET (tamoxifen or an aromatase inhibitor).

Specific Aims: To evaluate the impact on adherence to ET by 1) potentially modifiable psychosocial factors 2) side effects and 3) clinical factors.

Statistical Method: Adherence responses will be transformed into dummy coded variables (0=take ET as prescribed; 1=does not take ET as prescribed). For each assessment, several separate univariate logistic regressions will be conducted with demographic (age, education, work and marital status, ethnicity), cognitive (illness and treatment perception), emotional (fear of recurrence and anxiety), coping (self-efficacy), and patient-physician relationship (role preference, trust and satisfaction), severity of side effects and clinical factors, as independent predictors of adherence. Only predictors which are significant at the 0.25 level will be entered in subsequent hierarchical multiple regression models to identify the main determinants of adherence.

Accrual: Expected study accrual is 200 over 12–18 months. Accrual started in May of 2011 and 36 patients have been accrued to the study.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-02-01.

Stable charged cosmic strings

We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius ≈10(-18)  m. The vacuum remains stable in our model, because neutral strings are not energetically favored.