Stage IIIA Non-Small Cell Lung Cancer Treatment and Outcomes: A Single Institution Retrospective Analysis

PURPOSE/OBJECTIVE(S)

Treatment of locally advanced non-small cell lung cancer (NSCLC) remains challenging, with a multitude of treatment options available for Stage III patients. We hypothesized that Stage IIIA outcomes differ by treatment received.

MATERIALS/METHODS

We performed a retrospective review of NSCLC patients ≥18 years old with Stage IIIA disease treated 1/1/2010-03/01/2022. Demographics, treatment received, treatment outcomes, and failure patterns were collected. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier analysis. Kruskal-Wallis ANOVA was used to compare groups.

RESULTS

Of 352 patients identified, 160 had Stage IIIA NSCLC with a median follow-up of 29.1 months. Patients had a median age of 63 years, 79 (49.4%) were male, and 137 (85.6%) were current/former smokers (with 30 median pack-years). Patients were treated as follows: 17 (11%) surgery alone (S), 91 (57%) definitive radiation ± chemotherapy (CRT), 52 (33%) neoadjuvant therapy followed by surgery (Neo). 6 (12%) of the Neo group received chemoimmunotherapy, and 21 (51%) of the 41 CRT patients received adjuvant immunotherapy. Between the three groups, there were no significant differences in tumor size as measured by T-staging (p = 0.83) and baseline FEV1/FVC (p = 0.92). Median PFS was 33.5mo (95% CI 13.2-NA) for group S, 18.4mo (95% CI 12.7-42.2) for CRT, and 19.7mo (95% CI 13.9-NA) for Neo with no significant intergroup difference (p = 0.72). Median OS was 33.5mo (95% CI 13.2-NA) for S, 48.7mo (95% CI 36.0-88.9) for CRT, and 50.9mo (95% CI 41.9-NA) for Neo with no significant intergroup difference (p = 0.94). Among the 17 primary surgical patients, 11 (65%) experienced failure: 6 (35%) local, 5 (29%) regional, and 7 (41%) distant. Among the 91 CRT patients, 57 (63%) experienced failure: 40 (44%) local, 35 (38%) regional, and 28 (31%) distant. Among the 52 Neo patients, 26 (50%) experienced failure: 14 (27%) local, 15 (29%) regional, and 17 (33%) distant. There were no significant differences in rates of local failure (p = 0.26), regional failure (p = 0.59), distant failure (p = 0.79), or any failure (p = 0.41) among the three treatment groups. The most common locations for distant failure were pleural effusions (n = 15, 29%), CNS (n = 14, 27%), and bone (n = 11, 21%).

CONCLUSION

In this single institution retrospective study, we find no significant differences in PFS, OS, and failure patterns between patients with Stage IIIA NSCLC treated with definitive (chemo)radiation and neoadjuvant therapy. Numeric improvement in PFS in surgery-only patients is consistent with expected patient selection of this group. Further work in the immunotherapy era is needed.

Abstract PR008: Development and testing of a polygenic risk score for breast cancer. Aggressiveness

Background: Aggressive breast cancers have increased proliferation or metastatic potential and portend a poor prognosis. The ability to identify women at elevated risk of aggressive cancers could have major implications for screening and prevention, yet there are no available tools for predicting aggressive cancer risk. We sought to construct a polygenic risk score (PRS) for aggressive breast cancers by leveraging the associations of single nucleotide polymorphisms (SNPs) with tumor gene expression. We used as our measure of aggressiveness the risk of recurrence score weighted on proliferation (ROR-P), a validated tumor prognostic signature. We hypothesized that known breast cancer susceptibility SNPs would have differential associations with ROR-P, which could then be used to construct a PRS for ROR-P. Methods: We developed our PRS in a case-only analysis of 3 studies containing SNP genotypes and tumor gene expression: The Cancer Genome Atlas, METABRIC, and the I-SPY 2 TRIAL (total n=2,363). We used linear regression models to evaluate individual SNP associations with ROR-P, adjusted for genetic ancestry and study. We then constructed PRS using varying p-value thresholds and used cross-validation to identify the PRS with highest model r2. To assess whether the ROR-P PRS was associated with poor prognosis, we performed survival analysis in two longitudinal cohorts of breast cancer patients: the UK Biobank (women with incident invasive cancers only) and the Pathways Study. These studies included 10,196 total cases with 785 deaths. We built Cox proportional hazards models to evaluate the association between the ROR-P PRS (adjusted for genetic ancestry) and breast cancer-specific survival (BCSS) in both studies. We then performed meta-analysis of the Cox model results. We also constructed joint models containing the ROR-P PRS and a PRS representing the case-case risk of ER-negative vs. ER-positive cancer, PRSER-/ER+. Results: We tested the associations between 226 breast cancer susceptibility SNPs and ROR-P. The best-performing PRS contained 76 SNPs and had a cross-validated r2 of 0.051. In the UK Biobank and Pathways Study, higher ROR-P PRS was associated with worse BCSS, with nearly identical effects observed in each study, HR per standard deviation of 1.13 (95% CI 1.05-1.21, p=9.0x10-4) in meta-analysis. The ROR-P PRS’s effect was minimally attenuated when adjusted for PRSER-/ER+, suggesting that the ROR-P PRS was providing additional prognostic information beyond ER status. Conclusions: We used breast cancer susceptibility SNPs to construct a PRS for ROR-P, a prognostic signature recapitulating aggressiveness, and found the ROR-P PRS to be associated with worse BCSS. Our findings represent an improvement on current PRS for overall breast cancer risk, which preferentially predict cancers with favorable prognosis. Given that aggressive cancers are more likely to present as advanced cancers even among women undergoing routine screening, our findings could potentially identify women who may benefit from more intensive screening.

Citation Format: Yiwey Shieh, Jacquelyn Roger, Christina Yau, Denise Wolf, Gillian Hirst, Lamorna Swigart, Scott Huntsman, Donglei Hu, Jovia Nierenberg, Pooja Middha, Rachel Heise, Linda Kachuri, Qianqian Zhu, Song Yao, Christine Ambrosone, Marilyn Kwan, Bette Caan, John Witte, Lawrence Kushi, Laura van ’T. Veer, Laura Esserman, Elad Ziv. Development and testing of a polygenic risk score for breast cancer. Aggressiveness. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr PR008.

Abstract C29: Social networks at diagnosis and recurrence, breast cancer-specific mortality, and overall mortality in white and non-white women in the Pathways Study

Background: Women with larger social networks generally have better breast cancer survival. However, previous work has been conducted predominantly in white women. Therefore, we evaluated associations of social networks, social support, and breast cancer-specific and overall mortality in a large, Northern California cohort of women with breast cancer, evaluating whether associations differed in white and non-white women.

Methods: This study included 4,505 women from the Pathways Study, a prospective cohort study examining predictors of outcomes in women diagnosed from 2006-2013 with stages I-IV breast cancer in Kaiser Permanente Northern California. Participants responded to questions on social ties (marital/intimate partner, close friends and relatives, community and religious participation) and to the Medical Outcomes Study social support survey approximately two months following diagnosis. We used proportional hazards regression to evaluate associations between social networks, social support and recurrence, breast cancer-specific mortality, and overall mortality. We further stratified by white vs. non-white race since the number of outcomes were too small in specific non-white racial/ethnic groups, which included African-American (AA), Asian/Pacific Islander (API), and Hispanic women. We then evaluated evidence of effect modification by this variable.

Results: The cohort included 2,894 white and 1,611 non-white women. In multivariable-adjusted analyses of the full cohort, adjusted for sociodemographic characteristics, disease severity, treatment, and presence of comorbidity, women with small social networks had higher breast cancer-specific and overall mortality. However, associations differed substantially by race/ethnicity (p-value, test for interaction=0.02 for recurrence, p=0.07 for breast-cancer specific mortality, and p<0.001 for overall mortality). In white women, socially isolated women had higher breast cancer-specific (hazard ratio (HR)=2.41, 95% confidence interval (CI): 1.30-4.49, p-trend<0.001) and overall (HR=2.98, 95% CI: 1.94-4.58) mortality compared with those who were socially integrated. These associations were driven by the strong associations seen in white women with hormone-receptor positive cancer. Associations with recurrence were nonsignificant. By contrast, in non-white women, those who were moderately integrated had a significantly lower risk of recurrence (HR=0.68, 95% CI: 0.47-0.98) than those who were socially integrated. Associations with breast cancer-specific and overall mortality were nonsignificant but similar qualitatively. In additional exploration, larger social networks appeared beneficial in white and AA women but we noted possible direct associations between social network size and outcomes in API and Hispanic women. Though each of the different types of ties contributed to associations in white women, a larger number of close friends and relatives was related to worse outcomes in the non-white women in this sample. Social support was not significantly related to outcomes in either white or non-white women.

Conclusions: In white women, larger social networks were related to better survival, whereas among non-white women, those with moderate-sized networks had the lowest risks of recurrence and breast cancer-specific mortality. The influence of social networks on breast cancer outcomes may differ by race/ethnicity.

Citation Format: Candyce Kroenke, Scarlett Lin Gomez, Marilyn Kwan, Lawrence Kushi. Social networks at diagnosis and recurrence, breast cancer-specific mortality, and overall mortality in white and non-white women in the Pathways Study [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr C29.

Abstract 2250: Systemic inflammation and sarcopenia predict colorectal cancer survival

Importance: A higher neutrophil-to-lymphocyte ratio (NLR, indicating systemic inflammation), and sarcopenia (reduced skeletal muscle mass) predict morbidity/mortality in a variety of cancers, but no prior research examines associations of pre-diagnostic NLR with at-diagnosis sarcopenia, nor whether NLR and sarcopenia combined identify early-stage patients with poor prognosis in colorectal cancer (CRC).Objective: To evaluate the association between pre-diagnosis NLR and at-diagnosis sarcopenia and of their combination with CRC survival, controlling for age, ethnicity, sex, body mass index, stage, and cancer site.

Design, Setting, and Participants: This observational cohort with prospectively-collected data included 2470 patients diagnosed with stage I-III CRC at Kaiser Permanente from 2006-2011 with computed tomography (CT) scans from clinical care (mean days pre-diagnosis=6).

Exposures: Systemic inflammation measured via average NLR in the 24 months pre-diagnosis (mean count=3 measures, mean months pre-diagnosis=7). The reference value was NLR below 3, indicating low/no inflammation.

Main Outcomes and Measures: Sarcopenia, defined by published cutoffs for skeletal muscle index (CT muscle area in cm2 at the third lumbar vertebra divided by squared height in m2; below 52-cm2/m2 and 38-cm2/m2 for normal/overweight men and women, respectively, and below 54-cm2/m2 and 47-cm2/m2 for obese men and women, respectively), and incident death (overall or CRC-related).

Results: Average age was 63 years; half of patients were female. NLR above 3 and sarcopenia were common (46% and 44%, respectively). Over a median of 6 years, we observed 656 deaths, 357 from CRC. Elevated NLR was associated with sarcopenia in a dose-response manner (compared to NLR below 3, Odds Ratio [OR]=1.35; 95%CI:1.10-1.67 for NLR 3-5; OR=1.47; 95%CI:1.16-1.85 for NLR above 5). NLR above 3 and sarcopenia were also independently associated with survival (Hazard Ratio [HR]=1.65; 95%CI:1.45-1.98 for overall death and HR=1.29; 95%CI:1.09-1.53 for CRC death); patients with both sarcopenia and NLR above 3 (versus neither), had double the risk of death overall (HR=2.53; 95%CI:1.87-3.41) and from CRC (HR=2.19; 95%CI:1.74-2.75).

Conclusions and Relevance: Host inflammatory/immune response shortly prior to diagnosis predicts muscularity at diagnosis. Low muscle combined with systemic inflammation predicts worse CRC prognosis regardless of stage. A better understanding of the crosstalk between inflammatory/immune responses and the onset of changes in skeletal muscle may open new therapeutic avenues to improve cancer outcomes.

Citation Format: Elizabeth M. Cespedes Feliciano, Candyce H. Kroenke, Jeffrey Meyerhardt, Carla M. Prado, Patrick T. Bradshaw, Marilyn Kwan, Jingjie Xiao, Stacey Alexeef, Erin K. Weltzien, Adriemme L. Castillo, Bette J. Caan. Systemic inflammation and sarcopenia predict colorectal cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2250. doi:10.1158/1538-7445.AM2017-2250

Spatial and temporal trends of alternative flame retardants and polybrominated diphenyl ethers in ringed seals (Phoca hispida) across the Canadian Arctic

Concentrations of alternative flame retardants and polybrominated diphenyl ethers (PBDEs) were analyzed in ringed seal (Phoca hispida) blubber collected across the Canadian Arctic during subsistence hunts between 1998 and 2013. More than 80% of sampled animals were females and juvenile males. The highest mean ΣPBDE concentrations (sum of 13 congeners) were found in seals from Nain (Nunatsiavut) as well as Inukjuaq and Arviat (Hudson Bay) and the lowest mean levels were found in seals from Lancaster Sound. BDE-47 and -99 were the predominant PBDE congeners quantified in ringed seals. The most frequently detected non-PBDE flame retardants were polybrominated biphenyl 101 (BB-101, 57% of samples analyzed for this chemical), hexabromocyclododecane (HBCDD; 38%), hexabromobenzene (HBB, 30%), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTeBB, 23%). The relative trophic position of seals, estimated using stable isotopes, did not vary over time and did not influence flame retardant blubber concentrations. The relative carbon source increased over time at Arviat and Resolute Bay and weak relationships were observed with ΣPBDEs in blubber of seals. ΣPBDEs increased significantly from 1998 to 2008 in ringed seals from East Baffin and subsequently decreased in recent years. PBDE levels at other sites fluctuated slightly over time. HBCDD concentrations increased at several sites over the past decade. The presence of flame retardants in ringed seals suggests their persistence and their continuous inputs in the Canadian Arctic environment. Monitoring and research on the effects of these contaminants in seals are warranted given the importance of this species in Arctic marine food webs and for local communities.

Evaluation of the effect of energy conservation techniques in the performance of activity of daily living tasks

Objective: To determine whether energy conservation techniques during common activity of daily living tasks actually result in lower energy expenditure, and to document subjective comments regarding any differences in the perceived level of effort.

Design: Descriptive study comparing energy expenditure in three tasks with and without energy conservation techniques, taking into account the effect of age.

Setting: Occupational therapy department of a rehabilitation hospital in Hong Kong.

Subjects: One hundred and eight subjects (30 < 60 years; 78 ≥ 60 years) were recruited from staff and members of an elderly social centre in the community.

Measurements: Energy expenditure was measured using a portable indirect calorimetry system for three tasks (shopping, washing clothes and hanging laundry) with and without energy conservation techniques. Dyspnoea, fatigue and perceived exertion were measured using visual analogue scales.

Results: Reduction in energy expenditure using energy conservation techniques for shopping and hanging laundry was documented in younger subjects only (O2 consumption fell from 13.89&plusmn;3.7 to 12.29&plusmn;3.8 mL/min per kg for shopping, P < 0.001 and 5.9&plusmn;1.2 to 5.0&plusmn;1.2 mL/min per kg, P < 0.001 for hanging laundry), although the older subjects experienced less perceived exertion with the energy conservation techniques. For washing clothes, no reduction in energy expenditure was observed in either age groups.

Conclusion: Measurable benefits were observed with use of labour-saving equipment and avoidance of overhead reaching in younger subjects only.

Local country food sources of methylmercury, selenium and omega-3 fatty acids in Nunavik, Northern Quebec

Country foods are central to Inuit culture and replete in selenium (Se) and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA). However, some marine country foods bioaccumulate high concentrations of methylmercury (MeHg). Se and n-3 are associated with several health benefits in Nunavik, Northern Quebec, but, recent studies show that prenatal MeHg exposure is associated with visual, cognitive and behavioral deficit later in childhood. The study objectives are to identify contemporary country food sources of MeHg, Se and long-chain n-3 PUFA in Nunavik, particularly among childbearing-age women, taking into account regional differences in consumption profiles. The contribution of different country foods to daily MeHg, Se, long-chain n-3 PUFA intake (μg/kg body weight/day) was estimated using: (i) country food consumption and blood biomarkers data from the 2004 Nunavik Health Survey (387 women, 315 men), and (ii) data on MeHg, Se, long-chain n-3 PUFA concentrations found in Nunavik wildlife species. In the region where most traditional beluga hunting takes place in Nunavik, the prevalence of at-risk blood Hg (≥ 8 μg/L) in childbearing-age women was 78.4%. While most country foods presently consumed contain low MeHg, beluga meat, not a staple of the Inuit diet, is the most important contributor to MeHg: up to two-thirds of MeHg intake in the beluga-hunting region (0.66 of MeHg intake) and to about one-third in other regions. In contrast, seal liver and beluga mattaaq - beluga skin and blubber - only mildly contributed to MeHg (between 0.06 and 0.15 of MeHg intake), depending on the region. Beluga mattaaq also highly contributed to Se intake (0.30 of Se intake). Arctic char, beluga blubber and mattaaq, and seal blubber contributed to most long-chain n-3 PUFA intake. This study highlights the importance of considering interconnections between local ecosystems and dietary habits to develop recommendations and interventions promoting country foods' benefits, while minimizing the risk of MeHg from beluga meat, especially for childbearing-age women.

Pre- to post-diagnosis weight change and associations with physical functional limitations in breast cancer survivors

PURPOSE

We investigated pre- to post-diagnosis weight change and functional limitations in a cohort of breast cancer survivors.

METHODS

A cohort of 1,841 early-stage breast cancer survivors provided information on pre- and post-diagnosis weight and physical function on average 2 years post-diagnosis. The mean number of limitations for each BMI category and each weight change category were compared using the Wilcoxon test. Cross-sectional associations between weight change, from 1 year prior to diagnosis to 2 years post-diagnosis, and functional limitations were determined using logistic regression.

RESULTS

Women with BMI ≥ 30 kg/m(2) had significantly higher physical limitations compared to women with BMI < 25 kg/m(2) (2.06 vs 0.96 for moderate/severe limitations, 3.92 vs 3.27 for mild limitations, 1.31 vs 0.47 for lower body limitations, and 0.76 vs 0.49 for all other limitations; P < 0.0001). Women who reported a large weight gain (≥10% of pre-diagnosis weight) were more likely to report any limitation (OR = 1.79; 95% confidence interval (CI) = 1.23-2.61), a moderate/severe limitation (OR = 2.30; 95% CI = 1.75-3.02), and a lower body limitation (OR = 2.05; 95% CI = 1.53-2.76) compared to women who maintained weight within 5% of pre-diagnosis weight. However, associations between weight loss and functional limitations depended on pre-diagnosis BMI and comorbidity status. Among women without comorbidity, large weight loss (≥10% of pre-diagnosis weight) in normal-weight women was associated with higher risk of functional limitations, whereas among overweight/obese women, large weight loss appeared to be associated with a lower risk of limitations. Among women with comorbidity, moderate weight loss in overweight/obese women was associated with a higher risk of a moderate/severe physical limitation.

CONCLUSIONS

Large weight gain was associated with a higher risk of physical functional limitations, but associations between weight loss and functional limitations may depend on initial BMI and comorbidity status.

IMPLICATIONS FOR CANCER SURVIVORS

In this study we found that both weight loss and weight gain among breast cancer survivors were associated with a higher risk of physical functional limitations. Weight maintenance, therefore, may be an important factor in preventing and/or reducing the risk of functional decline in breast cancer survivors.

Abstract 131: Race and breast cancer prognosis by PAM50 subtype in the LACE and Pathways studies

Background: African-Americans have poorer breast cancer (BC) prognosis, and Asians and Hispanics have better prognosis, compared with Whites. The Black-White difference is unexplained and has been attributed to diagnosis with less treatable tumor subtypes in African-Americans. However, little research has examined whether race-survival differences exist by breast cancer subtype. Therefore, we examined associations between race and BC survival by PAM50 breast cancer subtypes (luminal A, luminal B, basal-like, HER2 enriched) in a prospective cohort of 1,282 breast cancer survivors from the Life After Cancer Epidemiology and Pathways cohorts.

Methods: Self-reported race was obtained at study entry from mailed questionnaires. 1 mm punches were obtained from areas of representative tumor in formalin-fixed, paraffin-embedded tumor blocks. Expression of the PAM50 genes for molecular subtype was determined by RT-PCR of extracted RNA. After a median 6.3 years of follow-up (range 0.3-15.5 years), 213 deaths, with 118 from breast cancer, were reported. Delayed entry Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of BC mortality, controlling for time from diagnosis to enrollment, socioeconomic status, BC severity, BC subtype, treatment, and other known prognostic factors. Logistic regression was used to evaluate associations between race and subtype. Survival analyses stratified by subtype were adjusted for age, time from diagnosis to enrollment, BC severity, and BC treatment.

Results: Consistent with previous research, adjusted for stage and breast cancer treatment, BC mortality was significantly higher in African-Americans (HR=2.90, 95% CI: 1.74-4.86) and lower in Latinas and Asians (HR=0.51, 95% CI: 0.26-0.99), compared with Whites. In addition, compared with Whites, African-Americans had a lower likelihood of the luminal A (OR=0.61, 95% CI: 0.38-0.98) and luminal B (OR=0.43, 95% CI: 0.23-0.82) subtypes and a greater likelihood of the less treatable basal subtype (OR=2.93, 95% CI: 1.94-4.44). Asians were less likely to be diagnosed with the basal subtype (OR=0.41, 95% CI: 0.23-0.71) and somewhat more likely to be diagnosed with the HER2-enriched subtype (OR=1.47, 95% CI: 0.97-2.21). Stratified by subtype, African-Americans had poorer prognosis among those with luminal A (HR=2.64, 95% CI: 0.93-7.49), luminal B (HR=2.20, 95% CI: 0.43-11.26), basal-like (HR=1.66, 95% CI: 0.78-3.54), and HER2 enriched (HR=3.25, 95% CI: 1.04-10.15) subtypes than Whites.

Conclusion: African-Americans had worse breast cancer survival than other racial/ethnic groups and had less treatable types of breast cancer. However, breast cancer mortality was higher in African-Americans across tumor subtypes, suggesting that the Black-White survival difference may not be attributable to differential diagnosis by subtype.

Citation Format: Candyce Kroenke, Marilyn Kwan, Philip Bernard, Adrienne Castillo, Carole Davis, Rachel Factor, Laurel Habel, Larry Kushi, Charles Quesenberry, Kaylynn Shakespear, Inge Stijleman, Carol Sweeney, Erin Weltzien, Bette Caan. Race and breast cancer prognosis by PAM50 subtype in the LACE and Pathways studies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 131. doi:10.1158/1538-7445.AM2013-131

The molecular and clinicopathologic characteristics of bilateral breast cancer

In this study, we compared the clinicopathologic characteristics between the bilateral breast cancer (BiBC) and unilateral breast cancer (UBC) and investigated the role of CXC chemokine receptor type 4 (CXCR4) in BiBC. 48 BiBC and 1650 UBC were studied. We found BiBC patients were associated with family history of cancer, invasive lobular histology in the first tumor and an advanced nodal status as compared with UBC patients with. Survival analysis indicated that BiBC was not associated with impaired survival. The time interval between the development of first breast cancer and the contralateral cancer did not correlate with the prognosis. Patients with BiBC were more likely to have bone metastasis (P = 0.011) and visceral metastasis (P < 0.001) than those with UBC. However, CXCR4 was not found in any association with poor clinical outcome and increasing visceral metastasis in BiBC patients.

The impact of p53 in predicting clinical outcome of breast cancer patients with visceral metastasis

In the study, we analyzed role of p53 in predicting outcome in visceral metastasis breast cancer (VMBC) patients. 97 consecutive VMBC patients were studied. P53 positivity rate was 29.9%. In the p53-negative group, median disease free survival (DFS), and time from primary breast cancer diagnosis to death (OS1), time from metastases to death (OS2) were 25, 42.5, and 13.5 months, respectively. In the p53-positive group, they were 10, 22, and 8 months, respectively. Statistically significant differences in DFS and OS1 were detected between the p53-negative and p53-positive subtypes. However, p53 appears to have no influence on OS2. In Cox regression analysis, p53 expression and TNM stage were predictive factors of DFS. In the multivariate analysis, p53 expression and the duration of DFS correlated with OS1, but not for OS2. Taken together, our data indicate p53 showing predicting role in OS1 for VMBC, but not for OS2.

Abstract P3-07-05: Bisphosphonate use after primary breast cancer and risk of contralateral breast cancer using pharmacy data

Background: It is not clear if bisphosphonates (BP) are associated with improved breast cancer prognosis in women with early breast cancer. Clinical trials have reported mixed results, yet BPs may be most beneficial in patients with low estrogen levels. However, BPs and risk of second (contralateral) breast cancer has been minimally studied. We examined the association of oral BP use (ever/never and duration) on risk of contralateral breast cancer (CBC) in 17,224 women with early stage breast cancer treated with tamoxifen.

Materials and Methods: A cohort was assembled of women diagnosed with their first primary breast cancer (Stage 0, I, II) from 1996 to 2007 on tamoxifen and followed through 31 December 2009 at Kaiser Permanente Northern and Southern California. Demographic, tumor, pharmacy, and cancer treatment information was extracted from electronic medical records and SEER-affiliated cancer registries at each site. Second (contralateral) tumors were identified from the cancer registries. Detailed information on oral BP use (before and after initial breast cancer diagnosis) was obtained from pharmacy databases. A record of &gt;90 days supply was considered the minimum exposure. Initiation and duration of post-diagnosis use was categorized as 1) non-use (≤90 days supply) and use (&gt;90 days supply) and 2) non-use (≤90 days supply), 91 days–&lt;1 year supply, 1-&lt;2 years supply, and ≥2 years supply. Delayed entry Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) with BP use modeled as a time-varying covariate. Women were followed through CBC, health plan disenrollment, death, or end of study, whichever occurred first. We adjusted for age, stage and year of diagnosis; race/ethnicity; income; comorbidity; tumor factors; primary and adjuvant cancer treatments; previous BP use, and study site.

Results: Over a mean (SD) follow-up of 6.4 (6.3) years, 586 women (3.4%) were diagnosed with CBC after their initial breast cancer diagnosis. Around 19.2% (n = 3303) of the cohort used a BP post-initial breast cancer diagnosis (&gt;93% alendronate). To minimize confounding by indication, all models were adjusted for prior use of BPs before breast cancer diagnosis (n = 1047, 6.1%) and excluded women with prior 5-year history of osteopenia, osteoporosis, and fractures (n = 1808, 10.5%). Compared to non-users, ever use (&gt;90 days supply) was associated with a modestly lower CBC risk (HR = 0.80; 95% CI: 0.61, 1.16). However, stratified analyses by age at breast cancer diagnosis (&lt;50 years vs. ≥50 years) suggested lower risk among older women (HR = 0.80; 95% CI: 0.57, 1.12) compared with younger women (HR = 1.00; 95% CI: 0.39, 2.52). Increasing duration of use was not associated with CBC risk compared to non-use and possibly reflective of some residual confounding by indication: &lt;1 year (HR = 0.56; 95% CI: 0.30, 1.02), 1-&lt;2 years (HR = 0.99; 95% CI: 0.56, 1.72), ≥2 years (HR = 0.91; 95% CI: 0.58, 1.42).

Discussion: While we found modestly lower CBC risk with BP use after diagnosis of primary breast cancer, the protective effects were perhaps confined to older women compared with younger women. Next steps include adding BMD to further explore confounding by indication and examining BP use and breast cancer recurrence and mortality.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-07-05.

Early discontinuation and non-adherence to adjuvant hormonal therapy are associated with increased mortality in women with breast cancer

Despite the benefit of adjuvant hormonal therapy (HT) on mortality among women with breast cancer (BC), many women are non-adherent with its use. We investigated the effects of early discontinuation and non-adherence to HT on mortality in women enrolled in Kaiser Permanente of Northern California (KPNC). We identified women diagnosed with hormone-sensitive stage I-III BC, 1996-2007, and used automated pharmacy records to identify prescriptions and dates of refill. We categorized patients as having discontinued HT early if 180 days elapsed from the prior prescription. For those who continued, we categorized patients as adherent if the medication possession ratio was ≥80%. We used Cox proportional hazards models to estimate the association between discontinuation and non-adherence with all-cause mortality. Among 8,769 women who filled at least one prescription for HT, 2,761 (31%) discontinued therapy. Of those who continued HT, 1,684 (28%) were non-adherent. During a median follow-up of 4.4 years, 813 women died. Estimated survival at 10 years was 80.7% for women who continued HT versus 73.6% for those who discontinued (P < 0.001). Of those who continued, survival at 10 years was 81.7 and 77.8% in women who adhered and non-adhered, respectively (P < 0.001). Adjusting for clinical and demographic variables, both early discontinuation (HR 1.26, 95% CI 1.09-1.46) and non-adherence (HR 1.49, 95% CI 1.23-1.81), among those who continued, were independent predictors of mortality. Both early discontinuation and non-adherence to HT were common and associated with increased mortality. Interventions to improve continuation of and adherence to HT may be critical to improve BC survival.

Early discontinuation and non-adherence to adjuvant hormonal therapy are associated with increased mortality in women with breast cancer

Despite the benefit of adjuvant hormonal therapy (HT) on mortality among women with breast cancer (BC), many women are non-adherent with its use. We investigated the effects of early discontinuation and non-adherence to HT on mortality in women enrolled in Kaiser Permanente of Northern California (KPNC). We identified women diagnosed with hormone-sensitive stage I-III BC, 1996-2007, and used automated pharmacy records to identify prescriptions and dates of refill. We categorized patients as having discontinued HT early if 180 days elapsed from the prior prescription. For those who continued, we categorized patients as adherent if the medication possession ratio was ≥80%. We used Cox proportional hazards models to estimate the association between discontinuation and non-adherence with all-cause mortality. Among 8,769 women who filled at least one prescription for HT, 2,761 (31%) discontinued therapy. Of those who continued HT, 1,684 (28%) were non-adherent. During a median follow-up of 4.4 years, 813 women died. Estimated survival at 10 years was 80.7% for women who continued HT versus 73.6% for those who discontinued (P < 0.001). Of those who continued, survival at 10 years was 81.7 and 77.8% in women who adhered and non-adhered, respectively (P < 0.001). Adjusting for clinical and demographic variables, both early discontinuation (HR 1.26, 95% CI 1.09-1.46) and non-adherence (HR 1.49, 95% CI 1.23-1.81), among those who continued, were independent predictors of mortality. Both early discontinuation and non-adherence to HT were common and associated with increased mortality. Interventions to improve continuation of and adherence to HT may be critical to improve BC survival.

Alcohol Consumption and Breast Cancer Recurrence and Survival among Women with Early-Stage Breast Cancer

Purpose: To describe alcohol consumption and examine its association with breast cancer recurrence and mortality in the Life After Cancer Epidemiology (LACE) study, a prospective cohort study of early-stage breast cancer survivors.Methods: Patients included 1897 participants diagnosed with early-stage breast cancer between 1997 and 2000 and recruited primarily from the Kaiser Permanente Northern California Cancer Registry. Alcohol consumption (beer, wine, and liquor) was assessed at cohort entry using a food frequency questionnaire. A total of 349 breast cancer recurrences and 332 overall deaths were ascertained after an average follow-up of 5.93 years. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals.Results: A total of 958 women (51%) were considered drinkers (&gt;0.5 g of alcohol per day), and the majority drank wine (90%), followed by liquor (43%), and beer (36%). Drinking ≥6 g/day of alcohol compared to minimal or no drinking (≤0.5 g/day) was associated with an increased risk of breast cancer recurrence (HR = 1.34; 95% CI: 1.00, 1.82) and death (HR = 1.51; 95% CI: 1.00, 2.28). The increased risk of recurrence appeared to be greater among postmenopausal (P for trend = .03) and overweight or obese women (P for trend = .03). No associations were observed for risk of overall mortality and alcohol use.Conclusions: Consuming 3 to 4 alcoholic drinks or more per week might be related to an increased risk of breast cancer recurrence, particularly among postmenopausal and heavier women, regardless of other prognostic factors. While additional prospective studies are needed, these observations suggest that after a breast cancer diagnosis, women should consider limiting their consumption of alcohol.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 17.

The standard oxygen consumption value equivalent to one metabolic equivalent (3.5 ml/min/kg) is not appropriate for elderly people

In epidemiological studies, estimation of total energy expenditure can only be carried out from using metabolic equivalent (MET) units calculated physical activity questionnaires, where 1 MET is generally assumed to be 3.5 ml/min/kg resting oxygen consumption (VO2 resting). Since the basal metabolic rate varies with age, the energy expenditure equivalent to 1 MET is likely to vary with age. The objective of this study was to determine the energy value for 1 MET in elderly Chinese people compared with younger subjects, using a cross-sectional study. The participants were 138 young adults (88 female, 50 male) aged 16-64 years and 70 elderly adults (35 female, 35 male) aged 65-89 years. VO2 resting was determined by indirect calorimetry (Deltatrac; Datex Division Instrumentraium Corp, Helsinki, Finland). The height and weight were measured. The body fat percentage and lean mass was estimated by body mass index, tricep and bicep skinfold thickness and Bio-impedance analysis. Both VO2 resting and VO2 resting/kg body weight were significantly lower in elderly than young subjects in both gender groups (P<0.01). The significant age difference in VO2 resting remained after adjustment for weight, height and lean mass in both the male group (P<0.001) and the female group (P<0.01). In conclusion, age had an independent effect on VO2 resting, independent of the change of body composition. The present study suggested that the assumption of 1 MET=3.5 ml/min/kg VO2 resting may over-estimate energy expenditure when apply to elderly people.

Physical activity and risk of recurrence and mortality in breast cancer survivors: findings from the LACE study

INTRODUCTION

Identifying modifiable factors that reduce the risk of recurrence and improve survival in breast cancer survivors is a pressing concern. The purpose of this study was to examine the association of physical activity following diagnosis and treatment with the risk of breast cancer recurrence and mortality and all-cause mortality in women with early-stage breast cancer.

MATERIALS AND METHODS

The sample consisted of 1,970 women from the Life After Cancer Epidemiology study, a prospective investigation of behavioral risk factors and health outcomes. Self-reported frequency and duration of work-related, household and caregiving, recreational, and transportation-related activities during the six months prior to enrollment were assessed. Outcomes were ascertained from electronic or paper medical charts. Hazard ratios and 95% confidence intervals were estimated from delayed entry Cox proportional hazards models.

RESULTS

Although age-adjusted results suggested that higher levels of physical activity were associated with reduced risk of recurrence and breast cancer mortality (P for trend = 0.05 and 0.07, respectively for highest versus lowest level of hours per week of moderate physical activity), these associations were attenuated after adjustment for prognostic factors and other confounding variables (P for trend = 0.36 and 0.26). In contrast, a statistically significant protective association between physical activity and all-cause mortality remained in multivariable analyses (hazard ratio, 0.66; 95% confidence interval, 0.42-1.03; P for trend = 0.04).

CONCLUSIONS

These findings do not support a protective effect of physical activity on breast cancer recurrence or mortality but do suggest that regular physical activity is beneficial for breast cancer survivors in terms of total mortality.

Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends

This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of contaminants in biota, including the marine food species that northern peoples traditionally consume. Compared to other circumpolar countries, concentrations of many organochlorines (OCs) in Canadian Arctic marine biota are generally lower than in the European Arctic and eastern Greenland but are higher than in Alaska, whereas Hg concentrations are substantially higher in Canada than elsewhere. Spatial coverage of OCs in ringed seals, beluga and seabirds remains a strength of the Arctic contaminant data set for Canada. Concentrations of OCs in marine mammals and seabirds remain fairly consistent across the Canadian Arctic although subtle differences from west to east and south to north are found in the proportions of various chemicals. The most significant development since 1997 is improvement in the temporal trend data sets, thanks to the use of archived tissue samples from the 1970s and 1980s, long-term studies using archeological material, as well as the continuation of sampling. These data cover a range of species and chemicals and also include retrospective studies on new chemicals such as polybrominated diphenyl ethers. There is solid evidence in a few species (beluga, polar bear, blue mussels) that Hg at some locations has significantly increased from pre-industrial times to the present; however, the temporal trends of Hg over the past 20-30 years are inconsistent. Some animal populations exhibited significant increases in Hg whereas others did not. Therefore, it is currently not possible to determine if anthropogenic Hg is generally increasing in Canadian Arctic biota. It is also not yet possible to evaluate whether the recent Hg increases observed in some biota may be due solely to increased anthropogenic inputs or are in part the product of environmental change, e.g., climate warming. Concentrations of most "legacy" OCs (PCBs, DDT, etc.) significantly declined in Canadian Arctic biota from the 1970s to the late 1990s, and today are generally less than half the levels of the 1970s, particularly in seabirds and ringed seals. Chlorobenzenes and endosulfan were among the few OCs to show increases during this period while summation operatorHCH remained relatively constant in most species. A suite of new-use chemicals previously unreported in Arctic biota (e.g., polybrominated diphenyl ethers (PBDEs), short chain chlorinated paraffins (SCCPs), polychlorinated naphthalenes (PCNs), perfluoro-octane sulfonic acid (PFOS) and perfluorocarboxylic acids (PFCAs)) has recently been found, but there is insufficient information to assess species differences, spatial patterns or food web dynamics for these compounds. Concentrations of these new chemicals are generally lower than legacy OCs, but there is concern because some are rapidly increasing in concentration (e.g., PBDEs), while others such as PFOS have unique toxicological properties, and some were not expected to be found in the Arctic because of their supposedly low potential for long-range transport. Continuing temporal monitoring of POPs and Hg in a variety of marine biota must be a priority.

Nutritional status of older Tibetans in rural Sichuan China

OBJECTIVE

To examine the nutritional status of older Tibetans in rural China.

DESIGN

Cross sectional study.

SETTING

Remote mountainous region of Sichuan province of Western China.

SUBJECTS AND METHOD

Forty four male and forty six female Tibetans, over 60 years old were recruited. Body weight, standing height, triceps and bicep skinfold thicknesses (TSF, BSF), mid arm circumference (MAC) and waist circumference (WC) were measured. Dietary intakes were assessed by a twenty-four hour dietary recall. Based on skinfold thicknesses and MAC, total body fat and corrected arm muscle area (CAMA) were calculated by published equations. Their nutritional status and dietary intakes were compared with those of normal older people in Hong Kong and a rural area near Tianjin in the east coast of China.

RESULTS

Compared with Hong Kong older women, the Tibetan older women had similar BMI and total body fat, but their CAMA was significantly greater (p<0.01). The Tibetan older men had lower BMI, total body fat (p<0.05), and higher CAMA than the Hong Kong older men (p<0.05). The average calorie intake in the Tibetans was lower than that of older people in Hong Kong and rural Tianjin. Intakes of protein, vitamins and minerals were the lowest in Tibetans and the highest in older people in Hong Kong.

CONCLUSIONS

Older Tibetans had more lean mass than Hong Kong older Chinese despite having lower caloric and protein intakes. Older Tibetan women were fatter than their male counterparts, and they were as fat as the older people in Hong Kong, despite having low caloric intakes.

Does low lactose milk powder improve the nutritional intake and nutritional status of frail older Chinese people living in nursing homes?

BACKGROUND

Malnutrition is prevalent among nursing home residents in Hong Kong. Nutrient dense oral supplements and yoghurt are unpopular among the Chinese older people because of their unfamiliar tastes and relatively high costs. Vitamin and mineral supplements do not address the problem of protein calorie undernutrition. Milk powder may be a suitable alternative supplement, but diarrhoea resulting from lactase deficiency is common in Chinese people.

OBJECTIVE

We hypothesized that a low lactose milk powder would be better tolerated in Chinese nursing home residents and result in improvement in nutritional intake without reducing habitual intake.

DESIGN

Forty-seven residents were randomized to receive milk powder twice daily, or no supplement for seven weeks. Twenty-four hour food record, body weight, upper limb skinfold thicknesses and midarm circumference, grip strength, Barthel Index, and abbreviated mental test score were carried out at baseline and at seven weeks.

RESULTS

The overall compliance was nearly 100%, and no subjects developed diarrhoea. Compared with controls, milk supplementation increased intake of calcium, vitamin D, vitamin A, riboflavin and potassium. There was no significant reduction in habitual dietary intake in supplemented subjects. There was a trend of weight gain in supplemented subjects, though this did not reach statistical significance. There was no change in handgrip strength, mental function and disability level.

CONCLUSION

The study shows that low lactose milk powder is a well-accepted nutritional supplement without reducing habitual dietary intake.

Ephrin-B2 selectively marks arterial vessels and neovascularization sites in the adult, with expression in both endothelial and smooth-muscle cells

The Eph receptor tyrosine kinases and their membrane-tethered ephrin ligands provide critical guidance cues at points of cell-to-cell contact. It has recently been reported that the ephrin-B2 ligand is a molecular marker for the arterial endothelium at the earliest stages of embryonic angiogenesis, while its receptor EphB4 reciprocally marks the venous endothelium. These findings suggested that ephrin-B2 and EphB4 are involved in establishing arterial versus venous identity and perhaps in anastamosing arterial and venous vessels at their junctions. By using a genetically engineered mouse in which the lacZ coding region substitutes and reports for the ephrin-B2 coding region, we demonstrate that ephrin-B2 expression continues to selectively mark arteries during later embryonic development as well as in the adult. However, as development proceeds, we find that ephrin-B2 expression progressively extends from the arterial endothelium to surrounding smooth muscle cells and to pericytes, suggesting that ephrin-B2 may play an important role during formation of the arterial muscle wall. Furthermore, although ephrin-B2 expression patterns vary in different vascular beds, it can extend into capillaries about midway between terminal arterioles and postcapillary venules, challenging the classical conception that capillaries have neither arterial nor venous identity. In adult settings of angiogenesis, as in tumors or in the female reproductive system, the endothelium of a subset of new vessels strongly expresses ephrin-B2, once again contrary to earlier views that such new vessels lack arterial/venous characteristics and derive from postcapillary venules. While earlier studies had focused on a role for ephrin-B2 during the earliest embryonic stages of arterial/venous determination, our current findings using ephrin-B2 as an arterial marker in the adult challenge prevailing views of the arterial/venous identity of quiescent as well as remodeling adult microvessels and also highlight a possible role for ephrin-B2 in the formation of the arterial muscle wall.

Is narcolepsy a REM sleep disorder? Analysis of sleep abnormalities in narcoleptic Dobermans

Narcolepsy is a chronic sleep disorder marked by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. Since the discovery of sleep onset REM periods (SOREMPs) in narcoleptic patients, narcolepsy has often been regarded as a disorder of REM sleep generation: REM sleep intrudes in active wake or at sleep onset, resulting in cataplexy, sleep paralysis, or hypnagogic hallucinations. However, this hypothesis has not been experimentally verified. In the current study, we characterized the sleep abnormalities of genetically narcoleptic-cataplectic Dobermans, a naturally occurring animal model of narcolepsy, in order to verify this concept. Multiple sleep latency tests during the daytime revealed that narcoleptic Dobermans exhibit a shorter sleep latency and a higher frequency of SOREMPs, compared to control Dobermans. The total amount of time spent in wake and sleep during the daytime is not altered in narcoleptic dogs, but their wake and sleep patterns are fragmented, and state transitions into and from wake and other sleep stages are altered. A clear 30 min REM sleep cyclicity exists in both narcoleptic and control dogs, suggesting that generation of the ultradian rhythm of REM sleep is not altered in narcoleptics. In contrast, cataplexy displays no cyclicity and can be elicited in narcoleptic animals anytime with emotional stimulation and displays no cyclicity. Stimulation of a cholinoceptive site in the basal forebrain induces a long-lasting attack of cataplexy in narcoleptic dogs; however, bursts of rapid eye movements during this state still occur with a 30 min cyclicity. Sites and mechanisms for triggering cataplexy may therefore be different from those for REM sleep. Cataplexy and a dysfunction in the maintenance of vigilance states, but not abnormal REM sleep generation, may therefore be central to narcolepsy.

An intron transcriptional enhancer element regulates IL-4 gene locus accessibility in mast cells

The cell type-specific expression of a gene is dependent on developmentally regulated modifications in chromatin structure that allow accessibility of basal and inducible transcription factors. In this study, we demonstrate that a cis-acting element in the second intron of the murine IL-4 gene has a dual function in regulating transcription in mast cells as well as chromatin accessibility of the IL-4 gene locus through its influence on the methylation state of the gene. Previous studies have shown that mast cell-restricted transcription factors GATA-1/2 and PU.1 associate with the intron element and regulate its activity. In this study, we use DNase I footprinting and mutational analyses to identify two additional sites that contribute to the element's ability to enhance transcription. One of these sites associates preferentially with STAT5a and STAT5b. We also demonstrate that deletion of the element or mutation of the GATA binding site in the context of a stably integrated IL-4 genomic construct prevents maintenance of a demethylated locus in IL-4-producing mast cells. These data indicate that, analogous to Ig and TCR intron regulatory elements, the intron enhancer has an essential role in maintaining developmentally regulated demethylation at the IL-4 gene locus. In addition, they indicate that members of the GATA family of transcription factors likely play an important role in these processes.

Chronic oral administration of CG-3703, a thyrotropin releasing hormone analog, increases wake and decreases cataplexy in canine narcolepsy

The effects on cataplexy and daytime sleep of acute and chronic oral administration of CG-3703, a potent TRH analog were assessed in canine narcolepsy. CG-3703 was found to be orally active and to reduce cataplexy (0.25 to 16 mg/kg) and sleep (8 and 16 mg/kg) in a dose-dependent manner. Two-week oral administration of CG-3703 (16 mg/kg) significantly reduced cataplexy and daytime sleep. The anticataplectic effects of CG-3703 were not associated with changes in general behavior, heart rate, blood pressure, rectal temperature, blood chemistry and thyroid function. Although drug tolerance for the effects on cataplexy and sleep were observed during the second week of chronic drug administration, therapeutic efficacy on cataplexy was improved with individual dose adjustment (final dose range: 16 to 28 mg/kg, p.o.). These results suggest that TRH analogs could be a promising new form of treatment for human narcolepsy.

Regional and cellular distribution of CYP2D subfamily members in rat brain

1. Human CYP2D6 is present in brain, metabolizes many drugs and has been implicated in Parkinson's and Alzheimer's diseases and some cancers. It is still unclear which of the six known rat CYP2D subfamily members is/are homologous to human CYP2D6. 2. In this study, RT-PCR, Southern and Western blotting and immunohistochemical techniques were used to study the distribution of CYP2D subfamily member mRNA and proteins across 10 rat brain regions. CYP2D subfamily mRNA and protein levels were correlated with brain dextromethorphan O-demethylation (DOD), a measure of human CYP2D6 and rat CYP2D1 activities. 3. The data showed a strong relationship between CYP2D1 and CYP2D1-18 with brain DOD activity. In addition, it was shown that CYP2D proteins are present in brain mitochondrial as well as microsomal membranes. CYP2D subfamily member mRNA and proteins varied across brain regions and were highly concentrated in specific cell types. 4. These data strongly suggest that CYP2D1 and not CYP2D5 mediates DOD activity in rat brain, and may be the rat homologue of human CYP2D6. The highly localized nature of CYP2D indicates that in specific neurones enzyme levels may approach hepatic levels and, hence, contribute to local alterations in brain drug metabolism.

Neisseria gonorrhoeae MS11mkC opacity protein expression in vitro and during human volunteer infectivity studies

BACKGROUND AND OBJECTIVES

Neisseria gonorrhoeae MS11mkC harbors 11 independently expressed opacity (Opa) protein genes with distinct in vitro expression frequencies. In experimental infections in which human male volunteers were inoculated with transparent (Opa), piliated (P+) strains, the authors associate onset of symptoms with recovery of opaque (Opa+) gonococci.

GOALS

In vitro and recovered (Opa) protein expression rates were compared to determine if the human host influences Opa expression.

STUDY DESIGN

Opa expression was determined using Western immunoblot analysis; Opa sizes were determined using a scanning densitometer.

RESULTS

Seven of 10 Opa proteins were identified in gonococci recovered from all of the volunteers at frequencies consistent with in vitro results (Opa C, 29.5 kDa; Opa K, 30 kDa; Opa G, 31 kDa; Opa I, 32 kDa; Opa J, 33 kDa; Opa D, 34 kDa; and Opa H, 37 kDa) (P > or = 0.01, Fisher exact test). Opa B (30.5 kDa) was identified at lower than expected frequencies, whereas Opa E (31.2) and F (31.5) were identified at higher' than expected frequencies. When recovered gonococci were reanalyzed for in vitro expression frequencies, they were consistent with preinfection frequencies.

CONCLUSIONS

The host may influence the prevalence of some Opa proteins.

Coupling of the murine protein tyrosine phosphatase PEST to the epidermal growth factor (EGF) receptor through a Src homology 3 (SH3) domain-mediated association with Grb2

The involvement of murine protein tyrosine phosphatase-PEST (MPTP-PEST) in signal transduction pathways is suggested by its ability to dephosphorylate phosphotyrosine residues, its interaction with the adaptor protein SHC and by the presence of five proline-rich stretches in its non-catalytic carboxyl terminus. Proline-rich sequences have been identified as binding sites for Src homology 3 (SH3) domains found in proteins associated with signal transduction events. The ability of these sequences to act as SH3 domain recognition motifs was investigated using bacterially expressed SH3 domains derived from several different signalling proteins. In vitro binding assays indicate that four of these proline-rich sequences constitute specific binding sites for both SH3 domains of the adaptor molecule Grb2. Wild type Grb2, but not Grb2 proteins corresponding to loss-of-function mutants in the Caenorhabditis elegans sem-5 protein, associate with MPTP-PEST in vivo. Experiments in EGF receptor expressing cells show that the interaction between MPTP-PEST and Grb2 results in the binding of this complex to activated EGF receptors. In addition, identification of putative substrate(s) of MPTP-PEST have revealed a candidate protein of approximately 120 kDa which is tyrosine phosphorylated upon EGF stimulation. Together, these results describe a novel SH3 domain-dependent recruitment of a protein tyrosine phosphatase to an activated receptor tyrosine kinase and establish a potential role for MPTP-PEST in signalling pathways at the molecular level.

Collagen fiber architecture of a cultured dermal tissue

Advances in tissue engineering have led to the development of artificially grown dermal tissues for use in burn and ulcer treatments. An example of such an engineered tissue is Dermagraft, which is grown using human neonatal fibroblasts on rectangular sheets of biodegradable mesh. Using small angle light scattering (SALS), we quantified the collagen fiber architecture of Dermagraft with the mesh scaffold contributions removed through the use of a structurally based optical model. Dermagraft collagen fibers were found to have a preferred direction nearly parallel to the long dimension of the kite-shaped mesh opening with small spatial variations over the mesh. This study demonstrated the utility of SALS as a rapid and inexpensive technique for the evaluation of gross collagen fiber architecture in engineered tissues.

A natural disruption of the secretory group II phospholipase A2 gene in inbred mouse strains

The synovial fluid or group II secretory phospholipase A2 (sPLA2) has been implicated as an important agent involved in a number of inflammatory processes. In an attempt to determine the role of sPLA2 in inflammation, we set out to generate sPLA2-deficient mice. During this investigation, we observed that in a number of inbred mouse strains, the sPLA2 gene was already disrupted by a frameshift mutation in exon 3. This mutation, a T insertion at position 166 from the ATG of the cDNA, terminates out of frame in exon 4, resulting in the disruption of the calcium binding domain in exon 3 and loss of both activity domains coded by exons 4 and 5. The mouse strains C57BL/6, 129/Sv, and B10.RIII were found to be homozygous for the defective sPLA2 gene, whereas outbred CD-1:SW mice had variable genotype at this locus. BALB/c, C3H/HE, DBA/1, DBA/2, NZB/BIN, and MRL lpr/lpr mice had a normal sPLA2 genotype. The sPLA2 mRNA was expressed at very high levels in the BALB/c mouse small intestine, whereas in the small intestine of the sPLA2 mutant mouse strains, sPLA2 mRNA was undetectable. In addition, PLA2 activity in acid extracts of the small intestine were approximately 40 times higher in BALB/c than in the mutant mice. Transcription of the mutant sPLA2 gene resulted in multiple transcripts due to exon skipping. None of the resulting mutant mRNAs encoded an active product. The identification of this mutation should not only help define the physiological role of sPLA2 but also has important implications in mouse inflammatory models developed by targeted mutagenesis.

(-)-Deprenyl reduces PC12 cell apoptosis by inducing new protein synthesis

(-)-Deprenyl, a monoamine oxidase (MAO)-B inhibitor, has been shown to increase neuronal survival and to alter protein synthesis and gene expression in astrocytic or PC12 cells independently of MAO-B inhibition. We used serum and nerve growth factor withdrawal to induce apoptotic death in PC12 cells to determine whether (-)-deprenyl increases neuronal survival by reducing apoptosis. (-)-Deprenyl reduced both cell death and internucleosomal DNA degradation in a concentration-dependent manner and was effective at concentrations too low to inhibit MAO (< 10(-9) M). (+)-Deprenyl did not increase PC12 cell survival, and, with the exception of pargyline, other MAO-A and MAO-B inhibitors did not alter apoptotic death. Transcriptional and translational inhibition showed that the reduction in apoptosis required the induction of new protein synthesis by (-)-deprenyl. Increased survival was induced if transcription was maintained for 4 h and translation for 6 h after (-)-deprenyl addition. The findings suggest that transcriptional induction may underlie the other MAO-independent actions of (-)-deprenyl.

Effects of acute graded strain on efferent conduction properties in the rabbit tibial nerve

This study examines effects of acute stretch on electrophysiologic properties of rabbit tibial nerve. Compound motor action potentials (CMAP) were measured in 30 rabbits, during and after two hours of acute, graded strain. The rabbits were assigned to one of three groups defined by the degree of stretch (0%, 8%, or 15%) beyond original resting length. These groups were subdivided according to ankle position during nerve strain (ankle dorsiflexion or ankle plantar flexion). Two hours of 8% strain did not significantly decrease CMAP amplitude. Fifteen percent strain with the ankle in dorsiflexion produced a significant and profound drop (99%) in CMAP amplitude. These findings are clinically relevant to nerve stretch injuries and to surgical procedures that induce acute nerve strain.

The use of polylactic acid matrix and periosteal grafts for the reconstruction of rabbit knee articular defects

In order to find a material that would improve cartilage repair, we investigated the use of porous polylactic acid matrix (PLA) with and without periosteal grafts in large articular defects in the medial femoral condyles of 18 New Zealand white rabbit knees. The right knee defect was filled with PLA, the left defect was filled with PLA and a periosteal graft. All animals were killed at 12 weeks. PLA allowed for the de novo growth of neocartilage at the articular surface in all specimens and appeared to serve as a scaffolding for cell migration and matrix formation. Histologically, small amounts of PLA remained under the neocartilage with the majority being replaced by bone. PLA was a suitable carrier for periosteal grafts with a high graft survival rate (89%) and proliferation of a neocartilage which was thicker and more closely resembled articular cartilage than PLA alone knees. Biochemically, there was more type II collagen in the grafted knees (83%) than in the PLA alone knees (65%). Biomechanical tests of the neocartilage included equilibrium displacement, aggregate modulus, and apparent permeability. These tests were not statistically different between PLA alone and grafted knees. Comparison to normal cartilage indicated that the neocartilage was less stiff but had similar permeability. A consistent repair of the articular defects was achieved with and without periosteal grafts resulting in a tissue that closely resembled hyaline articular cartilage.

Factors affecting the success of artificial insemination by frozen donor semen

The records of 227 couples who received artificial insemination by frozen donor semen in 984 treatment cycles were analysed to find out the factors affecting the pregnancy rates. The cumulative pregnancy rate at 6 months was 46.8% and the pregnancy rate per cycle was 10%. The pregnancy rates were adversely affected by (1) increase in the recipient age above 30 years, (2) irregularity of menstrual cycles, (3) the use of clomiphene citrate for induction of ovulation, and (4) low cervical mucus scores. Among our donor semen samples selected with a set of criteria, the sperm counts and initial and post-thaw motility did not affect the pregnancy rates.

Indistinguishable patterns of protooncogene expression in two distinct but closely related tumors: Ewing's sarcoma and neuroepithelioma

Genetic characterization of human tumors promises new insights of biological importance and clinical relevance. We have found that two solid tumors, peripheral neuroepithelioma and Ewing's sarcoma of bone, which share a common cytogenetic rearrangement, are characterized by an indistinguishable and highly reproducible pattern of protooncogene expression. c-myc, N-myc, c-myb, and c-mil/raf-1 are all expressed at similar levels in these tumors. c-fes and c-sis expression was not detected in any specimens of either tumor. In contrast, the protooncogene c-ets-1, located near the breakpoint of the chromosomal translocation in these tumors, is variable in its expression. We also detected high levels of choline acetyltransferase in these tumors, which suggests a common neural origin. Since it is likely that the clinical behavior and therapeutic responsiveness of tumors relate closely to their biological and genetic features, the pattern of protooncogene expression of individual tumors may provide a novel basis for their characterization.

Non-surgical sterilization using phenol-mucilage: acceptability versus efficacy

Sterilization has become a popular means of birth control and many methods have been developed to meet the needs of different groups of women. In a pilot study, non-surgical sterilization using phenol-mucilage was found to be extremely acceptable to a group of Chinese women despite its failure rate. The method is simple, safe and inexpensive. It is suggested that this method would be suitable for women who are afraid of surgical sterilization.