Tracking Changes in Global Longitudinal Strain in Lung Cancer Patients Receiving Thoracic Radiation

PURPOSE/OBJECTIVE(S)

Thoracic radiation improves survival in many lung cancer patients. However, radiation-induced cardiotoxicity is a major source of morbidity and mortality in such patients. Global longitudinal strain (GLS), a novel echocardiography (ECHO) method of assessing left ventricular function, has been shown to predict long-term adverse cardiovascular risk in diverse patient populations. We hypothesized that receipt of thoracic radiation is associated with GLS changes in lung cancer patients.

MATERIALS/METHODS

We retrospectively identified patients with lung cancer treated at our institution between 2005-2020 who had ECHOs performed both before and after RT, and in whom GLS was extractable. ECHO Board-Certified cardio-oncologists measured GLS and left ventricular ejection fraction (LVEF) from these ECHOs.

RESULTS

A total of 40 patients met inclusion criteria. Median time to ECHO was 78 days prior and 172 days after RT. Two chamber (2C), 3C, 4C, and average GLS were significantly decreased after RT on paired t-test [mean difference (SD) 2.23 (3.29), 2.99 (2.78), 2.25 (3.63), 2.51 (2.66) respectively, all p < 0.001]. Thirteen patients (32.5%) had abnormal GLS (<18%) prior to RT. 5 of those 13 patients (38.5%) had abnormal LVEF (< 50%). 27/40 patients (67.5%) had an abnormal GLS or clinically significant (≥15%) drop in GLS after RT. This difference (32.5% patients pre-RT vs 67.5% post-RT) was statistically significant (p < 0.01). Among patients (n = 27) who had normal LVEF before RT, 1 patient (3.7%) developed abnormal LVEF (<50%) after RT. Backwards logistic regression showed significant interaction between heart volume receiving 5 Gray and change in GLS.

CONCLUSION

This cohort exhibited a significant decrease in 2C, 3C, 4C, and average GLS after RT. ∼1/3 of patients had abnormal GLS at baseline (suggesting a high-risk group for cardiac complications) and 67.5% of patients had clinically significant decrease in GLS after RT. Among the patients with normal GLS before RT, although 51.9% of patients demonstrated a clinically significant drop in GLS after RT, only 3.7% of patients developed abnormal LVEF, suggesting that this is a late occurrence. GLS changes may serve as a valuable tool for early identification of patients who are at high risk for future cardiac complications after receiving thoracic radiation.

Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus-United States, May 2013-August 2016

November 11, 2016/65(44);1234-1237. What is already known about this topic? Candida auris is an emerging pathogenic fungus that has been reported from at least a dozen countries on four continents during 2009-2015. The organism is difficult to identify using traditional biochemical methods, some isolates have been found to be resistant to all three major classes of antifungal medications, and C. auris has caused health care-associated outbreaks. What is added by this report? This is the first description of C. auris cases in the United States. C. auris appears to have emerged in the United States only in the last few years, and U.S. isolates are related to isolates from South America and South Asia. Evidence from U.S. case investigations suggests likely transmission of the organism occurred in health care settings. What are the implications for public health practice? It is important that U.S. laboratories accurately identify C. auris and for health care facilities to implement recommended infection control practices to prevent the spread of C. auris. Local and state health departments and CDC should be notified of possible cases of C. auris and of isolates of C. haemulonii and Candida spp. that cannot be identified after routine testing.

Attitudes towards prenatal HIV testing and treatment among pregnant women in southern India

During June and July 1999, oral interviews were conducted on 666 women seeking prenatal care at 9 medical facilities in Chennai and Mysore, India, to assess their attitudes towards prenatal HIV testing and antiretroviral prophylaxis for preventing perinatal HIV transmission if needed. Seventy-eight per cent were aware of the risk of perinatal HIV transmission and 36% knew that intervention could reduce the chances of such transmission. Eighty-six per cent would agree to undergo prenatal HIV testing but only 21% of all respondents would make this decision independently while 46% said their husband would have to decide. Of those women who would not agree to testing, 21% would agree if testing were compulsory. Ninety-seven per cent of respondents would undergo antiretroviral prophylaxis to prevent vertical transmission, and 94% would consider alternatives to breastfeeding if HIV positive. Considering its widespread acceptability, prenatal voluntary counselling and testing may be an affordable method of HIV prevention for this population.

Abstract P4-02-10: Significance of ER-Coregulator-Src Axis in Hormonal Resistance

Background: The estrogen receptor (ER) is implicated in the progression of breast cancer. Endocrine therapy using Tamoxifen, a selective estrogen receptor modulator (SERM), improves disease-free survival in postmenopausal women. Despite positive effects, initial or acquired resistance to endocrine therapies frequently occurs. Recent studies suggested the presence of alternative signaling pathways (including HER2 and c-Src kinase) that contribute to ER activation in the absence of estrogen. ER-coregulators play an essential role in hormonal responsiveness and coregulators such as PELP1 couples Src axis to ER thus representing a new pathway for targeted drug therapy. In this study, we examined the therapeutic efficacy of targeting the PELP-Src axis in blocking therapy resistance.

Methods: Three breast cancer model cell lines with resistance to Tamoxifen were used in this study: (1) MCF7-PELP1 (2) MCF7-HER2/neu and (3) MCF7-Tam. To establish the significance of ER-PELP1 coregulator-Src axis, we have generated additional model cells that stably express Src-ShRNA (MCF7-PELP1 -Src-shRNA and MCF7-HER2-SrcshRNA). Model cells were tested for proliferation using CellTiter-Glo assays, anchorage dependence and ER-extranuclear signaling by Western analysis using phospho-antibodies. Orally soluble Src inhibitor Dasatinib (SPRYCEL)was used to test whether it (a) blocks of ER-coactivator-Src signaling and (b) sensitizes the resistant breast cancer cells to endocrine therapy. Pre-clinical nude mice xenograft based studies were performed to validate the effect of Dasatinib alone or in combination with tamoxifen in vivo. IHC analysis of the tumors was performed to examine the effect of Dasatinib on ER signaling components.

Results: Src knock down or Dasatinib (100 nM) treatment substantially inhibited the growth of MCF7-PELP1, MCF7-HER2/neu and MCF7- Tam model cells in proliferation assays. Depletion of Src using siRNA substantially reduced E2 mediated activation of Src, MAPK and AKT in resistant model cells. In post-menopausal xenograft based studies, treatment with Dasatinib significantly inhibited the growth of therapy resistant cells. IHC analysis revealed that the tumors are ER positive, and Dasatinib (15 mg/kg/d) treated tumors exhibited alterations in Src and AKT pathways. Combinatorial therapy of Tamoxifen (100 μg/mouse/day) with Dasatinib showed better therapeutic effect compared to single agent therapy on the growth of therapy resistant tumors.

Conclusions: The results from this study showed that ER-PELP1 coregulator-Src axis play an important role in promoting hormonal resistance and blocking this axis prevents the development of hormonal independence in vivo. ER coregulator PELP1 and Src kinase are commonly deregulated in breast cancers therefore combination therapies using both endocrine agents and Dasatinib may have better therapeutic effect by delaying the development of hormonal resistance This study is supported by DOD grant W81XWH-08-1-0604.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-02-10.

A randomised control trial of structured interrupted generic antiretroviral therapy versus continuous therapy in HIV-infected individuals in Southern India

This randomised control trial, conducted in Chennai, India, compared structured interrupted therapy (SIT) and continuous therapy (CT) in relation to immunologic and virologic outcomes, adverse events (AEs) and cost of therapy. ART-naïve adult HIV1-infected participants with CD4 counts 50-350 cells/mm(3), and plasma viral load (PVL)>5000 copies/mL were enrolled and placed on Indian-manufactured generic ART: zidovudine(AZT)/stavudine(d4T)+lamivudine(3TC)+efavirenz(EFV). After at least six months of continuous therapy, subjects were randomised to SIT (one-week-on/one-week-off cycles) or CT. The primary end-point was the proportion of subjects maintaining CD4>200 cells/mm(3) at six and 12 months after randomisation. Secondary end-points were effective viral suppression (PVL<400 copies/mL), AEs and cost. All analyses used intention-to-treat methodology. Of 40 participants (69% male; mean age 36+/-7; median baseline CD4 and PVL: 162 cell/mm(3)and 259,000 copies/mL), 17 were randomised to SIT and 18 to CT. At randomisation, median CD4s for SIT and CT were 378 cells/mm(3) and 357 cells/mm(3), respectively. All participants had PVL<400 copies/mL at time of randomisation. Median CD4 six months after randomisation was 498 cells/mm(3) and 417 cells/mm(3) for SIT and CT respectively. All participants had CD4>200 cells/mm(3). One participant on CT and two on SIT had sustained PVL>400 copies/mL. There were no serious AEs or deaths. Structured interrupted therapy cost was half of CT. Structured interrupted therapy was effective at maintaining CD4 above 200 cells/mm(3). Adverse events were comparable in both groups, with 50% reduction in cost for SIT. Further research on such strategies may benefit resource-constrained settings.