432 Nemvaleukin alfa, a novel engineered IL-2 cytokine, in combination with the anti-PD-1 antibody pembrolizumab in patients with recurrent/metastatic head and neck squamous cell carcinoma (ION-01 study)

Background

Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel engineered cytokine that selectively binds to the intermediate-affinity IL-2R to preferentially activate and expand anti-tumor CD8+ T and NK cells with minimal expansion of regulatory T cells (Treg), thereby leveraging antitumor effects of the IL-2 pathway while mitigating potential toxicity that limits use.1 Nemvaleukin single-agent activity has been demonstrated in checkpoint inhibitor-experienced patients, and deep and durable responses have been achieved in combination with pembrolizumab in multiple tumor types (eg, breast, head and neck, gastrointestinal, genitourinary, gynecological).2

Methods

ION-01 (NCT04144517) is a nonrandomized trial in adult patients with histologically/cytopathologically confirmed diagnosis of metastatic/recurrent head and neck squamous cell carcinoma. Eligible patients have progressive disease after ≥8 weeks on anti-PD-(L)1 therapy. The primary endpoint is the rate of new or improved antitumor response after the addition of nemvaleukin. Secondary objectives include characterization of the antitumor response and evaluation of safety and tolerability of the combination regimen. Patients receive intravenous nemvaleukin (3 μg/kg) once daily for the first 5 days and pembrolizumab (200 mg) on day 1 of each 21-day cycle. Tumor imaging and biopsies were performed at baseline and at pre-specified times. We present preliminary safety and antitumor activity (RECIST v1.1) data as of June 2021.

Results

Fourteen patients with progressive disease received combination therapy with nemvaleukin and pembrolizumab; 8 had no prior response to pembrolizumab, 6 had previous best response of stable disease or partial response. Mean (± SD) age was 62 ± 12 years, 86% were male, and all were Caucasian. Prior anti-cancer therapy included radiotherapy (93%) and surgery (50%). ECOG performance status was 0 (14%) and 1 (86%) at baseline. Treatment-related adverse events of any grade in ≥30% of patients were chills (64.3%), pyrexia (57.1%), fatigue (42.9%), and nausea (35.7%). Five patients had stable disease as best response. One patient achieved a partial response (complete response in the target lesion) and remains on treatment (8+ cycles). Expansion of CD8+ T and NK cells with minimal Treg expansion was observed.

Conclusions

Nemvaleukin and pembrolizumab combination therapy was generally well tolerated; adverse events were consistent with those observed with intravenous nemvaleukin in ARTISTRY studies [2]. Peripheral immune cell expansion profiles are comparable to that observed with the same regimen in the ARTISTRY 1 phase 1 study. Emerging data from pretreatment and on-treatment paired biopsies will further characterize specific antitumor effects of nemvaleukin and pembrolizumab in this patient population.

Acknowledgements

The authors would like to thank all the patients who are participating in this study and their families. The study is sponsored by Alkermes, Inc. Medical writing and editorial support was provided by Parexel, and funded by Alkermes, Inc.

Trial Registration

ClinicalTrials.

gov NCT04144517

References

Lopes JE, Fisher JL, Flick HL, et al. ALKS 4230: a novel engineered IL-2 fusion protein with an improved cellular selectivity profile for cancer immunotherapy. J Immunother Cancer 2020;8:e000673. doi: 10.1136/jitc-2020-000673.

Boni V, Winer IS, Gilbert L, et al. ARTISTRY-1: Nemvaleukin alfa monotherapy and in combination with pembrolizumab in patients (pts) with advanced solid tumors. J Clin Oncol 2021;39(Suppl 15):abstr 2513.

Ethics Approval

This study was approved by Quorum Review IRB (now Advarra IRB), approval number QR 33752.

Spontaneous Formation of Star-Shaped Surface Patterns in a Driven Bose-Einstein Condensate

We observe experimentally the spontaneous formation of star-shaped surface patterns in driven Bose-Einstein condensates. Two-dimensional star-shaped patterns with l-fold symmetry, ranging from quadrupole (l=2) to heptagon modes (l=7), are parametrically excited by modulating the scattering length near the Feshbach resonance. An effective Mathieu equation and Floquet analysis are utilized, relating the instability conditions to the dispersion of the surface modes in a trapped superfluid. Identifying the resonant frequencies of the patterns, we precisely measure the dispersion relation of the collective excitations. The oscillation amplitude of the surface excitations increases exponentially during the modulation. We find that only the l=6 mode is unstable due to its emergent coupling with the dipole motion of the cloud. Our experimental results are in excellent agreement with the mean-field framework. Our work opens a new pathway for generating higher-lying collective excitations with applications, such as the probing of exotic properties of quantum fluids and providing a generation mechanism of quantum turbulence.

Design of BET Inhibitor Bottlebrush Prodrugs with Superior Efficacy and Devoid of Systemic Toxicities

Prodrugs engineered for preferential activation in diseased versus normal tissues offer immense potential to improve the therapeutic indexes (TIs) of preclinical and clinical-stage active pharmaceutical ingredients that either cannot be developed otherwise or whose efficacy or tolerability it is highly desirable to improve. Such approaches, however, often suffer from trial-and-error design, precluding predictive synthesis and optimization. Here, using bromodomain and extra-terminal (BET) protein inhibitors (BETi)-a class of epigenetic regulators with proven anticancer potential but clinical development hindered in large part by narrow TIs-we introduce a macromolecular prodrug platform that overcomes these challenges. Through tuning of traceless linkers appended to a "bottlebrush prodrug" scaffold, we demonstrate correlation of in vitro prodrug activation kinetics with in vivo tumor pharmacokinetics, enabling the predictive design of novel BETi prodrugs with enhanced antitumor efficacies and devoid of dose-limiting toxicities in a syngeneic triple-negative breast cancer murine model. This work may have immediate clinical implications, introducing a platform for predictive prodrug design and potentially overcoming hurdles in drug development.

Perturbed myoepithelial cell differentiation in BRCA mutation carriers and in ductal carcinoma in situ

Myoepithelial cells play key roles in normal mammary gland development and in limiting pre-invasive to invasive breast tumor progression, yet their differentiation and perturbation in ductal carcinoma in situ (DCIS) are poorly understood. Here, we investigated myoepithelial cells in normal breast tissues of BRCA1 and BRCA2 germline mutation carriers and in non-carrier controls, and in sporadic DCIS. We found that in the normal breast of non-carriers, myoepithelial cells frequently co-express the p63 and TCF7 transcription factors and that p63 and TCF7 show overlapping chromatin peaks associated with differentiated myoepithelium-specific genes. In contrast, in normal breast tissues of BRCA1 mutation carriers the frequency of p63⁺TCF7⁺ myoepithelial cells is significantly decreased and p63 and TCF7 chromatin peaks do not overlap. These myoepithelial perturbations in normal breast tissues of BRCA1 germline mutation carriers may play a role in their higher risk of breast cancer. The fraction of p63⁺TCF7⁺ myoepithelial cells is also significantly decreased in DCIS, which may be associated with invasive progression.

Deletion of Cdkn1b in ACI rats leads to increased proliferation and pregnancy-associated changes in the mammary gland due to perturbed systemic endocrine environment

Mammary epithelial progenitors are the normal cell-of-origin of breast cancer. We previously defined a population of p27⁺ quiescent hormone-responsive progenitor cells in the normal human breast whose frequency associates with breast cancer risk. Here, we describe that deletion of the Cdkn1b gene encoding the p27 cyclin-dependent kinase inhibitor in the estrogen-induced mammary tumor-susceptible ACI rat strain leads to a decrease in the relative frequencies of Cd49b⁺ mammary luminal epithelial progenitors and pregnancy-related differentiation. We show by comprehensive gene expression profiling of purified progenitor and differentiated mammary epithelial cell populations that p27 deletion has the most pronounced effects on luminal progenitors. Cdkn1b^-/- females have decreased fertility, but rats that are able to get pregnant had normal litter size and were able to nurse their pups implying that loss of p27 in ACI rats does not completely abrogate ovarian function and lactation. Reciprocal mammary gland transplantation experiments indicate that the p27-loss-induced changes in mammary epithelial cells are not only caused by alterations in their intrinsic properties, but are likely due to altered hormonal signaling triggered by the perturbed systemic endocrine environment observed in Cdkn1b^-/- females. We also observed a decrease in the frequency of mammary epithelial cells positive for progesterone receptor (Pr) and FoxA1, known direct transcriptional targets of the estrogen receptor (Erα), and an increase in phospho-Stat5 positive cells commonly induced by prolactin (Prl). Characterization of genome-wide Pr chromatin binding revealed distinct binding patterns in mammary epithelial cells of Cdkn1b^+/+ and Cdkn1b^-/- females and enrichment in genes with known roles in Notch, ErbB, leptin, and Erα signaling and regulation of G1-S transition. Our data support a role for p27 in regulating the pool size of hormone-responsive luminal progenitors that could impact breast cancer risk.

The frequency and proliferation of tissue-specific stem and progenitor cells is associated with the risk of malignancy. Thus, regulators of the pool size and proliferation of progenitor cells determine cancer risk. p27 is a key regulator of cellular proliferation and is required for the terminal differentiation of a number of cell types. Here we show that genetic deletion of Cdkn1b in ACI rats susceptible to estrogen-induced mammary tumors decreases the relative fraction of Cd49b⁺ luminal progenitors identifying p27 as a key regulator of the proliferation and pool size of these cells. Progesterone, acting via the progesterone receptor (Pr), is an important regulator of mammary epithelial cell proliferation and differentiation. Based on ChIP-seq we found that Pr targets different sets of genes in Cdkn1b^+/+ and Cdkn1b^-/- mammary epithelium and that this is associated with differences in proliferation and differentiation states. Thus, p27 regulates breast cancer risk and tumor development via regulating the pool size and hormonal-responsiveness of luminal progenitors.

Publisher Correction: Reduction of liver fibrosis by rationally designed macromolecular telmisartan prodrugs

In the version of this Article originally published, the author Peter Blume-Jensen was not denoted as a corresponding author; this has now been amended and the author's email address has been added. The 'Correspondence and requests for materials' statement was similarly affected and has now been updated with the author's initials 'P.B-J.'

Reduction of liver fibrosis by rationally designed macromolecular telmisartan prodrugs

At present there are no drugs for the treatment of chronic liver fibrosis that have been approved by the Food and Drug administration of the United States. Telmisartan, a small-molecule antihypertensive drug, displays antifibrotic activity, but its clinical use is limited because it causes systemic hypotension. Here, we report the scalable and convergent synthesis of macromolecular telmisartan prodrugs optimized for preferential release in diseased liver tissue. We optimized the release of active telmisartan in fibrotic liver to be depot-like (that is, a constant therapeutic concentration) through the molecular design of telmisartan brush-arm star polymers, and show that these lead to improved efficacy and to the avoidance of dose-limiting hypotension in both metabolically and chemically induced mouse models of hepatic fibrosis, as determined by histopathology, enzyme levels in the liver, intact-tissue protein markers, hepatocyte necrosis protection, and gene-expression analyses. In rats and dogs, the prodrugs are retained long-term in liver tissue and have a well-tolerated safety profile. Our findings support the further development of telmisartan prodrugs that enable infrequent dosing in the treatment of liver fibrosis.

Abstract B62: Perturbed myoepithelial cell differentiation in BRCA mutation carriers and in DCIS (ductal carcinoma in situ)

The normal mammary gland is composed of multiple cell types, including luminal and myoepithelial cells. Myoepithelial cells have also been referred to as natural tumor suppressors due to their inhibitory effect on various neoplastic phenotypes, including tumor cell growth, invasion, and angiogenesis. We have previously determined that DCIS-associated myoepithelial cells lack clonal genetic aberrations, but their DNA methylation and gene expression patterns are distinct from that of normal myoepithelial cells, implying perturbed differentiation. We also showed that myoepithelial cells play key roles in preventing tumor growth and invasive progression in experimental models of DCIS, and in immune escape in breast cancer. These data support the hypothesis that the progressive loss of normal myoepithelial cell function in DCIS is a key step in the transition to invasive breast carcinomas, and assessing myoepithelial markers may identify patients with high risk of progression. However, the mechanisms underlying myoepithelial cell aberrations and eventual loss in DCIS are not well understood. In the present study, we used a combination of genomic profiling of human tissue samples and functional assays in a DCIS model to investigate regulators of normal myoepithelial cells and perturbations of these in BRCA mutation carriers and in DCIS. We first explored cellular heterogeneity of the CD10+ cell population in normal human breast tissues of nulliparous and parous women, from reduction mammoplasties and BRCA1 and BRCA2 mutation carriers undergoing prophylactic mastectomy. We identified two distinct CD10+ cell populations distinguished by the expression of CD44 and characterized their gene expression profiles. We also profiled CD10+ cells from BRCA1 and BRCA2 mutation carriers compared to normal noncarriers and found a clear separation of three distinct groups reflecting germline mutation status. Next we defined the p63 cistrome and the enhancer landscape of normal myoepithelial cells and identified alterations of these due to germline BRCA mutation status. Based on our initial results, we focused in p63 and TCF7 as these two transcription factors appear to be central for establishing myoepithelial cell fate. To address the functional relevance of p63 and TCF7 in myoepithelial cell differentiation, we used the MCFDCIS xenograft model of DCIS. These results support the hypothesis that myoepithelial cells play key roles in invasive progression and have significant impact on our understanding of DCIS progression and the increased breast cancer risk of BRCA mutation carriers.

Citation Format: Lina Ding, Ying Su, Muhammad Ekram, Sung Jin Huh, Noga Bloushtain-Qimron, Sibgat Choudhury, William Hines, Jun Yao, Mina Bissell, Kornelia Polyak. Perturbed myoepithelial cell differentiation in BRCA mutation carriers and in DCIS (ductal carcinoma in situ) [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr B62.

Abstract LB-062: Development of macromolecular prodrugs of BET-bromodomain inhibitors with superior anti-tumor efficacy that are T-cell sparing and devoid of systemic toxicity

Small molecule BET inhibitors are promising anti-cancer agents, but their clinical development has been limited by hematological and gastrointestinal (GI) toxicity. For the prototype benzodiazepine-derived inhibitor (OTX-015), the dose-limiting toxicities (DLTs) are thrombocytopenia (96%), anemia (91%), and neutropenia (51%) with additional GI events (diarrhea, vomiting and mucositis) reported to limit patient compliance despite evidence of durable/objective tumor responses. Accordingly, based on a review of entries in www.clinicaltrials.gov from January 2017 to January 2018, 11 out of 12 programs are reporting protracted phase I/II development times and reduced patient enrollment targets. To improve the narrow therapeutic index of current BET inhibitors, we here report the development of macromolecular BET inhibitor prodrugs with a favorable bio-distribution and release of active drug in tumor compared to other tissues, including gut and bone marrow.

We successfully conjugated two structurally distinct BET inhibitors, including the OTX-015, to Brush polymers using an array of different linker chemistries and evaluated them for in vivo efficacy and toxicity using immunocompetent, orthotopically implanted mouse tumor models. Through rational design of drug conjugation and linker chemistry, we optimized the PK properties and drug release rates offering a ‘depot-like' release of drug in tumor tissue resulting in both improved efficacy and reduction of systemic dose-limiting toxicity. Specifically, these novel formulations were evaluated for myelosuppression and GI toxicity using an array of in vitro, clinical pathology and immunohistopathology techniques. Compared to non-conjugated BET inhibitors, which showed dose-dependent body weight loss, diarrhea, and suppression of white blood cells, the macromolecular BET-BRUSH prodrugs spared the lymphocytes, platelets and neutrophils and showed minimal suppression of the reservoir of myeloid cells in the bone marrow. The improved therapeutic index of the BET-Brush compounds was confirmed through detailed PK/PD/Efficacy studies correlating the concentration of both released and polymer-bound BET inhibitor in tumor and plasma with quantitative tissue biomarker modulation (c-MYC, HEXIM-1 and CD180). Whole organ bio-distribution studies using fluorophore-conjugated BET-Brush confirmed the favorable distribution into tumor over the gut and bone marrow, with BET-Brush showing profound modulation of biomarkers in tumor tissue, but not gut. Notably, the BET-Brush compounds showed suppression of PD-L1 expression in tumors, which in context of preserved T-cells, can make BET-Brush a promising combination with immuno-oncology therapy. Paired with an excellent safety profile of the polymer backbone in rat and non-human primates, these data support the further development of BET-Brush prodrugs as an infrequently dosed treatment for human cancers.

Citation Format: Farrukh Vohidov, Jannik N. Andersen, Kyriakos D. Economides, Michail V. Shipitsin, Olga Burenkova, Nolan M. Gallagher, Peyton Sheih, Matthew Golder, Jenny Liu, William K. Dahlberg, Hung V. Nguyen, Deborah J. Ehrlich, Julie Kim, Sung Jin Huh, Bhavatarini Vangamudi, Allison M. Neenan, James C. Ackley, Joelle Baddour, Sattanathan Paramasivan, Gaurab KC, David J. Turnquist, Jenny K. Saucier-Sawyer, Paul W. Kopesky, Samantha W. Brady, Michael J. Jessel, Lawrence A. Reiter, Donald E. Chickering, Jeremiah A. Johnson, Peter Blume-Jensen. Development of macromolecular prodrugs of BET-bromodomain inhibitors with superior anti-tumor efficacy that are T-cell sparing and devoid of systemic toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-062.

Immune Escape in Breast Cancer During In Situ to Invasive Carcinoma Transition

To investigate immune escape during breast tumor progression, we analyzed the composition of leukocytes in normal breast tissues, ductal carcinoma in situ (DCIS), and invasive ductal carcinomas (IDC). We found significant tissue and tumor subtype-specific differences in multiple cell types including T cells and neutrophils. Gene expression profiling of CD45+CD3+ T cells demonstrated a decrease in CD8+ signatures in IDCs. Immunofluorescence analysis showed fewer activated GZMB+CD8+ T cells in IDC than in DCIS, including in matched DCIS and recurrent IDC. T-cell receptor clonotype diversity was significantly higher in DCIS than in IDCs. Immune checkpoint protein TIGIT-expressing T cells were more frequent in DCIS, whereas high PD-L1 expression and amplification of CD274 (encoding PD-L1) was only detected in triple-negative IDCs. Coamplification of a 17q12 chemokine cluster with ERBB2 subdivided HER2+ breast tumors into immunologically and clinically distinct subtypes. Our results show coevolution of cancer cells and the immune microenvironment during tumor progression.Significance: The design of effective cancer immunotherapies requires the understanding of mechanisms underlying immune escape during tumor progression. Here we demonstrate a switch to a less active tumor immune environment during the in situ to invasive breast carcinoma transition, and identify immune regulators and genomic alterations that shape tumor evolution. Cancer Discov; 7(10); 1098-115. ©2017 AACR.See related commentary by Speiser and Verdeil, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

The Proliferative Activity of Mammary Epithelial Cells in Normal Tissue Predicts Breast Cancer Risk in Premenopausal Women

The frequency and proliferative activity of tissue-specific stem and progenitor cells are suggested to correlate with cancer risk. In this study, we investigated the association between breast cancer risk and the frequency of mammary epithelial cells expressing p27, estrogen receptor (ER), and Ki67 in normal breast tissue. We performed a nested case-control study of 302 women (69 breast cancer cases, 233 controls) who had been initially diagnosed with benign breast disease according to the Nurses' Health Studies. Immunofluorescence for p27, ER, and Ki67 was performed on tissue microarrays constructed from benign biopsies containing normal mammary epithelium and scored by computational image analysis. We found that the frequency of Ki67(+) cells was positively associated with breast cancer risk among premenopausal women [OR = 10.1, 95% confidence interval (CI) = 2.12-48.0]. Conversely, the frequency of ER(+) or p27(+) cells was inversely, but not significantly, associated with subsequent breast cancer risk (ER(+): OR = 0.70, 95% CI, 0.33-1.50; p27(+): OR = 0.89, 95% CI, 0.45-1.75). Notably, high Ki67(+)/low p27(+) and high Ki67(+)/low ER(+) cell frequencies were significantly associated with a 5-fold higher risk of breast cancer compared with low Ki67(+)/low p27(+) and low Ki67(+)/low ER(+) cell frequencies, respectively, among premenopausal women (Ki67(hi)/p27(lo): OR = 5.08, 95% CI, 1.43-18.1; Ki67(hi)/ER(lo): OR = 4.68, 95% CI, 1.63-13.5). Taken together, our data suggest that the fraction of actively cycling cells in normal breast tissue may represent a marker for breast cancer risk assessment, which may therefore impact the frequency of screening procedures in at-risk women. Cancer Res; 76(7); 1926-34. ©2016 AACR.

Abstract P1-08-08: Heterozygous germline mutations in RAD50 among Korean patients with high-risk breast cancer negative for BRCA1/2 mutation

Background: The MRE11-RAD50-nibrin (MRN) complex participates in pathways of double-strand break induced DNA repair and cell cycle checkpoint control. RAD50 interacts with the MRE11 and NBS proteins, is involved in the maintenance of genomic integrity. The association of RAD50 mutation and breast cancer susceptibility has been reported in European patients. However, the impact of RAD50 mutation on a breast cancer predisposition among Koreans remains uncertain. In the current analysis, we evaluated the incidence of RAD50 mutations among Korean patients with non-BRCA1/2 high-risk breast cancer.

Materials and Methods: A total of 247 Korean patients with high-risk breast cancer who tested negative for BRCA1/2 mutation were enrolled. The criteria for high-risk breast cancer were as follows: having a family history of breast or ovarian cancer in any relative; diagnosed at age 40 years or younger; bilateral breast cancer; and male breast cancer. All participants were screened for BRCA1/2 mutations using fluorescent-conformation sensitive capillary electrophoresis (F-CSCE) and traditional sequencing. The entire RAD50 gene of each patient was sequenced using F-CSCE. In silico analyses of the RAD50 variants was performed using PolyPhen-2 and SIFT.

Results: There were two novel deleterious mutations in RAD50 (p.Q426X, p.E1271del). These mutations were found in two patients, including one with p.Q426X and the other with p.E1271del. Besides, five sequence variants in RAD50 were identified: four exonic variants (p.I118T, p.R486C, p.L1264F, and p.R1279H) and one intronic variant (c.1246-11T>C). Among the four missense variants, p.R486C and p.L1264F were variants predicted to be deleterious by in silico analyses.

Conclusions: We found protein-truncating mutations in RAD50 gene in a small proportion of Korean patients with high-risk breast cancer. The contribution of the mutation to the development of breast cancer should be clarified in further researches.

Citation Format: Kim H, Cho D-Y, Choi DH, Jung GH, Shin I, Park W, Huh SJ, Nam SJ, Lee JE, Gil WH, Kim SW. Heterozygous germline mutations in RAD50 among Korean patients with high-risk breast cancer negative for BRCA1/2 mutation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-08-08.

Response and resistance to BET bromodomain inhibitors in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease for which there is no targeted therapy. BET bromodomain inhibitors, which have shown efficacy in several models of cancer, have not been evaluated in TNBC. These inhibitors displace BET bromodomain proteins such as BRD4 from chromatin by competing with their acetyl-lysine recognition modules, leading to inhibition of oncogenic transcriptional programs. Here we report the preferential sensitivity of TNBCs to BET bromodomain inhibition in vitro and in vivo, establishing a rationale for clinical investigation and further motivation to understand mechanisms of resistance. In paired cell lines selected for acquired resistance to BET inhibition from previously sensitive TNBCs, we failed to identify gatekeeper mutations, new driver events or drug pump activation. BET-resistant TNBC cells remain dependent on wild-type BRD4, which supports transcription and cell proliferation in a bromodomain-independent manner. Proteomic studies of resistant TNBC identify strong association with MED1 and hyper-phosphorylation of BRD4 attributable to decreased activity of PP2A, identified here as a principal BRD4 serine phosphatase. Together, these studies provide a rationale for BET inhibition in TNBC and present mechanism-based combination strategies to anticipate clinical drug resistance.

Age- and pregnancy-associated DNA methylation changes in mammary epithelial cells

Postnatal mammary gland development and differentiation occur during puberty and pregnancy. To explore the role of DNA methylation in these processes, we determined the genome-wide DNA methylation and gene expression profiles of CD24(+)CD61(+)CD29(hi), CD24(+)CD61(+)CD29(lo), and CD24(+)CD61(-)CD29(lo) cell populations that were previously associated with distinct biological properties at different ages and reproductive stages. We found that pregnancy had the most significant effects on CD24(+)CD61(+)CD29(hi) and CD24(+)CD61(+)CD29(lo) cells, inducing distinct epigenetic states that were maintained through life. Integrated analysis of gene expression, DNA methylation, and histone modification profiles revealed cell-type- and reproductive-stage-specific changes. We identified p27 and TGFβ signaling as key regulators of CD24(+)CD61(+)CD29(lo) cell proliferation, based on their expression patterns and results from mammary gland explant cultures. Our results suggest that relatively minor changes in DNA methylation occur during luminal differentiation compared with the effects of pregnancy on CD24(+)CD61(+)CD29(hi) and CD24(+)CD61(+)CD29(lo) cells.

Histone demethylase jumonji AT-rich interactive domain 1B (JARID1B) controls mammary gland development by regulating key developmental and lineage specification genes

The JmjC domain-containing H3K4 histone demethylase jumonji AT-rich interactive domain 1B (JARID1B) (also known as KDM5B and PLU1) is overexpressed in breast cancer and is a potential target for breast cancer treatment. To investigate the in vivo function of JARID1B, we developed Jarid1b(-/-) mice and characterized their phenotypes in detail. Unlike previously reported Jarid1b(-/-) strains, the majority of these Jarid1b(-/-) mice were viable beyond embryonic and neonatal stages. This allowed us to further examine phenotypes associated with the loss of JARID1B in pubertal development and pregnancy. These Jarid1b(-/-) mice exhibited decreased body weight, premature mortality, decreased female fertility, and delayed mammary gland development. Related to these phenotypes, JARID1B loss decreased serum estrogen level and reduced mammary epithelial cell proliferation in early puberty. In mammary epithelial cells, JARID1B loss diminished the expression of key regulators for mammary morphogenesis and luminal lineage specification, including FOXA1 and estrogen receptor α. Mechanistically, JARID1B was required for GATA3 recruitment to the Foxa1 promoter to activate Foxa1 expression. These results indicate that JARID1B positively regulates mammary ductal development through both extrinsic and cell-autonomous mechanisms.

Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II-III breast cancer? A multicentre retrospective study (KROG 12-05)

BACKGROUND

To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II-III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT).

METHODS

We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated.

RESULTS

After a median follow-up period of 66.2 months (range, 15.6-127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0-is vs 1 vs 2-4) and the number of LNs sampled (<13 vs ≥13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled.

CONCLUSIONS

ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials.

The microenvironment in breast cancer progression: biology and implications for treatment

Breast cancer comprises a heterogeneous group of malignancies derived from the ductal epithelium. The microenvironment of these cancers is now recognized as a critical participant in tumor progression and therapeutic responses. Recent data demonstrate significant gene expression and epigenetic alterations in cells composing the microenvironment during disease progression, which can be explored as biomarkers and targets for therapy. Indeed, gene expression signatures derived from tumor stroma have been linked to clinical outcomes. There is increasing interest in translating our current understanding of the tumor microenvironment to the development of novel therapies.

The JAK2/STAT3 signaling pathway is required for growth of CD44⁺CD24⁻ stem cell-like breast cancer cells in human tumors

Intratumor heterogeneity is a major clinical problem because tumor cell subtypes display variable sensitivity to therapeutics and may play different roles in progression. We previously characterized 2 cell populations in human breast tumors with distinct properties: CD44+CD24- cells that have stem cell-like characteristics, and CD44-CD24+ cells that resemble more differentiated breast cancer cells. Here we identified 15 genes required for cell growth or proliferation in CD44+CD24- human breast cancer cells in a large-scale loss-of-function screen and found that inhibition of several of these (IL6, PTGIS, HAS1, CXCL3, and PFKFB3) reduced Stat3 activation. We found that the IL-6/JAK2/Stat3 pathway was preferentially active in CD44+CD24- breast cancer cells compared with other tumor cell types, and inhibition of JAK2 decreased their number and blocked growth of xenografts. Our results highlight the differences between distinct breast cancer cell types and identify targets such as JAK2 and Stat3 that may lead to more specific and effective breast cancer therapies.

Abstract P6-13-05: Differences of Clinical Manifestations and Therapeutic Outcomes in Leptomeningeal Metastases (LM) According to Breast Cancer Subtypes

Backgrounds: Breast cancer is the solid tumor most commonly associated with leptomeningeal metastases (LM). Therapeutic modalities include intrathecal and systemic chemotherapy, radiotherapy and other palliative modality including placement of a ventricular reservoir. The aim of this study is to characterize clinical feature and outcomes of LM according to breast cancer subtypes in conjunction with whole CNS metastases.

Methods: A retrospective study was performed on breast cancer patients with LM who received palliative management at Samsung Medical Center between 1994 and 2008. Among 281 metastatic breast cancer patients, 71 breast cancer patients with LM were identified. They were divided into three biological subgroups. The propensity of biological subtypes for LM, clinical manifestation including recursive partitioning analysis of Radiation Therapy Oncology Group (RPA RTOG) prognostic class, and therapeutic outcomes were assessed.

Results: The median age was 48 (range 26-70) years. The rates of the patients with triple negative breast cancer (TNBC), human epidermal growth factor receptors 2 (HER2)-positive and hormone receptor (HR)- positive subtype breast cancer were 26 (44%), 15 (25%) and 18 (31%), respectively. Sixty-four patients (90%) had metastatic disease at sites other than LM. TNBC were more common in RPA RTOG prognostic class III than those in HER2 and HR-positive subtypes (61% vs 39% vs 0%, P&lt;0.0001). CNS including LM was the first site of distant metastasis in 65% of the TNBC patients. Treatment includes intrathecal chemotherapy (IT), whole brain radiotherapy (WBRT), and systemic chemotherapy. The median survival duration from the diagnosis of LM to death (OS-LM) was 4.5 months (range 0.2-26.4 months). Main causes of death were deterioration of neurologic sequelae associated with LM (55%), systemic disease progression (27%), and et cetera (18%). Death rates related with LM at each subtype were 64% for TNBC, 36% for HER2-positive, and 0% for HR-positive patients (p=0.060). In the univariate analysis, RPA RTOG classification (p=0.003), systemic disease control at LM (p=0.041), cytologic negative conversion to IT (p=0.001), systemic chemotherapy after LM diagnosis (p=0.002), and combined modality for LM treatment (p=0.005) were singled out as having prognostic value for OS-LM. Cox-regression multivariate analysis showed that RPA class (HR (Hazard Ratio) 1.8, p=0.022), cytologic negative conversion to IT (HR 0.4, p=0.043), and systemic chemotherapy (HR 0.24, p=0.004) are identified as independent prognostic factors.

Conclusion: TNBC and HER2-positive breast cancer appeared to have special predilection for LM as well as brain parenchymal metastases. High RPA class of TNBC may reflect more aggressive tumor biology in this sanctuary area. OS-LM depended on RPA class, cytologic negative conversion, and the use of systemic chemotherapy. The role of systemic chemotherapy and active local treatment modalities according to subtypes should be defined to improve dismal prognosis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-13-05.

Melanoma chemoprevention in skin reconstructs and mouse xenografts using isoselenocyanate-4

Melanoma incidence and mortality rates continue to increase despite the use of sunscreen as well as screening programs for early surgical excision of premalignant lesions. The steady increase in melanoma incidence suggests that additional preventive approaches are needed to augment these existing strategies. One unexplored area involves targeting genes whose deregulation promotes disease development to prevent melanoma. The Akt3 signaling pathway is one key signaling cascade that plays a central role by deregulating apoptosis to promote development of approximately 70% of melanomas. Isoselenocyanate-4 (ISC-4), derived from isothiocyanates by increasing the alkyl chain length and replacing sulfur with selenium, has been developed to target this important signaling pathway in melanomas; however, its chemopreventive potential is unknown. In this study, the chemopreventive efficacy of topical ISC-4 was evaluated in a laboratory-generated human skin melanoma model containing early melanocytic lesion or advanced stage melanoma cell lines and in animals containing invasive xenografted human melanoma. Repeated topical application of ISC-4 reduced tumor cell expansion in the skin model by 80% to 90% and decreased tumor development in animals by approximately 80%. Histologic examination of ISC-4-treated skin showed no obvious damage to skin cells or skin morphology, and treated animals did not exhibit markers indicative of major organ-related toxicity. Mechanistically, ISC-4 prevented melanoma by decreasing Akt3 signaling that lead to a 3-fold increase in apoptosis rates. Thus, topical ISC-4 can delay or slow down melanocytic lesion or melanoma development in preclinical models and could impact melanoma incidence rates if similar results are observed in humans.

Prognostic significance of MRI-detected bladder muscle and/or serosal invasion in patients with cervical cancer treated with radiotherapy

In cervical cancer, the prognostic significance of bladder wall invasion on MRI without pathological evidence of mucosal invasion is not known. From 454 consecutive patients with cervical cancer who were treated with radiation, we reviewed images and analysed the outcome of 92 patients with the Federation of International Gynecology and Obstetrics (FIGO) stage IIIB-IVA. We analysed the patients in three groups, normal, wall (muscle and/or serosal) invasion and mucosal invasion, according to the findings on the MRI. Kaplan-Meier life table analysis and the log-rank test were used to assess the survival rates and differences according to prognostic factors. MRI detected abnormalities in the bladder wall in 42 patients (45.6%): wall invasion in 24 and mucosal invasion in 18. 5 of 18 patients, suspected on MRI to have mucosal invasion, showed no pathological evidence of mucosal invasion. Median follow-up period was 34 months. 3-year cause-specific survival (CSS) in the normal group compared with the wall invasion group was 76.2% vs 71.4% (p = 0.48). 3-year CSS for the wall invasion group compared with the mucosal invasion group was 71.4% vs 54.3% (p = 0.04). Mucosal invasion on MRI (p = 0.03) and concurrent chemoradiotherapy (p = 0.01) was significant for CSS. The prognosis for patients with cervical cancer with evidence of muscle and/or serosal invasion of the bladder on MRI may not differ from that for patients without abnormality on MRI. In patients with the MRI finding of bladder mucosal invasion, further studies should be conducted regarding the role of cystoscopy to determine the need for pathological confirmation.

KLF6 Gene and early melanoma development in a collagen I-rich extracellular environment

BACKGROUND

A putative tumor suppressor gene at chromosome 10p15, which contains KLF6 and other genes, is predicted to be lost during melanoma development, and its identity is unknown. In this study, we investigated the biological roles and identity of this tumor suppressor gene.

METHODS

The human UACC 903 melanoma cell line containing introduced DNA fragments from the 10p15 region with (10E6/3, 10E6/11, and 10E6/18) and without (10ER4S.2/1) the tumor suppressor gene was used. Xenograft tumors were generated in a total of 40 mice with melanoma cell lines, and tumor size was measured. Cells were cultured on plastic or a gel of type I collagen. Viability, proliferation, and apoptosis were assessed. Expression of KLF6 protein was assessed by immunohistochemistry and immunoblot analysis. Expression of phosphorylated Erk1/2 and cyclin D1 was assessed by immunoblot analysis. Protein expression of KLF6 was inhibited with small interfering RNA (siRNA). KLF6 protein expression was assessed in 17 human nevi and human melanoma specimens from 29 patients. Statistical analyses were adjusted for multiple comparisons by use of Dunnett method. All statistical tests were two-sided.

RESULTS

Melanoma cells containing KLF6 generated smaller subcutaneous xenograft tumors with fewer proliferating cells than control cells. When grown on collagen 1, viability of cells with ectopic KLF6 expression (72%) was lower than that of control cells (100%) (group difference = -28%, 95% confidence interval = -31.3% to -25.2%, P < .001). Viability of melanoma cells with or without the KLF6 tumor suppressor gene on plastic dishes was similar. When KLF6 expression was inhibited with KLF6 siRNA, viability of cells with the tumor suppressor gene on collagen I gel increased compared with that of control cells carrying scrambled siRNA. KLF6 protein was detected in all nevi examined but not in human metastatic melanoma tissue examined. Ectopic expression of KLF6 protein in melanoma cells grown on collagen I decreased levels of phosphorylated Erk1/2 and cyclin D1 in the mitogen-activated protein kinase signaling pathway.

CONCLUSIONS

In melanoma cells, the tumor suppressor gene at 10p15 appears to be KLF6. Signaling from the collagen I-rich extracellular matrix appears to be involved in the tumor suppressive activity of KLF6 protein.

Transiently entrapped circulating tumor cells interact with neutrophils to facilitate lung metastasis development

It is unknown why only a minority of circulating tumor cells trapped in lung capillaries form metastases and involvement of immune cells remains uncertain. A novel model has been developed in this study showing that neutrophils regulate lung metastasis development through physical interaction and anchoring of circulating tumor cells to endothelium. Human melanoma cells were i.v. injected into nude mice leading to the entrapment of many cancer cells; however, 24 hours later, very few remained in the lungs. In contrast, injection of human neutrophils an hour after tumor cell injection increased cancer cell retention by approximately 3-fold. Entrapped melanoma cells produced and secreted high levels of a cytokine called interleukin-8 (IL-8), attracting neutrophils and increasing tethering beta(2) integrin expression by 75% to 100%. Intercellular adhesion molecule-1 on melanoma cells and beta(2) integrin on neutrophils interacted, promoting anchoring to vascular endothelium. Decreasing IL-8 secretion from melanoma cells lowered extracellular levels by 20% to 50%, decreased beta(2) integrin on neutrophils by approximately 50%, and reduced neutrophil-mediated extravasation by 25% to 60%, resulting in approximately 50% fewer melanoma cells being tethered to endothelium and retained in lungs. Thus, transendothelial migration and lung metastasis development decreased by approximately 50%, showing that targeting IL-8 in melanoma cells has the potential to decrease metastasis development by disrupting interaction with neutrophils.

Macrophage inhibitory cytokine-1 regulates melanoma vascular development

Expression of macrophage inhibitory cytokine-1 (MIC-1), a member of the transforming growth factor-beta family, normally increases during inflammation or organ injury. MIC-1 is also expressed at higher levels in melanomas; however, its role in tumorigenesis is unknown. This report identifies a novel function for MIC-1 in cancer. MIC-1 was overexpressed in approximately 67% of advanced melanomas, accompanied by fivefold to six-fold higher levels of secreted protein in serum of melanoma patients compared with normal individuals. Constitutively active mutant (V600E)B-Raf in melanoma regulated downstream MIC-1 expression. Indeed, small-interfering RNA-mediated targeting of MIC-1 or (V600E)B-Raf reduced expression and secretion by three-fold to fivefold. This decrease in MIC-1 levels reduced melanoma tumorigenesis by approximately threefold, but did not alter cultured cell growth, suggesting a unique function other than growth control. Instead, inhibition of MIC-1 was found to mechanistically retard melanoma tumor vascular development, subsequently affecting tumor cell proliferation and apoptosis. This role in melanoma angiogenesis was confirmed by comparing MIC-1 and vascular endothelial growth factor (VEGF) function in chick chorioallantoic membrane and matrigel plug assays. Similar to VEGF in melanomas, MIC-1 stimulated directional vessel development, acting as a potent angiogenic factor. Thus, MIC-1 is secreted from melanoma cells together with VEGF to promote vascular development mediated by (V600E)B-Raf signaling.

Targeting Akt3 signaling in malignant melanoma using isoselenocyanates

PURPOSE

Melanoma is the most invasive and deadly form of skin cancer. Few agents are available for treating advanced disease to enable long-term patient survival, which is driving the search for new compounds inhibiting deregulated pathways causing melanoma. Akt3 is an important target in melanomas because its activity is increased in approximately 70% of tumors, decreasing apoptosis in order to promote tumorigenesis.

EXPERIMENTAL DESIGN

Because naturally occurring products can be effective anticancer agents, a library was screened to identify Akt3 pathway inhibitors. Isothiocyanates were identified as candidates, but low potency requiring high concentrations for therapeutic efficacy made them unsuitable. Therefore, more potent analogs called isoselenocyanates were created using the isothiocyanate backbone but increasing the alkyl chain length and replacing sulfur with selenium. Efficacy was measured on cultured cells and tumors by quantifying proliferation, apoptosis, toxicity, and Akt3 pathway inhibition.

RESULTS

Isoselenocyanates significantly decreased Akt3 signaling in cultured melanoma cells and tumors. Compounds having 4 to 6 carbon alkyl side chains with selenium substituted for sulfur, called ISC-4 and ISC-6, respectively, decreased tumor development by approximately 60% compared with the corresponding isothiocyanates, which had no effect. No changes in animal body weight or in blood parameters indicative of liver-, kidney-, or cardiac-related toxicity were observed with isoselenocyanates. Mechanistically, isoselenocyanates ISC-4 and ISC-6 decreased melanoma tumorigenesis by causing an approximately 3-fold increase in apoptosis.

CONCLUSIONS

Synthetic isoselenocyanates are therapeutically effective for inhibiting melanoma tumor development by targeting Akt3 signaling to increase apoptosis in melanoma cells with negligible associated systemic toxicity.

Synthesis and anticancer activity comparison of phenylalkyl isoselenocyanates with corresponding naturally occurring and synthetic isothiocyanates

Synthesis and identification of novel phenylalkyl isoselenocyanates (ISCs), isosteric selenium analogues of naturally occurring phenylalkyl isothiocyanates (ITCs), as effective cytotoxic and antitumor agents are described. The structure-activity relationship comparison of ISCs with ITCs and effect of the increasing alkyl chain length in inhibiting cancer cell growth were evaluated on melanoma, prostate, breast, glioblastoma, sarcoma, and colon cancer cell lines. IC(50) values for ISC compounds were generally lower than their corresponding ITC analogues. Similarly, in UACC 903 human melanoma cells, the inhibition of cell proliferation and induction of apoptosis were more pronounced with ISCs compared to ITCs. Further, ISCs and ITCs effectively inhibited melanoma tumor growth in mice following intraperitoneal xenograft. A similar reduction in tumor size was observed at 3 times lower doses of ISCs compared to corresponding ITCs.

PBISe, a novel selenium-containing drug for the treatment of malignant melanoma

Malignant melanoma is the most deadly form of skin cancer due to its highly metastatic nature. Untargeted therapies are ineffective for treating metastatic disease, leading to the development of agents specifically inhibiting proteins or pathways deregulated in melanoma. The deregulation of inducible nitric oxide synthase (iNOS) is one such event occurring in melanoma, and is correlated with poor survival. Current iNOS inhibitors, such as PBIT [S,S'-1,4-phenylenebis(1,2-ethanediyl)bis-isothiourea], require high concentrations for clinical efficacy causing systemic toxicity. To develop more potent agents effective at significantly lower concentrations, a novel isosteric analogue of PBIT was synthesized, called PBISe [S,S'-1,4-phenylenebis(1,2-ethanediyl)bis-isoselenourea], in which sulfur was replaced with selenium. PBISe kills melanoma cells >10-fold more effectively than PBIT, and cultured cancer cells are 2- to 5-fold more sensitive than normal cells. Like PBIT, PBISe targets iNOS but also has new inhibitory properties acting as an Akt3 pathway inhibitor and mitogen-activated protein kinase (MAPK) cascade activator, which causes decreased cancer cell proliferation and increased apoptosis. Inhibition of cellular proliferation mediated by PBISe induced a G2-M phase cell cycle block linked to excessively high MAPK activity causing decreased cyclin D1 and increased p21 as well as p27 levels. PBISe promotes apoptosis by inhibiting Akt3 signaling, elevating cleaved caspase-3 and PARP levels. Compared with PBIT, PBISe reduced tumor development by 30% to 50% in mice inducing a 2-fold increase in apoptosis with negligible associated systemic toxicity. Collectively, these results suggest that PBISe is a potent chemotherapeutic agent with novel properties enabling the targeting of iNOS, Akt3, and MAPK signaling, thereby promoting melanoma cell apoptosis and inhibition of proliferation.

Two cases of post-radiation osteosarcoma of the sacrum after pelvic irradiation for uterine cervical cancer

BACKGROUND

Post-radiation pelvic bone sarcoma can result as a long-term sequela of pelvic irradiation for uterine cervical cancer.

CASE

A 59-year-old woman who had received pelvic irradiation for Stage IIB uterine cervical cancer 16 years before was diagnosed as having post-radiation osteosarcoma of the sacrum. Another 66-year-old woman who had received pelvic irradiation for Stage IIIB uterine cervical cancer seven years previously was also diagnosed as having pleomorphic sarcoma of the sacrum.

CONCLUSION

When a bone lesion is observed at a previously irradiated field, post-radiation sarcoma should be considered and differentiated from bone metastases.

Preliminary results of consolidation chemotherapy following concurrent chemoradiation after radical surgery in high-risk early-stage carcinoma of the uterine cervix

AIMS

To evaluate the efficacy and toxicity of consolidation chemotherapy after concurrent chemoradiation (CCRT) with 5-fluorouracil (5-FU) and cisplatin in the treatment of high-risk, early stage cervical carcinoma after radical surgery.

MATERIALS AND METHODS

Women with clinical stage IB and IIA cervical carcinoma, initially treated with radical hysterectomy and pelvic lymphadenectomy, and who had positive pelvic lymph nodes, positive margins, parametrial involvement, or all three, were divided into either a CCRT alone group or a consolidation chemotherapy after CCRT group. Three cycles of chemotherapy were given to the CCRT alone group, and six cycles to the consolidation chemotherapy group. Women in each group received 50.4 Gy external radiation in 28 fractions to a standard pelvic field. Chemotherapy consisted of cisplatin 60 mg/m2 (X 1) and 5-FU 1000 mg/m2/d (X 5) every 3 weeks, with the first and second cycles given concurrent with radiation. Survival and toxicity were compared between the two groups.

RESULTS

Forty women were evaluable (25 in the CCRT alone group and 15 in the consolidation chemotherapy group). The estimated 2-year progression-free survival was 87.7% in the CCRT alone group and 67.0% in the consolidation chemotherapy group. The estimated 2-year overall survival was 95.8% in the CCRT alone group and 100% in the consolidation chemotherapy group. However, no significant differences were found in progression-free and overall survival in the two groups (P = 0.17 and P = 0.29, respectively). Grade 2 or higher leukopenia and neutropenia were significantly more frequent in the consolidation chemotherapy group than in the CCRT alone group (P = 0.02 and P < 0.01, respectively).

CONCLUSIONS

Although the sample size was small, and this study was not randomised, these results suggest that consolidation chemotherapy may not improve survival. Rather, it may increase haematologic toxicities for women with high-risk, early stage cervical carcinoma who undergo radical surgery followed by CCRT.

A case of alveolar soft part sarcoma with vaginal metastasis: successful control of vaginal bleeding with external beam irradiation

Alveolar soft part sarcoma (ASPS) of the vagina is an exceptionally rare neoplasm. Furthermore, vaginal metastasis of ASPS has not been reported. A 28-year-old woman with a history of a right thigh mass diagnosed as ASPS excised 8 years ago presented to the emergency room with massive vaginal bleeding and anemia. Biopsy of a vaginal mass revealed that the tumor was a vaginal metastasis of ASPS. For control of intractable bleeding and preventing further transfusions, palliative radiation therapy was planned. She received a total of 39 Gy (daily 3 Gy, using 15-MV photons), and after 6-Gy irradiation, there was no more vaginal bleeding and no more transfusion needed. This is the first case of vaginal metastasis of ASPS reported in the literature that was manifested by intractable vaginal bleeding, which was controlled successfully with radiation therapy.

Low-power hybrid wireless network for monitoring infant incubators

We have created a pilot wireless network for the convenient monitoring of temperature and humidity of infant incubators. This system combines infrared and radio frequency (RF) communication in order to minimize the power consumption of slave devices, and we therefore call it a hybrid wireless network. The slave module installed in the infant incubator receives the calling signal from the host with an infrared receiver, and sends temperature and humidity data to the host with an RF transmitter. The power consumption of the host system is not critical, and hence it uses the maximum power of infrared transmission and continuously operating RF receiver. In our test implementation, we included four slave devices. The PC calls each slave device every second and then waits for 6 s, resulting in a total scan period of 10 s. Slave devices receive the calling signals and transmit three data values (temperature, moisture, and skin temperature); their power demand is 1 mW, and can run for about 1000 h on four AA-size nickel-hydride batteries.

Small-bowel displacement system for the sparing of Small bowel in three-dimensional conformal radiotherapy for cervical cancer

AIMS

The efficacy of the small-bowel displacement system (SBDS) in three-dimensional conformal radiotherapy (3-D CRT) planning for sparing the volume of small bowel is presented for cervical cancer.

MATERIALS AND METHODS

Ten consecutive patients, who received pelvic radiation therapy for uterine cervical cancer with the SBDS from January to March 2003, were included in this study. The SBDS consists of a customised Styrofoam compression device, which can displace the small bowel out of the radiation fields, and an individualised immobilisation board. With oral contrast before scanning, computed tomography was taken in the prone position with and without the SBDS. 3-D conformal planning was carried out, and dose distribution was compared in the target volumes and in the organs-at-risk with and without the SBDS.

RESULTS

In all patients, the SBDS significantly reduced the small-bowel volume within radiation fields. The median small-bowel volume with SBDS was reduced by 56.4% compared with the small-bowel volume without SBDS (from 491 to 214 cm3; P = 0.004). Among the 10 patients, the highest small-bowel volume reduction was 70.2% (from 544 to 62 cm3). At the prescription dose, the median volume of small bowel irradiated was reduced significantly with SBDS (9.8% vs 1.2%; P = 0.005). Differences in the dose-volume histogram for the rectum and the bladder between the 3-D CRT plans with and without SBDS were not statistically significant (P > 0.1). All patients completed radiotherapy without a break in treatment.

CONCLUSION

The SBDS is a novel method that can be used to displace the small bowel away from the 3-D CRT fields effectively, and reduce radiation therapy morbidity.

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Web-based remote monitoring of infant incubators in the ICU

A web-based real-time operating, management, and monitoring system for checking temperature and humidity within infant incubators using the Intranet has been developed and installed in the infant Intensive Care Unit (ICU). We have created a pilot system which has a temperature and humidity sensor and a measuring module in each incubator, which is connected to a web-server board via an RS485 port. The system transmits signals using standard web-based TCP/IP so that users can access the system from any Internet-connected personal computer in the hospital. Using this method, the system gathers temperature and humidity data transmitted from the measuring modules via the RS485 port on the web-server board and creates a web document containing these data. The system manager can maintain centralized supervisory monitoring of the situations in all incubators while sitting within the infant ICU at a work space equipped with a personal computer. The system can be set to monitor unusual circumstances and to emit an alarm signal expressed as a sound or a light on a measuring module connected to the related incubator. If the system is configured with a large number of incubators connected to a centralized supervisory monitoring station, it will improve convenience and assure meaningful improvement in response to incidents that require intervention.

Connexin expression and cell coupling fail to reverse the v-src transformed growth characteristics of a Cx43-/- cell line

Gap junctions, composed of connexins, have been shown to suppress transformation in a variety of malignancies and transformed cell types. In addition, transforming factors such as the src oncogene have been shown to directly phosphorylate some connexins (e.g., Cx43) and inhibit coupling. To investigate the role of gap junctions in cell transformsation by v-src, we utilized a clonal cell line derived from Cx43 knockout mice (KoA) that was immortalized, but not transformed. Transfection by v-src induced a marked transformed phenotype characterized by growth in low serum and anchorage-independent conditions. Subsequent transfections by Cx43, Cx32 or vector alone were then tested for their effects on growth. Activity of pp60v-src was confirmed in all transfectants as well as the ability of pp60v-src to phosphorylate Cx43 in several clones. Despite the documented effect of pp60v-src on Cx43 channel closure, modest coupling was still retained in many of the Cx43 and Cx32 transfectants. However, none of the four Cx43 transfected clones showed significant inhibitory effects on proliferation in either anchorage-independent or low serum growth conditions. Of the Cx32 clones, only one in five showed effects on growth in both assays, which was the same ratio observed for the control transfectants. Thus, based on the levels of expression achieved, which were comparable to endogenous levels in established cell lines, neither Cx43 nor Cx32 serve as effective suppressors of the transformed growth phenotype of this v-src expressing cell line.

Quantitative analysis of errors in fractionated stereotactic radiotherapy

Fractionated stereotactic radiotherapy (FSRT) offers a technique to minimize the absorbed dose to normal tissues; therefore, quality assurance is essential for these procedures. In this study, quality assurance for FSRT of 58 cases, between August 1995 and August 1997 are described, and the errors for each step and overall accuracy were estimated. Some of the important items for FSRT procedures are: accuracy in CT localization, transferred image distortion, laser alignment, isocentric accuracy of linear accelerator, head frame movement, portal verification, and various human errors. A geometric phantom, that has known coordinates was used to estimate the accuracy of CT localization. A treatment planning computer was used for checking the transferred image distortion. The mechanical isocenter standard (MIS), rectilinear phantom pointer: (RLPP), and laser target localizer frame (LTLF) were used for laser alignment and target coordinates setting. Head-frame stability check was performed by a depth confirmation helmet (DCH). A film test was done to check isocentric accuracy and portal verification. All measured data for the 58 patients were recorded and analyzed for each item. 4-MV x-rays from a linear accelerator, were used for FSRT, along with homemade circular cones with diameters from 20 to 70 mm (interval: 5 mm). The accuracy in CT localization was 1.2+/-0.5 mm. The isocentric accuracy of the linear accelerator, including laser alignment, was 0.5+/-0.2 mm. The reproducibility of the head frame was 1.1+/-0.6 mm. The overall accuracy was 1.7+/-0.7 mm, excluding human errors.

Preoperative concurrent chemoradiotherapy for stage IIIA non-small cell lung cancer

Thirty-one patients with stage IIIA non-small cell lung cancer (NSCLC) were treated with preoperative concurrent chemoradiotherapy (CCRT) followed by surgery. The treatment protocol could not be completed in eight patients. The acute hematologic toxicities of grade III or IV occurred in 48.4%, (15/31) after the first chemotherapy cycle, and in 39.1% (9/23) after the second cycle. The most common non-hematologic toxicity was radiation esophagitis. Surgery was attempted in 23 patients and successful in 22 patients (resection rate = 71.0%. Pathologic complete response and down-staging were achieved in 13.6% (3/22) and 68.2% (15/22). The median survival period, 2-year overall survival, local control and disease-free survival rates of all 31 patients and of 22 patients who underwent surgery were 19 months, 37.2%, 49.1%, 35.5%, and 19 months, 43.2%, 51.8%, 25.6%, respectively. On the basis of our observations, preoperative CCRT followed by surgery for stage IIIA NSCLC has resulted in outcomes comparable with those in previous reports.

Combined Chemotherapy and Radiotherapy for Primary CNS Lymphoma

PURPOSE

This study was performed in order to evaluate the effectiveness of combined chemotherapy and radiotherapy (RT) in primary central nervous system lymphoma (PCNSL).

MATERIALS AND METHODS

From January 1995 to August 1999, 21 patients with a diagnosis of PCNSL were treated with combined chemotherapy and radiotherapy. Their median age was 47 years with range of 19 to 78 years. Twelve patients were male and nine patients were female. All patients were immunocompetent and they had no evidence of systemic lymphoma. All patients underwent placement of an Ommaya reservoir and recieved a combination regimen using pre-RT systemic and intra-Ommaya methotrexate (MTX), 40 Gy whole-brain RT with a 14.4 Gy boost, and 2 courses of post-RT high-dose cytarabine. The median follow-up period of all patients and survived patients were 22 months and 36 months, respectively.

RESULTS

The median overall survival duration was 21 months and the overall two- and four-year survival rates were 51% and 43%, respectively. Complete response (CR), partial response, stable disease, and progressive disease were achieved in 12, 3, 1, and 5 patients, respectively. All nine patients without CR expired within 1-31 months (median 6 months). Two patients among the patients with CR developed recurrence after 13 and 14 months, respectively. The location of recurrent disease was within the port of radiation boost. Survival was influenced by age, performance status, and CR. There was one episode of MTX neurotoxicity and hepatotoxicity,respectively.

CONCLUSION

Combined chemotherapy and radiotherapy was an effective treatment for PCNSL, and was associated with a minimum toxicity. However, we must pay attention to the recurrence and late toxicity, particularly within two years following treatment.

Interleukin 12 gene therapy of cancer by peritumoral injection of transduced autologous fibroblasts: outcome of a phase I study

A phase I dose-escalation clinical trial of peritumoral injections of interleukin 12 (IL-12)-transduced autologous fibroblasts was performed in patients with disseminated cancer for whom effective treatment does not exist. The goals of this study were to assess the safety and toxicities as well as the efficacy, and ancillarily the immunomodulatory effects, of peritumoral IL-12 gene transfer. Primary dermal fibroblasts cultured from the patients were transduced with retroviral vector carrying human IL-12 genes (p35 and p40) as well as the neomycin phosphotransferase gene (TFG-hIL-12-Neo). Patients received four injections at intervals of 7 days. Nine patients were enrolled in this dose-escalation study, with secreted IL-12 doses ranging from 300 ng/24 hr for the first three patients to 1000, 3000, and 5000 ng/24 hr for two patients in each subsequent dosage level. Although a definite statement cannot be made, there appears to be perturbation of systemic immunity. Also, the locoregional effects mediated by tumor necrosis factor alpha (TNF-alpha) and CD8+ T cells were observed with tumor regression. Treatment-related adverse events were limited to mild to moderate pain at the injection site; clinically significant toxicities were not encountered. Transient but clear reductions of tumor sizes were observed at the injected sites in four of nine cases, and at noninjected distant sites in one melanoma patient. Hemorrhagic necrosis of tumors was observed in two melanoma patients. These data indicate that gene therapy by peritumoral injection of IL-12-producing autologous fibroblasts is feasible, and promising in patients with advanced cancer.

Physical properties of new collimator cone system for stereotactic radiation therapy developed in samsung medical center

PURPOSE

A new collimator cone system has been developed at the Samsung Medical Center that overcomes some of the limitations of present commercially supplied collimator cones. The physical properties of the newly developed cone system are described in this report.

METHODS AND MATERIALS

The new cones have relatively larger aperture sizes (3.0-7.0 cm in diameter) and are 16 cm in length. Each new cone is fabricated with cerrobend alloy melted and poured into a stainless steel housing that is permanently fixed to a mounting plate. The mounting plate of the new cone is designed to insert into the wedge mount slot of the gantry head. The mechanical accuracy of the central axis of the cone pointing to the isocenter was tested using film, a steel ball positioned at the isocenter by the mechanical isocenter device. For the evaluation of beam flatness and penumbra, off-axis ratios at 5 cm depth were measured by film dosimetry using polystyrene phantom.

RESULTS

The average error of the mechanical isocenter was 0.27 mm (+/- 0.16 mm). The beam flatness was excellent in the central region of the beam, and the average penumbra width was 3.35 mm (+/- 0.25 mm). The new cone design has more clearance between the patient's head and the gantry, and can more easily be removed from the gantry head because it slides in and out of the wedge slot. This facilitates changing cone sizes during one treatment session, and makes the process of double exposure port films easier.

CONCLUSIONS

A new collimator cone system for stereotactic radiation therapy has been developed. The mechanical accuracy and physical properties are satisfactory for clinical use, and the new design permits a wider range of clinical applications for stereotactic radiation therapy.

Fractionated stereotactic radiation therapy for extracranial head and neck tumors

BACKGROUND

This study is to report the clinical experiences of fractionated stereotactic radiation therapy (FSRT) for extracranial head and neck tumors.

METHODS AND MATERIALS

Between the period of July 1995 and November 1998, 48 patients with extracranial head and neck tumors were given FSRT as a boost and sole modality. Individualized treatment planning was performed using XKnife-3 system with relocatable Gill-Thomas-Cosman frame. In 24 patients, FSRT was applied as a boost technique following the 2-dimensional conventional external radiation therapy (ERT); in 24 patients FSRT was the sole radiotherapy modality. The primary diseases in the boost group consisted of nasopharynx cancer (19), lacrimal gland adenoid cystic carcinoma (3), orbital lymphoma (1), and skull-base recurrence of maxillary sinus adenoid cystic carcinoma (1). The primary diseases in the sole modality group consisted of recurrent nasopharynx cancer (12), orbital pseudotumor (4), skull-base recurrence of maxillary sinus, submandibular gland, and hypopharynx cancers (3), orbital rhabdomyosarcoma (2), orbital lymphoma (1), orbital metastasis of neuroblastoma (1), and nasal cavity melanoma (1). The fractionation schedule was to give 5 treatments per one week and the fractional doses were 2.0-3 Gy depending on the treatment aim and the FSRT volume. The FSRT doses varied depending on the nature of the primary diseases.

RESULTS

The local tumor response in nasopharynx cancer patients was excellent compared to retrospective data without occurrence of unexpectedly severe complication. FSRT to other regions was well tolerated by the patients and resulted in good to excellent local tumor responses with no unacceptable side effects as expected by the authors.

CONCLUSION

Based on the current observations, FSRT is a very effective and safe modality in the treatment of extracranial head and neck tumors.

Prompt radiation oncology record access by patient centered digital image chart system

The authors have developed and evaluated a radiation oncology digital image chart system (RODICS). With this system we could achieve paperless and filmless practice, and thus improved operational efficiency within the department. In this paper, we describe characteristics and clinical usage of RODICS.

An integrated service digital network (ISDN)-based international telecommunication between Samsung Medical Center and Hokkaido University using telecommunication helped radiotherapy planning and information system (THERAPIS)

This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology.

A glass compensator filter to improve breast image quality in radiation therapy simulation

PURPOSE

To improve the image quality of simulation films in tangential radiotherapy for breast cancer, we have designed a new compensator filter for the variation of breast contour using high-density-glass material.

METHODS AND MATERIALS

The measurements and analyses of the body contour were done using CT scans, taken in the treatment position, of 20 breast cancer patients. The maximum tissue deficit that needed to be compensated for was 8 cm, and the authors fabricated the compensator system using high-density-glass material to maintain transparency. The glass compensator can be attached to the accessory mount of the simulator head and its position can be easily adjusted according to breast shape and position. The image qualities of simulation films taken with and without the glass compensator in tangential breast radiotherapy field were compared and the film densitometry was performed using the humanoid phantom.

RESULTS

Using this compensator system, the overall image quality improved, resulting in enhanced contrast and resolution of the breast simulation image. The delineator wires for the beam margins were also well depicted, and the surgical clips within the breast tissue can be easily demonstrated. The film densitometry resulted in much less saturation over the breast tissue when using the glass compensator.

CONCLUSION

Using the glass compensator system, the geographical miss may be reduced with the virtue of the improved image quality.

Fractionated stereotactic radiation therapy for locally recurrent nasopharynx cancer: report of three cases

BACKGROUND

This article reports on experience with fractionated stereotactic radiation therapy (FSRT) for locally recurrent nasopharynx cancer.

METHODS

Three patients with locally recurrent nasopharynx cancer were given FSRT as reirradiation between September 1995 and August 1996. Application of FSRT was the third radiation therapy in two patients. Authors used the individually made relocatable Gill-Thomas-Cosman (GTC) stereotactic frame, and the radiation dose planning was performed using XKnife-3. The total doses to the recurrent tumor were 45 Gy/18 fractions in two patients, who were given concurrent chemotherapy as a radiosensitizer, and 50 Gy/20 fractions in the other patient. In all three patients the dose per fraction was 2.5 Gy, and the fraction schedule was to give five daily treatments per week.

RESULTS

Authors observed satisfactory symptomatic improvement and remarkable objective tumor size decrease through the magnetic resonance (MR) images taken one month post-FSRT in all three patients. No neurological side effect was observed. All three patients died with regional and distant seeding outside the FSRT field at seven, nine, and nine months, respectively.

CONCLUSION

FSRT as reirradiation for locally recurrent nasopharynx cancer seemed to be effective and safe.

Analysis of correlation between rectal complications and rectal dose following high dose rate intracavitary radiotherapy in patients with uterine cervix cancer: in vivo dosimetric analysis

PURPOSE

To investigate the correlation between late rectal complications and rectal dose in uterine cervix cancer patients treated with high dose rate intracavitary radiotherapy (HDR ICR) and to analyze dose factors reducing complications.

METHODS

A retrospective analysis was done of 74 patients treated with external beam RT and HDR ICR between 1995 and 1997. Radiotherapy (RT) consisted of a median 50.4 Gy external beam plus six fractions of HDR ICR given two times per week, concurrent with the last three weeks of external beam therapy, to a total dose of median 24 Gy to point A or the reference point. Rectal doses were calculated at rectal reference points using barium contrast criteria. In vivo measurement of rectal dose was performed with thermoluminescent dosimeters (TLD) immediately prior to the first fraction of HDR ICR.

RESULTS

Eight patients developed rectal complications (11%). There was a significant difference between measured rectal doses for patients with rectal complications and those without (p < 0.05), and the doses were higher in complicated patients. A significant increase in the probability of development of complications was found for patients receiving measured rectal doses of ICR fractional dose 320 cGy or more, ICR total dose 2000 cGy or more, and ICR% to point A 80% or more.

CONCLUSIONS

This study showed that in vivo dosimetry using TLD during HDR ICR could have a useful role as a predictor of late rectal complications. Dose limitation to the rectum could possibly be achieved by thorough vaginal packing or use of an applicator with proper shielding while maintaining a high dose to the tumor.

Design and development of new collimator cones for fractionated stereotactic radiation therapy in Samsung Medical Center

PURPOSE

In stereotactic radiotherapy using X-Knife system, the commercially supplied collimator cone system had a few mechanical limitations. The authors have developed new collimator cones to overcome these limitations and named them "SMC type" collimator cones.

METHODS

We made use of cadmium-free cerrobend alloy within the stainless steel cylinder housing. We made nine cones of relatively larger sizes (3.0 cm to 7.0 cm in diameter) and of shorter length with bigger clearance from the isocenter than the commercial cones. The cone housing and the collimator cones were designed to insert into the wedge mount of the gantry head to enable double-exposure linac-gram taking.

RESULTS

The mechanical accuracy of pointing to the isocenter was tested by ball test and cone rotation test, and the dosimetric measurements were performed, all of which were with satisfactory results. A new innovative quality assurance procedure using linac-grams on the patients at the actual treatment setup was attempted after taking 10 sets of AP and lateral linac-grams and the overall mechanical isocenter accuracy was excellent (average error = 0.4 +/- 0.2 mm).

CONCLUSIONS

We have developed the SMC type collimator cone system mainly for fractionated stereotactic radiation therapy use with our innovative ideas. The new cones' mechanical accuracy and physical properties were satisfactory for clinical use, and the verification of the isocenter accuracy on the actual treatment setup has become possible.

Portal vein embolization with use of a new liquid embolic material: an experimental study

PURPOSE

To evaluate the efficacy and safety of a new liquid embolic material in portal vein embolization (PVE).

MATERIALS AND METHODS

A new embolic material (Embol) was percutaneously injected into the left portal vein of 13 swine, using a balloon catheter to prevent reflux. The swine were killed immediately (n = 6), 2 weeks (n = 4), and 4 weeks (n = 3) after the PVE, and the volumes of the right and left lobes were measured. The changes in body temperature, aspartate aminotransferase (AST) (formerly SGOT), alanine aminotrasferase (ALT) (formerly SGPT), and bilirubin levels after the PVE were studied, and the histopathologic changes in the embolized and nonembolized lobes were examined with light microscopy.

RESULTS

The average volume ratio of the right:left lobe immediately after the PVE was 55(+/-2):45(+/-1), and changed to 71(+/-3):29(+/-3) at 2 weeks and 82(+/-3):18(+/-3) at 4 weeks after embolization. There were only mild changes in AST, ALT, and bilirubin levels, and only one pig showed a significant elevation in body temperature after PVE. Microscopically, the embolized lobe showed contraction of hepatocyte without any sign of necrosis and the nonembolized lobe expansion of hepatocyte.

CONCLUSIONS

The new embolic material seems effective and safe for PVE.