Akiko Hisamoto

Role of Survival Post-Progression in Phase III Trials of Systemic Chemotherapy in Advanced Non-Small-Cell Lung Cancer: A Systematic Review

Background In advanced non-small-cell lung cancer (NSCLC), with the increasing number of active compounds available in salvage settings, survival after progression to first-line chemotherapy seems to have improved. A literature survey was conducted to examine whether survival post-progression (SPP) has improved over the years and to what degree SPP correlates with overall survival (OS). Methods and Findings Median progression-free survival (MPFS) time and median survival time (MST) were extracted in phase III trials of first-line chemotherapy for advanced NSCLC. SPP was pragmatically defined as the time interval of MST minus MPFS. The relationship between MPFS and MST was modeled in a linear function. We used the coefficient of determination (r 2) to assess the correlation between them. Seventy trials with 145 chemotherapy arms were identified. Overall, median SPP was 4.7 months, and a steady improvement in SPP was observed over the 20 years (9.414-day increase per year; p<0.001) in parallel to the increase in MST (11.253-day increase per year; p<0.001); MPFS improved little (1.863-day increase per year). Overall, a stronger association was observed between MST and SPP (r 2 = 0.8917) than MST and MPFS time (r 2 = 0.2563), suggesting SPP and MPFS could account for 89% and 25% of the variation in MST, respectively. The association between MST and SPP became closer over the years (r 2 = 0.4428, 0.7242, and 0.9081 in 1988–1994, 1995–2001, and 2002–2007, respectively). Conclusions SPP has become more closely associated with OS, potentially because of intensive post-study treatments. Even in advanced NSCLC, a PFS advantage is unlikely to be associated with an OS advantage any longer due to this increasing impact of SPP on OS, and that the prolongation of SPP might limit the original role of OS for assessing true efficacy derived from early-line chemotherapy in future clinical trials.

Synergistic Effect of Olaparib with Combination of Cisplatin on PTEN-Deficient Lung Cancer Cells

PARP enzyme plays a key role in the cellular machinery responsible for DNA damage repair. PTEN is a tumor-suppressor gene deactivating PI3K downstream of EGFR signaling. We hypothesize that PTEN-deficient lung cancer cells suppressed DNA damage signaling and that the absence of PTEN can sensitize these cells to a concurrent treatment of a DNA-damaging agent (cisplatin) and a PARP inhibitor (olaparib). To investigate the effect of olaparib and cisplatin on PTEN-deficient lung tumors, two EGFR-mutant (deletion in exon19) non–small cell lung cancer (NSCLC) cell lines, PC-9 (PTEN wild-type) and H1650 (PTEN loss), were used. We transfected intact PTEN gene into H1650 cells (H1650PTEN+) and knocked down PTEN expression in the PC-9 cells (PC-9PTEN−) using short hairpin RNA (shRNA). Combination of cisplatin with olaparib showed a synergistic effect in vitro according to the combination index in H1650 cells. Restoration of PTEN in the H1650 cells decreased sensitivity to the combination. Ablation of PTEN in PC-9 cells increased sensitivity to olaparib and cisplatin. We also examined the effectiveness of cisplatin and olaparib in a xenograft model using H1650 and PC-9PTEN− cells. The combination of cisplatin with olaparib was more effective than each agent individually. This effect was not observed in a xenograft model using H1650PTEN+ and PC-9 cells. Mechanistic investigations revealed that PTEN deficiency caused reductions in nuclear RAD51 and RPA focus formation and phosphorylated Chk1 and Mre11. Thus, genetic inactivation of PTEN led to the suppression of DNA repair. Mol Cancer Res; 11(2); 140–8. ©2012 AACR.

Human herpes virus-8-negative primary effusion lymphoma in a patient with common variable immunodeficiency

Primary effusion lymphoma (PEL) is a newly described high-grade B cell lymphoma developing in association with human herpes virus type 8 (HHV-8) in human immunodeficiency virus (HIV)-infecting individuals. Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by reduced serum immunoglobulin and heterogeneous clinical features. The risk of cancer in CVID patients is increased. Here, we describe a PEL that developed in the pleural and pericardial cavities of an HIV-negative and HHV-8-negative patient with CVID.

Phase II Study of Amrubicin Combined with Carboplatin for Thymic Carcinoma and Invasive Thymoma: North Japan Lung Cancer Group Study 0803

Background: There has been no standard chemotherapy for advanced or recurrent thymic malignancies including thymic carcinoma (TC) and invasive thymoma (IT), though platinum and anthracycline have been reported as effective agents for the treatment of these diseases. The objective of this study was to evaluate the efficacy and safety of the combination of amrubicin (AMR), a new anthracycline agent, and carboplatin (CBDCA) in patients with advanced thymic malignancies. Methods: Patients with histologically confirmed thymic malignancies received AMR (35 mg/m2, days 1–3) and CBDCA (area under the curve 4.0, day 1) every 3 weeks. Patients who had received previous chemotherapy were treated with a reduced dose of AMR (30 mg/m2). The primary end point was objective response rate (ORR), and secondary endpoints were progression-free survival, overall survival, and toxicity profile. Results: From December 2008 to October 2012, 51 patients (33 TC and 18 IT) were enrolled. The median number of treatment cycles was four in each group. The ORR and progression-free survival were 30% (95% confidence interval, 14–46) and 7.6 months in the TC group, and 17% (95% confidence interval, 0–34) and 7.6 months in the IT group, respectively. The ORR of TC patients without previous chemotherapy (n = 19) was 42%. Although grade 3 or 4 hematological toxicities were common including neutropenia (82%) and febrile neutropenia (22%), these were transient and manageable. Nonhematological toxicities were moderate and no treatment-related death was observed. Conclusions: The combination of AMR with CBDCA was active for TC with acceptable toxicity, although it was not effective for IT. Further investigation of this regimen for advanced TC is warranted.

Treatment-Related Death in Patients with Small-Cell Lung Cancer in Phase III Trials over the Last Two Decades

Introduction Treatment-related death (TRD) remains a serious problem in small-cell lung cancer (SCLC), despite recent improvements in supportive care. However, few studies have formally assessed time trends in the proportion of TRD over the past two decades. The aim of this study was to determine the frequency and pattern of TRD over time. Methods We examined phase 3 trials conducted between 1990 and 2010 to address the role of systemic treatment for SCLC. The time trend was assessed using linear regression analysis. Results In total, 97 trials including nearly 25,000 enrolled patients were analyzed. The overall TRD proportion was 2.95%. Regarding the time trend, while it was not statistically significant, it tended to decrease, with a 0.138% decrease per year and 2.76% decrease per two decades. The most common cause of death was febrile neutropenia without any significant time trend in its incidence over the years examined (p = 0.139). However, deaths due to febrile neutropenia as well as all causes in patients treated with non-platinum chemotherapy increased significantly (p = 0.033). Conclusions The overall TRD rate has been low, but not negligible, in phase III trials for SCLC over the past two decades.

Influence of the timing of tumor regression after the initiation of chemoradiotherapy on prognosis in patients with limited-disease small-cell lung cancer achieving objective response.

PURPOSE Chemoradiotherapy (CHRT) yields a favorable antitumor activity in patients with limited-stage small-cell lung cancer (LD-SCLC) with a response rate of around 80%. Even in such responders, the majority recur, indicating the importance of identifying a subset of patients with a poor outcome earlier through the treatment. We investigated whether the timing of obtaining tumor regression with the CHRT could affect the prognosis in LD-SCLC patients who finally achieved the objective response through the treatment. PATIENTS AND METHODS We retrospectively reviewed medical charts of 70 LD-SCLC patients who obtained complete response (CR) or partial response (PR) with the 3 or 4 cycles of first-line CHRT between 1988 and 2006. RESULTS In the whole 70 patients with CR/PR, the median survival time and median progression free survival (PFS) were 39.6 and 12.3months, respectively. Fifty-two (74.3%) of the 70 patients entered CR/PR after the first cycle of CHRT, and their 2-year survival rates were significantly longer than that in the remaining 18 patients without entering CR/PR yet at the end of first cycle (72.3% and 7.1%, respectively, p<0.001). Cox regression analysis showed that the early response to the treatment was a significant prognostic factors (hazard ratio=0.098; 95% confidence interval=0.036-0.269). Regarding PFS, similar findings were observed. CONCLUSIONS Patients without entering CR/PR yet after the first course had a poorer outcome even though the objective response was finally confirmed through the treatment. Development of more effective treatments for these high-risk patients is warranted to improve their poor prognosis.

Abstract 2048: PTEN deficient lung cancer cells are sensitive to the combination of olaparib with cisplatin through suppressing DNA damage signaling.

PARP inhibition in combination with DNA-damaging agents is one of the most promising new therapeutic approaches to cancer. PTEN is a tumor-suppressor gene deactivating PI3K downstream of EGFR signaling. In H1650 cells harboring EGFR deletion mutation in exon 19 with PTEN loss, we reported that synergistic effects of a PARP inhibitor (olaparib) and a DNA-damaging agent (cisplatin) were observed in vitro and in vivo (#4686, AACR 2012). We further clarified how PTEN loss affected DNA damage signaling. H1299 and A549 are lung cancer cells harboring wild type PTEN. Antagonistic effects of olaparib with cisplatin were shown in H1299 and A549 cells according to combination index (CI). Sensitivity to a PARP inhibitor was reported to be associated with a defect in Mre11 expression. H1650 cells exhibited lower levels of Mre11 compared with PTEN-transfected H1650 cells (designated H1650PTEN+ cells). To address how lower expression levels of Mre11 affects the synergism between cisplatin and olaparib, Mre11 expression vector was transfected into H1650 cells (designated H1650Mre11+ cells). CIs were 0.23, 0.20, 0.57 and 0.29 when concentration ratios of cisplatin and olaparib were designed to be molar ratios of 1:1, 1:2, 1:3 and 1:5, respectively, in H1650 cells, while CIs were 0.76, 0.91, 0.97 and 0.77 in H1650Mre11+ cells. Although these CIs in H1650Mre11+ were somewhat elevated compared with those observed in original H1650 cells, these results indicated that lower levels of Mre11 alone could not be the sole reason for the synergism. On the other hand, PTEN has other nuclear functions, including transcriptional regulation of the RAD51 gene, whose product is essential for homologous recombination (HR) repair of DNA breaks. RPA is displaced from single stranded DNA by RAD51 to initiate HR. There were no significant differences of RAD51 and RPA levels by Western blotting. Meanwhile, PTEN deficiency resulted in significant reduction in RAD51 and RPA focus formation after drug-exposure or irradiation compared to H1650PTEN+ cells although γH2AX was similarly increased in both cells. As RPA binds to single stranded DNA, the RPA focus could be a marker for end resection at the double stranded DNA ends. Thus, inactivation of PTEN might lead to suppression of DNA damage signaling, leading to the lower levels of end resection and, hence, less RPA focus formation. As shown above, reduced levels of Mre11 alone could not provide a sufficient explanation for this, though Mre11 is involved in the molecular mechanisms of the end resection. The combination of cisplatin with olaparib in PTEN deficient lung tumors might be pursued in clinical trials although further investigations should be required to clarify whether and to what extent the molecular events including Mre11, RAD51 and RPA are responsible for the synergic effect. Citation Format: Daisuke Minami, Nagio Takigawa, Hiromasa Takeda, Minoru Takata, Nobuaki Ochi, Eiki Ichihara, Akiko Hisamoto, Katsuyuki Hotta, Mitsune Tanimoto, Katsuyuki Kiura. PTEN deficient lung cancer cells are sensitive to the combination of olaparib with cisplatin through suppressing DNA damage signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2048. doi:10.1158/1538-7445.AM2013-2048

Docetaxel for non small cell lung cancer harboring the activated EGFR mutation with T790M at initial presentation

A 72-year-old woman was referred to our hospital with Stage IV non-small-cell lung cancer (NSCLC). Chest computed tomography revealed a mass in the upper lobe of the right lung, with pleural effusion. Cytologic examination identified adenocarcinoma cells in the right pleural effusion. Furthermore, both a deletion mutation in exon 19 and a threonine–methionine substitution mutation at position 790 in exon 20 (T790M) were detected in the epidermal growth factor receptors (EGFR) in the malignant cells. As systemic chemotherapy consisting of carboplatin and pemetrexed or erlotinib proved ineffective, docetaxel monotherapy was initiated as a third-line treatment. Following salvage chemotherapy, her Eastern Cooperative Oncology Group performance status improved from 3 to 1, with tumor regression over 5 months. To the best of our knowledge, this is the first report of successful docetaxel treatment for a patient with NSCLC harboring the T790M EGFR-activating mutation identified before treatment with EGFR tyrosine kinase inhibitors.

Abstract 915: Effect of AZD1480 on lung tumor in transgenic mice carrying activating EGFR mutation

Signal transducer and activator of transcription 3 (STAT3) plays a major role in inducing and maintaining a pro-carcinogenic inflammatory microenvironment and is reported to be a critical mediator of the oncogenic effects of epidermal growth factor receptor (EGFR) mutations. STAT3 activation is mediated through the Janus family kinases (JAK) and SRC. JAK1/2 inhibitors such as AZD1480 suppress activation of STAT3 in human solid tumor cell lines and xenografts. Furthermore, they show anticancer effects in various cancer cell lines and xenograft models, including lung cancer. However, the effect of the JAK inhibitors on non-small cell lung cancer harboring EGFR mutation remains unclear. PC-9 is a lung adenocarcinoma cell line harboring exon19 EGFR deletion mutation. Four EGFR tyrosine kinase inhibitors-resistant cell lines, RPC-9, PC-9/Van-R, PC-9/ER3 and PC-9/GR, were established from PC-9 in our laboratory and the resistant mechanisms were mainly caused by a secondary mutation of T790M, JAK2 overexpression or ERK reactivation. Growth inhibition was measured by MTT assays. The drug concentration required to inhibit the growth of tumor cells by 50% (IC50) for 96 h exposure was used to evaluate the effectiveness of AZD1480. Protein expression was determined by Western blotting. The IC50s were 2.4 μM for PC-9, 1.7 μM for RPC-9, 1.2 μM for PC-9/Van-R, 1.2 μM for PC-9/ER3 and 1.6 μM for PC-9/GR. Thus, no cross-resistance was observed. Phosphorylated JAK2 and phosphorylated STAT3 were suppressed by treatment with AZD1480. We generated transgenic mice expressing the delE748-A752 mutant of mouse Egfr, which corresponded to the delE746-A750 mutant of human EGFR. In the absence of treatment, the transgenic mice developed adenocarcinoma at 6 to 7 weeks of age and died due to tumor progression at 13 to 18 weeks. To investigate the effect of AZD1480 on lung tumors induced by an activating EGFR mutation, the transgenic mice were treated with oral AZD1480 (30 mg/kg/day) or vehicle alone from 7 to 10 weeks of age. The number of lung tumors (long axis exceeding 1 mm) ± SE in the AZD1480-treated group and control group was 0.37 ± 0.18 and 2.25 ± 0.53 (t-test, p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 915. doi:1538-7445.AM2012-915

Abstract 4686: Synergistic effect of olaparib (AZD2281) with combination of cisplatin on PTEN-deficient lung cancer cell lines

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Poly(ADP-ribose) polymerase (PARP) enzyme plays a key role in the cellular machinery responsible for DNA damage repair. Although inhibition of this enzyme using a pharmacological inhibitor is postulated to enhance the cytotoxicity of DNA-damaging cytotoxic chemotherapy, this has not been profoundly studied in lung cancer. PTEN (phosphatase and tensin homologue deleted on chromosome ten) is a tumor-suppressor gene deactivating PI3K downstream of EGFR (epidermal growth factor receptor) signaling. Approximately 2% to 9% of non-small cell lung cancers (NSCLC) are considered to have PTEN loss, and a recurrent gross-mutation of the PTEN gene is identified in lung cancer with deficient DNA double-strand break repair. We hypothesize that there is a cellular threshold for error-free DNA-repair in lung cancer cells and that the absence of PTEN can sensitize these cells to a concurrent treatment of a DNA-damaging agent (cisplatin) and a PARP inhibitor (olaparib). To investigate the effect of olaparib and cisplatin on PTEN deficient lung tumors, two EGFR mutant (deletion in exon19) NSCLC cell lines, PC-9 (PTEN wild type) and NCI-H1650 (PTEN loss) were used. Two additional cell lines with PTEN loss, prostate cancer cell line (PC-3) and glioblastoma cell line (U-87MG) were also examined. We transfected intact PTEN gene into H1650 cells and knocked down PTEN expression in the PC-9 cells using shRNA. Antiproliferative activity was determined by MTT assay in terms of 50% inhibitory concentration (IC50) values. Olaparib alone was not effective for H1650 cells and other PTEN-deficient cells. IC50 values ranged from 6 to 40 μM for olaparib and from 0.2 to 2 μM for cisplatin. Combination of cisplatin with olaparib showed a synergistic effect in vitro according to the combination index (CI). CIs were 0.23, 0.20, 0.57 and 0.29 when concentration ratios of cisplatin and olaparib were designed to be molar ratios of 1:1, 1:2, 1:3 and 1:5, respectively. Restoration of PTEN in the H1650 cells decreased sensitivity to olaparib and cisplatin (CI >1). Ablation of PTEN in PC-9 cells increased sensitivity to olaparib and cisplatin (CI <1). We also examined the effectiveness of the cisplatin (5 mg/kg/week) and olaparib (50 mg/kg/day) in a xenograft model using H1650 cells. The combination of cisplatin with olaparib was more effective than each agent individually. This effect was not observed in a xenograft model using PTEN transfected H1650 cells. Mechanistic investigations revealed that PTEN-deficiency caused a reduction in radiation-induced nuclear RAD51 focus formation and activation of Chk1 S345. Thus, genetic inactivation of PTEN led to suppression of DNA repair. The combination of cisplatin with olaparib in PTEN deficient lung tumors should be further pursued. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4686. doi:1538-7445.AM2012-4686