Sakiko Otani

Circulating tumor cells as a prognostic factor in patients with small cell lung cancer

The detection of circulating tumor cells (CTCs) in peripheral blood is currently an important field of study. Detection of CTCs by the OBP-401 assay (TelomeScan®) has previously been reported to be useful in the diagnosis, prognosis and evaluation of therapeutic efficacy in breast and gastric cancer. The aim of the present study was to evaluate the OBP-401 assay as a novel method of detecting CTCs of small cell lung cancer (SCLC) patients and to evaluate whether CTC count is associated with prognosis. Prospectively, 30 consecutively diagnosed SCLC patients who had commenced chemotherapy or chemoradiotherapy were enrolled as subjects of the current study. Peripheral blood specimens were collected from the SCLC patients prior to and following the initiation of treatment and the viable CTCs were detected in the specimens following incubation with a telomerase-specific, replication-selective, oncolytic adenoviral agent, which was carrying the green fluorescent protein gene. CTCs were detected in 29 patients (96%). The group of 21 patients with a CTC count of <2 cells/7.5 ml prior to treatment (baseline) had a significantly longer median survival time than the group of eight patients with a CTC count of ≥2 cells/7.5 ml prior to treatment (14.8 and 3.9 months, respectively; P=0.007). The results of a multivariate analysis showed that the baseline CTC count was an independent prognostic factor for survival time (hazard ratio, 3.91; P=0.026). Among the patients that achieved a partial response to treatment, patients who had a CTC count of <2 cells/7.5 ml following two cycles of chemotherapy tended to have a longer median progression-free survival compared with patients who had a CTC count of ≥2 cell/7.5 ml (8.3 and 3.8 months, respectively; P=0.07). Therefore, CTCs may be detected via OBP-401 assay in SCLC patients and the CTC count prior to treatment appears to be a strong prognostic factor.

Successful rechallenge with erlotinib in a patient with EGFR-mutant lung adenocarcinoma who developed gefitinib-related interstitial lung disease

Small-molecule tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) pathways are used clinically for patients with non-small cell lung cancer (NSCLC). It is well established that somatic mutations in the kinase domain of the EGFR (Lynch et al. in N Engl J Med 350:2129–2139, 2004; Paez et al. in Science 304:1497–1500, 2004) are strongly associated with the tumor response and clinical outcomes in patients with NSCLC receiving EGFR-TKIs (Mitsudomi and Yatabe in Cancer Sci 98:1817–1824, 2007). Although the most common adverse events are skin rash and diarrhea, the most serious adverse effect reported is drug-related interstitial lung disease (ILD) (Inoue et al. in Lancet 361:137–139, 2003; Ando et al. in J Clin Oncol 24:2549–2556, 2006). The precise mechanism underlying the development of drug-related ILD remains unknown. Here, we describe a case of EGFR-mutant NSCLC who was rechallenged with the small-molecule EGFR antagonist erlotinib after developing gefitinib-related ILD.

Pemetrexed for previously treated patients with non-small cell lung cancer and differences in efficacy according to thymidylate synthase expression.

The purpose of this study was to evaluate the efficacy of pemetrexed monotherapy in previously treated patients with advanced non-small cell lung cancer (NSCLC) including salvage treatment, and to evaluate whether thymidylate synthase (TS) expression is a predictor for pemetrexed efficacy. Hundred and four previously treated patients with advanced NSCLC who received pemetrexed monotherapy were retrospectively evaluated for clinical efficacy and toxicity. If available, tissue specimens of patients were also analyzed immunohistochemically for TS expression. The patients’ median age was 65 years (range: 43–82). An overall response rate of 9.6% and a median progression-free survival (PFS) time of 3.4 months were achieved. The response rates for the second-line, third-line, fourth-line or further treatments were 9.1, 9.3 and 10.2% (p = 0.33); the median PFS were 3.3, 3.2 and 3.8 months (p = 0.21). The median follow-up duration was 14.9 months; the median overall survival (OS) was 11.9 months. The median PFS and OS were significantly longer in the TS-negative group than in the TS-positive group (5.8 months vs. 1.6 months; p = 0.03, and 14.7 months vs. 8.6 months; p = 0.04, respectively). Pemetrexed monotherapy could be considered as an option in the fourth or later lines of treatment of previously treated patients with advanced NSCLC as well as a second- or third-line treatment, and TS expression may be a potentially predictive factor for pemetrexed efficacy in NSCLC patients.

Impact of PD-L1 Expression in Patients with Surgically Resected Non-Small-Cell Lung Cancer

Background: Immunotherapy can become a crucial therapeutic option to improve the prognosis of patients with non-small-cell lung cancer (NSCLC). Here, we evaluated the impact of programmed cell death ligand-1 (PD-L1) expression in surgically resected NSCLCs. Methods: We estimated PD-L1 expression in 229 consecutive NSCLC specimens using rabbit polyclonal antibodies to human PD-L1 in a SP263 immunohistochemical assay and evaluated PD-L1 expression for potential associations with clinicopathological parameters and survival time. Results: PD-L1 expression was significantly higher in tumors from men or current smokers. Squamous cell carcinoma histology was independently associated with high PD-L1 expression according to multivariate analysis (p = 0.015). The 5-year survival rate of patients was 70%, and the difference in the 5-year survival rate according to PD-L1 expression was not statistically significant (high expression group [67%] vs. low expression group [68%]); however, the squamous cell carcinoma group exhibited significantly lower 5-year survival rates as compared to the non-squamous cell carcinoma group (53 and 71%, respectively; p = 0.026). Conclusion: Here, we revealed high PD-L1 expression and poor prognosis observed in patients with surgically resected squamous NSCLC as compared with non-squamous NSCLC. Our results support the identification of patient subsets that most likely respond to anti-PD-1 therapy as the first step in precision medicine.

Effect of gefitinib on warfarin antithrombotic activity.

BackgroundDespite the literature indicating adverse interactions between warfarin and cytotoxic agents, whether such an interaction occurs when warfarin and gefitinib are used concomitantly is unknown. We analyzed the prevalence of the concomitant use of warfarin and gefitinib, and the incidence of prothrombin time-international normalized ratio (PT-INR) alterations or adverse interactions in concomitant users of warfarin and gefitinib.MethodsWe conducted a retrospective study of patients with non-small cell lung cancer treated at the Kitasato University Hospital who received concomitant warfarin and gefitinib between September 2002 and January 2007. Medical information, including the indication for warfarin use, warfarin dosing and dosing changes, and exposure to gefitinib were collected from computerized databases and medical records.ResultsTwelve (4.1%) of 296 patients treated with gefi— tinib received warfarin. PT-INR elevation occurred in 6 patients (50.0%). Two (16.7%) of the 12 patients had liver metastases. Liver dysfunction was associated with PT-INR elevation (P = 0.0100).ConclusionAs there is a possibility of PT-INR abnormalities occurring during the concomitant use of gefitinib and warfarin, clinicians should be aware of this interaction. Because of the potentially severe consequences of this interaction, close monitoring of PT-INR and warfarin dose adjustment are recommended for patients receiving warfarin and gefitinib, especially during the first 2 weeks in the beginning of warfarin therapy.

Comparison of the efficacy of gefitinib in patients with non-small cell lung cancer according to the type of epidermal growth factor receptor mutation.

Background: Exon 19 deletion and L858R point mutation of the epidermal growth factor receptor (EGFR) are the most commonly encountered EGFR mutations in non-small cell lung cancer (NSCLC), and predict higher clinical outcomes following treatment with gefitinib. The objective of this study was to evaluate the differential clinical outcomes of gefitinib in patients with NSCLC according to the type of active EGFR mutation, i.e. exon 19 deletion or L858R point mutation. Methods: We identified patients with advanced NSCLC harboring the exon 19 deletion or the L858R point mutation of EGFR who were on gefitinib treatment. The clinical outcomes were evaluated. Results: Of the 124 patients with NSCLC harboring active EGFR mutations, the overall response rate, progression-free survival and overall survival were 60.5%, 11.3 and 27.3 months, respectively, and did not differ significantly between patients with the exon 19 deletion (61.8%, 11.3 and 32.2 months, respectively) and those with the L858R point mutation (58.9%, 9.0 and 27.7 months, respectively). Conclusion: It may be considered that there is no difference in the clinical efficacy of gefitinib between NSCLC patients who harbor the exon 19 deletion and those with the L858R point mutation.

Impact of Smoking History on the Efficacy of Gefitinib in Patients with Non-Small Cell Lung Cancer Harboring Activating Epidermal Growth Factor Receptor Mutations.

Background: Gefitinib treatment has come to be recognized as the standard therapy for patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. However, resistance to gefitinib has been observed in certain subpopulations of these patients. The purpose of this study was to evaluate the impact of smoking status on the efficacy of gefitinib in patients with NSCLC harboring EGFR mutations. Methods: The records of NSCLC patients harboring EGFR mutations who were treated with gefitinib at Kitasato University Hospital were retrospectively reviewed, and the treatment outcomes were evaluated. Results: In 153 patients with NSCLC harboring EGFR mutations, the overall response rate and progression-free survival (PFS) were 66.7% and 9.0 months, respectively. PFS differed significantly among the current smokers and never-smokers/former light smokers (10.7 vs. 5.4 months, p = 0.0002), and the response rate was significantly higher in the never-smokers/former light smokers than in the current smokers (72.3 vs. 55.8%, p = 0.04). Multivariate analysis identified smoking status as an independent predictor of PFS. Conclusion: The clinical data obtained in this study provide a valuable rationale for considering smoking status as a predictor of the efficacy of gefitinib in patients with NSCLC harboring activating EGFR mutations.

The role of prophylactic cranial irradiation for patients with small-cell lung cancer

Small-cell lung cancer (SCLC) has a particular propensity to metastasize to the brain, affecting ~10% of SCLC patients at diagnosis, but may occur in more than 50% of 2-year survivors. Most cytotoxic drugs have limited ability to cross the blood-brain barrier, and the effectiveness of chemotherapy for brain metastasis is limited. Therefore, prophylactic cranial irradiation (PCI) has been proposed to treat SCLC. A meta-analysis revealed that PCI significantly decreased the risk of brain metastasis and increased the 3-year survival rate; it has been established as a standard therapy for limited-disease SCLC. However, certain aspects of PCI remain unclarified, including the roles in resected SCLC and extensive-disease SCLC, and its neurotoxicities. In addition, information on PCI has been obtained from old clinical trials without the use of new imaging devices, such as magnetic resonance imaging. Evidence from advanced imaging techniques is needed in this era.

Correlation between the efficacy of amrubicin and the previous chemotherapy regimen for relapsed small cell lung cancer

Amrubicin has been demonstrated to be beneficial in the treatment of patients with relapsed small cell lung cancer (SCLC). The aim of the present study was to evaluate whether there is a significant difference in the efficacy of amrubicin between patients with relapsed SCLC who were previously treated with a platinum agent in combination with a topoisomerase I inhibitor, and those patients previously treated with a platinum agent in combination with a topoisomerase II inhibitor. The medical records of patients with SCLC, who were diagnosed as having relapsed following treatment with a platinum-based regimen and subsequently received amrubicin monotherapy, were retrospectively reviewed. Of a total of 48 patients with SCLC who were treated with amrubicin, the overall response rate, median progression-free survival (PFS) time and median survival time (MST) were determined to be 31.3%, 7.1 and 17.0 months, respectively. The response rate, PFS time and MST did not differ significantly between the patients treated previously with a platinum agent in combination with irinotecan, a topoisomerase I inhibitor, (36.4%, 5.7 and 11.4 months, respectively) and those treated previously with a platinum agent in combination with etoposide, a topoisomerase II inhibitor (30.0%, 4.7 and 14.8 months, respectively). The results indicate that amrubicin may be effective as a second-line chemotherapeutic agent for patients with SCLC, irrespective of which platinum agent and topoisomerase inhibitor-based chemotherapy regimen was previously administered.

Smoking History as a Predictor of Pemetrexed Monotherapy in Patients with Non-Squamous Non-Small Cell Lung Cancer.

Background: Pemetrexed monotherapy has come to be recognized as the standard of care for second-line therapy of non-squamous non-small cell lung cancer (NSCLC). Thymidylate synthase (TS) expression is recognized as a potential predictor of the response to pemetrexed-based chemotherapy in patients with advanced NSCLC. The purpose of this study was to identify useful predictors of the response to pemetrexed other than TS expression. Methods: The records of non-squamous NSCLC patients without driver mutations who received pemetrexed monotherapy as a second or later line of chemotherapy at Kitasato University Hospital between March 2009 and October 2015 were retrospectively reviewed, and the treatment outcomes were evaluated. Results: In the 116 patients with non-squamous NSCLC, the overall response rate and progression-free survival (PFS) were 10.3% and 2.1 months, respectively. The disease control rate and PFS differed significantly among current smokers and never-smokers/former light smokers (44.9 vs. 65.8%, and 1.8 vs. 4.0 months, respectively). Furthermore, multivariate analysis identified Eastern Cooperative Oncology Group Performance Status and smoking status as independent predictors of the PFS. Conclusion: The clinical data obtained in this study may provide a valuable basis for the use of smoking status as a predictor of pemetrexed monotherapy in wild-type NSCLC patients.