Sung Hee Lim

Association Between PD-L1 and HPV Status and the Prognostic Value of PD-L1 in Oropharyngeal Squamous Cell Carcinoma

Purpose Oropharyngeal squamous cell carcinoma (OSCC) has been recognized as an immunosuppressive disease. Various mechanisms have been proposed for immune escape, including dysregulation of immune checkpoints such as the PD-1:PD-L1 pathway. We investigated the expression of programmed cell death-ligand 1 (PD-L1) in HPV-negative and HPV-positive OSCC to determine its prevalence and prognostic relevance. Materials and Methods Using immunohistochemistry, 133 cases of OSCC were evaluated for expression of PD-L1. Formalin-fixed paraffin-embedded tumor samples were stained with monoclonal antibody (clone 5H1) to PD-L1. PD-L1 positivity was defined as membrane staining in ≥20% of tumor cells. Correlations between PD-L1 expression and HPV status and survival parameters were analyzed. Results Of the 133 patients, 68% showed PD-L1 expression, and 67% of patients were positive for p16 expression by immunohistochemistry. No significant difference in PD-L1 expression was observed between HPV(-) and HPV(+) tumors (61% vs. 71%, p=0.274). No significant difference in age, gender, smoking history, location of tumor origin, or stage was observed according to PD-L1 status. With a median follow-up period of 44 months, older age (≥65) (p=0.017) and T3-4 stage (p<0.001) were associated with poor overall survival (OS), whereas PD-L1 expression did not affect OS in univariate and multivariate analysis. Conclusion PD-L1 expression was observed in the majority of OSCC patients regardless of HPV status. Further large prospective studies are required to determine the role of PD-L1 expression as a prognostic or predictive biomarker, and clinical studies of immune checkpoint inhibitors in OCSS are warranted regardless of HPV status.

Changes in tumour expression of programmed death-ligand 1 after neoadjuvant concurrent chemoradiotherapy in patients with squamous oesophageal cancer

BACKGROUND Programmed death-ligand 1 (PD-L1) expression has been suggested as a potential predictive biomarker of response to anti-PD-1/PD-L1 therapy. In this study, we investigated whether the expression of PD-L1 in tumour cells is affected by neoadjuvant concurrent chemoradiotherapy (CCRT) or chemotherapy in oesophageal squamous cell carcinoma. PATIENTS AND METHODS Between 2004 and 2014, we collected the medical records of locally advanced oesophageal cancer patients consecutively diagnosed and treated with neoadjuvant CCRT or chemotherapy, followed by curative resection. PD-L1 expression in acquired tissue specimens was evaluated by immunohistochemistry using the H-score. The changes in PD-L1 expression between paired samples were evaluated and we also analysed PD-L1 expression in surgical tumour specimens to evaluate its prognostic role. RESULTS Twenty-eight paired tumour tissues that were acquired before and after neoadjuvant therapy were available: 19 patients with CCRT and 9 with chemotherapy before complete oesophagectomy. The PD-L1 H-score increased significantly from baseline tumour tissues to surgical tumour tissues after neoadjuvant CCRT (P = 0.007, median H-score from 28 to 52), whereas it decreased significantly after neoadjuvant chemotherapy (P = 0.048, median H-score from 53 to 22). In a total of 73 patients, including 45 additional cases for the prognosis analysis, patients with higher PD-L1 H-scores (≥ 20) had poorer overall survival (median 16.7 versus 32.9 months, P = 0.02) than those with lower H-scores (<20). CONCLUSIONS PD-L1 expression in tumour cells increased in oesophageal cancer patients who received neoadjuvant CCRT. Further studies with more cases are necessary to validate these findings.

A randomized phase III trial of stereotactic radiosurgery (SRS) versus observation for patients with asymptomatic cerebral oligo-metastases in non-small cell lung cancer

BACKGROUND It is unclear whether treating brain metastasis before starting systemic chemotherapy can improve survival compared with upfront chemotherapy in non-small-cell lung cancer (NSCLC) with asymptomatic cerebral oligo-metastases. PATIENTS AND METHODS We undertook a randomized, controlled trial of 105 patients with one to four brain metastases, admitted to Samsung Medical Center between 2008 and 2013. Patients were randomly assigned to receive stereotactic radiosurgery (SRS) (49 patients) followed by chemotherapy or upfront chemotherapy (49 patients). The primary end point was overall survival (OS) and secondary end points included central nervous system (CNS) progression-free survival, progression to symptomatic brain metastasis and brain functional outcome. RESULTS The median age was 58 years (range, 29-85) with ECOG 0-1 performance status, and 40% of patients were never smokers. Most patients had adenocarcinoma, and about half of patients had only one brain metastasis, while the rest had multiple cerebral metastases. The median OS time was 14.6 months [95% confidence interval (CI), 9.2-20.0] in the SRS group and 15.3 months (95% CI, 7.2-23.4) for the upfront chemotherapy group (P = 0.418). There was no significant difference in time to CNS disease progression [median, 9.4 months (SRS) versus 6.6 months (upfront chemotherapy), P = 0.248]. Symptomatic progression of brain metastases was observed more frequently in the upfront chemotherapy group (26.5%) than the SRS group (18.4%) but without statistical significance. CONCLUSIONS Although this study included smaller sample size than initially anticipated due to early termination, SRS followed by chemotherapy did not improve OS in oligo-brain metastases NSCLC patients compared with upfront chemotherapy. Further study with large number of patients should be needed to confirm the use of upfront chemotherapy alone in this subgroup of patients. CLINICAL TRIALS NUMBER NCT01301560.

Mutational profiling of brain metastasis from breast cancer: matched pair analysis of targeted sequencing between brain metastasis and primary breast cancer

Although breast cancer is the second most common cause of brain metastasis with a notable increase of incidence, genes that mediate breast cancer brain metastasis (BCBM) are not fully understood. To study the molecular nature of brain metastasis, we performed gene expression profiling of brain metastasis and matched primary breast cancer (BC). We used the Ion AmpliSeq Cancer Panel v2 covering 2,855 mutations from 50 cancer genes to analyze 18 primary BC and 42 BCBM including 15 matched pairs. The most common BCBM subtypes were triple-negative (42.9%) and basal-like (36.6%). In a total of 42 BCBM samples, 32 (76.2%) harbored at least one mutation (median 1, range 0–7 mutations). Frequently detected somatic mutations included TP53 (59.5%), MLH1 (14.3%), PIK3CA (14.3%), and KIT (7.1%). We compared BCBM with patient-matched primary BC specimens. There were no significant differences in mutation profiles between the two groups. Notably, gene expression in BCBM such as TP53, PIK3CA, KIT, MLH1, and RB1 also seemed to be present in primary breast cancers. The TP53 mutation frequency was higher in BCBM than in primary BC (59.5% vs 38.9%, respectively). In conclusion, we found actionable gene alterations in BCBM that were maintained in primary BC. Further studies with functional testing and a delineation of the role of these genes in specific steps of the metastatic process should lead to a better understanding of the biology of metastasis and its susceptibility to treatment.

Gene Expression Profiling of Breast Cancer Brain Metastasis

The biology of breast cancer brain metastasis (BCBM) is poorly understood. We aimed to explore genes that are implicated in the process of brain metastasis of primary breast cancer (BC). NanoString nCounter Analysis covering 252 target genes was used for comparison of gene expression levels between 20 primary BCs that relapsed to brain and 41 BCBM samples. PAM50-based intrinsic subtypes such as HER2-enriched and basal-like were clearly over-represented in BCBM. A panel of 22 genes was found to be significantly differentially expressed between primary BC and BCBM. Five of these genes, CXCL12, MMP2, MMP11, VCAM1, and MME, which have previously been associated with tumor progression, angiogenesis, and metastasis, clearly discriminated between primary BC and BCBM. Notably, the five genes were significantly upregulated in primary BC compared to BCBM. Conversely, SOX2 and OLIG2 genes were upregulated in BCBM. These genes may participate in metastatic colonization but not in primary tumor development. Among patient-matched paired samples (n = 17), a PAM50 molecular subtype conversion was observed in eight cases (47.1%), with a trend toward unfavorable subtypes in patients with the distinct gene expression. Our findings, although not conclusive, reveal differentially expressed genes that might mediate the brain metastasis process.

Hepatitis B reactivation in multiple myeloma patients with resolved hepatitis B undergoing chemotherapy.

Despite increasing reports of hepatitis B virus (HBV) reactivation in multiple myeloma (MM), HBV reactivation in patients with resolved hepatitis B [hepatitis B surface antigen (HBsAg)‐negative/anti‐hepatitis B core antigen antibody (anti‐HBc)‐positive] is still poorly characterized. The aim of this study was to clarify its frequency and risk factors.

A Phase Ib/II Study of Afatinib in Combination with Nimotuzumab in Non-Small Cell Lung Cancer Patients with Acquired Resistance to Gefitinib or Erlotinib

Purpose: In this phase Ib/II study, we aimed to assess the safety and efficacy of afatinib plus nimotuzumab (N) in advanced non–small cell lung cancer (NSCLC) patients with acquired resistance to gefitinib or erlotinib. Experimental Design: In phase Ib stage, patients received afatinib (40 mg or 30 mg once daily) plus nimotuzumab (100 mg or 200 mg once weekly) for 28-day cycles to determine the recommended phase II dose (RPIID). The safety and efficacy of RPIID dose was evaluated in phase II stage. Results: In total, 50 patients were enrolled (13 to phase Ib and 37 to phase II). In the first dose-finding cohort (afatinib 40 mg plus nimotuzumab 100 mg), one patient experienced dose-limiting toxicity (DLT) of grade 3 diarrhea and in the subsequent cohort (afatinib 40 mg plus nimotuzumab 200 mg), two DLTs (grade 3 diarrhea and grade 3 neutropenia) occurred in 2 of 6 patients. Accordingly, RPIID was determined as afatinib 40 mg plus nimotuzumab 100 mg. In 44 patients treated with RPIID, 7 (16%) patients had grade 3 toxicities; skin rash (7%), diarrhea (5%), acne (2%), and fatigue (2%). The overall response rate was 23% and the median duration of response was 4.3 months (range, 0.7–16.2 months). The median progression-free survival and overall survival were 4.0 months [95% confidence interval (CI), 2.3–5.7 months] and 11.7 months (95% CI, 9.4–14.0 months), respectively. Conclusions: Combination treatment of afatinib and nimotuzumab demonstrated an acceptable safety profile and encouraging antitumor activity in advanced NSCLC patients with acquired resistance to gefitinib or erlotinib. Larger phase III trial is warranted to confirm its efficacy and safety. Clin Cancer Res; 22(9); 2139–45. ©2015 AACR.

The BIM Deletion Polymorphism and its Clinical Implication in Patients with EGFR-Mutant Non-Small-Cell Lung Cancer Treated with EGFR Tyrosine Kinase Inhibitors

Introduction: A germline BIM deletion polymorphism has been proposed to predict poor treatment response to certain kinase inhibitors. The purpose of this study was to explore whether the BIM deletion polymorphism predicts treatment efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in Korean patients with EGFR-mutant non–small-cell lung cancer (NSCLC). Methods: Peripheral blood samples from a total of 205 patients with EGFR-mutant NSCLC who were treated with EGFR TKIs between July 2008 and April 2013 were included. The incidence of BIM deletions in these samples was detected by polymerase chain reaction. We compared the clinical outcomes in patients with and without the polymorphism after treatment with EGFR TKIs (gefitinib or erlotinib). Results: The BIM deletion polymorphism was present in 15.6% (32 of 205) of patients. One patient was homozygous for the deletion, and the remaining 31 had heterozygous deletions. The majority of patients were younger than 65 years (74%), female (68%), never smokers (76%), and had stage IV NSCLC (67%). There were no associations between the BIM deletion polymorphism and clinicopathological features including gender, age, smoking status, histology, stage, and number of metastasis sites. Patients with and without the BIM deletion polymorphism had similar objective response rates (91 vs. 84%, p = 0.585). Progression-free survival and overall survival did not differ significantly between patients with and without the BIM deletion polymorphism (median progression-free survival 12 vs. 11 months, p = 0.160; median overall survival 31 vs. 30 months, p = 0.452). Multivariate analysis identified significantly predictive markers for clinical outcomes of EGFR TKIs including Eastern Cooperative Oncology Group performance status 0–1, adenocarcinoma histology, recurrent disease, and EGFR mutation type. The results were validated in an independent cohort of 69 NSCLC patients. Conclusions: It remains to be determined whether the BIM deletion polymorphism provides intrinsic resistance or decreased sensitivity to EGFR TKIs in EGFR-mutant NSCLC patients.

Cross-sectional Study of Patients with Diffuse Large B-Cell Lymphoma: Assessing the Effect of Host Status, Tumor Burden, and Inflammatory Activity on Venous Thromboembolism

Purpose The risk factors for venous thromboembolism (VTE) in diffuse large B-cell lymphoma (DLBCL) are not clear although thrombosis can be associated with host status, tumor burden, and inflammatory activity. We assessed the effect of those factors on VTE in a cross-sectional study of patients enrolled in a prospective cohort study. Materials and Methods We analyzed the occurrence of VTE in 322 patients with newly diagnosed DLBCL who received rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) between 2008 and 2011. Serum levels of inflammatory cytokines were measured from serum samples archived at diagnosis. Results With a median follow-up duration of 41.9 months, VTE was documented in 34 patients (10.6%). A comparison of baseline characteristics indicated the group with VTE had higher percentage of old age, stage III/IV and extranodal involvements than the group without VTE (p < 0.05). Thus, the International Prognostic Index was significantly associated with VTE, but the Khorana score was not. A univariate competing risk factor analysis for VTE revealed that increased levels of inflammatory cytokines such as interleukin (IL)-6 and IL-10 were also associated with VTE (p < 0.05) in addition to host and tumor burden. However, a multivariate analysis showed that two host factors including age (≥ 60 years) and poor performance were independent risk factors for VTE. Conclusion Among potential risk factors for VTE including tumor burden and inflammatory activity, age and performance status had a strong impact on the occurrence of VTE in patients with DLBCL who received R-CHOP.

CD133-positive tumor cell content is a predictor of early recurrence in colorectal cancer.

BACKGROUND The aims of this study were to demonstrate the tumorigenicity of CD133+ colon cancer cells in vitro, analyze the correlations between spheroid formation and clinicopathologic variables, and screen for overexpressed genes in CD133+ colon cancer stem cells. Moreover, the aim of this study was to establish a living tumor tissue bank using surgically resected specimens. METHODS Using LoVo cell line, we isolated CD133+ cells and performed clonogenic assay and animal experiment to test tumorigenicity of CD133+ cells. Twenty-nine surgical samples were freshly collected from 27 patients who received curative or palliative surgery, and the samples were mechanically and enzymatically dissociated into single cells. RESULTS We confirmed the enhanced tumorigenicity of CD133+ cells isolated from LoVo cell line both in vitro and in vivo. Of these 29 samples, 8 (28%) contained >3% CD133+ cells. Sphere formation was significantly higher in samples from patients with lymphatic invasion than in those without lymphatic invasion [54.5% (6/11) vs. 12.5% (2/16); P=0.033] and in samples containing >3% of CD133+ cells than in those containing ≤3% of CD133+ cells [36.4% (4/11) vs. 0% (0/16); P=0.019]. CONCLUSIONS These findings indicate that CD133 is a valid marker for identifying cancer stem cells from fresh surgically resected colorectal cancer tissues. Furthermore, we successfully established a living tumor tissue bank using surgically resected colorectal tissues with a viability of >70%.