Kosuke Kashiwabara

An Immunogram for the Cancer-Immunity Cycle: Towards Personalized Immunotherapy of Lung Cancer.

Introduction: The interaction of immune cells and cancer cells shapes the immunosuppressive tumor microenvironment. For successful cancer immunotherapy, comprehensive knowledge of antitumor immunity as a dynamic spatiotemporal process is required for each individual patient. To this end, we developed an immunogram for the cancer‐immunity cycle by using next‐generation sequencing. Methods: Whole exome sequencing and RNA sequencing were performed in 20 patients with NSCLC (12 with adenocarcinoma, seven with squamous cell carcinoma, and one with large cell neuroendocrine carcinoma). Mutated neoantigens and cancer germline antigens expressed in the tumor were assessed for predicted binding to patients’ human leukocyte antigen molecules. The expression of genes related to cancer immunity was assessed and normalized to construct a radar chart composed of eight axes reflecting seven steps in the cancer‐immunity cycle. Results: Three immunogram patterns were observed in patients with lung cancer: T‐cell–rich, T‐cell–poor, and intermediate. The T‐cell–rich pattern was characterized by gene signatures of abundant T cells, regulatory T cells, myeloid‐derived suppressor cells, checkpoint molecules, and immune‐inhibitory molecules in the tumor, suggesting the presence of antitumor immunity dampened by an immunosuppressive microenvironment. The T‐cell–poor phenotype reflected lack of antitumor immunity, inadequate dendritic cell activation, and insufficient antigen presentation in the tumor. Immunograms for both the patients with adenocarcinoma and the patients with nonadenocarcinoma tumors included both T‐cell–rich and T‐cell–poor phenotypes, suggesting that histologic type does not necessarily reflect the cancer immunity status of the tumor. Conclusions: The patient‐specific landscape of the tumor microenvironment can be appreciated by using immunograms as integrated biomarkers, which may thus become a valuable resource for optimal personalized immunotherapy.

Validation and Potential of Albumin-Bilirubin Grade and Prognostication in a Nationwide Survey of 46,681 Hepatocellular Carcinoma Patients in Japan: The Need for a More Detailed Evaluation of Hepatic Function

Background/Aim: Recently, albumin-bilirubin (ALBI) scoring/grading, consisting of only albumin and total bilirubin, has been proposed. We examined the efficacy of this grading system for determining hepatic function in patients with hepatocellular carcinoma (HCC). Methods/Materials: The prognoses of 46,681 HCC patients based on results obtained from a nationwide survey conducted in Japan from 2001 to 2007 were evaluated using (1) Japan Integrated Staging (JIS), consisting of Child-Pugh classification and TNM staging (TNM), (2) modified JIS (m-JIS), consisting of liver damage grading and TNM, and (3) ALBI-TNM (ALBI-T), consisting of ALBI grading and TNM, and the results were compared. A subanalysis was also performed to define a cutoff value for ALBI scores for a more detailed stratification of hepatic function. Results: ALBI-T, JIS, and m-JIS each showed good capacity for the stratification of prognoses. Although the Akaike information criterion for ALBI-T was nearly equal to that for JIS and m-JIS, the Kaplan-Meier curves and median survival times obtained with ALBI-T were always superior to the corresponding scores. When the indocyanine green retention test (<30%) was used as an additional cutoff value for ALBI score (-2.270, area under the curve 0.828) to divide ALBI grade into 4 levels (modified ALBI [mALBI] grade), mALBI grade was able to stratify the prognosis of patients at any TNM stage in order of grade. Modified ALBI-T (mALBI-T), using mALBI grading and TNM, produced a more detailed stratification for prognosis. Conclusion: The predictive value for prognosis of ALBI-T was found to be equal to that of JIS and m-JIS. In addition, mALBI grading and mALBI-T, as proposed in the present study, might provide a more detailed assessment of the hepatic function and prognosis of HCC patients.

Impact of postoperative complications on the colorectal cancer survival and recurrence: analyses of pooled individual patients’ data from three large phase III randomized trials

This study assessed the impact of postoperative complications on the colorectal cancer survival and recurrence after curative surgery using pooled individual patients’ data from three large phase III randomized trials. In total, 5530 patients were included in this study. The patients were classified as those with postoperative complications (C group) and those without postoperative complications (NC group). The risk factors for the overall survival (OS) and the disease‐free survival (DFS) were analyzed. Postoperative complications were found in 861 (15.6%) of the 5530 patients. The OS and DFS rates at 5 years after surgery were 68.9% and 74.8%, respectively, in the C group and 75.8% and 82.2%, respectively, in the NC group, values that were significantly different between the two groups (P < 0.001). The multivariate analysis demonstrated that postoperative complications were a significant independent risk factor for the OS and DFS. Postoperative complications can worsen the colorectal cancer survival and risk of recurrence. Surgical morbidity must be considered as a stratification factor in future phase III trials evaluating the effects of adjuvant chemotherapy on colorectal cancer.

Clinical impact of tumor location on the colon cancer survival and recurrence: analyses of pooled data from three large phase III randomized clinical trials

The aim of the present study was to determine whether or not the overall survival (OS) and disease‐free survival (DFS) were affected by the tumor location in patients who underwent curative resection for colon cancer in a pooled analysis of three large phase III studies performed in Japan. In total, 4029 patients were included in the present study. Patients were classified as having right‐side colon cancer (RC) if the primary tumor was located in the cecum, ascending colon, hepatic flexure or transverse colon, and left‐side colon cancer (LCC) if the tumor site was within the splenic flexure, descending colon, sigmoid colon or recto sigmoid junction. The risk factors for the OS and DFS were analyzed. In the present study, 1449 patients were RC, and 2580 were LCC. The OS rates at 3 and 5 years after surgery were 87.6% and 81.6% in the RC group and 91.5% and 84.5% in the LCC group, respectively. Uni‐ and multivariate analyses showed that RRC increased the risk of death by 19.7% (adjusted hazard ratio = 1.197; 95% confidence interval, 1.020–1.408; P = 0.0272). In contrast, the DFS was similar between the two locations. The present study confirmed that the tumor location was a risk factor for the OS in patients who underwent curative treatment for colon cancer. Tumor location may, therefore, need to be considered a stratification factor in future phase III trials of colon cancer.

Evaluation of oral care to prevent oral mucositis in estrogen receptor-positive metastatic breast cancer patients treated with everolimus (Oral Care-BC): randomized controlled phase III trial

This is a randomized, multi-center, open-label, phase III study to evaluate the efficacy of professional oral care in preventing oral mucositis induced by everolimus in postmenopausal estrogen receptor-positive metastatic breast cancer. Patients will be randomized into professional oral care and control groups (1:1 ratio). All patients will receive everolimus with exemestane and will continue everolimus until disease progression. In the professional oral care group, patients will receive teeth surface cleaning, scaling and tongue cleaning before starting everolimus, and will continue to receive professional oral care weekly from oral surgeons throughout the 8 week treatment. In the control group, patients will brush their own teeth and gargle with 0.9% sodium chloride solution or water. The primary endpoint is the incidence of all grades of oral mucositis. Target accrual is 200 patients with a two-sided type I error rate of 5% and 80% power to detect 25% risk reduction.

A Bayesian Stopping Rule for Sequential Monitoring of Serious Adverse Events

In an ongoing clinical trial, there will always be a risk for unanticipated critical safety problems, such as excessive occurrence of serious adverse events. When such a problem arises, the trial administrators must conduct an immediate evaluation to determine whether the trial should be terminated to protect patients. This decision is complicated but may be aided by statistical stopping rules. Sequential stopping rules are appropriate for immediate decisions, but frequentist approaches may not be useful because the unknown truncated end of the trial makes it impossible to define type I errors. Thus, a Bayesian stopping rule is proposed that is based on the posterior distribution with an informative prior distribution, and a guideline to construct this stopping rule is presented. Some operating characteristics are evaluated and compared with those of the modified sequential probability ratio test (SPRT), the maximized SPRT, and Pocock’s test. The proposed method has flexibility for construction and could provide a more desirable performance than the other compared methods.

Hazard rate of tumor recurrence over time in patients with colon cancer: Implications for postoperative surveillance from three Japanese Foundation for Multidisciplinary Treatment of Cancer (JFMC) clinical trials

Purpose: Reliable risk estimates of recurrence are necessary to establish optimal postoperative surveillance strategies. The purpose of the present study was to clarify changes in the hazard rate (HR) for tumor recurrence over time in Japanese patients with colon cancer. Methods: Data for 3984 patients from three clinical trials evaluating the benefit of adjuvant chemotherapy for colon cancer were analyzed. Estimated HRs were plotted over time for the entire cohort, as well as for node-positive and node-negative patients separately. The changes in risk were further analyzed according to eight clinical variables, and factors predictive of early (<3 years) and late (>3 years) recurrence were explored using Coxs regression analysis. Results: In node-positive patients, there was a prominent HR peak 0.6 years after surgery, whereas HR remained at consistently low levels in node-negative patients. In node-positive patients, HR decreased steadily until 3 years, after which the decline in HR plateaued. Those with T4 tumors had a prominent HR peak around 1 year, including node-negative patients. The HR for T1/T2 Stage III colon cancers showed a similar pattern as that for T1-T3 node-negative colon cancers. Cox regression analysis revealed that a lack of adjuvant chemotherapy, positive node status, T3/T4 factors, and male gender predict early recurrence, whereas patients with lymph node metastasis, T4 tumors, and a lesser extent of lymph node removal have a higher risk of recurrence 3-4 years after surgery (P<0.05). Conclusion: The present study supports the concept of intensive surveillance during the first 3 years after curative resection. However, a reduction in surveillance intensity may be acceptable for patients with T3 Stage II and T1/T2 Stage III colon cancer.

Reasonable two-stage adaptive designs for single-arm phase II clinical trials

In cancer phase II trials, determining the sample size of a single-arm two-stage design remains a challenge. To overcome this problem, Simons two-stage design was extended to an adaptive design: at the interim analysis, the total sample size can be set to either of the two preplanned values. However, without any restriction on design construction, an optimal or suboptimal design derived may have counter-intuitive or unreasonable design features, which make the chosen design less persuasive and inefficient. Thus, we thoroughly examined how the expected, total, and maximum sample sizes of the optimal or suboptimal designs are affected by excluding the counter-intuitive or unreasonable designs. We adopted the four optimality criteria: minimizing the expected sample size at the null hypothesis (O1), minimizing the maximum expected sample size over the hypotheses (O2), and minimizing the maximum sample sizes with additional adaption of either of the former two (O3 or O4, respectively). We found that focusing on reasonable design may drastically reduce the maximum sample size when the first optimality criterion is applied. Under the other optimality criteria, although the impact on optimality brought by our proposed strategy may be slight, exclusion of unreasonable design is still useful to reduce the candidate designs, which will considerably reduce the computational time for design search and can facilitate the design choice among optimal and suboptimal designs. We further discuss the utility of our proposal in an example of a real clinical trial and conclude the paper with general recommendations.

High CCR4 expression in the tumor microenvironment is a poor prognostic indicator in lung adenocarcinoma

Background Clinical trials of anti-CCR4 antibody for solid cancers with or without other immune-modulating agents including immune checkpoint blockade therapy are currently underway. However, little is known about the roles of CCR4+ lymphocytes and their prognostic impact in lung cancer. We hypothesized that high CCR4 expression in the tumor microenvironment would be associated with a poor prognosis and would act as a biomarker in lung adenocarcinoma. Methods First, the prognostic impact of CCR4 gene expression was explored using pooled data from public transcriptomic databases with online survival analysis software. Second, tissue microarrays (TMAs) were constructed from resected lung adenocarcinoma specimens from tumors up to 3 cm in size. The density of CCR4+ lymphocytes infiltrating the tumor was then assessed by immunohistochemistry and related to survival. Confounding factors were controlled for by multivariate analysis using the Cox proportional hazards model. Results Higher than median expression of the CCR4 gene was identified as an independent poor prognostic factor for overall survival (OS) by multivariate analysis of 720 lung adenocarcinoma patients in the public databases [HR =1.55 (95% CI: 1.03-2.35), P=0.037]. Consistent with this, high CCR4+ tumor-infiltrating lymphocyte (TIL) density was found to be an independent poor prognostic factor for both OS [HR =2.24 (1.01-5.34), P=0.049] and recurrence-free survival (RFS) [HR =2.20 (1.16-4.39), P=0.017] in the patients from whom TMA were obtained (n=180). Age, male gender, predominantly non-lepidic histological subtype, nodal involvement, and low CD8+ TIL density were also independent poor prognostic factors. However, FOXP3 gene expression and Foxp3+ lymphocyte infiltration did not possess any prognostic value in either study. Conclusions High CCR4 expression in the tumor microenvironment may be a poor prognostic factor in lung adenocarcinoma. Patients with high CCR4+ lymphocyte infiltration may have a poor prognosis and thus be suitable candidates for clinical trials of anti-CCR4 antibody treatment.

Improved overall survival over recent decades in patients with hormone-receptor-positive, HER2-negative breast cancer: a single-center retrospective analysis of prognostic factors

Background Hormone receptor (HR)-positive HER2-negative breast cancer (BC) rates and associated mortality have been increasing among Japanese women. It is unclear whether the prognosis of these patients has improved. Methods We retrospectively analyzed 1806 Japanese women with operable invasive HR-positive HER2-negative BC, who underwent complete resection at the National Cancer Center Hospital East between July 1992 and December 2010. We investigated whether overall survival (OS) and recurrence-free survival (RFS) had improved by comparing the 4-year periods 1992-96, 1997-2001, 2002-06, and 2007-10. The prognostic factors were evaluated using uni- and multivariate analyses. Results The number of ER- and PgR-positive cancers had increased over the years (P < 0.001). Tumor sizes and numbers of involved lymph nodes both gradually decreased (P < 0.001 for both). OS and RFS of all patients significantly improved in each of the periods analyzed: 5-year OS was 92.6%, 94.8%, 95.4% and 97.6% (P < 0.001, Log-rank), and 5-year RFS was 82.1%, 82.8%, 88.6% and 94.5% (P < 0.001) in 1992-96, 1997-2001, 2002-06 and 2007-10, respectively. In multivariate analysis, the history of adjuvant AI and that of TAM had positive-correlation with RFS. Conclusions The prognosis for HR-positive HER2-negative BC patients after surgical therapy has improved, resulting in longer OS and RFS across the study periods. These changes could be associated with early detection of tumor and history of hormone therapy.