Yusuke Taniyama

Mutation Profiling and Microsatellite Instability in Stage II and III Colon Cancer: An Assessment of Their Prognostic and Oxaliplatin Predictive Value

Purpose: The purpose of this study was to examine the prognostic and oxaliplatin predictive value of mismatch repair (MMR) status and common hot spot mutations, which we previously identified in stage II and III colon cancer. Experimental Design: Mutations in BRAF, KRAS, NRAS, MET, and PIK3CA were profiled in 2,299 stage II and III colon tumors from National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trials C-07 (n = 1,836) and C-08 (n = 463) with Type Plex chemistry and mass spectrometry. C-07 tested the worth of adding oxaliplatin to 5-fluorouracil plus leucovorin, and C-08 tested the worth of adding bevacizumab to FOLFOX. Cox proportional hazard models were used to assess prognostic or oxaliplatin predictive value of mutations for tumor recurrence, overall survival (OS), and survival after recurrence (SAR). Results: BRAF mutations were associated with MMR-deficient tumors (P < 0.0001), poor OS [HR, 1.46; 95% confidence interval (CI), 1.20–1.79; P ≤ 0.0002], and poor SAR (HR, 2.31; 95% CI, 1.83–2.95; P < 0.0001). Mutations in KRAS, NRAS, MET, and PIK3CA were not associated with recurrence, OS, or SAR. MMR-deficient tumors were associated with an improved prognosis based on recurrence (HR, 0.48; 95% CI, 0.33–0.70; P < 0.0001). Mutations and MMR status were not predictive for oxaliplatin benefit. Conclusions: This study shows that BRAF mutations profiled from stage II and III colon cancer tumors were associated with poor SAR and validates and explains, at least in part, previous observations associating it with poor OS. Profiling of all of these mutations is warranted for future clinical trials testing new targeted therapies that block relevant signaling pathways. Such clinical trials are under development at NSABP. Clin Cancer Res; 18(23); 6531–41. ©2012 AACR.

A rapid, sensitive, reproducible and cost-effective method for mutation profiling of colon cancer and metastatic lymph nodes

BackgroundAn increasing number of studies show that genetic markers can aid in refining prognostic information and predicting the benefit from systemic therapy. Our goal was to develop a high throughput, cost-effective and simple methodology for the detection of clinically relevant hot spot mutations in colon cancer.MethodsThe Maldi-Tof mass spectrometry platform and OncoCarta panel from Sequenom were used to profile 239 colon cancers and 39 metastatic lymph nodes from NSABP clinical trial C-07 utilizing routinely processed FFPET (formalin-fixed paraffin-embedded tissue).ResultsAmong the 238 common hot-spot cancer mutations in 19 genes interrogated by the OncoCarta panel, mutations were detected in 7 different genes at 26 different nucleotide positions in our colon cancer samples. Twenty-four assays that detected mutations in more than 1% of the samples were reconfigured into a new multiplexed panel, termed here as ColoCarta. Mutation profiling was repeated on 32 mutant samples using ColoCarta and the results were identical to results with OncoCarta, demonstrating that this methodology was reproducible. Further evidence demonstrating the validity of the data was the fact that the mutation frequencies of the most common colon cancer mutations were similar to the COSMIC (Catalog of Somatic Mutations in Cancer) database. The frequencies were 43.5% for KRAS, 20.1% for PIK3CA, and 12.1% for BRAF. In addition, infrequent mutations in NRAS, AKT1, ABL1, and MET were detected. Mutation profiling of metastatic lymph nodes and their corresponding primary tumors showed that they were 89.7% concordant. All mutations found in the lymph nodes were also found in the corresponding primary tumors, but in 4 cases a mutation was present in the primary tumor only.ConclusionsThis study describes a high throughput technology that can be used to interrogate DNAs isolated from routinely processed FFPET and identifies the specific mutations that are common to colon cancer. The development of this technology and the ColoCarta panel may provide a mechanism for rapid screening of mutations in clinically relevant genes like KRAS, PIK3CA, and BRAF.Trial RegistrationClinicalTrials.gov: NSABP C-07: NCT00004931

Estrogen Receptor (ESR1) mRNA Expression and Benefit From Tamoxifen in the Treatment and Prevention of Estrogen Receptor–Positive Breast Cancer

PURPOSE Several mechanisms have been proposed to explain tamoxifen resistance of estrogen receptor (ER) -positive tumors, but a clinically useful explanation for such resistance has not been described. Because the ER is the treatment target for tamoxifen, a linear association between ER expression levels and the degree of benefit from tamoxifen might be expected. However, such an association has never been demonstrated with conventional clinical ER assays, and the ER is currently used clinically as a dichotomous marker. We used gene expression profiling and ER protein assays to help elucidate molecular mechanism(s) responsible for tamoxifen resistance in breast tumors. PATIENTS AND METHODS We performed gene expression profiling of paraffin-embedded tumors from National Surgical Adjuvant Breast and Bowel Project (NSABP) trials that tested the worth of tamoxifen as an adjuvant systemic therapy (B-14) and as a preventive agent (P-1). This was a retrospective subset analysis based on available materials. RESULTS In B-14, ESR1 was the strongest linear predictor of tamoxifen benefit among 16 genes examined, including PGR and ERBB2. On the basis of these data, we hypothesized that, in the P-1 trial, a lower level of ESR1 mRNA in the tamoxifen arm was the main difference between the two study arms. Only ESR1 was downregulated by more than two-fold in ER-positive cancer events in the tamoxifen arm (P < .001). Tamoxifen did not prevent ER-positive tumors with low levels of ESR1 expression. CONCLUSION These data suggest that low-level expression of ESR1 is a determinant of tamoxifen resistance in ER-positive breast cancer. Strategies should be developed to identify, treat, and prevent such tumors.

Predicting Degree of Benefit From Adjuvant Trastuzumab in NSABP Trial B-31

BACKGROUND National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-31 suggested the efficacy of adjuvant trastuzumab, even in HER2-negative breast cancer. This finding prompted us to develop a predictive model for degree of benefit from trastuzumab using archived tumor blocks from B-31. METHODS Case subjects with tumor blocks were randomly divided into discovery (n = 588) and confirmation cohorts (n = 991). A predictive model was built from the discovery cohort through gene expression profiling of 462 genes with nCounter assay. A predefined cut point for the predictive model was tested in the confirmation cohort. Gene-by-treatment interaction was tested with Cox models, and correlations between variables were assessed with Spearman correlation. Principal component analysis was performed on the final set of selected genes. All statistical tests were two-sided. RESULTS Eight predictive genes associated with HER2 (ERBB2, c17orf37, GRB7) or ER (ESR1, NAT1, GATA3, CA12, IGF1R) were selected for model building. Three-dimensional subset treatment effect pattern plot using two principal components of these genes was used to identify a subset with no benefit from trastuzumab, characterized by intermediate-level ERBB2 and high-level ESR1 mRNA expression. In the confirmation set, the predefined cut points for this model classified patients into three subsets with differential benefit from trastuzumab with hazard ratios of 1.58 (95% confidence interval [CI] = 0.67 to 3.69; P = .29; n = 100), 0.60 (95% CI = 0.41 to 0.89; P = .01; n = 449), and 0.28 (95% CI = 0.20 to 0.41; P < .001; n = 442; P(interaction) between the model and trastuzumab < .001). CONCLUSIONS We developed a gene expression-based predictive model for degree of benefit from trastuzumab and demonstrated that HER2-negative tumors belong to the moderate benefit group, thus providing justification for testing trastuzumab in HER2-negative patients (NSABP B-47).

Defective Mismatch Repair and Benefit from Bevacizumab for Colon Cancer: Findings from NSABP C-08

National Surgical Adjuvant Breast and Bowel Project protocol C-08 tested the worth of adding 1 year of bevacizumab to oxaliplatin-based standard adjuvant chemotherapy regimen in the treatment of stage II/III colon cancer. Although the overall result was negative, the possibility that a molecularly defined subset could benefit from bevacizumab cannot be ruled out. We performed post hoc Cox regression analyses to test for marker-by-treatment interactions for standard pathological features and survival analyses using the Kaplan-Meier method. All statistical tests were two-sided and considered statistically significant at the .05 level. Patients diagnosed with mismatch repair defective (dMMR) tumors derived statistically significant survival benefit from the addition of bevacizumab (hazard ratio [HR] = 0.52; 95% confidence interval [CI] = 0.29 to 0.94; P = .02) in contrast with no benefit in patients diagnosed with mismatch repair proficient tumors (HR = 1.03; 95% CI = 0.84 to 1.27; p = .78; P(interaction)= .04). Although a post hoc finding, this data suggests that a molecularly defined subset of colon cancer patients may derive clinical benefit from antiangiogenesis agents and underscores the need for independent validation in other clinical trials.

Significance of CD133 expression in esophageal squamous cell carcinoma

BackgroundCD133 was recently reported to be a cancer stem cell marker and a prognostic marker for several tumors. However, few studies have investigated CD133 expression in esophageal squamous cell carcinoma (ESCC). Therefore, we examined whether CD133 could serve as a prognostic marker of ESCC and investigated the correlation between CD133 expression and the clinicopathological findings of ESCC patients and several markers.MethodsWe studied 86 ESCC patients who underwent curative surgery without neoadjuvant treatment at Tohoku University Hospital (Sendai, Japan) between January 2000 and December 2005. We analyzed tissue specimens by immunohistochemical staining for CD133, p53, p16, p27, murine double minute 2 (MDM2), Ki-67, and epidermal growth factor receptor (EGFR).ResultsPathological tumor depth and tumor stage were significantly more advanced among CD133-negative patients than among CD133-positive patients. A log-rank test showed that CD133 immunoreactivity was significantly correlated with the overall survival of the patients (P = 0.049). However, multivariate analysis showed that it was not significantly correlated (P = 0.078). Moreover, CD133 was significantly positively correlated with p27 immunoreactivity (P = 0.0013) and tended to be positively correlated with p16 immunoreactivity (P = 0.057). In addition, p16 immunoreactivity was correlated with smoking history (P = 0.018), pathological lymph node status (P = 0.033), and lymphatic invasion (P = 0.018).ConclusionsThis study indicated that CD133 immunoreactivity is a good predictor of prognosis in ESCC patients. In addition, CD133 may play a role in the regulation of tumor cell cycle through p27 and p16 in ESCC. At present, it thus remains controversial whether CD133 expression is a valid prognostic marker for ESCC. To elucidate this relationship, further investigations are required.

Gene Expression–Based Prognostic and Predictive Markers for Breast Cancer: A Primer for Practicing Pathologists

CONTEXT Gene expression-based prognostic assays for breast cancer are now available as commercial reference laboratory tests covered by insurance. OBJECTIVE To provide practicing pathologists with information about the nature of these assays, differences among them, and their use by clinical oncologists in the management of patients diagnosed with breast cancer. DATA SOURCES Review of literature and unpublished data from the National Surgical Adjuvant Breast and Bowel Project. This review focused on a general conceptual description of the technology behind these assays and differences among them to aid understanding by pathologists in practice. CONCLUSIONS While these assays are clinically useful, they are still evolving. The future development of gene expression-based markers will need to be more clinical-context-specific to be clinically useful.

Comparison of short-term outcomes between prone and lateral decubitus positions for thoracoscopic esophagectomy

AbstractBackgroundProne thoracoscopic esophagectomy was introduced at our institution from 2012. This study describes our experiences of the main differences between thoracoscopic esophagectomy in the prone and traditional left lateral decubitus positions together with an analysis of the short-term surgical outcomes.MethodIn total, 87 patients undergoing thoracoscopic esophagectomy between January 2012 and October 2013 at Tohoku University Hospital were enrolled; of these, 54 and 33 patients were operated in the prone (Group P) and lateral decubitus (Group L) positions, respectively.ResultsThe background of the patients was similar, and there was no in-hospital mortality. There were no significant differences between the groups in terms of whole surgical duration, thoracic duration, and number of dissected lymph nodes. Total blood loss and thoracic estimated blood loss were significantly lower in Group P than Group L. Furthermore, postoperative pulmonary complications, intensive care unit stay, and hospital stay were significantly lower in Group P.ConclusionThoracoscopic esophagectomy in the prone position is feasible and safe. The prone position technique may be superior to conventional lateral decubitus position esophagectomy.

A Strategy for Supraclavicular Lymph Node Dissection Using Recurrent Laryngeal Nerve Lymph Node Status in Thoracic Esophageal Squamous Cell Carcinoma

BACKGROUND The desirability of supraclavicular lymph node (LN) dissection, which is the cervical part of three-field LN dissection, has been discussed for a long time. In this study, we examine the pattern of supraclavicular LN metastasis in esophageal cancer, with a particular focus on the correlation between recurrent laryngeal nerve (RLN) LN and supraclavicular LN metastasis. METHODS In all, 220 cases of R0 resected T1 to T3 squamous cell carcinomas were retrospectively examined. All of these patients underwent bilateral RLN LNs dissection; none received cancer treatment before surgery. RESULTS Of 21 upper esophageal cancer cases, 33.3% of the patients had metastasis in the supraclavicular LN. Every patient in whom supraclavicular LN metastasis developed had metastasis in the RLN LN. Of 141 cases of middle esophageal cancer, 19.1% had metastasis in the supraclavicular LN. Among the patients whose RLN LN metastasized, 38.3% had metastasis in the supraclavicular LN. A similar correlation between RLN LN and supraclavicular LN metastasis was observed in lower esophageal cancer cases, especially in T3 cases. When considering cancers of the esophagus and patients who had metastasis in the supraclavicular LN, our data demonstrated that RLN LN metastasis did not always lead to metastasis on the same side of the supraclavicular LN. CONCLUSIONS The status of the RLN LN can be an indicator of supraclavicular LN dissection in upper esophageal cancer patients and advanced cases of middle and lower esophageal cancer patients. Bilateral supraclavicular LN dissection should be recommended even when only unilateral RLN LN metastasis occurs.

Complications following recurrent laryngeal nerve lymph node dissection in oesophageal cancer surgery

OBJECTIVES The recurrent laryngeal nerve lymph node is one of the most common metastatic sites in oesophageal cancer, and dissection of this lymph node is considered beneficial. Although the risk of complications from this procedure, such as recurrent laryngeal nerve palsy, is well known, few reports have detailed those risks in a large number of cases. Our study examined the risks of recurrent laryngeal nerve lymph node dissection, with a special focus on recurrent laryngeal nerve palsy. METHODS Retrospectively collected data from 661 patients, who underwent transthoracic oesophagectomy for oesophageal cancer, were analysed. RESULTS Recurrent laryngeal nerve palsy occurred in 36% of the patients. Among these patients, except those in whom recurrent laryngeal nerve was intentionally excised due to metastatic lymph node, permanent palsy was detected in 12%. Bilateral recurrent laryngeal nerve lymph node dissection, cervical anastomosis and upper oesophageal cancer were independent risk factors for recurrent laryngeal nerve palsy. Although recurrent laryngeal nerve palsy was a risk factor for aspiration, tracheostomy and postoperative pneumonia, it did not directly correlate with death caused by pneumonia. Among postoperative complications, only recurrent laryngeal nerve palsy correlated with bilateral recurrent laryngeal nerve lymph node dissection. CONCLUSIONS Recurrent laryngeal nerve palsy is a complication that should be avoided but does not seem to be severe enough to affect patient survival after surgery. Although bilateral recurrent laryngeal nerve lymph node dissection can induce recurrent laryngeal nerve palsy in patients who undergo transthoracic oesophagectomy, this procedure did not correlate with aspiration and pneumonia.