Shinsuke Sasada

Metabolomic analysis of dynamic response and drug resistance of gastric cancer cells to 5-fluorouracil

Metabolomics has developed as an important new tool in cancer research. It is expected to lead to the discovery of biomarker candidates for cancer diagnosis and treatment. The current study aimed to perform a comprehensive metabolomic analysis of the intracellular dynamic responses of human gastric cancer cells to 5-fluorouracil (5-FU), referencing the mechanisms of drug action and drug resistance. Small metabolites in gastric cancer cells and 5-FU-resistant cells were measured by liquid chromatography-mass spectrometry. Candidates for drug targets were selected according to the presence or absence of resistance, before and after 5-FU treatment. In addition, the gene expression of each candidate was assessed by reverse transcription-polymerase chain reaction. The number of metabolites in cancer cells dramatically changed during short-term treatment with 5-FU. Particularly, proline was reduced to one-third of its original level and glutamate was increased by a factor of 3 after 3 h of treatment. The metabolic production of glutamate from proline proceeds by proline dehydrogenase (PRODH), producing superoxide. After 5-FU treatment, PRODH mRNA expression was upregulated 2-fold and production of superoxide was increased by a factor of 3. In 5-FU-resistant cells, proline and glutamate levels were less affected than in non-resistant cells, and PRODH mRNA expression and superoxide generation were not increased following treatment. In conclusion, the authors identified a candidate biomarker, PRODH, for drug effects using a meta-bolomic approach, a result that was confirmed by conventional methods. In the future, metabolomics will play an important role in the field of cancer research.

Prognostic value of the new IASLC/ATS/ERS classification of clinical stage IA lung adenocarcinoma

OBJECTIVES We analyzed and validated the prognostic utility of the new International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) for clinical stage IA lung adenocarcinoma (ADC) classification of adenocarcinoma (ADC). METHODS We retrospectively reviewed 347 patients with clinical stage IA nonmucinous ADC, who had undergone complete resection. The histological subtype was classified according to the predominant subtype, as proposed by the new IASLC/ATS/ERS ADC classification. RESULTS The histopathological subtypes, defined according to the new IASLC/ATS/ERS ADC classification, were ADC in situ (AIS) in 56 patients (16.1%), minimally invasive ADC (MIA) in 15 (4.3%), lepidic-predominant ADC in 109 (31.4%), papillary-predominant ADC in 70 (20.2%), acinar-predominant ADC in 61 (17.6%), solid-predominant ADC in 30 (8.6%), and micropapillary-predominant ADC in 6 (1.7%). The 5-year disease-free survival (DFS) rate was 100% for both AIS and MIA. All cases of recurrence involved invasive ADC. The 5-year DFS for lepidic-predominant ADC was 99.0%; acinar-predominant ADC, 82.4%; papillary-predominant ADC, 80.8%; solid-predominant ADC, 73.6%; and micropapillary-predominant ADC, 33.3%. The predominant subtype of ADC was significantly correlated with DFS (P<0.0001). Multivariate analysis indicated that the pathological stage was an independent predictor of DFS (P=0.031). Other independent predictors of increased risk of recurrence were the presence of vascular or lymphatic invasion (HR=4.96, P=0.001), and a pathological stage more advanced than IB (HR=2.87, P=0.010). The coincidence between the clinical stage and pathological stage was 79.8%. The stage migration was found in 53.3% of solid-predominat ADC and in 83.3% of micropapillary-predominant ADC. CONCLUSION The new IASLC/ATS/ERS ADC classification has prognostic value in predicting the recurrence and survival of patients with clinical stage IA ADC. The frequency of stage migration was found in more than half of solid and micropapillary predominant ADCs.

Negative prognostic influence of micropapillary pattern in stage IA lung adenocarcinoma

OBJECTIVES There is uncertainty as to which factors determine the aggressiveness of lung adenocarcinoma with a micropapillary pattern (MPP). The present study aimed to clarify the influence of a MPP on the malignant aggressiveness of clinical stage IA lung adenocarcinoma. METHODS We retrospectively examined 347 consecutive patients with clinical stage IA lung adenocarcinoma who underwent complete resection. We defined MPP-positive as accounting for ≥5% of the entire tumour. RESULTS Forty-eight (14%) and 299 (86%) patients were MPP-positive and negative, respectively. Lymphatic (P = 0.003) and vessel (P = 0.029) invasion as well as lymph node metastasis (P = 0.002) were more frequent in the MPP-positive than negative group. Five-year disease-free survival (DFS) rates were significantly lower in the MPP-positive than negative group (69.7 vs 89.3%, P < 0.001). Multivariate analysis for DFS showed that MPP (P = 0.048), lymphatic invasion (P = 0.003) and vessel invasion (P = 0.002) were independent poor prognostic factors. In addition, higher proportions (<5%, 5-30% and ≥30%) of MPP were associated with a poorer prognosis (89.3, 76.0, and 48.1%, respectively; P < 0.001). The prognosis of patients with MPP-positive tumours and negative tumours harbouring lepidic and solid predominant growth patents did not differ (100 vs 96.8%, P = 0.564; 66.7 vs 62.5%, P = 0.791, respectively). On the other hand, the prognosis tended to be poorer for patients with papillary predominant MPP-positive tumours than for those with negative tumours (62.5 vs 82.5%, P = 0.075). CONCLUSIONS MPP has an effect on tumour malignancy and patients with tumours harbouring a higher ratio of MPP or papillary predominant subtypes have worse survival.

Detectability of Breast Tumor by a Hand-held Impulse-Radar Detector: Performance Evaluation and Pilot Clinical Study

In this report, a hand-held impulse-radar breast cancer detector is presented and the detectability of malignant breast tumors is demonstrated in the clinical test at Hiroshima University Hospital, Hiroshima, Japan. The core functional parts of the detector consist of 65-nm technology complementary metal-oxide-semiconductor (CMOS) integrated circuits covering the ultrawideband width from 3.1 to 10.6 GHz, which enable the generation and transmission of Gaussian monocycle pulse (GMP) with the pulse width of 160 ps and single port eight throw (SP8T) switching matrices for controlling the combination of 4 × 4 cross-shaped dome antenna array. The detector is designed to be placed on the breast with the patient in the supine position. The detectability of malignant tumors is confirmed in excised breast tissues after total mastectomy surgery. The three-dimensional positions of the tumors in the imaging results are consistent with the results of histopathology analysis. The clinical tests are conducted by a clinical doctor for five patients at the hospital. The malignant tumors include invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS). The final confocal imaging results are consistent with those of Magnetic Resonance Imaging (MRI), demonstrating the feasibility of the hand-held impulse-radar detector for malignant breast tumors.

Role of Positron Emission Tomography/Computed Tomography Findings for Adjuvant Chemotherapy Indications in Stage T1b-2aN0M0 Lung Adenocarcinoma

BACKGROUND This study aimed to determine the significance of the maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) images on postoperative adjuvant chemotherapy for lung adenocarcinoma. METHODS We assessed recurrence-free interval (RFI) and overall survival (OS) based on SUVmax values derived from preoperative FDG-PET/CT images in 174 consecutive patients with completely resected pathologic stage T1b-2aN0M0 lung adenocarcinoma. RESULTS Ninety patients received adjuvant chemotherapy and 84 did not. Adjuvant chemotherapy conferred benefits on RFI and OS when compared with observation (p=0.007 and p=0.004, respectively). Multivariate Cox regression analyses revealed SUVmax as an independent prognostic factor for RFI. RFI and OS were significantly longer for patients who received adjuvant chemotherapy compared with those who did not in the group with SUVmax greater than or equal to 2.6 (p<0.001 and p<0.001, respectively). However, RFI and OS did not differ significantly between such patients in the group with SUVmax less than 2.6 (p=0.421 and p=0.452, respectively). CONCLUSIONS Preoperative SUVmax determined from FDG-PET/CT images reflected the effect of adjuvant chemotherapy after complete resection in patients with pathologic stage T1b-2aN0M0 lung adenocarcinoma. Indications for postoperative adjuvant chemotherapy among patients with lung adenocarcinoma might be more precisely determined using SUVmax derived from FDG-PET/CT images together with tumor size.

Visualization of HER2-specific breast cancer intratumoral heterogeneity using 64 Cu-DOTA-trastuzumab PET

Evaluation of human epidermal growth factor receptor 2 (HER2) expression in tumor tissues using immunohistochemistry (IHC) or in situ hybridization (ISH) has revealed heterogeneity in invasive breast cancers [1]. Previously, we reported that Cu-DOTA-trastuzumab PET (HER2 PET) imaging can noninvasively identify HER2-positive breast cancers [2–4]. A 53-year-old woman presented with right-side breast cancer. Her HER2 status of IHC 1+ was determined from a core needle biopsy specimen obtained from the center of the tumor. The patient underwent HER2 PET imaging, which revealed strong uptake at the tumor periphery. An additional biopsy from the shallow outer portion of the tumor, which exhibited the strongest uptake, had a HER2 expression IHC score of 2+. A dual-probe ISH test revealed a HER2/CEP17 ratio of 1.4 and an average HER2 copy number of 4.9 signals per cell (i.e., ISH equivocal) [5]. An additional ISH examination of a new specimen was also ISH equivocal, with a HER2/CEP17 ratio of 1.6 and an average HER2 copy number of 4.1 signals per cell. We have previously demonstrated HER2-specific CuDOTA-trastuzumab accumulation in a specimen of removed brain metastasis using IHC and autoradiography [3]. However, this is the first report describing the visualization of HER2-specific intratumoral heterogeneity (IHC 1+ and 2+) using HER2 PET imaging. This interesting finding suggests that HER2 PET imaging could facilitate decision making for clinical treatment strategies. The relationship between HER2 PET imaging and the effects of anti-HER2 therapy, as well as the use of a high-resolution dedicated breast PET scanner, remain to be evaluated.

Impact of Lepidic Component Occupancy on Effects of Adjuvant Chemotherapy for Lung Adenocarcinoma.

BACKGROUND The prognosis of lepidic predominant lung adenocarcinoma is favorable. We postulated that lepidic predominant tumors might not require postoperative adjuvant chemotherapy. The present study aims to determine whether lepidic component occupancy affects overall survival after postoperative adjuvant chemotherapy for lung adenocarcinoma. METHODS Clinical and pathologic data were collected from a database and from the medical records of 964 patients with completely resected lung adenocarcinoma. We assessed the influence of lepidic component occupancy in the tumor on the outcomes of adjuvant chemotherapy. RESULTS Among the patients, 270 received adjuvant chemotherapy and 694 did not, and 415 and 549 had lepidic predominant and non-lepidic predominant tumors, respectively. Adjuvant chemotherapy contributed to better overall survival compared with observation in non-lepidic predominant tumors (p = 0.025). Multivariate analyses revealed age, sex, stage, lepidic component occupancy, and adjuvant chemotherapy as independent prognostic factors for overall survival. The overall survival was significantly longer for patients with non-lepidic predominant tumors at stages IA, IB, and II-III under adjuvant chemotherapy compared with observation (p = 0.040, p = 0.007, and p = 0.012, respectively), whereas survival rates were similar for patients with all stages of lepidic predominant tumors even after propensity score matching study. CONCLUSIONS Lepidic component occupancy reflected the effect of adjuvant chemotherapy for lung adenocarcinoma. Adjuvant chemotherapy did not have much impact for lepidic predominant tumors and could be considered for non-lepidic predominant tumors even at stage IA.

Wnt5a-induced cell migration is associated with the aggressiveness of estrogen receptor-positive breast cancer

Elevated expression of Wnt5a is associated with malignancy, cell invasion, and metastasis. The role of Wnt5a expression in breast cancer remains elusive. We investigated the significance of Wnt5a expression in breast cancer. The relationship between Wnt5a expression and clinicopathologic factors was assessed in invasive breast cancer (n = 178) resected at Hiroshima University Hospital between January 2011 and February 2014. Wnt5a was expressed in 69 of 178 cases (39%) of invasive breast cancer and correlated strongly with estrogen receptor (ER) expression (P < 0.001). Wnt5a expression in ER-positive breast cancer correlated significantly with lymph node metastasis, nuclear grade, and lymphatic invasion. The recurrence-free survival was shorter in breast cancer patients with Wnt5a expression than in those without (P = 0.024). The migratory capacity of ER-positive breast cancer cells increased with constitutive expression of Wnt5a and decreased with Wnt5a knockdown. DNA microarray analysis identified activated leukocyte cell adhesion molecule (ALCAM) as the primary gene induced by Wnt5a. ALCAM was expressed in 69% of Wnt5a-positive but only 27% of Wnt5a-negative cancers (κ = 0.444; P < 0.001). The inhibition of ALCAM reversed the enhanced migratory effect of Wnt5a, confirming the importance of this protein in the migration of ER-positive breast cancer cells. Wnt5a expression is related to high malignancy and a poor prognosis in ER-positive breast cancer. We suspect that Wnt5a expression increases the malignancy of breast cancer by increasing the migratory capacity of cancer cells through the induction of ALCAM expression.

Application of PET/CT to adjuvant chemotherapy for early lung adenocarcinoma

The role of adjuvant chemotherapy for stage I lung cancer is unknown. Some Japanese trials demonstrated that tegaful-uracil chemotherapy improved the prognosis of stage I lung cancer over 2 cm.

Survival of patients treated by an autonomic nerve-preserving gastrectomy for early gastric cancer

PurposeAutonomic nerve preservation in a gastrectomy for gastric cancer improves the postoperative quality of life. We retrospectively examined the survival of patients treated by an autonomic nerve-preserving gastrectomy in comparison to the survival of the patients treated by a conventional gastrectomy.MethodsThe survival of 385 patients treated by an autonomic nerve-preserving gastrectomy for clinical early gastric cancer (the ANP group) was compared with that of 285 patients treated by a conventional gastrectomy (non-ANP group).ResultsAmong the ANP group, the numbers of patients with tumor invasion to the mucosa, submucosa, and muscularis propria were 210, 166, and 9, respectively, whereas the numbers of patients with lymph node metastasis grades of N0, N1, and N2 were 360, 21, and 4, respectively. The overall 5-year survival rate of the ANP group was 94.7%, which was superior to that of the non-ANP group (90.4%; P = 0.003). The 5-year survival rates of patients with lymph node metastasis were 94.9% and 91.8% in the ANP and non-ANP groups, respectively (P = 0.733). Only 3 patients in the ANP group died from gastric cancer.ConclusionsThe survival of patients treated by an autonomic nerve-preserving gastrectomy was equivalent to that of patients treated by a conventional gastrectomy, thus suggesting that an autonomic nervepreserving gastrectomy could be a useful procedure for the treatment of early gastric cancer.