Toshinori Kurahashi

Definitive chemoradiotherapy for patients with malignant stricture due to T3 or T4 squamous cell carcinoma of the oesophagus.

We retrospectively investigated the efficacy and feasibility of concurrent chemoradiotherapy for patients with severe dysphagia caused by oesophageal squamous cell carcinoma. Concurrent chemoradiotherapy was performed in 57 patients with T3 or T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil (5-FU) 400 mg m−2 24 h−1 on days 1–5 and 8–12, combined with 2-h infusion of cisplatin (CDDP) 40 mg m−2 on days 1 and 8. Radiation treatment at a dose of 30 Gy in 15 fractions of the mediastinum was administered concomitantly with chemotherapy. A course schedule with 3-week treatment and a 1 to 2-week break was applied twice, with a total radiation dose of 60 Gy, followed by two or more courses of 5-FU and CDDP. In all, 24 patients (42%) achieved a complete response, and the 3-year survival rate was 19%. Major toxicities were leukocytopenia and oesophagitis, and there were two (4%) treatment-related deaths. In contrast, 22 patients with T3 disease survived longer than 35 patients with T4 disease (P=0.001); however, the survival rate in 15 patients with M1 LYM disease did not differ significantly from that in 42 patients without M1 LYM disease (P=0.3545). Our results indicate that definitive chemoradiotherapy is potentially curative for locally advanced oesophageal carcinoma with malignant stricture. The efficacy and survival of patients treated with this regimen are related to the T factor.

Late toxicity in complete response cases after definitive chemoradiotherapy for esophageal squamous cell carcinoma

BackgroundWe retrospectively investigated long-term toxicity after concurrent chemoradiotherapy (CRT) for patients with esophageal squamous cell carcinoma (ESCC).MethodsConcurrent chemoradiotherapy was performed in 110 patients with T1 to T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil 400 mg/m2 per 24 h on days 1 to 5 and 8 to 12, combined with 2-h infusion of cisplatin 40 mg/m2 on days 1 and 8. Radiation treatment of the mediastinum at a dose of 30 Gy in 15 fractions was administered concomitantly with chemotherapy. A course schedule with a 3-week treatment and a 2-week break was applied twice, with a total radiation dose of 60 Gy. For the assessment of toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring schema was adopted.ResultsA total of 81 patients were recruited in patients with stage I to IVA. Of 34 patients with complete response, 1 patient died as a result of acute myocardial infarction. Grade 2, 3, and 4 late toxicities occurred with the following incidences: pericarditis in 3 patients, 1 patient, and 2 patients, respectively; heart failure in 0, 0, and 3 patients; pleural effusion in 2, 3, and 0 patients; and radiation pneumonitis in 0, 0, and 1 patient, respectively.ConclusionsDefinitive chemoradiotherapy for ESCC is effective with substantial toxicities. Further investigation is warranted to minimize the normal tissue toxicities.

Primary small cell carcinoma of the stomach.

Abstract  We report on an 80‐year‐old man with primary gastric small cell carcinoma (SmCC). He was admitted to hospital with hematemesis. An upper gastrointestinal examination revealed an irregularly ulcerated tumor, 60 mm in diameter, on the lesser curvature of the stomach body extending to the cardia. An endoscopic biopsy revealed a solid proliferation of intermediate‐sized tumor cells with hyperchromatic nuclei and scanty cytoplasm. Immunohistochemically, the neoplastic cells were positive for neuron‐specific enolase and chromogranin A, but negative for carcinoembryonic antigen. No tumor was detected on examination of the chest. Therefore, primary gastric SmCC was diagnosed preoperatively. To date, only 38 cases of primary gastric SmCC, including our case, have been reported. By using endoscopic biopsy, approximately two‐thirds of cases have been diagnosed incorrectly. In the reported cases of gastric SmCC, the endoscopic findings frequently indicated a submucosal tumor. Gastric SmCC is clinically aggressive and has an extremely poor prognosis, even when discovered at an early stage. Most patients with gastric SmCC die within 1 year of diagnosis. Although a standard treatment for gastric SmCC has not been established, intensive chemotherapy should be considered to promote long‐term survival. We believe that careful examination, including immunohistochemical investigation, is necessary for determining the therapeutic strategy whenever gastric SmCC is suspected during endoscopy.

Detection of mutation of the p53 gene with high sensitivity by fluorescence-based PCR-SSCP analysis using low-pH buffer and an automated DNA sequencer in a large number of DNA samples.

Detection of mutations in genes responsible for hereditary diseases or tumors is important clinically. It is necessary to establish a simple technique for screening mutations in large numbers of samples. The polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method has proved to be a useful technique for analyzing mutations or DNA polymorphisms. Non-radioisotopic versions using fluorescent dye and an automated DNA sequencer have also been exploited to extend this technique into the clinical field. We have examined mutations of exons 5-9 of the p53 gene in 112 colorectal, 28 esophageal and 33 hepatocellular carcinomas by fluorescence-based PCR-SSCP (F-SSCP) under various conditions. We found 64 types of mutations in 63, 17 and 12 cases of colon, esophageal and hepatocellular carcinomas by F-SSCP. We determined the sequence of all samples, and confirmed that all mutations were successfully detected by F-SSCP. With the low-pH buffer system, 61 types of mutants were detected, while 51 types were detected by TBE and 57 types were detected by TBE with glycerol gel. The polyacrylamide gel in TME or TBE without glycerol was tough and could be used repeatedly, but the glycerol containing gel was fragile and could not stand repeated use. Thus, use of a low-pH buffer in the electrophoresis of F-SSCP is simpler and better at detecting mutations than the conventional TBE buffer system. We believe that low-pH F-SSCP analysis is an efficient and powerful technique for examination of a large number of samples, in particular clinical specimens obtained by biopsy or surgery.

Prognostic value of p53 mutations in patients with locally advanced esophageal carcinoma treated with definitive chemoradiotherapy.

Purpose. A significant correlation has been found between p53 mutation and response to chemotherapy or radiotherapy. To determine the prognostic value of p53 mutation in patients with locally advanced esophageal carcinoma treated with definitive chemoradiotherapy, p53 mutation was analyzed using the biopsied specimens taken for diagnosis. Methods. Concurrent chemoradiotherapy was performed for 40 patients with severe dysphagia caused by esophageal squamous cell carcinoma associated with T3 or T4 disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil, combined with an infusion of cisplatinum. Radiation treatment of the mediastinum was administered concomitantly with chemotherapy. The p53 gene mutation was detected by fluorescence-based polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) methods. DNA sequences were determined for DNA fragments with shifted peaks by SSCP methods. Results. Of the 40 patients, 15 had T3 disease and 25 had T4 disease; 11 patients had M1 lymph node (LYM) disease. Of the 40 patients, 13 (33%) achieved a complete response. The median survival time was 14 months, and the 2-year survival rate was 20%. Among the 40 tumor samples, p53 mutation was detected in 24 tumors (60%). The survival rate in the 24 patients with p53 mutation did not differ significantly from that in the 16 patients without p53 mutation. In contrast, the 15 patients with T3 disease survived longer than the 25 patients with T4 disease (P = 0.016); however, the survival rate in the 11 patients with M1 LYM disease did not differ significantly from that in the 29 patients without M1 LYM disease. Conclusion. Concurrent chemoradiotherapy is potentially curative for locally advanced esophageal carcinoma, but p53 genetic abnormality has no impact on prognosis.

Study of p53 gene alteration as a biomarker to evaluate the malignant risk of Lugol-unstained lesion with non-dysplasia in the oesophagus

Mutations of the p53 gene are detected frequently in oesophageal dysplasia and cancer. It is unclear whether Lugol-unstained lesions (LULs) with non-dysplastic epithelium (NDE) are precursors of oesophageal squamous cell carcinoma (ESCC). To study the genetic alterations of NDE in the multistep process of oesophageal carcinogenesis, we determined the relationship between p53 mutations and LULs-NDE. Videoendoscopy with Lugol staining was performed prospectively in 542 oesophageal cancer-free subjects. Lugol-unstained lesions were detected in 103 subjects (19%). A total of 255 samples, including 152 LULs (NDE, 137; dysplasia, 15) and 103 paired samples of normal staining epithelium, were obtained from 103 subjects. After extraction of DNA and polymerase chain reaction analysis, direct sequencing method was applied to detect mutations of the p53 gene. The p53 mutation was detected in five of 137 samples with LULs-NDE (4%) and in five of 15 samples with dysplasia (33%). A hotspot mutation was found in 20% of LULs-NDE with p53 mutation and in 40% of dysplasia with p53 mutation. In contrast, no p53 mutations were found in 103 paired NDE samples with normal Lugol staining. In biopsy samples from oesophageal cancer-free individuals, the p53 missense mutations containing a hotspot mutation were found in NDE, which was identified as an LUL. These findings suggest that some LULs-NDE may represent the earliest state of oesophageal squamous cell carcinoma in Japanese individuals.

Colorectal carcinoma with special reference to growth pattern classifications: clinicopathologic characteristics and genetic changes

Background:Background: Many colorectal carcinomas are known to develop from preexisting polypoid adenomas; however, they can also develop from so-called “flat adenomas”. To elucidate the growth patterns of flat- or depressed-derived colorectal carcinomas, we investigated the clinicopathologic characteristics and genetic changes of invasive carcinomas. Methods: Seventy-five colorectal carcinomas were classified into three groups: 46 upward growth (UG) type, 22 downward growth (DG) type, and 7 lateral growth (LG) type. All of them had histologically infiltrated the submucosa (SM) and muscularis propria (MP). Ki-ras mutation was examined by polymerase chain reaction-single-strand conformation polymorphism analysis, and overexpression of p53 protein was analyzed by immunohistochemistry. Results: No DG or LG carcinomas histologically demonstrated an adenomatous remnant, whereas UG carcinomas did (SM, 19 of 26; 73%; MP, 3 of 20; 15%). The percentage of tumors existing in the right colon was significantly higher in LG carcinomas (71%) than in the UG type (28%; P= 0.037). The frequency of Ki-ras mutation was significantly higher in the UG carcinomas than in the DG and LG carcinomas (52% vs 0%; P < 0.0001; and vs 0%; P= 0.014). However, the frequency of this mutation in SM-UG carcinomas with an adenomatous remnant (9 of 19; 47%) did not differ significantly from that in SM-UG carcinomas without an adenomatous remnant (3 of 7; 43%). The frequency of p53 overexpression did not differ among UG (57%), LG (57%), and DG (50%) carcinomas. Conclusions: These results suggest that UG carcinomas develop on the basis of the adenoma-carcinoma sequence, while the development of DG and LG carcinomas is different from that of UG carcinomas.

Growth patterns of superficially elevated neoplasia in the large intestine

BACKGROUND The growth pattern and malignant potential of superficially elevated neoplastic lesions remain controversial. A flat adenoma is classified as a superficially elevated neoplasm that characteristically demonstrates high-grade dysplasia despite its small size. In contrast, a nodule-aggregating (NA) tumor, which consists of multiple small aggregated nodules, can also be classified as superficially elevated neoplasia. METHODS In this prospective study, 2720 consecutive patients undergoing total colonoscopy were examined for superficially for elevated lesions. Clinicopathologic characteristics, Ki-ras mutational status, and overexpression of p53 protein were compared in 25 NA tumors and 55 flat adenomas without a central depression (flat tumor). RESULTS All flat tumors had a tubular pattern, whereas 21 of 25 NA tumors showed a villotubular or tubulovillous pattern. Ki-ras mutation was observed in 44% of NA tumors but in none of the flat tumors. Overexpression of p53 protein was found in 12% of NA tumors and 7% of flat tumors. CONCLUSIONS NA tumors and flat tumors have different clinicopathologic and genetic characteristics, although both types of tumor are classified as superficially elevated lesions.

BRAF mutations and phosphorylation status of mitogen-activated protein kinases in the development of flat and depressed-type colorectal neoplasias.

Although some molecular differences between flat-depressed neoplasias (FDNs) and protruding neoplasias (PNs) have been reported, it is uncertain if the BRAF mutations or the status of phosphorylated mitogen-activated protein kinase (p-MAPK) are different between theses two groups. We evaluated the incidence of BRAF and KRAS mutations, high-frequency microsatellite instability (MSI-H), and the immunohistochemical status of p-MAPK in the nonserrated neoplasias (46 FDNs and 57 PNs). BRAF mutations were detected in four FDNs (9%) and none of PNs (P=0.0369 by Fishers exact test). KRAS mutations were observed in none of FDNs and in 14 PNs (25%; P=0.0002 by Fishers exact test). MSI-H was detected in seven out of 44 FDNs (16%) and in one out of 52 of PNs (2%) (P=0.022 by Fishers exact test). Type B and C immunostaining for p-MAPK was observed in 34 out of 46 FDNs (72%), compared with 24 out of 55 PNs (44%; P=0.0022 by χ2 test). There was no significant difference in the type B and C immunostaining of p-MAPK between FDNs with and without BRAF mutations. BRAF and KRAS mutations are mutually exclusive in the morphological characteristics of colorectal nonserrated neoplasia. Abnormal accumulation of p-MAPK protein is more likely to be implicated in the tumorigenesis of FDNs than of PNs. However, this abnormality in FDNs might occur via the genetic alteration other than BRAF or KRAS mutation.

Pathological features and genetic alterations in colorectal carcinomas with characteristics of nonpolypoid growth

We sought to clarify pathological features and genetic alterations in colorectal carcinomas with characteristics of nonpolypoid growth. Colorectal carcinomas resected at Showa University Hospital in Tokyo included 86 with characteristics of polypoid growth (PG) and 21 with those of nonpolypoid growth (NPG). Mutations of APC, Ki-ras, and p53 genes, as well as microsatellite instability (MSI), were analysed using fluorescence-based polymerase chain reaction–single-strand conformation polymorphism (PCR–SSCP). Carcinomas with an NPG pattern were smaller than PG tumours (P<0.0001). Carcinomas with a PG pattern were more likely to harbour Ki-ras mutations (36%) than NPG tumours (0%; P<0.0001). Mutation types in the APC gene differed significantly between PG and NPG carcinomas (P=0.0189), including frameshift mutations in 66% of PG carcinomas but no NPG carcinomas. Presence of a p53 mutation at a ‘hot spot’ also was more likely in PG carcinomas (37%) than in NPG carcinomas (0%; P=0.0124). No significant difference in presence of MSI was evident between carcinomas with PG and NPG patterns. In conclusion, significant genetic differences were evident between carcinomas with PG and NPG patterns. Genetic changes in NPG carcinomas differed from those of the conventional adenoma–carcinoma sequence. Assuming that some nonpolypoid growth lesions transform rapidly into advanced carcinomas, 20% of all colorectal carcinomas may progress in this manner.