Topoisomerase 2alpha plays a pivotal role in the tumor biology of stage IV thymic neoplasia.

BACKGROUND: Microsatellite studies in histologic types B3 and C thymic neoplasia detected gains on chromosome 17q, which contains the Her-2/neu and its juxtaposed topoisomerase 2alpha (T2alpha) genes. The study aimed to evaluate their impact on tumor biology and survival of advanced thymic neoplasia patients. METHODS: From 1991 to 2005, 36 consecutive stage IV thymic carcinoma patients were treated, 18 men and 18 women, aged 11 to 84 years. There were 22 thymic carcinoma, 13 type B3, and 1 type B2 thymoma. Patients received treatment consisting of surgical resection, combination chemotherapy with the CAP (cyclophosphamide, Adriamycin, cisplatin) regimen, or radiation therapy potentiated by high-dose weekly 5-fluorouracil infusion. Permutations of these 3 treatment modalities were prescribed as necessary. RESULTS: T2alpha gene amplification was detected in 4 of 14 thymic carcinoma and 1 of 15 type B3 thymoma. Three thymic carcinoma patients had Her-2/neu coamplification and these 3 patients had rapidly growing tumor and extensive disease at initial diagnosis. CAP was prescribed in 28 patients and 20 patients responded (response rate, 71.4%, 95% confidence interval [CI]: 52.8% to 85%); all responders overexpressed (> or = 10% nuclei positive) the T2alpha protein, whereas 4 nonresponders had very low expression. T2alpha overexpression predicts CAP response, and its absence predicts resistance (P = .001). Overall survival was significantly prolonged if the tumor was resectable (P = .001), of type B3 histology (P = .0039), and had no Her-2 gene amplification (P = .0081). CONCLUSION: T2alpha and Her-2/neu genes play a pivotal role in the tumor biology, CAP response, and survival of advanced thymic neoplasia patients.

Soil quality evolution after land use change from paddy soil to vegetable land.

A survey was done in 15 typical villages, 150 soil and 86 vegetable plant samples were taken in Jiaxin prefecture of the Taihu Lake region, northern Zhejian province. Results indicate that after 15-20 years land use changed from the paddy rice-wheat (or oilseed rape) double cropping system, to a continuous vegetable land has caused soil quality dramatic change. (1) Acidification: average soil pH was 5.4; about 61% of total samples were pH < 5.5. It was 0.9 units lower than 10 years ago with same upland vegetable cultivation and was 1.2 units lower than soil pH of paddy rice-wheat (or oilseed rape) rotation. (2) Fertilizer salt accumulation: the average salt content was 0.28%, among these about 36.2% of the total samples contained more than 0.3%. (3) Nitrate N and available phosphorus (P) over accumulation: on average it was 279 mg NO3-N/kg, and 45-115 mg P/kg. Nitrate N four times higher and available P 4-10 times more than it is in present paddy rice-wheat rotation soils respectively. This has caused wide concern because of possible groundwater and well drinking water pollution by leached nitrate N and the P losses to water by runoff from vegetable lands induce surface water eutrophication.

Colorectal cancer in patients 20 years old or less in Taiwan.

BACKGROUND: Colorectal cancer (CRC) is predominantly a disease of the elderly population, but it sometimes occurs in young patients. The diagnosis of CRC in youngsters is often overlooked by physicians or presentation may be delayed. METHODS: With assistance from the cancer registry center of Taipei Veterans General Hospital, we collected data on all types of colorectal malignancy, including carcinoma, adenocarcinoma, or lymphoma in patients aged 20 or younger. All available medical charts and pathologic specimens were reviewed in detail. RESULTS: A total of 28 cases were analyzed. The leading presenting symptom was abdominal pain (92%). The locations of the primary tumors were evenly distributed, and the major histologic type was predominantly adenocarcinoma. However, the proportion of mucinous adenocarcinoma was higher than that in the older population. Most of the cases were advanced (11 tumors were classified as Dukes stage C and another 11 as Dukes stage D). The overall 5-year survival rate was 21%. CONCLUSIONS: Despite the rarity of CRC during the first two decades of life, physicians need to be aware of the possibility and to evaluate suggestive signs and symptoms by colonoscopy or barium enema. Family history of CRC, inflammatory bowel disease, previous polyps, or familial polyposis did not play a crucial role in this group of young patients.