Greater intake of fruit and vegetables is associated with lower risk of nasopharyngeal carcinoma in Chinese adults: a case-control study.

PURPOSE: The effect of fruit and vegetable intake on the risk of nasopharyngeal carcinoma (NPC) remains uncertain due to limited published evidence. We performed a matched case-control study to investigate the relationship between the intake of fruit and vegetables and the risk of NPC. METHODS: Between July 2009 and March 2011, 600 (448 male, 152 female), NPC incident cases from a single hospital in Guangzhou, Guangdong Province, China, a high-incidence area, were enrolled in the study. 600 controls, matched by gender, age (± 3 years) and household type (urban/rural) were also enrolled. Face-to-face interviews were used to collect habitual dietary intakes and information on various covariates. RESULTS: Multivariate conditional logistic regression analyses showed significant, dose-dependent inverse associations between the intake of vegetables, fruit or a combination of the two and the risk of NPC, even after adjustments for social-economic status, body mass index, dietary factors and other potential covariates. The adjusted odds ratios (95% confidence intervals) for NPC in the top quartile of vegetable intake, fruit intake or a combination of the two, as compared to the lowest quartile, were 0.33 (0.22-0.50), 0.70 (0.47-1.04) and 0.37 (0.25-0.55), respectively. Dark green leafy vegetables, carrots, peppers and tomatoes, citrus fruit and pome fruit showed much more pronounced benefits with regards to NPC than other types of fruit and vegetables. Interaction analyses demonstrated that the effects of total combined vegetable and fruit intake were much more significant in subjects with a higher education level (p interaction: 0.027), and the benefits of fruit were observed in males, but not in females (p interaction: 0.088). CONCLUSION: Our findings suggest that a greater consumption of fruit and vegetables may lower the risk of NPC in Chinese adults.

[Experimental study of bio-distribution and tumor imaging of 131I in nude mice bearing human breast cancer].

BACKGROUND & OBJECTIVE: Previous study showed that about 85% of local and metastatic tissues of the estrogen-receptor-positive breast cancer express a large number of sodium/iodide symporter (NIS), which transfers the iodide from blood into cancer cells, leading to much higher cellular concentration in breast cancer than normal tissues. This study was designed to investigate the specific affinity of (131)I to the estrogen-receptor-positive breast cancer cells through the biodistribution and tumor imaging of the nude mice bearing breast cancer. METHODS: MCF-7/ER(+) and MCF-7/ER(-) nude mice bearing human breast cancer were prepared for the experiments. The animals were intraperitoneally injected with 37-55.5 MBq (131)I when the tumor grew to 0.8-1.0 cm. The tissue distribution of (131)I was determined at 6, 12, and 24 h after injection. The percentage of absorbed (131)I per gram of tissue (%ID/g) and the ratio of (131)I in tumor and non-tumor tissues (T/NT) were calculated. Meanwhile, the nude mice were imaged at different time. RESULTS: The (131)I was mainly concentrated in tumor, thyroid, blood, liver, stomach, and kidney at 6 h, and the concentration of (131)I in tumor of MCF-7/ER(+) group was significantly higher than that of MCF-7/ER(-) group at 6 h. At 12 h, the T/NT ratio of blood, heart, lung, intestine, and muscle were 2.39, 3.06, 3.94, 7.69, and 7.60, respectively, and increased to 5.15, 5.47, 5.29, 11.44, and 10.99 at 24 h. The T/NT ratio of MCF-7/ER(-) group was significantly lower than that of MCF-7/ER(+) group (P< 0.05). The imaging results showed that there was localized radioactivity in tumor tissue in the MCF-7/ER(+) group mice at 12 h, while no in MCF-7/ER(-) group mice. CONCLUSION: (131)I could be concentrated particularly in the estrogen-receptor-positive nude mice bearing breast cancer tissue.