DNA damage in workers occupationally exposed to pesticide mixtures.

Pesticides are used in agriculture to protect crops but represent at the same time a potential risk to farmers and environment. The aim of this work is the evaluation of 54 subjects occupationally exposed to pesticides and 30 subjects as a control group using the quantification of DNA damage level by means of the alkaline Comet assay and the evaluation of repair processes. Damage index Comet assay (DICA) and damage index repair assay (DIRA) were studied in 27 pesticide applicator workers, 27 non-pesticide applicators and controls. Our results show that both exposed groups revealed significant increase in DICA when compared with controls (P < 0.0001), as well as in DIRA (P < 0.0001). However, the spraying group exhibited a marginally significant difference in DICA (P = 0.05) when years of exposure are considered and a significant difference (P < 0.05) when the personal protective equipment used by individuals was taken as a comparison factor. The influence of confounding factors on the genotoxic effects of occupational exposure to pesticides was investigated and no significant differences were observed considering age, gender, smoking and alcohol consumption in relation to DICA and DIRA. Since DNA damage is an important step in events leading from carcinogen exposure to cancer disease, our study highlights the potential health risk associated with agrochemical exposure in developing countries with vast cultivated areas, such as Argentina.

Prognostic factors in head and neck oncology: a critical appraisal for use in clinical practice.

BACKGROUND: An ideal prognostic factor would provide information about the biological behaviour of a tumour, permitting the prediction of the outcome and response to therapy. Nowadays there is a considerable confusion concerning the value, significance and use of the know prognostic factors in head and neck cancer. MATERIAL AND METHODS: A meta-analysis of works published in literature between 1993 and August 1997 on prognostic factors in head and neck oncology was carried out. RESULTS: Prognostic factors were analysed and classified according to Wennenberg in the following groups: patient-related factors, tumour-related factors and factors predicting response to therapy. CONCLUSIONS: We propose a classification of prognostic factors in head and neck cancer according to their significance and reliability: factors of proven significance and experimental factors. This classification might be useful to select guidelines to use in clinical practice.

Successful topical treatment of oral lichen planus and leukoplakias with fenretinide (4-HPR).

Eight patients with diffuse (non-operable) pre-cancerous lesions (oral lichen or leukoplakias) were treated with fenretinidec (4-HPR) applied topically twice daily. After one month of therapy two patients had complete remission and the other six had a greater than 75% response. 4-HPR was well tolerated, and no local or distant side effects were observed. Topical treatment may be combined with oral administration at lower doses to obtain therapeutic results with less toxicity than observed with oral administration alone. A study to further evaluate the efficacy of topical treatment is in progress at our institute.