< 1991 S. Karger A G. Basel 0030 2414 91 0483 0194 5 2.75 0
Oncology 1991:48:194 195
Aflatoxins in Sera from Patients with Lung Cancer V. Cusunumo Microbiology Institute. Faculty of Medicine. Messina. Italy
Key Words. Aflatoxins • Lung cancer • Serum Abstract. Sera from patients with lung cancer and from healthy donors were screened for the presence of aflatoxins. Significant differences in levels of aflatoxins between the two groups were found. Only I of the neoplastic patients with aflatoxins in the serum was a smoker. However the percentage of sera from lung cancer containing aflatoxins is not significant enough to provide evidence for a casual relationship between aflatoxins exposure and development of lung cancer in humans.
The mutagenic and oncogenic effects of mycotic metabolites and of aflatoxins in particular are well known [1.2], Epidemiological data have revealed that hepatic and gastrointestinal neoplasms develop in poultry supplied w'ith feed that is contaminated by aflatoxin-producting moulds [3. 4]. In the case of hu mans , epidemiological studies of populations in developing countries in the Third World where food stuffs (such as cereals and their by-products) are contaminated w'ith aflatoxins have revealed very high frequencies of esophageal and hepatic neoplasms [6. 7], Significant levels of aflatoxins and of aflatoxins B1 in particular have been found in the blood and urine of these patients [7, 8). Experimental studies have shown that the addition of small quantities of aflatoxins to animal fodder or to cell culture medium for extended periods produces cellular anomalies that in the whole organism lead to hepatic, esophageal and gastrointestinal neoplasms [9,10], Both the formation and the excision of lesions in DNA induced by aflatoxin Bl in epithelioid human lung cells were reported by Wang and Cerrue . High-risk workers, such as those in charge of the processing and storing of cereals, may actually inhale mycotoxins; but, till now, pulmonary neoplasias fol lowing aflatoxin poisoning have been not reported. Basing our study on these earlier observations, w'e have screened sera and bronchial lavage fluids (ob
tained by bronchial aspiration) from patients with lung cancer for the presence of aflatoxins.
Materials and Methods 100 specimens of blood and bronchial lavage fluid from patients of both sexes (78% male) aged between 40 and 75 years with lung cancer at different stages were examined. The diagnosis o f neoplasia was established by endoscopy in all cases. The histological types of lung cancer were classified as follows: 32 microcytomas. 8 anaplastic carcinomas. 59 squamous cell carcinomas. I alveolar carcinoma. As control 150 specimens of blood from healthy donors, of the same range of ages with a similar ratio of males to females, were exam ined. Aflatoxins were extracted with acetonitrile water and with chloroform and were purified by affinity chromatography on a column of resin conjugated with monoclonal antibodies specific for aflatoxins Bl. B2. G l and G2. The eluents were analyzed by highpressure liquid chromatography. The results were statistically evaluated by the y 2 test.
Results and Discussion As reported in table 1, only 1 sample of serum from the 150 healthy donors examined contained a small quantity of aflatoxin Gl (0.40 ng/ml). By contrast. 7 samples of serum from the pool of 100 samples from patients with lung cancer contained aflatoxin at levels ranging from 0.40 to 1.20 ng/ml. These values were the means of levels obtained from several tests performed during hospitalization and, in some patients, after
Downloaded by: King's College London 22.214.171.124 - 1/13/2019 3:04:44 AM
Aflatoxins in Sera from Patients with Lung Cancer
Table 1. Screening for aflatoxins
Healthy donors sera Patients sera a
Negative for aflatoxins
Positive for aflatoxins Bl
B2 Gl G2 total
1 (0.66%) V (7%)
p < 0.05 by y2 test with Yates correction.
surgery. All tests performed several times on hospital food were negative for aflatoxins. Therefore the pres ence of similar aflatoxin levels in sera screened several times during a period ranging from 1 to 6 months is not due, in all probability, to casual acute exposure but rather to past and repeated exposures producing a slow building up of toxin which is not easily catabolized, and, therefore, liable to large cellular damage. The aflatoxins identified in sera were: B1 (the most carcinogenic), which was found in the sera of 5 pa tients, and B2, which was found in 2 other patients. A very small quantity of aflatoxin B1 was found in 1 sample of bronchial lavage fluid from a patient whose serum was positive for Bl. The relationship between aflatoxins and the type of carcinoma was as follows: 5 cases of anaplastic carcinoma (the most "primitive” type of tumor) were associated with the presence of aflatoxin Bl in the serum and 2 cases of squamous cell carcinoma were associated with the presence of afla toxin B2 in the serum. With regard to age, the range of patients who were positive for aflatoxins was 62-75 years and 100% of these patients were male. The analysis of the clinical history of neoplastic patients positive for aflatoxins in serum was interest ing for the following reason: only 1 of the 7 patients positive for aflatoxins in serum was a smoker, a proof that cigarette smoke could not be the source of afla toxin. Six of the 7 patients positive for aflatoxins in serum used to live in farm houses, where they could have inhaled aflatoxins from contaminated cereals. Only 1 lived in town and worked for many years in a
References 1 Porras. E.: Mycotoxins: their production by certain fungi and their carcinogenic and toxic properties. Agrie. Ann. 28: 8. 18. 20. 32. 36. 40. 56 57. 60. 65. 77 (1979). 2 Armbrecht. B.H.: Aflatoxicosis in sheep; in Mycotoxic fungi, mycotoxins. mycotoxicoses, vol. 2. p. 189 (Dckker. New York 1978). 3 Pier. A.C.: Mycotoxins and animal health. Adv. Vet. Sci. Comp. Med. 25: 185 (1981). 4 Kobbc. B.: Mould toxins: hazard to animal and human health. Calif. Agrie. 33: 18-19 (1979). 5 Linscll. C. A.: The mycotoxins and human health hazards. Annls Nutr. Aliment. 31: 977-1004 (1977). 6 Marasa. W.E.O.; Wrhncr. F.C.: Van Rensburg. S.J.: Van Schalkwyk. D.J.: Microflora of corn produced in human oeso phageal cancer in areas in Transkei-Southcrn-Africa. Phy topathology 71: 792-796 (1981). 7 Onymclukwc. G.C.; Ogbabu. G.H.; Salifu. A.: Aflatoxin Bl. B2. G l. G2 in primary liver cell carcinoma. Toxicol. Lett. 10: 309 312 (1970). 8 Autrup. H.: Bradley. K.A.; Shamsuddin. A.K.M.: Wakhisi. J.; Wasuma. A.: Detection of putative adduct with fluorescence characteristics identical to 2, 3-dihydro-2(7'-guanyl-3-hydroxy aflatoxin Bl in human urine collected in Murangia district. Kenya. Carcinogenesis 4: 1193 1195 (1983). 9 Hisa. A.: Tyian. B.L.; Harris. C.C.: Proliferative and cytotoxic effect of Fusarium T2 toxin on cultured human fetal csophagucs. Carcinogenesis 4: 1101 1107 (1983). 10 Thomson. V. F..; Evans. H.J.: Induction of sister-chromatid exchanges in human lymphocytes and Chinese hamster cells exposed to aflatoxins Bl and N-methyl-N-nitrosourea. Mutat. Res. 67: 47 53 (1979). 11 Wang. T. V.; Cerrue. P. A.: Formation and removal of aflatoxin BI-induced DNA lesions in epithelioid human lung cells. Cancer Res. 39: 5165 5170 (1979). Prof. Vitaliano Cusumano Istituto di Microbiología Medica Piazza XX Setiembre 1— 98100 Messina (Italy)
Downloaded by: King's College London 126.96.36.199 - 1/13/2019 3:04:44 AM
bakery, where he could have inhaled aflatoxins from contaminated meals. Statistical analysis of the results showed significant differences between the neoplastic patients and control groups. However the percentage of sera from lung cancer patients containing aflatoxins is small and does not provide evidence for a causal relationship between aflatoxins and lung cancer de velopment in humans.