[Frequency and rearrangements of alleles of proto-oncogene c-Ha-ras-1 and their association with development of various malignant tumors in man].

The c-Ha-ras-1 locus in 84 cancer patients was examined for allelic restriction fragment length's polymorphism, as well as for distribution of four common c-Ha-ras-1 alleles (a1, a2, a3 and a4) in lung, ovarian and thyroid cancer patients. In approximately half (8 out of 15) lung and ovarian carcinomas possessing a4 allele, alterations in the Ha-ras locus (deletion, amplification and change in allele length) were detected, as compared to 2 cases of rearrangements out of 40 tumors lacking the a4 allele. An increased a4 allele frequency was found in individuals with lung and ovarian carcinomas, as compared to both controls--summarized literature data, and thyroid cancer patients. On the other hand, homozygosity for the a2 locus, resulting from deletion in another allele, and increased a2 allele frequency in thyroid cancer patients were observed. Thus, a4 and a2 alleles of the c-Ha-ras-1 may perhaps be viewed as genetic markers of predisposition to lung, ovarian and thyroid cancer, respectively, in combination with other clinical parameters.