The prognostic value of the presence of mutations at the codons 12, 13, 61of K-ras oncogene in colorectal cancer

The predictive and prognostic value of the c-K-ras mutation is still unequi vocal despite extensive and intensive studies. Investigation of the occurre nce of mutations in 88 colorectal cancer patients' specimens using the poly merase chain reaction (PCR) is reported: age: 61.9 years (27-80), gender: 4 8 male 42 female, Dukes' stages: 43 at B, 35 at C, 10 at D, primary of tumo ur: 52 colon, 36 rectal adenocarcinoma. Mutation of one of the three ras-co dons was detectable in the 54 cases, more frequently at the Dukes' stage C (p < 0.05). The ras-mutation correlated to a more elevated death-rate in th e Dukes' B and C stages (p < 0.01). Mean survival time and time to progress ion were significantly longer at the Dukes' stage B if mutation was not det ected (p < 0.01). The genetic alteration occurred significantly more freque ntly at tumours of the right-side colon, than the left side (p < 0.02) or r ectum (p < 0.05). However, in the age group of 41-50 years; it was more sig nificantly identified in the cases of rectal cancer (p < 0.01). At the age of 51-60 years mutations were detected in men at a higher rate (p < 0.05). The mutation of the codon 13 appeared mon frequently in the cases of local recurrences (p < 0.05). The occurrence of the ras-oncogene is a sign of an extremely malignant potential of tumour This fact manifested itself in the time to progression and mean survival time of patients at the same clinical ol pathological stage. The higher frequency of genetic alterations at the proximal colon may be the reason for more unfavourable prognosis of the dis ease localised to this site. Reconstructing the molecular events, the prese nce of the ras mutation proved to be an important element for prognosis of the disease and should be a basis of potentially individualised therapeutic intervention.