Stomach cancer is the second leading cause of cancer death in both sexes worldwide and
is considered a public health problem in the Para state, due to its high incidence and
mortality. Its capital, Belém, has one of the highest incidence rate of the world. In
addition to the Helicobacter pylori infection and factors related to lifestyle, genetic
susceptibility has been linked to individual variation in risk of developing this type of
cancer. Despite advances in surgical techniques and adjuvant therapy, survival rates in
five years in patients whose tumors are resected, remains extremely poor because the
disease is usually asymptomatic in its early stages, preventing early diagnosis. Genetic
polymorphisms are associated with the development of cancer when combined with
environmental factors and can be considered biomarkers for studies involving the risk of
developing the disease, allowing for screening and early diagnosis. The present study
investigated the polymorphism PIN3 in the gene TP53, which consists of a INS/DEL 16
bp in intron 3, with patients with gastric cancer in the University Hospital Joao de Barros
Barreto and with a control group from Belem’s mixed population between july 1st, 2009
and march 1st, 2011. We collected blood samples from 99 patients with gastric cancer and
225 healthy controls. DNA was extracted by the method described by Sambrook et al.
(1989). We used the technique of polymerase chain reaction for genotyping the samples.
The results indicate an association of gastric cancer among males (67.7%) and age (mean
59.3 ± 1.2 years), predominance of Lauren’s diffuse-type and advanced stage disease
(70.7% had TNM III/IV). We found a significant association of susceptibility to gastric
cancer for genotypes INS/DEL (p = 0.007, OR = 3.990) and INS/INS + INS/DEL (p =
0.007, OR = 3.554) as well as average acceleration of approximately 15% in time of
onset of disease in patients with INS genotype (p = 0.002, OR = 1.15). Genotype
DEL/DEL presented related to protecting the development of gastric tumor (p = 0.020,
OR = 0.343). These results suggest that PIN3 may be associated with the development of
gastric cancer, as well as contribute to the formation of a panel of markers for its
diagnosis.
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