Thymidine uptake in vitro as a prognostic indicator for primary gastric cancer

Prognostic significance of in vitro thymidine uptake by cancer cells remains unclear in patients with gastric cancer.

In 173 patients with operable gastric cancer, the relations between thymidine uptake by gastric cancer cells in semi-solid media and their clinicopathologic features as well as their survival lengths were studied.

There were significant correlations between in vitro thymidine uptake and such clinicopathologic features as lymph node metastasis (P = 0.00002), lymphatic invasion (P = 0.003), vessel invasion (P = 0.006), peritoneal metastasis (P = 0.010), depth of invasion (P = 0.011), and hepatic metastasis (P = 0.032). Ninety-five of 173 cancers (54.9%) that incorporated 1000 or more cpm in a single well were designated as being a high uptake group. Other gastric cancers (78 of 173; 45.1%) were designated as being a low uptake group. The overall survival rate of the patients was demonstrated to be significantly longer in the group with a low thymidine uptake than with a high uptake (P < 0.00001). The multivariate analysis showed that thymidine is one of the two variables that are the most highly correlated with the probability of patient death (P = 0.00044).

These results indicated that in vitro thymidine uptake is an independent prognostic parameter for gastric cancer and may be useful for selecting patients who would benefit from more intensive therapy.