A study to understand more about how chemotherapy affects proteins and DNA

The study team found changes in hair follicles, blood samples and serum samples that may help predict how well cancers of the stomach, oesophagus and bowel respond to chemotherapy.

The study recruited over 100 people with cancer. And over 100 healthy people volunteered to join.

The researchers looked at

• A gene called P53
• A protein called CK18
• An enzyme called NAG

For the p53 gene, the researchers looked at hair follicles, blood samples and serum samples of people before each of their chemotherapy treatments. They found that they could measure the p53 gene in the hair follicles and that there was some evidence that it could also be measured in the blood sample.

For the CK18 protein, researchers looked at the levels of the protein in the blood samples of people with cancer and compared it with the levels in the healthy people. They found that the levels of CK18 were higher in the people with cancer than the healthy volunteers.

They also found that the level of CK18 was significantly higher in people whose cancer continued to get worse during, or after having, chemotherapy than in people whose cancer had stayed the same or shrunk.

For the NAG enzyme, researchers found that the levels in the serum samples increased with age. People whose cancer had spread to another part of their body (metastatic cancer) had higher levels of the NAG enzyme than people whose cancer had only spread into the surrounding tissue (locally advanced cancer ). People with low levels of NAG before treatment lived longer than those with high levels of NAG before treatment.

In a small number of people (a subgroup), researchers found a significant change in the level of NAG between day 1 and day 2 of the first cycle of chemotherapy. NAG levels were higher on day 2 in people whose cancer had responded to chemotherapy than in those whose cancer hadn’t.

The study team concluded that the p53 gene, CK18 protein and NAG enzyme could possibly be used by doctors to try to work out how well cancers of the stomach, oesophagus and bowel might respond to treatment. But studies with larger numbers of people need to be done to find out just how useful they may be.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.