Prognostic significance of preoperative alkaline phosphatase and lactate dehydrogenase in patients undergoing surgery for gastric cancer
This retrospective study of 4,666 gastric cancer patients demonstrates that preoperative levels of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) are significant independent prognostic factors, with lower levels correlating with favorable overall survival following curative resection.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Stomach cancer remains one of the most common and deadly diseases worldwide, claiming hundreds of thousands of lives each year. For patients whose cancer has not spread to distant organs, the primary hope lies in surgery to remove the tumor and surrounding tissue. However, even after a successful operation, doctors face a difficult question: how will this specific patient fare in the years to come? While the size of the tumor and whether it has reached nearby lymph nodes are well-known factors, researchers are constantly searching for simpler, earlier signals hidden within the patient's own body. Two such signals are found in routine blood tests: alkaline phosphatase and lactate dehydrogenase. These are enzymes, which are proteins that help speed up chemical reactions in the body. Lactate dehydrogenase is involved in how cells turn sugar into energy, a process that cancer cells often hijack to grow rapidly. Alkaline phosphatase is an enzyme that helps manage phosphate groups and is often linked to the health of the liver and bones. When these enzymes appear in the blood at higher than normal levels, it can sometimes signal that a tumor is active or that the body is under stress from disease.
A team of researchers at Harbin Medical University Cancer Hospital set out to see if these two specific enzymes could predict the long-term survival of patients undergoing surgery for stomach cancer. They looked back at the medical records of nearly 4,700 patients who had undergone a standard, radical removal of their stomach cancer between 2010 and 2015. The team was careful to exclude patients who had other major illnesses or incomplete records, ensuring that the data reflected the specific impact of the cancer and the surgery. Before the operation, every patient had their blood tested, and the researchers noted the levels of alkaline phosphatase and lactate dehydrogenase. They then followed these patients for years, tracking who was still alive and who had passed away, to see if the initial blood test results matched the final outcome.
The study revealed a clear and consistent pattern. Patients who entered surgery with lower levels of these two enzymes lived significantly longer than those with higher levels. Specifically, the researchers found that patients with lactate dehydrogenase levels below 205 units per liter and alkaline phosphatase levels below 110 units per liter had much better survival rates. For example, five years after surgery, more than half of the patients with low enzyme levels were still alive, whereas fewer than 40 percent of those with high levels survived that long. This difference held true even when the researchers looked at specific groups, such as older patients versus younger ones. In every group, having high levels of these enzymes before the operation was a strong warning sign of a poorer outcome, independent of other factors like the size of the tumor or the patient's age.
The researchers also examined whether other common factors, such as the time it took to perform the surgery or the amount of blood lost during the procedure, could explain these results. They found that while those factors mattered, the levels of alkaline phosphatase and lactate dehydrogenase stood out as independent predictors. This means that even if two patients had the same tumor size and the same surgical experience, the one with the higher enzyme levels was still at greater risk. The study did not find that liver function tests like ALT or AST were useful in this specific context, suggesting that the rise in alkaline phosphatase and lactate dehydrogenase was likely tied to the cancer itself rather than general liver damage. The team noted that their study was retrospective, meaning it looked at past data, so future studies would be needed to confirm these findings in a forward-looking setting. Nevertheless, the results suggest that a simple blood test taken before surgery could provide doctors with a powerful tool to understand the likely course of the disease, helping them identify which patients might need closer monitoring or different treatment strategies after their operation.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.