Combined detection of plasma HSP90α with conventional tumor markers improves postoperative recurrence detection and predicts survival in advanced gastric cancer: a retrospective cohort study

Gastric cancer, often called stomach cancer, remains one of the most formidable challenges in modern medicine. While surgery can cure the disease when caught early, the cancer frequently returns after treatment or spreads to other parts of the body before it is ever found. When this happens, the disease becomes much harder to manage, and doctors rely on blood tests to watch for trouble. These tests look for specific proteins released by tumors, known as tumor markers. For decades, doctors have used a small group of these markers to monitor patients, but they often miss the early signs of a comeback. The cancer cells can hide their presence, or the markers might not rise high enough to trigger an alarm until the disease has already grown significantly. Finding a way to see the cancer sooner, and to understand how aggressive it might be, is a critical goal for anyone trying to extend the lives of patients with advanced disease.

A new study from Jilin Cancer Hospital in China explores a promising addition to this monitoring toolkit: a protein called heat shock protein 90α, or HSP90α for short. This protein is produced by cells under stress, and cancer cells release large amounts of it into the blood. While previous research suggested this protein could help diagnose cancer, its ability to predict how a patient would fare after surgery or to spot a recurrence early was not fully understood. The researchers set out to see if measuring this protein in the blood, alongside the standard markers, could provide a clearer picture of the disease's behavior and help doctors make better decisions for patients with advanced gastric cancer.

The team looked back at the medical records of 293 patients who had been treated for gastric cancer and had their blood tested for HSP90α. They divided these patients into three groups to understand how the protein behaved in different situations. One group consisted of patients who had successful surgery and remained free of cancer during their follow-up. A second group included patients who had surgery but later saw the cancer return. The third group was made up of patients who were diagnosed with advanced, unresectable cancer from the start. By comparing the levels of HSP90α and the standard markers in these groups, the researchers could see how the protein changed as the disease progressed.

The results revealed a clear pattern. Patients whose cancer had returned or who had advanced disease at the start generally had higher levels of HSP90α in their blood compared to those who remained cancer-free. More importantly, the study found that the level of this protein at the beginning of treatment was a powerful predictor of survival. Patients with advanced gastric cancer who had HSP90α levels above 82 nanograms per milliliter lived significantly shorter lives than those with lower levels. Specifically, the group with higher levels had a median survival of 23 months, while the group with lower levels survived for a median of 47 months. This difference was even more striking in patients who had surgery and then saw the cancer return; those with high levels survived a median of 26 months, compared to 58 months for those with lower levels. The study confirmed that high levels of this protein were an independent warning sign of a poorer outcome, regardless of the patient's age or how well they were able to perform daily activities.

However, the study also highlighted a limitation when looking for a recurrence. When the researchers checked if a single marker could spot the cancer's return, they found that none of them were very good at it on their own. At the time of recurrence, the standard markers missed the cancer in more than 60 percent of cases, and HSP90α missed it in about two-thirds of cases. The protein did not rise high enough in every patient to serve as a standalone alarm. But when the researchers combined the results of HSP90α with the three standard markers, the picture changed. By looking at all four tests together, they were able to detect the return of the cancer in nearly 70 percent of cases, a significant improvement over any single test. This suggests that using a panel of markers is far more effective than relying on just one.

The researchers also investigated whether changes in these protein levels during treatment could predict how well a patient was responding. They checked the blood levels after two cycles of treatment to see if a drop in the numbers meant the therapy was working. Surprisingly, they found no clear link between a drop in HSP90α levels and longer survival. Patients whose levels went down did not live longer than those whose levels stayed the same or went up. This finding suggests that a single blood test taken early in treatment might not be enough to judge the success of a therapy, and that doctors should rely on imaging scans and other clinical signs alongside these blood tests.

The study concludes that measuring HSP90α offers valuable new information for managing advanced gastric cancer. While it may not be perfect at spotting a recurrence on its own, it serves as a strong indicator of how aggressive the disease is likely to be. When used in combination with the traditional markers, it helps doctors detect the return of cancer earlier than before. For patients with advanced disease, knowing their HSP90α level at the start of treatment can help stratify their risk, allowing for more personalized follow-up plans. The researchers emphasize that while these findings are encouraging, they come from a retrospective review of past data, and future studies are needed to confirm how best to use these dynamic changes in protein levels to guide treatment decisions in real time.