Prehabilitation exercise may increase the impact of chemotherapy given to patients with cancer of the digestive tract (esophagus) to shrink the tumor before surgery, reveals the first study of its kind, published online in the journal British Journal of Sports Medicine.
Tumor shrinkage was greater in those who exercised than in those who did not, data from the comparative trial show.
If the findings are confirmed in other, larger studies, they should strengthen the case for prehabilitation exercise becoming standard of care for all patients about to start cancer treatment, not just those who need surgery, the researchers say.
Prehabilitation exercise, called prehab, can be used to increase strength, stability, balance, and mobility in preparation for surgery or other medical intervention.
There is a growing body of evidence pointing to the effectiveness of exercise in cancer patients, and animal studies have indicated that it can help shrink tumors after chemotherapy.
The researchers wanted to find out if prehabilitation could increase the impact of pre-surgical chemotherapy, formally known as neoadjuvant chemotherapy, in patients with esophageal cancer.
Neoadjuvant chemotherapy can improve survival in patients with this type of cancer by shrinking the tumor and helping to stop it from spreading to other sites, an effect known as downstaging.
But pre-surgical chemotherapy can take a tremendous toll on the body, effectively deconditioning and accelerating loss of skeletal muscle mass and function (sarcopenia), which can limit subsequent treatment options and potentially survival, the researchers say. .
They offered patients with operable esophageal cancer a structured program of moderate exercise incorporating aerobic and strength training (prehabilitation) plus preoperative chemotherapy, or conventional best practice (lifestyle advice) plus preoperative chemotherapy.
The exercise program was designed to last until the day before surgery, an average period of about five months, and comprised 150 minutes of moderate-intensity activity per week plus two strength-based sessions.
Each patient underwent four cycles of chemotherapy before surgery.
To assess the impact of the exercise program during chemotherapy, blood samples were taken before starting treatment, within a week of finishing it, and again one, three, and six days after surgery to check levels of inflammation. and other key biochemical indicators of immunity. .
Each patient was also scanned for changes in skeletal muscle and visceral fat mass and tumor size before and after chemotherapy.
In total, 21 patients were assigned to prehabilitation and 19 to conventional best practice without additional structured exercise.
Analysis of all clinical data showed that after preoperative chemotherapy, the prehabilitation group had higher rates of tumor shrinkage than conventionally treated patients: 15/20 (75%) compared to 7/19 (37%) .
And based on tissue samples and the number of affected lymph nodes, more patients in the rehabilitation group had their cancer downstaged: nine (43%) vs. three (16%).
These patients also had higher skeletal muscle mass and less visceral fat, but no weight loss, as well as a stronger immune response and lower levels of inflammatory chemicals in the blood.
A relatively small number of patients were included in this clinical trial and were not randomized to try to eliminate the influence of unknown factors, so larger studies are needed to confirm the findings, the researchers say.
But they note: “Tumor downstaging and response to chemotherapy are possibly the most important prognostic factors in esophageal cancer.
“That structured exercise programs may contribute to better cancer regression, possibly through better immune and/or inflammatory modulation, is potentially clinically significant.”
They add: “The results showing improvements in pathologic regression in the primary tumor and clinical downstaging are hypothesis-generating and the first to be demonstrated in a clinical trial in esophageal cancer.”
They conclude: “While limitations in patient numbers and nonrandomized design warrant caution, the impact to patients is potentially significant.
“Further work is urgently required to confirm or refute these findings, including whether or not improvements in response to chemotherapy may translate into a survival advantage.
“Pending this, the current results further strengthen the case for prescribing exercise as standard of care in patients undergoing cancer treatment.”