Patients with cancer could benefit from tailored exercise prescriptions that improve their muscle strength and cardiorespiratory fitness (CRF) and could contribute to reducing cancer-related mortality, according to a systematic review published in the British Journal of Medicine.
The study may bring somewhat encouraging news at a time when cancer rates are rising. In its annual report on cancer facts and trends this month, the American Cancer Society (ACS) revealed some progress but also cause for concern.
While the cancer mortality rate in the U.S. decreased by 34% from 1991 to 2022, certain cancer types are on the rise among women and younger adults, according to the report. In particular, cancer incidence rates in women aged 50-64 have now surpassed those in men, and rates in women under 50 are 82% higher than in men—an increase from 51% in 2002.
The ACS also projects that in 2025, there will be an estimated 2,041,910 new cancer diagnoses in the U.S.—an average of 5,600 cases each day—and 618,120 cancer-related deaths.
As for the recent analysis, researchers conducted a systemic search in PubMed, CINAHL, SPORTDiscus, Web of Science and Embase from inception to August 2023 and examined 42 observational cohort studies that involved 46,694 adult patients with cancer with a median age of 64.
Muscle strength was measured in 24 studies using handgrip strength, while cardiorespiratory fitness (CRF) was assessed in 16 studies through cardiopulmonary exercise testing (CPET) or a six-minute walking test. According to the review, only two studies evaluated both measures.
The researchers observed that cancer patients—regardless of cancer type or stage—who had high muscle strength or CRF experienced a significant reduction (31-46%) in all-cause mortality compared to those with low physical fitness levels.
Similarly, muscle strength and CRF were associated with an 8–46% reduced risk of all-cause mortality in patients with advanced cancer stages, and a 19–41% reduced risk of all-cause mortality was seen in lung and digestive cancer patients. Per unit increments in muscle strength and CRF also reduced the risk of cancer-specific mortality (11% and 18%, respectively).
The researchers noted that, to the best of their knowledge, this is the first systematic review with meta-analysis examining the association between muscle strength and/or CRF of its kind.
“Collectively, such findings emphasize the importance of examining muscle strength and CRF in clinical practice to determine the mortality risk in patients with cancer, especially those with advanced cancer,” the authors wrote.
