This is hardly the first time that Glucosamine use is associated with lower cancer/mortality risks:
https://ard.bmj.com/content/79/6/829 - Associations of regular glucosamine use with all-cause and cause-specific mortality: a large prospective cohort study
Some of those still showed significant correlation even when accounting for NSAID use however there have been other studies where the correlation significance disappears when accounting for NSAIDs: https://www.nature.com/articles/s41598-018-20349-6
Mortality reduction with glucosamine has been directly shown in more controlled studies on other organisms such as nematodes and mice, but may do so through a path that hasn't been shown to work in humans:
https://www.nature.com/articles/ncomms4563
https://ard.bmj.com/content/79/6/829 - Associations of regular glucosamine use with all-cause and cause-specific mortality: a large prospective cohort study
https://pubmed.ncbi.nlm.nih.gov/33219063/ - Glucosamine/Chondroitin and Mortality in a US NHANES Cohort
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175750/ - Use of Glucosamine and Chondroitin and Lung Cancer Risk in the VITamins And Lifestyle (VITAL) Cohort
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5870876/ - Glucosamine Use and Risk of Colorectal Cancer: Results from the Cancer Prevention Study II Nutrition Cohort
https://cancerci.biomedcentral.com/articles/10.1186/1475-286... - Glucosamine suppresses proliferation of human prostate carcinoma DU145 cells through inhibition of STAT3 signaling (in vitro)
https://www.pharmacytoday.org/article/S1042-0991(17)30735-1/... - Glucosamine and chondroitin decrease colorectal cancer risk
Some of those still showed significant correlation even when accounting for NSAID use however there have been other studies where the correlation significance disappears when accounting for NSAIDs: https://www.nature.com/articles/s41598-018-20349-6
Mortality reduction with glucosamine has been directly shown in more controlled studies on other organisms such as nematodes and mice, but may do so through a path that hasn't been shown to work in humans: https://www.nature.com/articles/ncomms4563
And in an actual double blind study glucosamine (+ chondroitin) use was found to lower serum levels of C-reactive protein in men and women: https://journals.plos.org/plosone/article?id=10.1371/journal... (small sample size)