Hip replacement cancer risk ‘not major cause for concern’
medwireNews: Epidemiologic evidence may reassure patients with hip replacements that their prosthesis is unlikely to significantly increase their risk for cancer, UK researchers say.
The team examined Scottish hospital, cancer, and mortality registry data for 71,990 patients who underwent primary total hip arthroplasty (THA) between 1990 and 2009.
Over 547,001 person-years at risk, 13,946 cancers were diagnosed, giving an overall standardized incidence ratio (SIR) for cancer of 1.05, adjusting for age, gender, deprivation, and calendar period.
A significant increase in risk over the whole study period was also found among patients with THA for prostate cancer (SIR=1.07) and multiple myeloma and other immunoproliferative neoplasms (SIR=1.22).
However, the researchers emphasize that this increased risk was "small" and "unlikely to be of aetiological or clinical significance," noting that the study was unable to adequately adjust for confounding factors, such as comorbidity.
Furthermore, over the entire study period, the risk for esophagus, lung, stomach, and bladder cancer was significantly reduced in patients with THA (SIR=0.86, 0.79, 0.86, and 0.87, respectively).
The team also collated data for 1317 patients who underwent primary resurfacing between 2000 through 2009, including 5698 person-years at risk during which time 39 cancers were diagnosed. This gave an overall SIR for cancer of 1.23 but this was not statistically significant.
"The accumulated body of research on this topic does not suggest a major cause for concern," conclude David Brewster (Royal Infirmary of Edinburgh) and co-workers.
"However, follow-up of individuals operated on most recently, who are more likely to have been exposed to new-generation metal-on-metal prostheses, is necessarily limited and it will be important to re-assess the risk of cancer among this group after a further period of follow-up has accrued," they say.
The authors add in the British Journal of Cancer: "Discussions are currently taking place about the feasibility of developing a joint replacement register in Scotland, which in future would provide the possibility of examining cancer risk by type of prosthesis, thereby addressing one of the main limitations of this study."
By Lynda Williams, Senior medwireNews Reporter