WESTPORT, CT (Reuters Health) – While orthopedic implants contain potentially carcinogenic materials, hip replacement patients do not appear to have an elevated overall cancer risk, according to a report published in the September 19th issue of the Journal of the National Cancer Institute.
Certain types of cancer, however, are more common among implant patients than among the general population, the authors state.
Dr. Joseph K. McLaughlin, from the International Epidemiology Institute in Rockville, Maryland, and colleagues determined the cancer rates of 116,727 Swedish patients who underwent hip replacement surgery between 1965 and 1994. The cancer rates of this group were then compared with rates in the general Swedish population.
The overall cancer rate in the study cohort and in the general population were similar, the authors report. However, implant patients were more likely to develop prostate cancer and melanoma and less likely to develop gastric cancer than general population subjects.
Follow-up of 15 or more years after implantation revealed that cohort patients were at increased risk of developing multiple myeloma. An increased risk of bladder cancer was also noted among the cohort group on long-term follow-up, but this risk failed to reach statistical significance.
"In this, the largest study to date, hip implant patients had similar rates of most types of cancer to those in the general population," the researchers write. "Overall, the results of our study are largely reassuring."
However, the data suggest that hip replacement may be associated with an increased risk of certain types of cancer. "If these associations were causal in nature, they would represent serious public health issues," they add.
The increased risk of melanoma and prostate cancer can probably be explained by chance or confounding bias, the authors continue. However, "the associations that we observed with bladder cancer and multiple myeloma, while also potentially attributable to chance or bias, should be considered carefully and require further in-depth study."