Cancer risk after total hip replacements. A prospective study of 41,402 patients in the Norwegian Arthroplasty Register linked to the Cancer Registry of Norway

Background: Concerns have been raised that implants used in total hip replacements (THR) could lead to increased cancer risk. Several different materials, metals and fixation techniques are used in joint prostheses and different types of articulation can cause an increased invasion of particles or ions into the human body. Methods: Patients with THR registered in the Norwegian Arthroplasty Register during 1987-2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular components). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender and if the patient had additional THR-surgery in the same or the opposite hip. The study follows the STROBE guidelines.Results: Comparing patients with THR to the general population in Norway we found no differences in cancer risk. The overall SIR for the THR-patients after 10 years follow-up was 1.02 (95% CI: 0.97-1.07). For cemented THR, the SIR after 10 years follow-up was 0.99 (95% CI: 0.94-1.05), for uncemented, 1.16 (95% CI: 1.02-1.30), and for hybrid 1.12 (95% CI: 0.91-1.33). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk for cancer (hazard ratio: HR=1.24, 95% CI: 1.05-1.46, p=0.009) when compared to patients with cemented THRs after 10 years follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR=1.07, 95% CI: 0.85-1.35, p=0.55) compared to patients with cemented THRs.Conclusions: THR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk for cancer compared to cemented THR in males, but that this may be prone to unmeasured confounding.

Cancer risk after total hip replacements. A prospective study of 41,402 patients in the Norwegian Arthroplasty Register linked to the Cancer Registry of Norway

Background Concerns have been raised that implants used in total hip replacements (THR) could lead to a future increased cancer risk. Several different materials and, metals and fixation techniques are used in joint prosthesis, as well as prostheses and different fixation techniques and types of articulation for the surface of the joint can lead to cause an increased escapeinvasion of particles or ions into the human body. Methods Patients with THR registered in the Norwegian Arthroplasty Register during 1987-2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular componentcomponents). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender, and if the patient had additional THR-surgery in the same or the opposite hip. The study is according tofollows the STROBE guidelines.Results When comparingComparing patients with THR to the general population in Norway we found no differences in thecancer risk. The overall SIR for the THR-patients after 10 years of follow-up was 1.02 (95% CI: 0.97-1.07). For cemented THR, the SIR after 10 years of follow-up was 0.99 (95% CI: 0.94-1.05), while it wasfor uncemented, 1.16 (95% CI: 1.02-1.30) for uncemented THRs,), and for hybrid 1.12 (95% CI: 0.91-1.33) for hybrid THRs.). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk offor cancer (hazard ratio: HR=1.24, 95% CI: 1.05-1.46, p=0.009) when compared to patients with cemented THRs after 10 years of follow-up.follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR=1.07, 95% CI: 0.85-1.35, p=0.55) compared to patients with cemented THRs. Conclusions THR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk of cancer, in particular prostatefor cancer for younger mencompared to cemented THR in males, but that this may be prone to unmeasured confounding.

Cancer risk after total hip replacements. A prospective study of 41,402 patients in the Norwegian Arthroplasty Register linked to the Cancer Registry of Norway

Background Concerns have been raised that implants used in total hip replacements (THR) could lead to increased cancer risk. Several different materials, metals and fixation techniques are used in joint prostheses and different types of articulation can cause an increased invasion of particles or ions into the human body. Methods Patients with THR registered in the Norwegian Arthroplasty Register during 1987-2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular components). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender and if the patient had additional THR-surgery in the same or the opposite hip. The study follows the STROBE guidelines.Results Comparing patients with THR to the general population in Norway we found no differences in cancer risk. The overall SIR for the THR-patients after 10 years follow-up was 1.02 (95% CI: 0.97-1.07). For cemented THR, the SIR after 10 years follow-up was 0.99 (95% CI: 0.94-1.05), for uncemented, 1.16 (95% CI: 1.02-1.30), and for hybrid 1.12 (95% CI: 0.91-1.33). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk for cancer (hazard ratio: HR=1.24, 95% CI: 1.05-1.46, p=0.009) when compared to patients with cemented THRs after 10 years follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR=1.07, 95% CI: 0.85-1.35, p=0.55) compared to patients with cemented THRs.Conclusions THR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk for cancer compared to cemented THR in males, but that this may be prone to unmeasured confounding.

Cancer risk after total hip replacements. A prospective study of 41,402 patients in the Norwegian Arthroplasty Register linked to the Cancer Registry of Norway

Background Concerns have been raised that implants used in total hip replacements (THR) could lead to a future increased cancer risk. Several different materials and metals are used in joint prosthesis, as well as different fixation techniques and types of articulation for the surface of the joint can lead to an increased escape of particles or ions into the human body. Methods Patients with THR registered in the Norwegian Arthroplasty Register during 1987-2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular component). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender, and if the patient had additional THR-surgery in the same or the opposite hip. The study is according to the STROBE guidelines.Results When comparing patients with THR to the general population in Norway we found no differences in the risk. The overall SIR for the THR-patients after 10 years of follow-up was 1.02 (95% CI: 0.97-1.07). For cemented THR, the SIR after 10 years of follow-up was 0.99 (95% CI: 0.94-1.05), while it was 1.16 (95% CI: 1.02-1.30) for uncemented THRs, and 1.12 (95% CI: 0.91-1.33) for hybrid THRs. Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk of cancer (hazard ratio: HR=1.24, 95% CI: 1.05-1.46, p=0.009) when compared to patients with cemented THRs after 10 years of follow-up. The risk for patients with hybrid THRs was not significantly increased (HR=1.07, 95% CI: 0.85-1.35, p=0.55) compared to patients with cemented THRs. Conclusions We found that receiving an uncemented THR was associated with a small increased risk of cancer, in particular prostate cancer for younger men.