Cancer risk among patients with finger and hand joint and temporo-mandibular joint prostheses in Denmark

Site-specific cancer risk following cobalt exposure via orthopedic implants or in occupational settings: A systematic review and meta-analysis

In 2020, the European Commission up-classified metal cobalt as Class 1B Carcinogen (presumed to have carcinogenic potential) based primarily on data from rodent inhalation carcinogenicity studies. This up-classification requires an assessment under the Medical Device Regulations of cobalt cancer risk from medical devices. We performed a systematic review and meta-analysis to evaluate site-specific cancer risks with cobalt exposure from either total joint replacement (TJR) or occupational exposure (OC). Results were stratified by exposure type (OC or TJR), exposure level (metal-on-metal (MoM) or non-MoM), follow-up duration (latency period: <5, 5-10 or >10 years), and cancer incidence or mortality (detection bias assessment). From 30 studies (653,104 subjects, average 14.5 years follow-up), the association between TJR/OC and cancer risk was null for 22 of 27 cancer sites, negative for 3 sites, and positive for prostate cancer and myeloma. Significant heterogeneity and large estimate ranges were observed for many cancer sites. No significant increase in estimates was observed by exposure level or follow-up duration. The current evidence, including weak associations, heterogeneity across studies and no increased association with exposure level or follow-up duration, is insufficient to conclude that there exists an increased risk for people exposed to cobalt in TJR/OC of developing site-specific cancers.

Interaction between Comorbidity and Cancer

Background

Older patients have an average of three comorbidities in addition to their cancer. Oncologic studies have usually ignored this aspect when adjusting for confounders. There is mounting evidence that comorbidity interacts with risk, survival, disease progression, and treatment of elderly patients with cancer. The strength of many of these interactions increases with age.

Methods

A review of the literature was undertaken regarding two of these interactions: cancer risk and prognosis.

Results

In older patients, the risk and behavior of cancer can be strongly affected by comorbidities and their related treatment. Rather than a blanket effect, this effect might be attached to groups of syndromes with common pathophysiologic mechanisms. This is notably true for metabolic disorders and inflammatory diseases.

Conclusions

In addition to focusing on the influence of cancer treatment on comorbidity or on the effect of comorbidity in delivering cancer treatment, future endeavors will need to consider the direct impact of comorbidity on the risk and the behavior of the cancer in elderly patients.

Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.

Cancer after Total Joint Arthroplasty: A Meta-analysis

BACKGROUND

Some epidemiologic and laboratory studies have suggested that total joint arthroplasty could increase the risk of cancer. In this meta-analysis, we attempt to clarify the association of joint arthroplasty with subsequent cancer incidence.

METHODS

We identified population-based studies reporting standardized incidence ratios (SIR) for cancer following large joint arthroplasty. After summing the observed and expected numbers of cases across all qualifying studies, we calculated SIRs for all cancers, and for those at 28 anatomic sites. Latency analysis involving 175,166 patients characterized short-term and long-term cancer associations.

RESULTS

The analyses included 1,435,356 person-years of follow-up and 20,045 cases of cancer. Overall cancer risk among patients with arthroplasty was equal to that for the general population. The relative risk of lung cancer, reduced in the first 5 years after arthroplasty, increased significantly over time to approach that of the general population. Risks for all sites in the luminal gastrointestinal tract were significantly reduced by 10% to 20%; with relative risks that were generally stable over time. Increased risks were seen for cancer of the prostate (SIR, 1.12; 95% confidence interval, 1.08-1.16); similar relative risks were seen in each time period after the procedure. For melanoma, relative risks increased with follow-up to a SIR of 1.43 (95% confidence interval, 1.13-1.79) for 10 or more years after arthroplasty. There was a similar delayed emergence of increased risks for cancers of the urinary tract and oropharynx. The relative risk for bone cancer decreased with time after the procedure.

CONCLUSIONS

There does not seem to be an overall increased risk of cancer following total joint arthroplasty. Although the risks of prostate cancer and melanoma seem to be elevated, there is no obvious mechanism for these associations. Reductions in risk for some malignancies may not be causal.

Evaluation of the carcinogenic risks to humans associated with surgical implants and other foreign bodies - a report of an IARC Monographs Programme Meeting. International Agency for Research on Cancer

A meeting was held within the International Agency for Research on Cancer (IARC) Programme on the Evaluation of Carcinogenic Risks to Humans of surgical implants and other foreign bodies. This meeting report summarises the types of materials considered, their wear and degradation, their cancer epidemiology in both humans and other animals, the published experimental carcinogenicity data and selected data on their toxic, including genotoxic, effects. Evaluations resulting in a classification of Group 2B (possibly carcinogenic to humans) were reached for: (1) polymeric implants prepared as thin smooth films [with the exception of poly(glycolic acid)]; (2) metallic implants prepared as thin smooth films; and (3) implanted foreign bodies consisting of metallic cobalt, metallic nickel and a particular alloy powder consisting of 66-67% nickel, 13-16% chromium and 7% iron. Group 3 classifications (not classifiable as to their carcinogenicity to humans) were made for: (1) organic polymeric materials as a group; (2) orthopaedic implants of complex composition and cardiac pacemakers; (3) silicone breast implants; (4) dental materials; and (5) ceramic implants.