Experimental production of sarcomas by methyl methacrylate implants

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.

Malignant fibrous histiocytoma at the site of a total hip arthroplasty

Malignant fibrous histiocytoma is the most frequent sarcoma in adults. Predisposing factors for malignant fibrous histiocytoma are Paget's disease, bone infarcts, malignant disorders of the hematopoetic system, or prolonged intake of corticosteroids. Malignant fibrous histiocytoma has been described as occurring with increasing frequency after endoprosthetic therapy and has been attributed to the implants or to their alloy constituents. Malignant fibrous histiocytoma at the site of an endoprosthesis of the hip constitutes a distinct rarity. To our knowledge, only 13 cases have been described to date. In this report, we present the case of a 66-year-old woman with rheumatoid joint disease. Eight years after primary endoprosthetic surgery, loosening of the implant with severe osteolysis of the surrounding bone required replacement surgery. Histopathologic evaluation of resected tissue revealed scar and granulation tissue and Grade 3 malignant fibrous histiocytoma. The patient died 1 year after revision arthroplasty because of diffuse pulmonary and cerebral metastases. In patients with loosening of a total hip endoprosthesis in combination with severe periprosthetic osteolysis an accompanying malignancy should be in the differential diagnosis. The histopathologic examination of the resected tissue should be obligatory.

Arthroplasty-associated malignant fibrous histiocytoma: two case reports

AIMS

Sarcoma localized to the site of an arthroplasty procedure is a rare occurrence, and detailed histological depictions and descriptions are limited. We report the clinicopathological findings in two cases of arthroplasty-associated malignant fibrous histiocytoma (MFH) and review the literature.

METHODS AND RESULTS

The patients were an elderly man and woman. Medical histories, radiographs and slides were reviewed. Immunohistochemistry, electron microscopy, cytogenetics, and electron dispersion spectroscopy were performed in one case. Both were destructive femoral bone tumours that appeared 2 and 8 years post-total hip arthroplasty, and pursued aggressive clinical courses. The histology was similar in both tumours, consisting of high-grade, pleomorphic sarcoma with numerous osteoclastic giant cells, prominent phagocytic activity, and entrapped particles of bone cement. Literature review disclosed 14 previous reports of arthroplasty-associated MFH, representing the most common phenotype. A number of materials and factors related to arthroplasty procedure, such as metal corrosion, wear debris, osteonecrosis, and chronic inflammation, have been implicated as causative agents.

CONCLUSIONS

Arthroplasty-associated MFH is a rare and aggressive tumour. Although the aetiology remains unclear, the small number of arthroplasty-associated sarcomas compared with the large number of joint replacement operations performed over the past four decades suggests a coincidental as opposed to a causal relation.

Nationwide study of cancer risk among hip replacement patients in Sweden

BACKGROUND

Orthopedic implants and their fixatives contain materials with carcinogenic potential. Whether these implants are linked to subsequent cancer development remains unknown, mainly because large-scale, long-term follow-up data are scarce.

METHODS

We conducted a nationwide cohort study in Sweden to examine cancer incidence among 116,727 patients who underwent hip replacement surgery during the period from 1965 through 1994. Through record linkage to the Swedish Cancer Register, we identified all incident cancers through 1995 in this population (693,954 person-years of observation). For each cancer type, the observed number of cases was divided by that expected in the general Swedish population to produce standardized incidence ratios (SIRs).

RESULTS

Relative to the general population, the cohort had no overall cancer excess (SIR = 1.01; 95% confidence interval [CI] = 0.99 to 1.03). However, we observed elevated SIRs for prostate cancer (SIR = 1.16; 95% CI = 1.11 to 1.22) and melanoma (SIR = 1.15; 95% CI = 1.01 to 1.30) and a reduction in stomach cancer risk (SIR = 0.83; 95% CI = 0.75 to 0.92). Long-term follow-up (>or=15 years) revealed an excess of multiple myeloma (SIR = 1.86; 95% CI = 1.01 to 3.11) and a statistically nonsignificant increase in bladder cancer (SIR = 1.42; 95% CI = 0.98 to 1.99). There was no material increase in risk for bone or connective tissue cancer for either men or women in any follow-up period.

CONCLUSIONS

In this, the largest study to date, hip implant patients had similar rates of most types of cancer to those in the general population. Although the excesses of melanoma, multiple myeloma, and prostate and bladder cancers may be due to chance, confounding, or detection bias and should be interpreted cautiously, they warrant further investigation because of the ever-increasing use of hip implants at younger ages.

Total hip arthroplasty complicated by a malignant fibrous histiocytoma. A case report

Tumors associated with total hip arthroplasty are uncommon. The authors report the eighth case of a malignant fibrous histiocytoma associated with a total joint arthroplasty and discuss its etiology and significance.

Identification or urinary mercapturic acids formed from acrylate, methacrylate and crotonate in the rat

1. After administration to rats of methyl acrylate (I), methyl methacrylate (II) and methyl crotonate (III), urinary mercapturic acids were isolated and identified as the dicarboxylic acids N-acetyl-S-(2-carboxyethyl)cysteine (IV, R = H), N-acetyl-S-(2-carboxypropyl)cysteine (V, R = H) and N-acetyl-S-(1-methyl-2-carboxyethyl)cysteine (VI, R = H) and for a minor part as their monomethyl esters IV (R = CH3) and VI (R = CH3). 2. After a single dose of the acrylates (I), (II) and (III) (0.14 mmol/kg), the excretion of the thioethers amounted to 6.6 +/- 0.6, 0.0, and 2.0 +/- 0.6% dose respectively. 3. After 18 h previous administration of the carboxylesterase inhibitor tri-o-tolyl phosphate (0.34 mmol/kg) the excretion of the thioethers amounted to 40.6 +/- 2.1, 11.0 +/- 3.3, and 16.0 +/- 2.0% dose. 4. For methyl acrylate (I) the ratio of the excreted dicarboxylic acid and monomethyl ester was 20:1. After previous administration of tri-o-tolyl phosphate this ratio was 1:2.

Serum protein analysis following implantation of methyl methacrylate in rats

Thirty-six Sprague-Dawley white rats were implanted with methyl methacrylate and bone wax in a 1:1 ratio. At periods of 1, 3, 5, 7, 10 and 14 days-post-implantation arterial blood samples were drawn and the serum protein separated electrophoretically. A significant depression in the alpha 1 and alpha 2 fractions of the methacrylate animals was demonstrated as was a significant increase in the beta fraction of the 3 day group. There was a sustained depression of the alpha 1 fraction in the methacrylate animals in a 3 day and a 5 day time period. It is not felt, however, that this is indicative of a mechanism for the diverse phenomena that have been described secondary to implantation of methyl methacrylate.

The relationship between the latent period and animal age in the development of foreign body sarcomas

Either porous polyester-polyurethane cylindrical sponges with a diameter of 12 mm (thickness 6 mm) or rectangular sponges (dimensions 120 times 20 times 5 mm) were implanted paravertebrally in the subcutis of a total of 118 rats of different ages (1-15 1/2 months). It was established that the rate of tumor formation increased with the size of the implant from 12.1% (cylindrical sponges) to 26.6% (rectangular sponges). Furthermore is could be shown that in animal experiments it is the age of the rats that plays the decisive role in sarcogenesis and not the latend period (time from the implantation until development of the tumor), in that young animals first develop malignant mesenchymal tumors after a mean 17.2 months whereas in old rats these had already developed after 6.3 months.

Investigation of possible oncogenic action of zinc polycarboxylate cement by implantation in mice and hamsters

Powdered, sterilized zinc polycarboxylate was implanted subcutaneously in 56 young hamsters and 54 mice, using equal numbers of each sex, with 24 sham operated hamsters and 26 mice as controls. The hamsters were sacrificed after 15 months and the mice after 12. Implant material was recovered from one of 42 surviving mice and from 16 of 43 surviving hamsters. Benign adenomas of the gut, thyroid, sebaceous glands and ovary were found in 3 experimental mice and in one control. Benign adrenal adenomas were found in 3 experimental hamsters and in one control. One control hamster developed a rhabdomyosarcoma in a limb. One experimental hamster developed a leiomysarcoma in close relation to an implant.

Embryonic-fetal toxicity and teratogenic effects of a group of methacrylate esters in rats

Monomers of five methacrylate esters and acrylic acid were administered at three dose levels to female rats on days 5, 10, and 15 of gestation. The incidences of resorptions, dead fetuses, gross abnormalities, and skeletal malformations are presented for each of these groups. Mean fetal weights also were determined for each group, and those of the monomer-treated groups were significantly smaller (P ≤ 0.01) than those of the untreated controls.

Mouse cages and spontaneous tumors

Images