Three cases of malignant neoplasm, pneumonitis, and pancytopenia during treatment with low-dose methotrexate

Severe bone marrow suppression due to methotrexate toxicity following aceclofenac-induced acute kidney injury

Methotrexate is one of the most commonly used drugs in autoimmune disorders like rheumatoid arthritis. Gastrointestinal symptoms like nausea and stomatitis, skin rashes, alopecia, central nervous system symptoms like headache and confusion, hepatotoxicity and myelosuppression are some of the adverse effects. However, low oral doses on a weekly basis seldom show any signs of toxicity. Leucovorin or folinic acid is given along with methotrexate as rescue to reduce the toxic effects like bone marrow suppression. Non-steroidal anti-inflammatory drugs, like aceclofenac, are also used in chronic inflammatory conditions like rheumatoid arthritis and osteoarthritis. Nephrotoxicity is one of the adverse effects of both methotrexate and non-steroidal anti-inflammatory drugs; and its combined administration should be done with caution. This is a case of an elderly woman, a known case of rheumatoid arthritis, who presented in severe bone marrow suppression due to methotrexate toxicity following aceclofenac-induced acute kidney injury.

Methotrexate use in rheumatoid arthritis. A Clinician's perspective

Aminopterine, a precursor of methotrexate (MTX), was first used for the treatment of rheumatoid arthritis (RA) in 1951 [Gubner, R., 1951. Therapeutic suppression of tissue reactivity: I. Comparison of the effects of cortisone and aminopterin. Am. J. Med. Sci. 221, 169-175; Gubner, R., August, S., Ginsberg, V., 1951. Therapeutic suppression of tissue reactivity: II. Effect of aminopterin in rheumatoid arthritis and psoriasis. Am. J. Med. Sci. 221, 176-182.]. Corticosteroids, and to some extent cyclophosphamide, took MTX out of the rheumatologist's armamentarium until the late 1970s-early 1980s when the toxic profile of these compounds became apparent. By the mid 1980s, four randomized clinical trials (RCTs) had proven beyond doubt the beneficial effects of MTX when administered to patients with established disease who had failed to respond to other compounds such as gold salts and D-penicillamine [Thompson, R.N., Watts, C., Edelman, J., Esdaile, J., and Russell, A.S., 1984. A controlled two-centre trial of parenteral methotrexate therapy for refractory rheumatoid arthritis. J. Rheumatol. 11, 760-763; Andersen, P.A., West, S.G., O'Dell, J.R., Via, C.S., Claypool, R.G., and Kotzin, B.L., 1985. Weekly pulse methotrexate in rheumatoid arthritis. Clinical and immunologic effects in a randomized, double-blind study. Ann. Intern. Med. 103, 489-496; Weinblatt, M.E., Coblyn, J.S., Fox, D.A., Fraser, P.A., Holdsworth, D.E., Glass, D.N., and Trentham, D.E., 1985. Efficacy of low-dose methotrexate in rheumatoid arthritis. N. Engl. J. Med. 312, 818-822; Williams, H.J., Willkens, R.F., Samuelson, C.O.J., Alarcón, G.S., Guttadauria, M., Yarboro, C., Polisson, R.P., Weiner, S.R., Luggen, M.E., Billingsley, L.M., Dahl, S.L., Egger, M.J., Reading, J.C., and Ward, J.R., 1985. Comparison of low-dose oral pulse methotrexate and placebo in the treatment of rheumatoid arthritis. A controlled clinical trial. Arthritis Rheum. 28, 721-730.]. Subsequently, these four trials were included in a meta-analysis and the drug was approved by the Food and Drug Administration for use in RA [Health and Public Policy Committee, H.P.P.C. and American College Physicians, A.C.P., 1987. Methotrexate in rheumatoid arthritis. Ann. Intern. Med. 107, 418-419; Paulus, H.E., 1986. FDA Arthritis Advisory Committee meeting: Methotrexate; guidelines for the clinical evaluation of antiinflammatory drugs; DMSO in scleroderma. Arthritis Rheum. 29, 1289-1290; Tugwell, P., Bennett, K., and Gent, M., 1987. Methotrexate in rheumatoid arthritis. Indications, contraindications, efficacy, and safety. Ann. Intern. Med. 107, 358-366.]. Since then, rheumatologists have become aware of what Pincus et al. have called "the side effects" of RA comparing the morbidity and mortality caused by RA with that potentially caused by medications used to treat this disease [Pincus, T. and Callahan, L.F., 1993. The "side effects" of rheumatoid arthritis: joint destruction, disability and early mortality. Br. J. Rheumatol. 32, 28-37.]. Thus, during the 1990s the use of MTX for the treatment of RA became generalized [O'Dell, J.R., 1997. Methotrexate use in rheumatoid arthritis. Rheum. Dis. Clin. N Am. 23, 779-796 (a); Bannwarth, B., Vernhes, J., Schaeverbeke, T., and Dehais, J., 1995. The facts about methotrexate in rheumatoid arthritis. Rev. Rhum. 62, 471-473 (b); Bologna, C., Jorgensen, C., and Sany, J., 1997a. Methotrexate as the initial second-line disease modifying agent in the treatment of rheumatoid arthritis patients. Clin. Exp. Rheumatol. 15, 597-601; Bologna, C., Viu, P. (ABSTRACT TRUNCATED)

Does methotrexate increase the risk of infection or malignancy?

Most patients do not exhibit overt signs of immunosuppression. Studies cited in this article support a modest increase in the rate of bacterial respiratory and skin infections. Opportunistic infections occur rarely, however, and may be life threatening. The case for MTX carcinogenicity is less clear. The risk for malignancy other than lymphoproliferative disorders does not seem to be elevated, although multiple sporadic malignancies have been reported in treated patients. MTX is a superb agent for the therapy of a large group of immune-mediated diseases. Although an increased risk for infection and possible malignancy exists, the risk is small compared with the potential clinical benefit.

Noncutaneous malignant tumors in the PUVA follow-up study: 1975-1996

There is concern about possible association between PUVA treatment and an increased risk of noncutaneous cancer. An alteration in the risk of cancer among persons with psoriasis has also been postulated. To test this hypothesis, for nearly two decades we have prospectively followed 1380 patients who first began PUVA treatment for psoriasis in 1975-1976. We compare the risk of noncutaneous cancer in our cohort with that expected based on general population incidence rates. The overall risk of noncutaneous cancer was nearly identical to that expected in general population. For three separate sites, we noted significant increases: thyroid cancer (RR = 3.57, 95% CI = 1.16-8.34), breast cancer (RR = 1.81, 95% CI = 1.19-2.64), and central nervous system neoplasms (RR = 2.80, 95% CI = 1.13-5.57). Since 1987, however, the risk of central nervous system neoplasms has not been elevated (RR = 0.00, 95% CI = 0.00-3.35) and the relative risk of breast cancer was lower than in the prior decade and not statistically significant. There was no association between higher levels of exposure to PUVA and the risk of any of these cancers. We did not detect any significant increase in the risk of lymphoma or leukemia. Our study does not support the hypothesis that long-term PUVA treatment increases the risk of noncutaneous cancer.

Study of eight cases of cancer in 426 rheumatoid arthritis patients treated with methotrexate

OBJECTIVE

To report cancer cases in 426 rheumatoid arthritis patients treated with methotrexate, and determine whether there was an increased incidence of cancer compared with patients never treated with methotrexate (rheumatoid controls) and to the whole regional population.

METHODS

The duration of methotrexate treatment was 37.4 (SD 27.9) months. This population was compared with 420 rheumatoid arthritis controls and with a regional population of 812,344 people. Life table analysis was performed to compare the cancer incidence in the two rheumatoid populations. Adjustment for potentially confounding factors was done. The indirect standardisation methods was used to compare each rheumatoid population with the regional population.

RESULTS

Eight cases of cancer (1.88%; 4.04 cases/1000 person years) were diagnosed in the methotrexate population v six (1.43%; 58.8 cases/1000 person years) in the rheumatoid controls. The life table method showed a higher incidence of cancer in the rheumatoid controls (P = 0.0001). In a multivariate analysis (Cox model), the only significant factor explaining this difference in the cancer incidence was age (P = 0.02). In the regional population there were 6418 new cases of cancer (0.79%; 2.85 cases/1000 person years). By the indirect standardisation method, the ratio of observed cases to expected cases of cancer in each of the rheumatoid populations was not significantly different from 1.

CONCLUSIONS

In these eight cases, methotrexate was not found to be responsible for generating cancers. However, because of data regarding lymphomas and methotrexate, and because of the short follow up, especially in the control group, longer prospective studies are warranted.