Ocular side‐effects in breast cancer patients treated with tamoxifen and toremifene: a randomized follow‐up study

Abstract

ABSTRACT.Purpose: 3Tamoxifen and toremifene are non-steroidal anti-oestrogens widely used in the treatment of advanced breast cancer and as adjuvant therapy following surgery in early stage disease. Tamoxifene has also been approved for use in reducing the incidence of breast cancer amongst high risk women. However, certain well documented adverse effects, mainly involving the reproductive organs, have been reported amongst users of both drugs. The aim of this study was to monitor the ocular side-effects of both of these commonly used anti-oestrogens. Methods: Sixty postmenopausal (age range 50-79 years) breast cancer patients were randomized into adjuvant tamoxifen or toremifene therapy groups for 3 years. Prior to commencement of medication, a thorough ocular examination was undertaken. The first follow-up visit took place after 6 months and the remaining three at 12-month intervals thereafter. Results: Sixteen patients had cataract at the first visit (seven in the tamoxifen group and nine in the toremifene group). Ten patients developed cataract during the study period (five in each group), giving annual cataract rates of 6.8% and 6.2% in the tamoxifen and toremifene groups, respectively. Three patients had macular crystals at the first visit (one in the tamoxifen group and two in the toremifene group). The crystals remained stable throughout the follow-up. Macular drusen were diagnosed in five patients at the first ophthalmological check-up (two in the tamoxifen and three in the toremifene group). Two patients in the toremifene group developed drusen maculopathy during follow-up visits. Yellowish spots in the macular area were found in one tamoxifen-treated patient at the second visit. At the final visit after 3.5 years' follow-up the spots had disappeared. No abnormal corneal findings or keratopathy were documented during the follow-up. Conclusion: We observed no serious ocular side-effects among the 60 breast cancer patients treated with tamoxifen or toremifene over a 3.5-year period.

Toxicidad ocular de la quimioterapia sistémica anticancerosa

“…17 Posterior subcapsular cataract can occur with busulphan, 5,[18][19][20] methotrexate, 5 toremifene and tamoxifen. [21][22][23] In a prospective study of breast cancer patients treated with tamoxifen and toremifene, annual cataract rates were found to be 6.8% and 6.2% respectively.…”

“…17 Tamoxifen and toremifene may also cause macular crystals, macular drusen and yellowish spots in the macula area. 22 The prevalence of refractile retinal opacities in patients on tamoxifen has been shown to be 3.1% (mean duration of therapy-806 days). 34 Interferon is also a known cause of retinopathy.…”

Ocular toxicity during adjuvant chemoendocrine therapy for early breast cancer

“…5,7,8,11 Data on ocular toxicity due to selective estrogen-receptor modulators (SERMs) other than tamoxifen are even more limited. 12,13 Randomized controlled trials may underestimate the problem if side effects are not specifically assessed with clinical or instrumental examination at scheduled times.…”

“…In a recent small prospective study 13 (substudy of a larger randomized controlled trial), pathologic ocular findings were found at baseline ophthalmic examination in 26 of 60 (43.3%) patients aged 50 to 79 years. Another possible explanation lies in different daily doses and treatment duration, because higher cumulative doses have been shown for patients with ocular toxicity in comparison with patients without ocular toxicity.…”

“…Similarly, no significant differences were reported between these two drugs in patients with metastatic disease 12 as well as in the adjuvant setting where a small prospective study included regular ocular examination. 13 The small number of patients treated with prednisone and ovarian function suppression treatment makes difficult the assessment of their contribution to observed ocular toxicities.…”