According to a study in the Lancet Oncology, in the prevention of breast cancer reoccurrence, tamoxifen is not as effective as Aromatase inhibitors are. However, Aromatase inhibitors have an increased of musculoskeletal side effects, like the carpal tunnel syndrome. The aim of the study was to analyse the prognostic value of musculoskeletal symptoms, like the carpal tunnel syndrome, and the risk factors involved during the treatment of patients who were suffering from breast cancer using exemestane, a steroidal aromatase inhibitor, after two to three years of tamoxifen.
The intergroup exemestane study involved collecting data from four thousand seven hundred women who were in the postmenopausal stage and who had been treated for early invasive breast cancer. These women, who remained free from the disease on treatment after two to three years of tamoxifen, were randomly divided into two categories, one of which continued to take tamoxifen and the other was asked to switch to exemestane for the remainder of the five-year period of the treatment of the endocrine system. The chief endpoint of this retrospective analysis was set as the point when there would be any occurrence of any musculoskeletal events and carpel tunnel syndrome, within the safety population.
The safety population consisted of all the patients who had received trial treatment. In order to gain further more information regarding the cases of carpal tunnel syndrome, questionnaires were distributed among the patients besides supplying them with case-report forms. After six month from the date of randomization and then survival from 9 months onwards, the relation between musculoskeletal symptoms being reported in, was analysed by Cox proportional hazards models. The registry number of the trial is ISRCTN11883920. The accrual of the study has been completed and the follow up is on the continuation for the patients who are enrolled.
The conclusions drawn from the study were that out of 2,319 patients taking exemestane, 2.8 per cent of them were reported with carpal tunnel syndrome on the other hand, those 2,338 who were taking tamoxifen, had only 0.6 per cent patients who reported the carpal tunnel syndrome. Out of those who suffered from the syndrome, the average time for which the syndrome was effective was six months. Thus, this clearly shows that those who take exemestane for the treatment have more chances of developing carpal tunnel syndrome than those who are treated with tamoxifen. Although further investigation into the matter is warranted.