[Osteogenesis imperfecta and breast carcinoma. A case study of radiobiological interest]

Osteogenesis imperfecta (OI) is an inherited disorder of connective tissue with abnormal quality and/or quantity of type 1 collagen. The frequency of the association of OI and breast cancer as well as the frequency of radiation induced side-effects in patients with OI are not known. Certain diseases with widespread collagen alterations such as systemic lupus erythematodes or dermatomyositis--although not exactly comparable to congenital OI--carry a high risk for radiation injuries in case of irradiation with normal doses. The report of a patient with osteogenesis imperfecta type I and postmastectomy irradiation might therefore be of some radiobiological interest.

Report of a 46-year-old women with OI type I and breast cancer with a 14-year follow-up time after mastectomy and external beam irradiation.

During all the follow-up time there was no radiation injury in this patient with OI type I and breast cancer.

Mostly it is not possible to draw a valid conclusion from a case report, but with this experience the combination of OI type I and radiotherapy seems not to cause unusual radiation injury. Contrary to OI of type II and III, in the majority of the cases of OI type I there is a normal quality, but diminished quantity of collagen type I. This could be one of the possible reasons for the absence of adverse radiation effects. Finally, it might be of interest, that the gene-locus of the two alpha-1(I)-chains of collagen type I is situated at chromosome 17q21-22, where also the location of the "breast-cancer gene" is supposed to be. A genetic examination was, unfortunately, refused by the patient.