An association between cartilaginous tumours and breast cancer in the national pathology registration in The Netherlands points towards a possible genetic trait

Breast cancer and cartilaginous tumours (enchondroma and chondrosaroma) wer e found to occur rather frequently in the same patient. in order to identif y a possible association between occurrence of these tumour types, a popula tion-based study was performed, This was a nationwide case-control study, u sing the Dutch national pathology database. Between 1973 and 1998, the stud y identified 2295 cases of cartilaginous tumours in female patients and 132 636 females with breast cancer. Of these patients, 61 were diagnosed with both tumour types. To exclude a possible bias due to screening for occult b one metastases in breast cancer patients, a similar analysis was performed for lung cancer, since screening is performed similarly in lung cancer pati ents. Of 16 559 females diagnosed with lung cancer, only one Ease with a ca rtilaginous tumour was found. The odds ratio for a potential association of breast and cartilaginous tumours is 7.62, implicating a 7.62 increased ris k for the same female patient having both breast cancer and a cartilaginous tumour. Furthermore, the mean age of onset in patients with breast cancer as the first tumour is nearly 10 years earlier than breast cancer in genera l, i.e. 51 years versus 60.9 years. The association of breast cancer and ca rtilaginous tumours and the early age of onset of breast cancer in these pa tients may suggest a genetic trait. Copyright (C) 2000 John Wiley & Sons, L td.