Connective Tissue Oncology Society

2001 CTOS Annual Meeting Posters— Medical Oncology

ASSOCIATION BETWEEN BREAST CANCER AND CARTILAGINOUS TUMORS: PHENOTYPIC CHARACTERIZATION OF A HITHERTO UNRECOGNIZED POTENTIAL HEREDITARY TRAIT
M. Timmerman¹, A. M. Cleton-Jansen¹, M. J. v.d. Vijver¹, C. van Asperen², L. C. v.d. Broek¹, P. C. Hogendoorn¹
¹Department of Pathology, Leiden University Medical Center, ²Department of Medical Genetics, Leiden University Medical Center

OBJECTIVE: Recently we documented a strong association between the occurrence of cartilaginous tumors (enchondroma, chondrosarcoma) and breast cancer in the same patient, using a nation-wide case-control study. This study revealed an odds ratio of 7.62 for a potential association of breast and cartilaginous tumors, pointing statistically strongly towards a genetic trait. This is furthermore corroborated by the age of onset in patients with breast cancer as the first tumor, which is about 10 years earlier than breast cancer in the general population. Following this statistical/epidemiological analysis we report on the phenotypic characterization of the patient group.

METHODS: The Dutch BRCA1 and BRCA2 family database was searched for cases recording a cartilaginous tumor. Moreover using the national pathology database the tissue blocks of all patients reported to fulfil the associated tumors mentioned were retrieved. Reported diagnoses were reviewed; breast cancer specimens were classified and histologically characterized according to the procedures used by the Breast Cancer Linkage Consortium. In addition the cartilaginous tumors were analyzed with emphasis on the central versus peripheral localization in the skeleton as previous studies proved a different molecular mechanism to be operative in the different subtypes.

RESULTS: In the Dutch BRCA1 and BRCA2 database no case of chondrosarcoma nor enchondroma was reported, neither within the same patient nor within the pedigree pointing to a trait which is different from the afore mentioned breast cancer syndromes. Remarkably all cartilaginous tumors are of one common histological subtype being centrally localized whereas no peripheral cartilaginous tumor was registered. The breast tumors were histologically heterogeneous with varying differentiation grade. Results on immunohistochemical staining (p53, Bcl2, Her2-neu, p16, p21 estrogen and progesteron receptor and E-cadherin) will be presented.

CONCLUSION: Evidence is presented that the recently described association between the occurrence of breast cancer and cartilaginous tumors is different from other known breast cancer syndromes with a restricted spectrum of cartilaginous tumors.