Familial cancer among consecutive uterine cancer patients in Sweden.
BACKGROUND
Uterine cancer (UC) represents 5.1% of all female malignancies in Sweden. Accumulation of UC in families occurs in around 5% of cases. We wanted to identify any familial association between UC and other selected cancers and to study the frequency of Lynch,Cowden and cancer syndromes among consecutive UC patients in Sweden.


METHODS
481 UC patients were included. Information on the cancer diagnoses of their relatives (first- (FDRs) and second-degree (SDRs) relatives and first cousins) was obtained. The relative frequencies of different cancers among relatives were compared to those in the Swedish general cancer population in 1970 and 2010. Families that fulfilled the criteria for hereditary cancer syndromes were tested for mutations in the causative genes. Families with at least one case of UC in addition to the index patient were compared to families with no additional cases to investigate possible characteristics of putative hereditary cancer syndromes.


RESULTS
There was an increased prevalence of UC in our study population compared to the Swedish general cancer population in 1970 and 2010 (6% vs. 4% and 3%, respectively). Seven families had Lynch Syndrome according to the Amsterdam II criteria. No families fulfilled the criteria for Cowden syndrome. In total 13% of index patients had at least one relative with UC and these families tended to have more cases of early onset cancer among family members. In addition, 16% of index patients were diagnosed with at least one other cancer. No families fulfilled the criteria for Cowden syndrome.


CONCLUSIONS
We showed a familial clustering of UC among relatives of our index patients. Of the seven families with mutation-verified Lynch Syndrome, only one had been previously diagnosed, highlighting the need to increase gynecologists' awareness of the importance of taking family history. Our data on multiple cancers and young age of onset in families with uterine cancer is compatible with the existence of additional hereditary uterine cancer syndromes.
Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Karolinska University Hospital, Solna/Huddinge, Stockholm, Sweden ; Division of Obstetrics and Gynecology, Karolinska University Hospital Huddinge, Stockholm S-14186, Sweden.
Gerasimos
G
Tzortzatos
Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Karolinska University Hospital, Solna/Huddinge, Stockholm, Sweden.
Ofra
O
Wersäll
Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Karolinska University Hospital, Solna/Huddinge, Stockholm, Sweden.
Kristina Gemzell
KG
Danielsson
Department of Clinical Genetics, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden ; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Annika
A
Lindblom
Department of Clinical Genetics, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden ; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Emma
E
Tham
Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Karolinska University Hospital, Solna/Huddinge, Stockholm, Sweden.
Miriam
M
Mints
Familial cancer; Lynch Syndrome; Multiple tumors; Uterine cancer