Approach to early-onset colorectal cancer: clinicopathological, familial, molecular and immunohistochemical characteristics.
OBJECTIVE
To characterize clinicopathological and familial features of early-onset colorectal cancer (CRC) and compare features of tumors with and without microsatellite instability (MSI).


METHODS
Forty-five patients with CRC aged 45 or younger were included in the study. Clinical information, a three-generation family history, and tumor samples were obtained. MSI status was analyzed and mismatch repair genes were examined in the MSI families. Tumors were included in a tissue microarray and an immunohistochemical study was carried out with a panel of selected antibodies.


RESULTS
Early onset CRC is characterized by advanced stage at diagnosis, right colon location, low-grade of differentiation, mucin production, and presence of polyps. Hereditary forms represent at least 21% of cases. Eighty-one percent of patients who died during follow-up showed a lack of expression of cyclin E, which could be a marker of poor prognosis. beta-catenin expression was normal in a high percentage of tumors.


CONCLUSIONS
Early-onset CRC has an important familial component, with a high proportion of tumors showing microsatellite stable. Cyclin E might be a poor prognosis factor.
Perea
Jose
J
Department of Surgery, Hospital Universitario 12 de Octubre, Avda. de Córdoba s/n., Madrid, Spain. josepereag@hotmail.com
Alvaro
Edurne
E
Rodríguez
Yolanda
Y
Gravalos
Cristina
C
Sánchez-Tomé
Eva
E
Rivera
Barbara
B
Colina
Francisco
F
Carbonell
Pablo
P
González-Sarmiento
Rogelio
R
Hidalgo
Manuel
M
Urioste
Miguel
M
D000328:Adult; D017668:Age of Onset; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D053842:Microsatellite Instability; D008875:Middle Aged; D009154:Mutation