Caracterización clínica, molecular e inmunofenotípica del cáncer colorrectal en menores de 45 años

[EN] Early-onset colorectal cancer is not frequent, with an incidence rate of 2-8%. It is a very heterogeneous group: some of them are sporadic, and others are hereditary forms. They also have some characteristics which are different from the common forms of colorectal cancer, such as: proximal site at colon, a significant excess of synchronous and metachronous CRCs, more often poorly differentiated, with an excess of mucoid, and an advanced stage at diagnosis. Some of them have similar behaviour than Lynch syndrome´s CRC, and microsatellite instability as their molecular basis the tumour too. A significant part of this group has a MMR germline mutation. There is another group with microsatellite stability, which shows chromosomic instability, a similar form of CRC as the CCR in older ages. Nevertheless, there are a lot of molecular, anatomical and clinical characteristics that must need to be studied, in order to classify them in a similar way as Lynch syndrome or as a non hereditary CRC forms. We review 45 patients with CRC being diagnosed at 45 years old or younger, in two different hospitals, in two different geographic areas. The global characteristics were: a significant group has CRC in the right colon (44%), an important group with medium differentiated tumours, some of them had an excess of mucoid (24, 4%). The 33,3 % of them had polyps in their evolution. A very important fact, is that the 55,5% of them, had been diagnosed at an advanced stage. Some of them had hereditary familial cancer, or another cancer associated with Lynch syndrome (40%). We found some items associated with a worst prognosis, such as: left location tumours, an advanced stage, the activation of the Wnt way, or the lack of expression of cyclin E in the tumours. The 31% of the patients presents microsatellite instability, and the 61% of them had MMR germline mutations in MLH1 and MSH2. These tumours had some different characteristics from the others: an early age of onset and a larger cancer history in family members. They seem to have a better prognosis, except the patients with signet-cell or an unexpression of p53. In order to find out which patients are candidates of MMR germline mutations study, microsatellite instability with Bat 26 and the inmunohistochemistry of the mismatch repair proteins are both useful tools to carry it out. We must conclude that the behaviour of this CRC seem to be different, with more polyps in the evolution and more synchronous and metachronous tumours. Thus, we must follow up in a special way these patients, and perhaps, we may do a more extensive resective surgery.

Author

• Perea García, José

• Cáncer colorrectal
• Colrectal cancer
• Tumores
• Tumors
• Tesis y disertaciones académicas
• Oncology
• Universidad de Salamanca (España)
• Academic dissertations

Identifier

hdl:10366/76295

OAI identifier oai:identifier

oai:gredos.usal.es:10366/76295