This retrospective cohort study comprised 79 carriers of germline mutation in a MMR gene (18 MLH1, 55 MSH2, 4 MSH6, and 2 PMS2) from the Colon Cancer Family Registry who had had a proctectomy for index rectal cancer.
Moreover, MSH2 protein expression was absent in the tumors of the ovary, endometrium, ascending colon, and rectum, while the rectal cancer also lacked MLH1 protein.
The expression of MSH2 in the liposarcoma and rectal cancer of the patient was analyzed by immunohistochemistry, which revealed loss of MSH2 expression in the tumors.
We investigated p53 and its downstream effectors p21WAF1/CIP1, BAX, and hMSH2 as well as the proliferation marker Ki-67 (mki-67/MIB-1) in patients undergoing preoperative radiochemotherapy for rectal carcinoma to identify prognostic and predictive factors.
Five families had mutations in hMLH1, 4 of which were splice site mutations, 2 had frameshift mutations in hMSH2 and 1 patient with metachronous endometrial and rectal cancer but with a weak family history of cancer had a nonsense mutation in hMSH6.