KRAS Mutant Status, p16 and β-catenin Expression May Predict Local Recurrence in Patients Who Underwent Transanal Endoscopic Microsurgery (TEMS) for Stage I Rectal Cancer

Abstract

Abstract. Background The method of local excision, that has recently, gained wider acceptance, in early rectal cancer, is transanal endoscopic microsurgery (TEMS). TEMS generally offers advantages in operative access and oncological clearance over transanal resection (TAR), but recently a number of similar logic techniques with various rectal ports for endoscopic excision of rectal tumours has been invented. Those methods are collectively named transanal minimal-invasive surgery (TAMIS) and for oncological purposes they share the same features of local excision as TEMS (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14).TEMS is a minimally invasive technique that was introduced by Buess in the early 1980's (2). Through the new rectoscope with 3D binocular optic and the endoscopic instruments, it offers better access to proximal lesions with lower margin positivity and fragmentation and magnification of the operative field (2, 15). TEMS is a safe procedure that offers low complication rates and peri-operative morbidity (10.7%) (4). There have been multiple studies to suggest that TEMS is the operation of choice for rectal adenomas (1), retrorectal and submucosal rectal lesions (5). Furthermore, TEMS offers the advantage of not damaging the anorectal function (7).TEMS is indicated as a curative treatment for malignant neoplasms that are histologically confirmed as pT1 sm1 carcinomas, whereas T1 sm2-3 and T2 lesions are still under question (8). A number of studies have shown that TEMS can have comparable results with radical surgery (1,8,12,16) for rectal cancer.There has been concern about oncologic outcomes following TEMS (17). Some studies support that there is potentially a higher risk of local recurrence rate with TEMS (8,10,18). Efforts have been made to classify risk with morphological and histological criteria with better patients' selection (1, 6-9); however, the risk stratification remains 5315

KRAS Mutant Status May Be Associated with Distant Recurrence in Early-stage Rectal Cancer

“…This seems to support the assumption that early cancer recurrence can represent the reflection of a specific carcinogenesis pathway where KRAS plays an important role, and it is involved at early stages. Similar findings were reported in one of our recently published study (21), where KRAS is linked with local recurrence in Stage I Rectal Cancer following Transanal Endoscopic Microsurgery (TEMS).…”

The Role of KRAS in Endometrial Cancer: A Mini-Review

“…Similar notions have been discussed in the case of CRC, where in the classic adenoma-carcinoma pathway, KRAS mutations seem to appear early in the neoplastic route. Several studies concluded that KRAS may play a significant role in early stage CRC (27)(28)(29). In 1988, Vogelstein et al stated that early mutations of adenomatous polyposis coli gene result in deregulation of the wingless-related integration site (WNT) pathway (30); KRAS mutations follow deregulation of the WNT pathway and certainly take place prior to TP53 gene inactivation.…”

Combined analysis of KRAS mutation and p16INK4a and p14ARF methylation status in locally advanced rectal carcinoma treated with preoperative chemoradiotherapy

“…Firstly, in a subgroup of patients with concomitant KRAS mutation and p14 ARF methylation, local recurrences and/or metastases were significantly more often detected (P=0.027). Previous studies have shown that the presence of KRAS mutations in the early stages of RC is associated with the occurrence of distant recurrences in the later stages of the disease [22]. Mutation of this gene in LARC is common, but the mutational status of the KRAS gene is not enough to predict more aggressive tumor behavior, and other parameters are needed to indicate a potential risk of recurrence [23].…”