Local excision after polypectomy for rectal polyp cancer: when is it worthwhile?

Abstract

With the increase in screening endoscopy, the incidence of malignant polyps has increased [1,2]. The optimal management of these polyp cancers is unclear, particularly if the polyp was fragmented during removal and completeness of removal cannot be determined.Many can be considered cured by the simple polypectomy; however, there is a recognized small group that will develop extensive recurrent disease [3]. Completion local excision of the polyp stalk or scar has been advocated, but the benefit of this is unclear [4][5][6]. A review of the management of rectal polyps [7] notes the difficulties in decision-making after polypectomy when clear prognostic information about depth of invasion and margin clearance is not available due to fragmentation of the specimen or artefacts due to polypectomy technique. An additional challenge is assessing lymph node status. The determination of malignancy in mesorectal lymph nodes

International consensus recommendations on key outcome measures for organ preservation after (chemo)radiotherapy in patients with rectal cancer

“…Furthermore, inaccurate staging of cT1 tumours as cT2 rectal cancers (upstaging) can lead to unnecessary treatment with CRT within clinical trials. LE alone without CRT is considered sufficient and can reduce the risk of morbidities without jeopardizing long-term oncological outcomes [60][61][62][63] for patients with pT1 tumours and no adverse-risk features 15,16 . However, completion TME is recommended for patients with adverse histopathological features (location in the middle or lower third of the submucosa (SM ≥ 2), grade 3 disease, venous invasion and lymphatic invasion) detected in the resected LE specimen.…”

The Role of Transanal Endoscopic Surgery for Early Rectal Cancer

“…In another study by Jones et al, 63 patients who underwent TEM following polypectomy for pT1 tumors with clear, involved (≤1 mm), or unknown margins were retrospectively reviewed. 47 In 44% (28/63) of patients, histologic features were not reported due to limitations of the excision or fragmentation. In the pT1 specimens where histologic information was available, high-risk features were included such as sm3 invasion in 33% (9/27) of specimens, LVI in 11% (7/63), and tumor size > 3 cm in 5% (3/63).…”

“…This is based on the finding by Junginger et al and Jones et al that among 32 TEM specimens, when TEM was performed to further evaluate postpolypectomy margins deemed involved or unassessable, none had residual cancer. 45 47…”

Full-Thickness Scar Resection After R1/Rx Excised T1 Colorectal Cancers as an Alternative to Completion Surgery

“…Over the past years, unassessable (Rx) or positive (R1) resection margins after local excision of a T1 colorectal cancer (CRC) were considered an indication for completion surgery (CS) due to the high risk of local recurrence and unclear risk of lymph node metastasis (LNM) (1–3). Recently, a strategy of local full-thickness resection of the local excision scar (FTRS) with endoscopic full-thickness resection, transanal minimally invasive surgery, or combined endoscopic-laparoscopic surgery (4–9) was promoted as an alternative treatment strategy for patients with R1/Rx resection margins after local excision of a T1 CRC, in absence of other histological risk factors of LNM (10,11). If the locally resected scar tissue showed no local intramural residual cancer (LIRC), the local excision was considered complete and therefore managed as a low-risk T1 CRC (4,6,7).…”

“…Furthermore, in a recent prospective study on T1 CRC with R1/Rx resection margins without other histological risk factors of LNM, an unexpected high rate of LNM (8.3%) was detected during CS in cases without LIRC (13). Moreover, a study on transanal endoscopic microsurgery (TEM) without LIRC after endoscopic excision reported 9.4% recurrences in patients with R1/Rx resection margins (9). To refrain from CS and intensive follow-up after FTRS, it is essential that the oncological outcome of both strategies is known.…”