R3 정상완

Introduction  EGC : Tumor invasion is limited to the mucosa or submucosa, regardless of lymph node involvement.  Accumulated histopathological data : many EGC had no metastatic lesions  Surgical gastrectomy for resection of LNs is not always required and EMR may be a treatment option for patients at negligible risk of LN metastasis.  Standard indications for EMR of EGC : differentiated elevated intramucosal cancers less than 2 cm in size and depressed cancers without ulceration less than 1 cm in size.

Introduction  Expanded indications (in Japan) : other lesions with a negligible risk of lymph node metastasis, including larger lesions and lesions with ulceration.  However, currently available studies of outcomes after EMR have been limited by small patient numbers, old data obtained by using the strip biopsy method, and the absence of an appropriate comparison group such as patients treated with gastrectomy.  Evaluated clinical outcomes, including long-term outcomes, after complete EMR in patients with intramucosal gastric cancer and compared these outcomes with surgical treatment.

Methods - Study population  ~ , at Asan Medical Center  Inclusion : EGC confined to the mucosa that was completely resected by surgery or EMR Undifferentiated carcinoma who underwent EMR instead of gastrectomy d/t medical comorbidities precluding surgery or patient preference  Exclusion : Previous gastrectomy, Recurrent EGC at previous EMR site, Incomplete resection by EMR, Submucosal invasion on pathologic examination (possibility of LN invasion and incomplete resection)

EMR method  Standard single accessory channel endoscope by a single experienced GI endoscopist.  Circumferential precutting followed by snare resection. : several marking dots outside the lesion  a diluted epinephrine solution was injected into the submucosa  using a needle-knife, we made a circumferential incision  tumor was resected by snare  Complete Resection : removed en bloc or removed piecemeal, was reconstructed completely, with tumor-free lateral and vertical margins and without lymphovascular invasion.

Methods - Follow-up  Clinical, procedural, pathologic, and outcome data were collected by reviewing patient medical records and by interviewing patients by phone  Clinical follow-up after EMR and after gastrectomy : at 1 and 6 months, 1 year, and annually thereafter  Routine endoscopy and CT follow-up : at 6 months, 1 year, and annually thereafter

Methods - Outcome data  Primary endpoints : death and tumor recurrence  Death : death from any cause  Disease-related death : death from recurrent or metachronous gastric cancer  Recurrences : local, regional, peritoneal, or distant 1. Local : cancers diagnosed pathologically at the resection margins 2. Regional : lesions in regional gastric LNs without other gastric lesions 3. Peritoneal : carcinomatosis or ovarian metastasis 4. Distant metastases : LN recurrence outside the LN dissection field, liver metastases, or metastases at other extra-abdominal sites without other sites of malignancy  Metachronous gastric cancer : diagnosed pathologically after 1 year within the stomach distant from the site of anastomosis or EMR site

Results  302 pts with EGC underwent EMR  215 (71.2%) : complete resection  15 (5.0%) : submucosal invasion  71 (23.5%) : incompletely resected tumors or resected piecemeal  1 (0.3%) : failed EMR caused by uncontrolled bleeding  1680 pts underwent surgery for EGC  843 intramucosal gastric cancer vs 215 treated with EMR  All curative resection (distal gastrectomy 87.7%, total gastrectomy 10.3%, proximal gastrectomy 0.7%, segmental resection 0.7%, wedge resection 0.6%)  Median follow-up period : 81 months for the EMR group 88 months for the surgery group

Results

Results

Results  The complication rates were similar in the EMR and surgery groups (6.4% [11/172] vs 7.7% [29/379]; odds ratio [OR] 0.84; 95% CI, ; P.62).  In the EMR group  bleeding in 8 within 24 hours, 3 delayed bleeding.  In the surgery group  29 (7.7%) complications ( mechanical ileus, wound complications, anastomosis strictures, postoperative bleeding, acalculous cholecystitis, urethral injury, CBD injury, ARF )  There were no procedure-related mortalities in the EMR group compared with 2 in the surgery group (1 panperitonitis d/t perforation and 1 sepsis d/t small-bowel strangulation)

Conclusion  In intramucosal gastric cancer, EMR and surgery were associated with similar long-term rates of death and tumor recurrence.  Considering that the long-term safety and effectiveness of EMR are comparable to those of surgery, with lower medical costs and shorter duration of hospital stay, EMR could be an effective first-line treatment for patients who have intramucosal gastric cancer with negligible risk of LN metastasis.