Metachronous Multiple Cancers Research Articles

Clinical features, surgical treatment strategy, and feasibility of minimally invasive surgery for synchronous and metachronous multiple colorectal cancers: A 14-year single-center experience.

Patients with a history of colorectal cancer (CRC) are at increased risk of developing secondary synchronous/metachronous CRCs. The role of minimally invasive surgery (MIS) for multiple CRCs remains unclear. This study aimed to evaluate the short-term outcomes of MIS in patients with multiple CRCs and elucidate their clinical characteristics. This retrospective study reviewed CRC patients who underwent MIS between 2010 and 2023. Multiple CRC cases were categorized into synchronous and metachronous cohorts. Demographics, pathological findings, and perioperative outcomes were analyzed. Propensity score matching (PSM) analysis was performed as appropriate. A total of 1,272 patients met the inclusion criteria, with 99 (7.8%) having multiple CRCs (75 synchronous and 24 metachronous). Multiple CRC patients had a higher prevalence of strong family history (8.1% vs. 1.0%, P < 0.001) and right-sided colon cancer (55.6% vs. 34.4%, P < 0.001) compared to solitary CRC patients. MSI-high/MMR-deficient status, including Lynch syndrome, was frequently observed among patients with multiple CRCs. Synchronous CRCs requiring double-anastomosis were associated with longer operation times (P = 0.03) and increased blood loss (P = 0.03) compared to those with a single-anastomosis. In the metachronous cohort, repeat operation patterns were categorized based on tumor location and sacrificed arteries. Preservation of the left-colic artery avoided extended colectomy in some patients. Patients with multiple CRC involving rectal cancer had a higher anastomotic leakage (AL) rate (17.6% vs. 5.7%, P < 0.01); however, this difference in AL rate disappeared after PSM (8.8% vs. 8.8%, P = 1.0). In patients with multiple CRCs, AL has not been observed ever since the indocyanine green fluorescence imaging was implemented. MIS is feasible for multiple CRCs, with perioperative outcomes comparable to those for solitary CRCs. Preservation of critical arteries may benefit patients at high risk of secondary CRCs, particularly those with a strong family history of CRC, right-sided tumors, or MSI-high/MMR-deficient profiles, including Lynch syndrome.

Abstract 5659: Origin of synchronous or metachronous multiple pancreatic cancers

Abstract [Introduction] The majority of patients with pancreatic cancer are inoperable at the time of diagnosis and even those cases with successful tumor resection for early-stage tumors frequently had second tumors within the remaining pancreas shortly after the surgery, contributing to a poor clinical outcome. Additionally, synchronous multiple pancreatic cancers have been frequently documented. One of the long-standing issues about such synchronous and/or metachronous multiple pancreatic cancers is their clonal origins. This study is designed to elucidate the origin of multiple pancreatic cancers through an unbiased detection of somatic mutations in primary and metachronous cancers, along with adjacent precursor lesions. [Methods] Serially obtained formalin-fixed paraffin-embedded surgical specimens from 20 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for the enrichment of tumor and precancerous lesions, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. The investigation into the shared and private mutations across different samples aimed to unveil the clonal evolution history of these lesions. [Results] We analyzed 20 patients with multiple pancreatic cancers of 2 metachronous and synchronous, 16 metachronous, and 2 synchronous tumors. In metachronous cases, all patients exhibited margin-negative pathology for the primary cancer, with a median interval of 38.9 months (ranging from 7 to 85 months) between the initial and second surgery. In addition, a total of 20 pancreatic intraepithelial neoplasia (PanIN) from 5 of these cases were analyzed. We identified a median of 66 (range: 31-232) and 20 (14-42) somatic mutations in cancer and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In most cases (N=19), sharing many somatic mutations, multiple tumors had a common clonal origin. In another synchronous case, the synchronous tumors shared only one mutation, suggesting that they were clonally independent tumors. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor and cancer lesions. While multiple independent clones were observed in precancerous lesions, most of multiple cancers originated from a common ancestor. Moreover, negative pathology of the margins at the initial surgery suggested that those multiple lesions arose from distant dissemination or metastasis, rather than contiguous, intraductal invasion. [Conclusions] In conclusion, our study suggests that even in early pancreatic cancer, dissemination within the pancreas may occur, contributing to the development of synchronous and metachronous cancers. Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Yasuhide Takeuchi, Takayuki Anazawa, Kazuyuki Nagai, Toshihiko Masui, Sachiko Minamiguchi, Hironori Haga, Takeshi Tanaka, Atsuhiro Masuda, Yuzo Kodama, Norimitsu Uza, Hiroshi Seno, Satoru Miyano, Hiroko Tanaka, Seishi Ogawa. Origin of synchronous or metachronous multiple pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5659.

Characteristics of multiple early gastric cancer and gastric high-grade intraepithelial neoplasia.

This study evaluated the clinical characteristics of multiple early gastric cancer (MEGC) and high-grade intraepithelial neoplasia (HGIN) treated by endoscopic submucosal dissection. The clinical profiles of 23 patients with MEGC treated by endoscopic submucosal dissection from January 2008 to June 2019 at the Fujian Provincial Hospital or Fujian Provincial Hospital South Branch were analyzed. The following information was extracted from clinical records: general data, preoperative conditions, and pathological data of each lesion after surgery. In total, 23 patients with MEGC or HGIN were evaluated (average age 64 ± 6 years, 17 (73.9%) males). MEGC and HGIN accounted for 4.9 percent of all cases, in which 19 (4.1%) were synchronous multiple cancers and 4 (0.8%) cases were metachronous multiple cancers. Lesions of synchronous and metachronous MEGC groups did not differ in age, sex, smoking history, alcohol consumption, family history of tumors, Helicobacter pylori infection, mucosal background atrophy, or intestinal metaplasia (P > .05). The vertical locations of primary and secondary lesions of MEGC were correlated (R = 0.395, P = .034). The primary and secondary lesions of MEGC shared the same macroscopic subtype (R = 0.590, P = .015), infiltration depth (R = 0.455, P = .014), and pathological subtype (R = 0.736, P < .001). MEGC and HGIN were located in close proximity. Pathologic types tended to be low-grade malignancies. The macroscopic type, histology type, and infiltration depth of the 2 lesions were significantly correlated. When detecting early gastric cancer, we should inspect the stomach and carefully consider the pathological characteristics, to improve the diagnosis of MEGC.

MO56-3 Incidence of synchronous or metachronous multiple cancers and their predictive factors in patients with non-small cell lung cancer

MO56-3 Incidence of synchronous or metachronous multiple cancers and their predictive factors in patients with non-small cell lung cancer

Abstract 1511: Origin of synchronous or metachronous multiple pancreatic cancers

Abstract Introduction: The majority of patients with pancreatic cancer are inoperable at the time of diagnosis and even those cases with successful tumor resection for early-stage tumors frequently had second tumors within the remaining pancreas shortly after the surgery, contributing to a poor clinical outcome. Moreover, synchronous multiple pancreatic cancers were often reported. One of the long-standing issues about such synchronous and/or metachronous multiple pancreatic cancers is their clonal origins. In this study, we aimed to reveal the origin of multiple pancreatic cancers using an unbiased detection of somatic mutations in primary and metachronous cancers as well as adjacent precursor lesions. Methods: Serially obtained formalin-fixed paraffin-embedded surgical specimens from 18 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for the enrichment of tumor and precancerous lesions, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. Based on shared and private mutations across different samples, we interrogated history of clonal evolution of these lesions. Results: We analyzed 18 patients with multiple pancreatic cancers of 2 metachronous and synchronous, 14 metachronous, and 2 synchronous tumors. In metachronous cases, pathology for primary cancer were margin-negative in all patients, and the median interval between the initial and second surgery was 38.9 months (7 - 85 months). In addition, a total of 20 pancreatic intraepithelial neoplasia (PanIN) from 5 of these cases were analyzed. We identified a median of 66 (range: 31-232) and 20 (14-42) somatic mutations in cancer and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In most cases (N=17), sharing many somatic mutations, multiple tumors had a common clonal origin. In another synchronous case, the synchronous tumors shared only one mutation, suggesting that they were clonally independent tumors. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor and cancer lesions. While multiple independent clones were observed in precancerous lesions, most of multiple cancers originated from a common ancestor. Moreover, negative pathology of the margins at the initial surgery suggested that those multiple lesions arose from distant dissemination or metastasis, rather than contiguous, intraductal invasion. Conclusions: In conclusion, our study suggests that even early pancreatic cancer might be disseminated within the pancreas and contribute to synchronous and metachronous cancers. Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Yasuhide Takeuchi, Tomomi Nishimura, Toshihiko Masui, Kazuyuki Nagai, Takayuki Anazawa, Sachiko Minamigushi, Hironori Haga, Norimitsu Uza, Hiroshi Seno, Yuzo Kodama, Atsuhiro Masuda, Takeshi Tanaka, Seishi Ogawa, Hiroko Tanaka, Satoru Miyano. Origin of synchronous or metachronous multiple pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1511.

Abstract 6198: Genetic analysis of synchronous or metachronous multiple pancreatic cancers

Abstract [Introduction] The majority of patients with pancreatic cancer are inoperable at the time of diagnosis and even those cases with successful tumor resection for early-stage tumors frequently had second tumors within the remaining pancreas shortly after the surgery, contributing to a poor clinical outcome. Moreover, synchronous multiple pancreatic cancers were often reported. One of the long-standing issues about such synchronous and/or metachronous multiple pancreatic cancers is their clonal origins. In this study, we aimed to reveal the origin of multiple pancreatic cancers using an unbiased detection of somatic mutations in primary and metachronous cancers as well as adjacent precursor lesions. [Methods] Serially obtained formalin-fixed paraffin-embedded surgical specimens from 17 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for the enrichment of tumor and precancerous lesions, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. Based on shared and private mutations across different samples, we interrogated history of clonal evolution of these lesions. [Results] We analyzed 17 patients with multiple pancreatic cancers of 2 metachronous and synchronous, 10 metachronous, and 2 synchronous tumors. In metachronous cases, pathology for primary cancer were margin-negative in all patients, and the median interval between the initial and second surgery was 37.7 months (12 - 85 months). In addition, we analyzed 5 adjacent pancreatic intraepithelial neoplasia (PanIN) in one of these cases. We identified a median of 66 (range: 31-232) and 20 (14-42) somatic mutations in cancer and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In most cases (N=16), sharing many somatic mutations, multiple tumors had a common clonal origin. In another synchronous case, the synchronous tumors shared only one mutation, suggesting that they were clonally independent tumors. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor and cancer lesions. While multiple independent clones were observed in precancerous lesions, most of multiple cancers originated from a common ancestor. Moreover, negative pathology of the margins at the initial surgery suggested that those multiple lesions arose from distant dissemination or metastasis, rather than contiguous, intraductal invasion. [Conclusions] In conclusion, our study suggests that even early pancreatic cancer might be disseminated within the pancreas and contribute to synchronous and metachronous cancers. Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Takeuchi Yasuhide, Tomomi Nishimura, Toshihiko Masui, Kazuyuki Nagai, Takayuki Anazawa, Sachiko Minamiguchi, Hironori Haga, Norimitsu Uza, Hiroshi Seno, Yuzo Kodama, Atsuhiro Masuda, Takeshi Tanaka, Yuichi Shiraishi, Satoru Miyano, Seishi Ogawa. Genetic analysis of synchronous or metachronous multiple pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6198.

Metachronous multiple primary cancer of the pancreatic head and liver: a case of hepatocellular carcinoma 10 years after pancreatoduodenal resection

The Aim. Study of a clinical case of metachronous primary multiple cancer of the head of the pancreas and liver.Materials and methods. The work was carried out with modern domestic and foreign literature sources devoted to the problem of primary multiple malignant neoplasms. A retrospective analysis of the patient’s clinical and anamnestic data was performed, the necessary medical documentation was studied.Results. In 2011, a pancreatoduodenal resection was performed on a patient for ductal adenocarcinoma of the head of the pancreas. In 2021, an MRI scan revealed a formation in S5-S6 with dimensions up to 34x35x29 mm. According to the histological examination of the biopsy material, hepatocellular carcinoma was confirmed. Resection of the 5th segment of the liver was performed in the conditions of the NMIC Oncology in Rostov-on-Don.Conclusion. The presented case of primary multiple cancer of the head of the pancreas and hepatocellular carcinoma of the liver is of direct interest both from the point of view of oncological surgery and chemotherapy.

A Case of Lynch's Syndrome Diagnosed with Metachronous Multiple Colorectal Cancer and Crohn's Disease

A Case of Lynch's Syndrome Diagnosed with Metachronous Multiple Colorectal Cancer and Crohn's Disease

Medical guidelines for Li\u2013Fraumeni syndrome 2019, version 1.1

Li–Fraumeni syndrome (LFS) is a hereditary tumor that exhibits autosomal dominant inheritance. LFS develops in individuals with a pathogenic germline variant of the cancer-suppressor gene, TP53 (individuals with TP53 pathogenic variant). The number of individuals with TP53 pathogenic variant among the general population is said to be 1 in 500 to 20,000. Meanwhile, it is found in 1.6% (median value, range of 0–6.7%) of patients with pediatric cancer and 0.2% of adult patients with cancer. LFS is diagnosed by the presence of germline TP53 pathogenic variants. However, patients can still be diagnosed with LFS even in the absence of a TP53 pathogenic variant if the familial history of cancers fit the classic LFS diagnostic criteria. It is recommended that TP53 genetic testing be promptly performed if LFS is suspected. Chompret criteria are widely used for the TP53 genetic test. However, as there are a certain number of cases of LFS that do not fit the criteria, if LFS is suspected, TP53 genetic testing should be performed regardless of the criteria. The probability of individuals with TP53 pathogenic variant developing cancer in their lifetime (penetrance) is 75% for men and almost 100% for women. The LFS core tumors (breast cancer, osteosarcoma, soft tissue sarcoma, brain tumor, and adrenocortical cancer) constitute the majority of cases; however, various types of cancers, such as hematological malignancy, epithelial cancer, and pediatric cancers, such as neuroblastoma, can also develop. Furthermore, approximately half of the cases develop simultaneous or metachronous multiple cancers. The types of TP53 pathogenic variants and factors that modify the functions of TP53 have an impact on the clinical presentation, although there are currently no definitive findings. There is currently no cancer preventive agent for individuals with TP53 pathogenic variant. Surgical treatments, such as risk-reducing bilateral mastectomy warrant further investigation. Theoretically, exposure to radiation could induce the onset of secondary cancer; therefore, imaging and treatments that use radiation should be avoided as much as possible. As a method to follow-up LFS, routine cancer surveillance comprising whole-body MRI scan, brain MRI scan, breast MRI scan, and abdominal ultrasonography (US) should be performed immediately after the diagnosis. However, the effectiveness of this surveillance is unknown, and there are problems, such as adverse events associated with a high rate of false positives, overdiagnosis, and sedation used during imaging as well as negative psychological impact. The detection rate of cancer through cancer surveillance is extremely high. Many cases are detected at an early stage, and treatments are low intensity; thus, cancer surveillance could contribute to an improvement in QOL, or at least, a reduction in complications associated with treatment. With the widespread use of genomic medicine, the diagnosis of LFS is unavoidable, and a comprehensive medical care system for LFS is necessary. Therefore, clinical trials that verify the feasibility and effectiveness of the program, comprising LFS registry, genetic counseling, and cancer surveillance, need to be prepared.

A case report of gallbladder cancer and pancreas cystic neoplasm associated with pancreaticobiliary maljunction.

Introduction and importancePancreaticobiliary maljunction (PBM) is a rare congenital anomaly that is frequently associated with carcinoma of the biliary tract. However, there is still no clear evidence that PBM is associated with pancreatic tumors. Here we describe a case of gallbladder cancer and intraductal papillary mucinous neoplasm (IPMN) that is associated with PBM.Case presentationA 72-year-old man underwent a cholecystectomy with hepatectomy (S4a + S5) and regional lymph node dissection for gallbladder adenocarcinoma invading the front lobe branch of the hepatic artery. A pylorus-preserving pancreaticodudenectomy was also performed for pancreatic IPMN.Clinical discussionPresence of mucin type 6 (MUC6) -positive pyloric gland metaplasia in both the dilated pancreatic duct and the gallbladder background mucosa suggests that pancreatic IPMN and gallbladder cancer may have a common phenotypic origin. Additionally, analysis of 41 reported cases of pancreatic cancer associated with PBM revealed that in all metachronous multiple cancer cases, biliary tract cancer preceded the pancreatic cancer with congenital biliary dilatation accompanied by PBM. The analysis also revealed an increased proportion of pancreatic cancer cases with PBM in patients who had not undergone a flow diversion procedure located in pancreatic head.ConclusionWe show an interesting relationship between pancreatic/gallbladder cancer and PBM. More comprehensive evaluations of the whole pancreaticobiliary system in follow-up of patients with PBM is required to understand the full extent of this relationship.

A Case of Metachronous Multiple Cancers Including Double Primary Lung Cancers

A Case of Metachronous Multiple Cancers Including Double Primary Lung Cancers

A case of metachronous multiple esophageal cancer controlled by multimodality therapy after hypopharyngeal cancer operation

A case of metachronous multiple esophageal cancer controlled by multimodality therapy after hypopharyngeal cancer operation

Endoscopic findings corresponding to multiple Lugol-voiding lesions in the esophageal background mucosa.

Multiple Lugol-voiding lesions (LVLs) on Lugol chromoendoscopy can predict the development of metachronous multiple cancers in the esophagus and the head and neck regions. However, Lugol chromoendoscopy sometimes causes adverse events such as chest pain and discomfort. We therefore investigated the endoscopic findings on narrow band imaging (NBI) or blue laser imaging (BLI) that correspond to the presence of multiple LVLs in patients with esophageal squamous cell carcinoma. First, we investigated the NBI/BLI findings corresponding to individual small LVLs (one-to-one correspondence). Second, we investigated the association between the grade of multiple LVLs and the five endoscopic findings, including multiple foci of dilated vessels (MDV), multiple small brownish areas without microvascular irregularity, and a nonuniform color tone. One-to-one correspondence of endoscopic findings was analyzed in 106 small LVLs. The main findings matched with small LVLs were a focus of dilated vessels (44 lesions), a small brownish area (17 lesions), and a small brownish area with a focus of dilated vessels (19 lesions). The relationship between multiple LVLs and each finding assessed by NBI/BLI was assessed in 155 patients. Multivariate logistic regression indicated that the presence of MDV was the only finding independently associated with multiple LVLs (P<0.01). The presence of MDV in the noncancerous background esophageal mucosa was significantly associated with multiple LVLs. This pilot study demonstrates that MDV has the potential to be a new risk factor for the development of metachronous multiple esophageal squamous cell carcinoma.

PS01.141: TREATMENT STRATEGY FOR THORACIC ESOPHAGEAL CARCINOMA COMPLICATED WITH HEAD AND NECK CANCER

Abstract Background The frequency of complication of head and neck cancer to thoracic esophageal cancer is high, and treatment methods and their order will be determined from the viewpoints of curability and quality of life. Methods We review the course of three cases we experienced and give some consideration. Results [Case 1] A 68-year-old man with cT2N0M0 Mt esophageal cancer and cT2N0M hypopharyngeal cancer. Two courses of DCF (DOC + CDDP + 5 FU) made the hypopharyngeal lesion CR. After thoracoscopic subtotal esophagectomy with three fields lymph nodes dissection, one course of DCF was added, and CRT (60 Gy/30 fr) combined with weekly CBDCA was administered to the neck. The case is alive without recurrence for 5 years and 9 months from the start of treatment. [Case 2] A 72-year-old man with cT2N0M0 Mt esophageal cancer and cT3N2bM0 hypopharyngeal cancer. Three courses of TCS (DOC + CBDCA + TS-1) made the hypopharyngeal lesion CR. After thoracoscopic subtotal esophagectomy, CRT (60 Gy) combined with biweekly CDDP was administered to the neck. The case is alive without recurrence for 5 years and 7 months. [Case 3] A 63-year-old man with LtMt multiple esophageal cancer (4 lesions, cT3N2M0) and cT2N1M0 hypopharyngeal cancer, and cT1bN0M0 gastric cancer. Though the hypopharyngeal cancer remained in PR after 2 courses of DCF, aiming at larynx preservation, thoracoscopic subtotal esophagectomy was performed, and gastric lesion was excised at the time of creating the stomach tube. After the operation, CRT (70 Gy) combined with weekly CBDCA made the hypopharyngeal lesion CR. Another cancer was demonstrated in the residual esophagus in 1 year and 3 months and surgical resection of the residual esophagus and the larynx with reconstruction with free jejunal transplantation was performed. The case is alive without recurrence for 2 years and 5 months after reoperation. Conclusion Salvage surgery may be necessary for metachronous multiple cancer cases, non-CR cases, and local recurrence cases as in case 3. We think that we can aim at compatibility of curability and maintenance of quality of life by treatment method which aims at preservation of larynx, combining with chemoradiotherapy and esophagectomy. Disclosure All authors have declared no conflicts of interest.

異時性多発肝外胆管癌の1例

異時性多発肝外胆管癌の1例

Scheduled endoscopic surveillance controls secondary cancer after curative endoscopic resection for early gastric cancer: a multicentre retrospective cohort study by Osaka University ESD study group

BackgroundAfter endoscopic submucosal dissection (ESD) of early gastric cancer (EGC), patients are at high risk for synchronous or metachronous multiple gastric cancers.ObjectiveTo elucidate the time at which multiple cancers develop...

Elimination of esophageal multiple precancerous lesions by chemotherapy: potential chemoprevention of metachronous multiple cancer development after curative treatment

Background Dysplastic squamous epithelium is a precancerous lesion for squamous cell carcinoma. It is often present in the esophagus and head and neck region, and can be visualized as a Lugol-voiding lesion (LVL) by iodine chromoendoscopy. However, effective treatment for such dysplastic epithelia has not yet been developed.

Tu1627 Clinical Features of Metachronous Multiple Cancers in the Esophagus and Primary Cancers in the Other Organs After Endoscopic Resection for Superficial Esophageal Cancer

The outcome of patients with esophageal cancer after endoscopic resection has recently improved because of advancement in endoscopic instruments and progressive endoscopic procedures. During follow-up, it has been noted that the number of metachronous squamous cell carcinoma in the esophagus (MEsCa) or primary cancers in the other organs (MPCa) have been increasing. So the aim of this study was to clarify the clinical features of those metachronous cancers, especially at the point of association between the development of metachronous cancers and multiple Lugol-voiding lesions (mLVLs).

Submucosal Dissection for Superficial Pharyngeal Cancer

Objective: We have previously reported that narrow band imaging (NBI) combined with magnifying endoscopy is useful in detecting early superficial pharyngeal cancers, which are difficult to detect with a standard endoscopy. In this study, we investigated the usefulness of submucosal dissection for such superficial lesions of pharyngeal cancer retrospectively. Method: Fifty patients with superficial pharyngeal cancer were treated since September 2007. Under general anesthesia, a curved laryngoscope was inserted trans-orally, the extent of the lesion was determined by the NBI endoscope, and the lesion was dissected with an orally inserted curved electric knife. Results: Tracheostomy was performed in 5 cases, which had synchronous multiple lesions in the hypopharynx. Regarding adverse effects, postoperative bleeding occurred in one case, which needed emergency tracheostomy. With a median follow-up period of 20 months, metachronous multiple laryngo-pharyngeal cancer occurred in 4 cases and recurrence occurred in 2 cases. All the metachronous cancer cases and the recurrent case were controlled with additional endoscopic submucosal dissection. The cause-specific survival rates at 2 years were 100%. All the patients retained their pharynx and their speaking, breathing, and swallowing functions. Conclusion: Endoscopic submucosal dissection for early pharyngeal cancer allows excellent survival and preservation of swallowing and voice functions. Early detection of superficial pharyngeal cancer with narrow band imaging technology and treatment with endoscopic submucosal dissection can be a new treatment strategy for head and neck cancer.

1173 Surveillance Strategy After Endoscopic Submucosal Dissection for Early Gastric Cancer: A Multicenter Study by Osaka University ESD Study Group

Endoscopic submucosal dissection (ESD) has been accepted as a treatment for early gastric cancer (EGC). However, it is known that the patient after endoscopic treatment of EGC is at risk of synchronous and metachronous multiple cancers, even though initial lesion is completely resected, and there is not enough evidence concerning surveillance strategy after ESD for EGC. The aim of this multicenter study is to clarify the surveillance strategy after ESD by assessing the incidence of multiple cancers during follow-up.