Billroth-I anastomosis in distal subtotal gastrectomy for non-early gastric adenocarcinoma.

BACKGROUND: Billroth-I (B-I) anastomosis is known as a simple and physiological reconstruction method after distal subtotal gastrectomy for early gastric cancer. Yet its role and oncological validity in non-early gastric adenocarcinoma (NEGA) remain unclear. PATIENTS AND METHODS: Patients with NEGA without distant metastases operated between May 2004 and December 2020 were included. Surgical and oncologic outcomes of distal subtotal gastrectomy were studied in patients with B-I and Billroth II (B-II) anastomoses. Propensity score matching (PSM) was used to adjust for age, gender, tumor size, location, resection type, pT and pN stages. RESULTS: A total number of 332 patients underwent distal subtotal gastrectomy for NEGA followed by B-I and B-II anastomoses in 165 (49.7%) and 167 (50.3%) cases, respectively. B-I was applied in patients with smaller tumor size, less advanced pT stage and tumor location in the gastric antrum. The former was also associated with lower proportion of multiorgan resections and shorter operative time. After PSM, these differences became statistically non-significant, except operative time. Postoperative outcomes were similar before and after PSM. Greater lymph node yield was observed in patients with B-I anastomosis. The incidence of recurrence, specifically local recurrence was lower in patients with B-I anastomosis. However, this association was not statistically significant in the multivariable model. Median overall survival was 38 months, without significant differences between the groups. CONCLUSIONS: The use of B-I anastomosis after distal subtotal gastrectomy for NEGA is associated with satisfactory surgical and oncologic outcomes. B-I anastomosis should be considered as a valid reconstruction method in these patients.

A real-world study comparing perioperative chemotherapy and EGFR-tyrosine kinase inhibitors for treatment of resected stage III EGFR-mutant adenocarcinoma.

BACKGROUND: The patient population with stage III non-small-cell lung cancer (NSCLC) is heterogeneous, with varying staging characteristics and diverse treatment options. Despite the potential practice-changing implications of randomized controlled trials evaluating the efficacy of perioperative epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), concerns have been raised due to conflicting overall survival (OS) results. Few real-world studies have examined the survival outcomes of patients with resected EGFR-mutant stage III adenocarcinoma receiving perioperative chemotherapy and EGFR-TKIs. METHODS: In this retrospective observational study, we enrolled patients with resected stage III adenocarcinoma with EGFR mutations between January 2011 and December 2021. Patients were classified into two groups: perioperative chemotherapy and perioperative EGFR-TKIs. Outcomes and prognostic factors were analyzed using Cox proportional hazards regression analysis. RESULTS: Eighty-four patients were enrolled in the analysis. Perioperative EGFR-TKIs led to longer progression-free survival (PFS) than chemotherapy (38.6 versus 14.2 months; p = 0.019). However, only pathological risk factors predicted poor PFS in multivariate analysis. Patients receiving perioperative chemotherapy had longer OS than those receiving EGFR-TKIs (111.3 versus 50.2 months; p = 0.052). Multivariate analysis identified perioperative treatment with EGFR-TKIs as an independent predictor of poor OS (HR: 3.76; 95% CI: 1.22-11.54). CONCLUSION: Our study demonstrates that chemotherapy should be considered in the perioperative setting for high-risk patients, when taking pathological risk factors into consideration, and that optimized sequencing of EGFR-TKIs might be the most critical determinant of OS.

Assessment of the level III of Inoue by preoperative endoscopic ultrasound and elastography: a novel approach to predict a periarterial divestment technique in borderline resectable (BR) or locally advanced (LA) pancreatic adenocarcinoma-How I do it.

BACKGROUND: Periarterial divestment is a surgical technique to approach borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC) with arterial involvement. There are no reports in the literature regarding the role of endoscopic ultrasound and elastography (EUS-EG) in exploring the integrity of Inoue's level III and its correlation with the periarterial divestment technique feasibility. Our research is aimed at exploring the role of EUS-EG in this scenario. METHODS: We describe our approach to Inoue's level II by EUS-EG in patients with BR and LA pancreatic cancer patients after neoadjuvant chemotherapy. RESULTS: Between June 2019 and December 2020, four patients out of 25 were eligible to perform a preoperative EUS-EG. In all cases, Inoue's level III integrity was corroborated by EUS-EG and confirmed posteriorly in the surgical scenario where a periarterial divestment technique was feasible. Vein resections were necessary in all cases, with no need for arterial resection. An R0 (> 1 mm) margin was achieved in all patients, and the histopathological assessment showed the presence of neurovascular tissue at the peripheral arterial margin. CONCLUSION: Preoperatively, EUS-EG is a novel approach to explore the integrity of Inoue's level III and could be helpful to preclude a periarterial divestment technique in borderline resectable or locally advanced pancreatic adenocarcinoma with arterial involvement.

Platelets as a prognostic factor for patients with adenocarcinoma of the gastroesophageal junction.

OBJECTIVE: The aim of this study was to investigate the prognostic role of plasma platelet count (PLT), mean platelet volume (MPV), and the combined COP-MPV score in patients with resectable adenocarcinomas of the gastroesophageal junction. BACKGROUND: Platelet activation, quantified by PLT and elevated MPV, plays an essential part in the biological process of carcinogenesis and metastasis. An increased preoperative COP-MPV is associated with poor survival in various tumor entities. METHODS: Data of 265 patients undergoing surgical resection for adenocarcinoma of the gastroesophageal junction were abstracted. COP-MPV score was defined for each patient. Utilizing univariate and multivariate Cox proportional hazard analyses, survival was determined. RESULTS: In univariate analysis, elevated PLT (HR 3.58, 95% CI 2.61-4.80, p<0.001) and increased COP-MPV (HR 0.27, 95% CI 0.17-0.42, p<0.001 and HR 0.42, 95% CI 0.29-0.60, p<0.001) significantly correlated with shorter patients' overall and disease-free survival, for all 256 patients, as well as in the subgroups of neoadjuvantly treated (p<0.001) and primarily resected patients (p<0.001). COP-MPV remained a significant prognostic factor in multivariate analysis for OS. However, PLT alone showed significant diminished OS and DFS in all subgroups (p<0.001) in univariate and multivariate analysis. CONCLUSION: PLT is a potent independent prognostic biomarker for survival in a large prospective cohort of patients with resectable adenocarcinoma of the gastroesophageal junction. Additionally, we confirm that the COP-MPV score is significantly associated with worse outcome in these patients, but has no benefit in comparison to PLT.

A prospective Canadian gastroesophageal cancer database: What have we learned?

BACKGROUND: Minimal literature exists on outcomes for Canadian patients with gastroesophageal adenocarcinoma (GEA). The objective of our study was to establish a prospective clinical database to evaluate demographic characteristics, presentation and outcomes of patients with GEA. METHODS: Patients diagnosed with GEA were recruited from Jan. 30, 2017, to Aug. 30, 2020. Data collected included demographic characteristics, presentation, treatment and survival. A multivariable model for overall survival in patients treated with curative intent was created using sex, lymph node status, resection margin status, age and tumour location as variables. RESULTS: A total of 122 patients with adenocarcinoma of the stomach or gastroesophageal junction were included. Median age was 65 years (interquartile range [IQR] 59-74), 70% of patients were male and 26% were born outside of Canada. Median follow-up time was 14.5 (IQR 8.0-31.0) months. Following staging computed tomography scanning, 88% of patients were deemed to have potentially resectable disease. Eighty-one (76%) received staging laparoscopy and 74 (61%) were treated with curativeintent surgery. Forty-six (62%) patients had nodal metastases. The median number of nodes harvested was 22 (IQR 18-30). The R0 resection margin rate was 82%. The 3-year overall survival for patients who received curative-intent treatment was 63% and 38% for all patients. On multivariable analysis, female sex (hazard ratio [HR] 3.88, p = 0.01), positive nodal status (HR 3.58, p = 0.02), positive margins (HR 3.11, p = 0.03) and tumour location (HR 3.00, p = 0.03) were associated with decreased overall survival. CONCLUSION: Many of the patients with GEA in this study presented with advanced disease, and only 61% were offered curative-intent surgery. A prospective multicentre national GEA database is now being established.

Correlation Between Intranodular Vessels and Tumor Invasiveness of Lung Adenocarcinoma Presenting as Ground-glass Nodules: A Deep Learning 3-Dimensional Reconstruction Algorithm-based Quantitative Analysis on Noncontrast Computed Tomography Images.

PURPOSE: To evaluate the role of quantitative features of intranodular vessels based on deep learning in distinguishing pulmonary adenocarcinoma invasiveness. MATERIALS AND METHODS: This retrospective study included 512 confirmed ground-glass nodules from 474 patients with 241 precursor glandular lesions (PGL), 126 minimally invasive adenocarcinomas (MIA), and 145 invasive adenocarcinomas (IAC). The pulmonary blood vessels were reconstructed on noncontrast computed tomography images using deep learning-based region-segmentation and region-growing techniques. The presence of intranodular vessels was evaluated based on the automatic calculation of vessel prevalence, vascular categories, and vessel volume percentage. Further comparisons were made between different invasive groups by the Mantel-Haenszel χ 2 test, χ 2 test, and analysis of variance. RESULTS: The detection rate of intranodular vessels in PGL (33.2%) was significantly lower than that of MIA (46.8%, P = 0.011) and IAC (55.2%, P < 0.001), while the vascular categories were similar (all P > 0.05). Vascular changes were more common in IAC and MIA than in PGL, mainly in increased vessel volume percentage (12.4 ± 19.0% vs. 6.3 ± 13.1% vs. 3.9 ± 9.4%, P < 0.001). The average intranodular artery and vein volume percentage of IAC (7.5 ± 14.0% and 5.0 ± 10.1%) was higher than that of PGL (2.1 ± 6.9% and 1.7 ± 5.8%) and MIA (3.2 ± 9.1% and 3.1 ± 8.7%), with statistical significance (all P < 0.05). CONCLUSIONS: The quantitative analysis of intranodular vessels on noncontrast computed tomography images demonstrated that the ground-glass nodules with increased internal vessel prevalence and volume percentages had higher possibility of tumor invasiveness.

[Perioperative management and operative treatment of malignant tumor of anal canal merging severe abdominal protuberance].

Objective: To report the perioperative management and robot-assisted minimally invasive surgery results of one case with malignant tumor of anal canal combined with severe abdominal distention. Methods: A 66-year-old male suffer from adenocarcinoma of anal canal (T3N0M0) with megacolon, megabladder and scoliosis. The extreme distention of the colon and bladder result in severe abdominal distention. The left diaphragm moved up markedly and the heart was moved to the right side of the thoracic cavity. Moreover, there was also anal stenosis with incomplete intestinal obstruction. Preoperative preparation: fluid diet, intravenous nutrition and repeated enema to void feces and gas in the large intestine 1 week before operation. Foley catheter was placed three days before surgery and irrigated with saline. After relief of abdominal distention, robotic-assisted abdominoperineal resection+ subtotal colectomy+colostomy was performed. Results: Water intake within 6 hours post-operatively; ambulance on Day 1; anal passage of gas on Day 2; semi-fluid diet on Day 3; safely discharged on Day 6. Conclusion: Robotic-assisted minimally invasive surgery is safe and feasible for patients with malignant tumor of anal canal combined with severe abdominal distention after appropriate and effective preoperative preparation to relieve abdominal distention.

Incidence and survival of adenocarcinoma with mixed subtypes in patients with colorectal cancer.

BACKGROUND: Limited attention was paid to adenocarcinoma with mixed subtypes (AM) of the colon and rectum due to its low incidence. This study aims to assess the frequency and survival rates of tumors in the population. METHODS: The data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2019. The incidence of tumors was evaluated based on patient gender, age, race, and location. Univariate and multivariate Cox analyses were performed to identify risk factors associated with tumor survival. Additionally, a nomogram was constructed using these risk factors to predict cancer-specific survival (CSS) at 1, 2, and 3 years. Receiver operating characteristic (ROC) and calibration curves were applied to examine the model's accuracy. RESULTS: The overall incidence of colorectal AM reached its highest level in 2016 (2.350 (95% CI: 2.241-2.462)). AM is more frequent in elderly patients and predominantly located in the rectum. By forest plot for multivariable Cox regression analysis, patient age, the number of regional positive lymph nodes and lymph nodes removed, tumor N/M stage, and postoperative chemotherapy were identified as independent risk indicators for CSS. Nomogram was constructed and validated as a feasible prediction model of CSS in patients with colorectal AM. CONCLUSION: The presence of colorectal AM in elderly patients, particularly in the rectum, is frequent and often associated with poor prognosis. Our nomograms can offer a relatively accurate prediction of CSS of patients with AM after tumor resection.

Impact of para aortic lymph node removal on survival following resection for pancreatic adenocarcinoma.

INTRODUCTION: For PDAC patients undergoing resection, it remains unclear whether metastases to the paraaortic lymph nodes (PALN+) have any prognostic significance and whether metastases should lead to the operation not being carried out. Our hypothesis is that PALN + status would be associated with short overall survival (OS) compared with PALN-, but longer OS compared with patients undergoing surgical exploration only (EXP). METHODS: Patients with registered PALN removal from the nationwide Danish Pancreatic Cancer Database (DPCD) from May 1st 2011 to December 31st 2020 were assessed. A cohort of PDAC patients who only had explorative laparotomy due to non-resectable tumors were also included (EXP group). Survival analysis between groups were performed with cox-regression in a multivariate approach including relevant confounders. RESULTS: A total of 1758 patients were assessed, including 424 (24.1%) patients who only underwent explorative surgery leaving 1334 (75.8%) patients for further assessment. Of these 158 patients (11.8%) had selective PALN removal, of whom 19 patients (12.0%) had PALN+. Survival analyses indicated that explorative surgery was associated with significantly shorter OS compared with resection and PALN + status (Hazard Ratio 2.36, p < 0.001). No difference between PALN + and PALN- status could be demonstrated in resected patients after controlling for confounders. CONCLUSION: PALN + status in patients undergoing resection offer improved survival compared with EXP. PALN + should not be seen as a contraindication for curative intended resection.

[Application of robotic (or laparoscopic) surgery combined with colonoscopy in T1 stage colorectal cancer surgery: 13 cases].

Objective: To investigate the feasibility and safety of a robotic surgical system (or laparoscopy) in combination with colonoscopy (combined) for the treatment of stage T1N0M0 colorectal cancer. Methods: This was a descriptive case series. Indications for combined dual-scope surgery in this study were as follows: (1) preoperative colonoscopic examination of lesions in the middle and upper rectum and colon with pathologically confirmed high-grade intraepithelial neoplasia, intramucosal adenocarcinoma, or adenocarcinoma; (2) no distant or local lymph node metastases; and (3) endoscopic ultrasound and magnetic resonance imaging evidence of tumor invasion of the mucosal or submucosal, but not the muscular, layer (i.e., T1). The clinical data of 13 patients with stage T1 colorectal cancer who had undergone dual-scope combined resection using a robotic surgery system or laparoscope-assisted combined colonoscopy surgery at the First Affiliated Hospital of Zhengzhou University from April to October 2022 were retrospectively collected, including 6 males and 7 females, with a median age of 59 (48~88) years old. The tumors were located in the upper and middle rectum in six patients, in the sigmoid colon in three, and in the ascending colon in four. The median maximum diameter of the tumors was 3.0 (1.8-5.0) cm. The surgery was performed by a robotic surgery system (or laparoscopy) with peritumoral D1 lymph node dissection at the first station in the tumor area. The tumors were resected under direct vision and the defects in the intestinal wall were using a robotic surgery system (or laparoscopy). A robotic surgery system was combined with colonoscopy in eight cases and laparoscopy combined with colonoscopy in the remaining five. Studied variables includes surgical and pathological features, postoperative factors, and outcomes. Results: Surgery was successful in all 13 patients with no need for conversion to open surgery or intraoperative blood transfusion. The median operating time was 85 (60-120) minutes, median intraoperative bleeding 3 (2-5) mL, median number of lymph nodes harvested 3 (1-5), and the median circumferential resection margin 0.8 (0.5-1.0) cm. Postoperative pathological examination showed lymph node metastasis in one patient, who therefore underwent additional radical surgery. The median postoperative time to ambulation was 1 (1-2) days. The urinary catheters of all patients were removed 1 day after surgery and the median length of stay was 4 (3-5) days. No abdominal infection, anastomotic leakage or bleeding occurred in any of the study patients. The median follow-up time was 10 (6-12) months, during which no tumor recurrence or metastasis was found, and the quality of life was satisfactory. Conclusions: The combination of two minimally invasive platforms, a robotic surgery system (or laparoscopy) and colonoscopy, is safe and feasible for resection of stage T1 colorectal cancer and has a good short-term prognosis.

Feline minor salivary gland adenocarcinoma: retrospective case series and literature review.

CASE SERIES SUMMARY: Salivary gland adenocarcinoma, of major or minor salivary gland origin, is an uncommon tumor in cats. This article describes the clinical features, morbidity and survival rates of four cats with salivary gland adenocarcinoma arising from minor salivary gland tissue. Medical records from a private multicenter dentistry and oral surgery practice were reviewed for the period between 2007 and 2021. Four cats were included in this retrospective case series study, with oral masses on either the right or left caudal mandibular labial buccal mucosa. The inclusion criteria included a diagnosis of salivary gland adenocarcinoma in an anatomical location with lack of involvement of a major salivary gland, complete medical history and a follow-up of at least 6 months. The age range of the cats was 9-15 years; three of the cats were castrated males and one was a spayed female. Curative intent surgery was performed in three cats, whereas palliative surgery (debulking) owing to extensive soft tissue invasion was performed in one cat. Survival times were in the range of 210-1730 (mean 787) days. All four cats were euthanized owing to local recurrence and decreased quality of life, regardless of treatment modality. RELEVANCE AND NOVEL INFORMATION: There are limited documented studies reporting the prevalence of salivary gland neoplasia affecting minor disseminated glands in the oral cavity of feline patients. Salivary gland adenocarcinoma should be a differential in cats presenting with caudal labial masses. Surgical resection has been the recommended treatment for salivary gland neoplasia of major salivary gland origin. According to this current case series, we propose that early aggressive surgical treatment with wide surgical margins should be performed for cats with salivary gland adenocarcinoma of minor salivary gland origin. Surgery increased the quality and duration of life; however, each patient was euthanized owing to local recurrence and morbidity.

Radical antegrade modular pancreatosplenectomy (RAMPS) versus standard retrograde pancreatosplenectomy (SRPS) for resectable body and tail pancreatic adenocarcinoma: protocol of a multicenter, prospective, randomized phase III control trial (CSPAC-3).

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy. Radical surgical resection offers the only potential cure. There is increasing agreement that radical antegrade modular pancreatosplenectomy (RAMPS) may benefit patients with tumors in the body and tail of the pancreas. To address this, the Chinese Study Group for Pancreatic Cancer (CSPAC)-3 trial is proposed to compare the effect of RAMPS and standard retrograde pancreatosplenectomy (SRPS) on patient survival and preoperative safety METHODS: The randomized controlled trial will be multicenter and two-armed with blinded outcomes and intention-to-treat analysis. Three hundred patients with resectable body and tail pancreatic adenocarcinoma will be enrolled and randomly assigned to RAMPS or SRPS. Adjuvant chemotherapy based on an initial regimen will be recommended 4-6 weeks after surgery if no serious complication occurs. The hypothesis that RAMPS improves survival outcomes compared with SRPS will be tested using a superiority trial. The primary outcome will be overall survival (OS). Secondary outcomes will include recurrence-free survival (RFS), R0 resection rate, the number of harvested lymph nodes, postoperative complications, and quality of life scores. DISCUSSION: The use of RAMPS has increased over the past decade. It is reported that RAMPS is superior to SRPS in improving both the rate of R0 resection and lymph node yield. Despite these advantages, however, there is little high-level documentation of the superiority of RAMPS in terms of survival and this needs to be investigated. To address this issue, CSPAC has instigated the first prospective, randomized phase III control trials, aiming to explore the optimal surgical strategy for improving the prognosis and OS of patients with left-sided pancreatic cancer Trial registration Chinese Clinical Trial Registry ChiCTR2100053844; pre-results. Registered on December 1, 2021.

[A Case of Primary Duodenal Adenocarcinoma in the Third Portion Treated with Partial Duodenectomy and Adjuvant Chemotherapy].

A 69-year-old man was referred for vomiting. CT and upper gastrointestinal endoscopy revealed a circumferential stenotic lesion in the third portion of the duodenum, and partial duodenectomy and lymph node dissection were performed for the diagnosis of duodenal adenocarcinoma. The histopathological diagnosis was pT3, pN0, pStage ⅡA(UICC 8th)well differentiated tubular adenocarcinoma. The patient was treated with FOLFOX as adjuvant chemotherapy and is alive 2 years and 4 months postoperatively without recurrence. Primary duodenal adenocarcinoma in the third portion is rare, and further case experience is required for selection of the operation and adjuvant therapy.

[A Case of Advanced Esophagogastric Junction Adenocarcinoma with Enlarged Lymph Node Metastases of the Middle Mediastinum and Intraperitoneal That Exhibited pCR by Preoperative SOX Therapy].

A 79-year-old man was diagnosed with esophagogastric junction adenocarcinoma, cT3N3M0, cStage Ⅲ, including enlarged lymph node metastases(Bulky N)in the middle mediastinum and intraperitoneal. A total of 2 cycles of S-1 plus oxaliplatin(SOX)was administered. After neoadjuvant chemotherapy, the primary tumor and enlarged lymph nodes had greatly decreased in size. Subsequently, thoracoscopic subtotal esophagectomy and reconstruction with a gastric tube were performed. Histopathological examinations showed no residual cancer cells in the primary lesion and dissected lymph nodes (pathological complete response). Preoperative chemotherapy containing SOX could be a useful treatment strategy for patients with esophagogastric junction adenocarcinoma with enlarged lymph node metastasis.

Adenocarcinoma arising from heterotopic pancreas at the first portion of the duodenum: a case report.

Malignant transformation of a heterotopic pancreas in the duodenum is very rare. To our knowledge, only 15 cases have been reported worldwide, including the present case. We herein report a rare case of malignant transformation of a heterotopic pancreas in the duodenum along with a review of the literature.A 65-year-old man was admitted to our hospital for evaluation of dyspepsia and vomiting. Esophagogastroduodenoscopy showed a stricture of the duodenal bulb. Laparoscopic distal gastrectomy was performed. Although a duodenal tumor had not been suspected, histopathological examination of the surgical specimen showed adenocarcinoma arising from a heterotopic pancreas (Heinrich type III) in the duodenum. Four months postoperatively, the patient received adjuvant chemotherapy. He was still alive without recurrence at 24 months of follow-up.Adenocarcinoma arising in a heterotopic pancreas is rare; therefore, preoperative diagnosis is difficult to obtain. Effective management of a heterotopic pancreas depends on the presence or absence of symptoms. Awareness of the possibility of malignant change in a heterotopic pancreas of the duodenum prior to surgery is helpful for the diagnosis and appropriate management of such patients.

The Prognostic Utility of the Metastatic Lymph Node Ratio and the Number of Regional Lymph Nodes Removed from Patients with Small Bowel Adenocarcinomas.

Background and Objectives: Small bowel adenocarcinomas (SBAs) are rare tumors of the gastrointestinal system. Lymph node metastasis in patients with curatively resected SBAs is associated with poor prognosis. In this study, we determined the prognostic utility of the number of removed lymph nodes and the metastatic lymph node ratio (the N ratio). Materials and Methods: The data of 97 patients who underwent curative SBA resection in nine hospitals of Turkey were retrospectively evaluated. Univariate and multivariate analyses of potentially prognostic factors including the N ratio and the numbers of regional lymph nodes removed were evaluated. Results: Univariate analysis showed that perineural and vascular invasion, metastatic lymph nodes, advanced TNM stage, and a high N ratio were significant predictors of poor survival. Multivariate analysis revealed that the N ratio was a significant independent predictor of disease-specific survival (DSS). The group with the lowest N ratio exhibited the longest disease-free survival (DFS) and DSS; these decreased significantly as the N ratio increased (both, p < 0.001). There was no significant difference in either DFS or DSS between groups with low and high numbers of dissected lymph nodes (i.e., <13 and ≥13) (both, p = 0.075). Conclusions: We found that the N ratio was independently prognostic of DSS in patients with radically resected SBAs. The N ratio is a convenient and accurate measure of the severity of lymph node metastasis.

Effect of tumor size on prognosis in colorectal cancer.

AIM: This study aimed to reveal the effect of tumor size on overall survival and disease-free survival. MATERIAL AND METHODS: This study retrospectively evaluated the data of 593 patients who underwent colorectal surgery for colorectal cancer (CRC) between May 2012 and December 2018. The patients were divided into two groups based on their tumor size; those with a tumor size <5 cm were grouped as group 1 and those with a tumor size ≥ 5 cm were grouped as group 2. RESULTS: The present study included 222 patients with colorectal adenocarcinoma. The median follow-up period of the patients was 36.0 (1.4-107.4) months, mean tumor size was 5.1±2.3 cm, and number of patients with a tumor size of ≥5 cm was 117 (52.7%). There were statistically significant differences between the groups in terms of overall survival (Log-Rank = 12.559, p<0.001). DISCUSSION: According to the American Joint Committee on Cancer's Cancer Staging Manual (8th edition), the CRC staging system considers the tumor's depth of invasion of the intestinal wall but not the tumor's size. Moreover, it considers the size of the tumors developing in the parenchymal organs (breasts and lungs) but not tumors developing in luminal organs (stomach, colon, etc.). CONCLUSIONS: Tumor size ≥5 cm was found to be a risk factor for poor prognosis. To a certain extent, we believe that this study will aid in elucidating the link between tumor size in and prognosis of patients with CRC. KEY WORDS: Colorectal cancer, Prognosis, Tumor size.