Objectives: Serum carcinoembryonic antigen (CEA) has been widely used for postoperative surveillance for colorectal cancer. However, serum CEA has a poor diagnostic accuracy for detecting recurrence. We tested the hypothesis that determining cutoff values according to the preoperative serum CEA levels would enhance the diagnostic accuracy. Methods: Serum CEA was measured before and 1-6 months after surgery in 783 patients with curatively resected colon cancer from 2005 through 2013. The cutoff values during surveillance were determined separately according to preoperative serum CEA levels. Results: In patients with negative preoperative serum CEA, the diagnostic accuracy for recurrence was 89.1% when a postoperative cutoff value was set at 5 ng/mL. However, in patients with positive preoperative serum CEA, the diagnostic accuracy was 58.4% when a postoperative cutoff value was set at 5 ng/mL, and was 75.6% when a cutoff value was set at 8 ng/mL. Among patients with positive preoperative serum CEA, the recurrence-free survival rate was significantly lower in patients with a serum CEA of ≥8 ng/mL than those with a serum CEA of <8 ng/mL (p = 0.0018). Conclusions: The diagnostic accuracy of serum CEA for recurrence is enhanced by separately setting cutoff values according to preoperative serum CEA.

Objectives: Carcinoembryonic antigen (CEA) is widely used for postoperative surveillance of colon cancer. Even if serum CEA is negative at initial surgery, it may turn positive at recurrence. We investigated the relation between serum CEA levels and the immunohistochemical staining status of CEA in the primary and resected metastatic tissues. Methods: Out of 224 patients with recurrent colon cancer between 1998 and 2012, we studied 46 patients in whom serum CEA levels were measured and immunohistochemical staining for CEA was possible in the primary and metastatic tissues. Results: The positive rate of serum CEA did not differ between initial surgery and recurrence, regardless of whether the cutoff value was set at 5 or 10 ng/ml (p = 0.829, p = 0.671). There was no relation between the CEA staining status and serum CEA level at initial surgery. However, the CEA staining status of metastatic tissue was significantly related to the serum CEA level at recurrence (p = 0.0046 and p = 0.0026). Conclusions: The immunohistochemical staining status of CEA in metastatic tissue is closely related to the serum CEA level. This finding suggests that serum CEA levels are influenced not only by the CEA production capacity of cancer cells but also by the ability of the surrounding tissue to release CEA into the blood.

BackgroundRectal cancer is associated with a higher rate of surgical complications. The ability to predict the risk of complications before treatment would facilitate the design of personalized treatment strategies optimally suited for each patient.MethodsWe retrospectively studied 260 patients with rectal cancer who underwent radical surgery to examine the relations between complications and 5 types of risk scores.ResultsComplications developed in 56 patients (21.5%). Nineteen patients had infectious complications, 16 had intestinal obstruction, and 12 had other complications. Twelve patients out of 187 patients who received low anterior resection had anastomotic leakage. Estimation of Physiologic Ability and Surgical Stress Comprehensive Risk Score (E-PASS CRS) and Neutrophil-to-lymphocyte Ratio (NLR) were significantly related to all complications, infectious complications, and anastomotic leakage. Surgical Apgar Score was significantly related to infectious complications. Prognostic Nutritional Index was significantly related to all complications and intestinal obstruction. Colorectal Physiologic and Operative Severity Score for the Enumeration of Mortality and Morbidity was significantly related to all complications, and infectious complications. A multivariate analysis showed that body-mass index, E-PASS CRS, and NLR were independent risk factors for anastomotic leakage. In particular, NLR was the only score that could be evaluated before surgery.ConclusionsFive types of risk scores were useful methods for evaluating the risks of complications in patients with rectal cancer. NLR is a score that can be evaluated before surgery and predicted the risk of anastomotic leakage, suggesting that it is useful for assessing the need for a diverting colostomy.

Regorafenib and trifluridine/tipiracil (TAS-102) are novel antitumor agents for patients with refractory metastatic colorectal cancer. However, it is unclear which patients may derive a survival benefit from these drugs in real-life clinical practice. We evaluated retrospectively the efficacy and safety of regorafenib and TAS-102 at a single institution between June 2013 and November 2015. Cox regression analysis was carried out to obtain predictive scores (the nearest integers of hazard ratio) for survival benefit. Forty-four patients treated with regorafenib or TAS-102 were included in the analysis; among them, 17 received crossover treatment. The median overall survival (OS) was 9.1 months for regorafenib and 9.3 months for TAS-102, and the corresponding values after crossover were 7.1 and 5.3 months, respectively. OS was not correlated to relative dose intensity, but was proportional to the total administered dose of each drug. Adverse events were tolerable even after crossover. We identified three variables as significant for prediction of OS with good discrimination (C-statistic=0.70): Poor Eastern Cooperative Oncology Group performance status, time since diagnosis of metastatic disease ≤18 months, and previous chemotherapy continued ≥2 months beyond progression were all predictors of poor OS. Regorafenib and TAS-102 can be recommended for patients with better performance status and slow progression of metastatic disease. Optimal survival benefit was provided by prompt administration of either drug after failure of previous chemotherapy, with flexible titration to the optimal dose for each individual patient.

PurposeIn stage II colon cancer, patients with many retrieved lymph nodes (LNs) have been reported to have better oncological outcomes. We tested the hypothesis that the greater number of retrieved LNs is related to a larger LN size.MethodsThe subjects comprised 320 patients with stage II colon cancer who underwent curative resection. All operations were elective and were performed by the same surgeons. The maximum long axis and short axis diameters of LNs were measured on hematoxylin-eosin-stained specimens.ResultsA total of 4,744 LNs were evaluated. The number of retrieved LNs was 14.8 ± 10.1 (mean ± SD). The long axis diameter was 4.8 ± 2.6 mm, with a median value of 4.3 mm, a maximum value of 20.4 mm, and a minimum value of 0.6 mm. The corresponding short axis diameters were 3.4 ± 1.7, 3.0, 15.1, and 0.5 mm, respectively. The highest correlation coefficient for the association with the number of LNs was obtained for the maximum value of the long axis diameter (0.59). Multivariate analysis revealed that age, tumor location, pathological T stage, and the maximum long axis diameter were independent prognostic factors. The number of LNs was not a significant factor. Patients with less than 12 LNs and a maximum long axis diameter of less than 10 mm had significantly poorer outcomes (p < 0.001).ConclusionIn patients with stage II colon cancer, the maximum long axis diameter of LNs correlated with the number of LNs and was an independent prognostic factor.

Background Seprafilm did not decrease small bowel obstruction (SBO), but significantly decreased reoperation in patients with inflammatory bowel disease. However, the preventive effect in colon cancer remains unclear. Methods We conducted a randomized controlled trial in patients with colon cancer. The study group comprised 345 patients with colon cancer. In the seprafilm group (n = 166), two sheets of seprafilm were inserted under a midline incision. Patients who were admitted and required decompression were considered to have SBO. Results The median follow‐up was 61.9 months. Patient characteristics were well balanced. There was no significant difference in the incidence of SBO between the seprafilm group (7.8%) and the control group (10.6%) (P = .46). In patients who underwent reoperation, SBO occurred in a midline incision in one patient and at other sites in four patients in the seprafilm group as compared with two patients and five patients, respectively, in the control group. Multivariate analysis showed that only a history of laparotomy was an independent risk factor for SBO. Conclusions Seprafilm did not decrease SBO or reoperation in colon cancer. The incidence of SBO caused by adhesion to the midline incision was relatively low as compared with that caused by adhesion to other sites.

The degree of tumor shrinkage is closely related to the final histologic response. Two-dimensionally evaluated tumor-shrinkage rates based on barium enema are adequate for the prediction of histologic response.

Background: To prevent surgical site infection (SSI) in colorectal surgery, the combination of mechanical bowel preparation (MBP), oral antibiotic bowel preparation (OABP), and the intravenous antibiotics have been proposed as standard treatment. We conducted an RCT comparing the incidence of SSI between MBP + OABP and OABP alone after receiving a single dose of intravenous antibiotics. Methods: The study group comprised 254 patients who underwent elective surgery for colon cancer. Patients were randomly assigned to receive MBP + OABP and intravenous antibiotics (MBP + OABP group) or to receive OABP and intravenous antibiotics (OABP alone group). Results: Overall, 125 patients in MBP + OABP group and 126 patients in OABP alone group were eligible. Incisional SSI occurred in 3 patients (2.4%) in MBP + OABP group, and 8 patients (6.3%) in the OABP-alone group. Organ/space SSI developed in 0 patients (0%) and in 4 patients (3.2%) in each group respectively. The OABP-alone group was thus not shown to be noninferior to the MBP + OABP group in the incidences of incisional SSI or organ/ space SSI. Other infectious complications developed in 7 pa-tients (5.6%) and in 6 patients (4.8%) in each group, indicating the non-inferiority of OABP alone to MBP + OABP. Conclusions: MBP combined with oral antibiotics and intravenous antibiotics remains standard in elective colon cancer surgery.