In vivo imaging of T cell lymphoma infiltration process at the colon

The infiltration and proliferation of cancer cells in the secondary organs are of great interest, since they contribute to cancer metastasis. However, cancer cell dynamics in the secondary organs have not been elucidated at single-cell resolution. In the present study, we established an in vivo model using two-photon microscopy to observe how infiltrating cancer cells form assemblages from single T-cell lymphomas, EL4 cells, in the secondary organs. Using this model, after inoculation of EL4 cells in mice, we discovered that single EL4 cells infiltrated into the colon. In the early stage, sporadic elongated EL4 cells became lodged in small blood vessels. Real-time imaging revealed that, whereas more than 70% of EL4 cells did not move during a 1-hour observation, other EL4 cells irregularly moved even in small vessels and dynamically changed shape upon interacting with other cells. In the late stages, EL4 cells formed small nodules composed of several EL4 cells in blood vessels as well as crypts, suggesting the existence of diverse mechanisms of nodule formation. The present in vivo imaging system is instrumental to dissect cancer cell dynamics during metastasis in other organs at the single-cell level.

Evaluation of liquid biopsies for detection of emerging mutated genes in metastatic colorectal cancer

BACKGROUND

Detection of gene mutations is important for planning molecular targeted therapy. Although most gene mutations are concordant between primary colon cancers and their liver metastases, new mutations can emerge in metastases. The liquid biopsy is a newly developed, gene analytic method to detect mutations in metastatic tumors. In this prospective study, we evaluated the applicability of liquid biopsies in the detection of mutations in primary and metastatic tumors.

METHODS

We included 22 patients with liver metastases from colorectal cancer and extracted DNA from primary colorectal tumors, metastatic liver tumors, and peripheral blood (liquid biopsy). Next-generation sequencing (NGS) and digital PCR were performed to detect mutations in these three sample types.

RESULTS

We found a total of 36 different mutations in samples from primary tumors, liver metastases, and liquid biopsies using NGS. Twenty-eight of these mutations were found in all three types of samples, whereas liquid biopsy did not identify four mutations that had been found in both primary tumors and liver metastases, but did identify four mutations that were found in liver tumors but not in primary tumors. The sensitivity of liquid biopsies for detecting mutations in liver metastases was 64% (23/36) using NGS and 89% (32/36, P = 0.02) using dPCR. The specificities of NGS and dPCR were 100% (23/23) and 100% (32/32), respectively.

CONCLUSIONS

Emerging mutations, which are not found in primary tumors, can be detected in their metastases and liquid biopsies.

Combined use of preoperative lymphocyte counts and the post/preoperative lymphocyte count ratio as a prognostic marker of recurrence after curative resection of stage II colon cancer

Purpose

Diagnostic markers for recurrence of colorectal cancer have not been established. The aim of the present study was to identify new diagnostic markers for recurrence after curative surgery of stage II colon cancer.

Materials and Methods

In this study, the prognostic values of the preoperative lymphocyte count and the post/preoperative lymphocyte count ratio (PPLR) were evaluated in 142 patients with localized colon cancer treated with surgery at a single medical center. The associations of patient demographics, blood chemistry, and serum biochemical indices with recurrence-free survival (RFS) and cancer-specific survival (CSS) were examined by univariate and multivariate analyses.

Results

Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off values of the lymphocyte count and PPLR were, respectively, 1555.2/μl and 1.151 for RFS. On univariate analysis, tumor depth of invasion, carbohydrate antigen 19-9 (CA19-9), and preoperative low lymphocyte count (≤1555.2/μl) were all correlated with poorer RFS (p < 0.05). On multivariate analysis, T4, low lymphocyte count, and low PPLR were independent predictors of poor RFS. Furthermore, the patients were categorized into four categories based on preoperative lymphocyte count high/low and PPLR high/low. Patients with a low preoperative lymphocyte count and low PPLR had the poorest RFS and CSS compared to the other patients.

Conclusion

The combination of the preoperative lymphocyte count and the PPLR appears to be a potential marker for predicting recurrence of stage II colon cancer.

Oncological Assessment of Stent Placement for Obstructive Colorectal Cancer from Circulating Cell-Free DNA and Circulating Tumor DNA Dynamics

BACKGROUND

The self-expanding metallic stent (SEMS) provides effective decompression for patients with malignant large bowel obstruction (MLBO); however, mechanical damage to malignant cells from insertion may negatively affect prognosis, similar to surgical manipulation, and its oncological safety is unclear. We examined mechanical damage from SEMS placement using circulating cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA).

METHODS

Between 1 November 2014 and 30 June 2017, 35 MLBO patients were analyzed, comprising 25 SEMS patients and 10 transanal decompression tube (TDT) patients (control). Blood samples were collected before and after decompression on days 0, 1, 3, and 7. cfDNA, ctDNA, white blood cells, C-reactive protein, and lactate dehydrogenase were analyzed.

RESULTS

The clinical success rates of SEMS and TDT were 88 and 90%, respectively (p = 1.0). The cfDNA concentration on day 7 was significantly higher in the SEMS group than in the TDT group (992 vs. 308 ng/mL; p = 0.005). A significant increase in ctDNA was observed in the SEMS group compared with the TDT group (83% vs. 22%; p = 0.002). The cfDNA concentration showed strong positive correlations with ctDNA and lactate dehydrogenase (R ² = 0.838 and 0.593, respectively), and a weak positive correlation with C-reactive protein (R ² = 0.263).

CONCLUSIONS

Despite equivalent clinical success rates, SEMS placement increased plasma levels of cfDNA and ctDNA by tumor manipulation, but TDT did not. Colonic stenting showed oncological risk in terms of molecular analysis.

[Obstructive Colon Cancer with Triple-Vessel Coronary Artery Disease - A Case Report]

The patient was a 70-year-old woman who was diagnosed with obstructive transverse colon cancer suspected of invading the abdominal wall by abdominal CT imaging. Since the preoperative electrocardiogram showed an ischemic change, echocardiography and coronary angiography were performed. We diagnosed chronic heart failure and angina pectoris because echocardiography showed low cardiac function(left ventricular ejection fraction; LVEF 37%)and coronary angiography indicated triple-vessel disease. We firstly performed coronary artery bypass graft surgery following self-expanding metallic stent placement as a bridge to surgery(BTS), because we judged this patient as a perioperative high-risk case. After improvement of cardiac function(LVEF 49%), expanded right hemicolectomy with partial resection of abdominal wall could be performed without perioperative complications. Colonic stenting as a BTS allowed us to treat comorbidities properly, and perform a radical surgery safely for such a high-risk patient.

Oxaliplatin-induced increase in splenic volume; irreversible change after adjuvant FOLFOX

BACKGROUND AND OBJECTIVES

Oxaliplatin can cause hepatic sinusoidal obstruction syndrome (SOS). SOS can cause chemotherapy-related adverse effects or morbidity after liver resection. Conventionally, SOS is diagnosed using liver biopsy. Recently, it was reported that increased splenic volume (SV) can be used to detect SOS. In this study, we evaluated the changes in SV during adjuvant chemotherapy.

METHODS

We enrolled 103 consecutive patients with stage III and high-risk stage II colorectal cancer treated with mFOLFOX6 (n = 37) or oral fluorouracil and leucovorin (n = 66) after curative surgery. SV was measured three times; pre-operatively, after chemotherapy, and 1 year after chemotherapy.

RESULTS

SV was higher after mFOLFOX6 (median 135.89 mL) than pre-operatively (105.75 mL) (P < 0.001); SV at 1-year after finishing mFOLFOX6 (114.16 mL) returned to the same level as before surgery (P = 0.0015). SV increased in 28 patients (75.7%) treated with mFOLFOX6 (95%CI, 61.8-89.5), but had not recovered in 12 of these cases (42.9%) 1 year after finishing treatment (95%CI, 17.3-47.5). In contrast, oral fluorouracil and leucovorin did not change SV.

CONCLUSIONS

SV increased after adjuvant mFOLFOX6, and had not recovered in almost half of cases 1-year after finishing chemotherapy. This increase may indicate continuous SOS, which can adversely affect treatment after recurrence.

Abstract 5682: Circulating tumour DNA following decompression using selfexpandable metallic stent

Background: Decompression using selfexpandable metallic stent (SEMS) has been reported to improve short-term outcomes in patients with malignant large bowel obstruction (MLBO). However, some reports suggest that SEMS worsen long-term survival. Conversely, trans-anal drainage tubes (TDT), which are similar to the ileus tubes widely used in Japan for MLBO, have had no reports suggesting reduced survival. SEMS worsen long-term survival by compressing tumor continuously and induce tumor cell death which can lead production of various types of mediator which could negatively affect prognosis. In this study, we investigated tumor cell death induced by decompression procedure by using circulating tumour DNA (ctDNA).

Methods: Plasma samples were obtained before and 1, 3 and 7 days after decompression. First, we purified circulating cell free DNA (ccfDNA) from 1 mL of plasma and measured the concentration using fluorometer. Second, we measured mutated fragment of ccfDNA (circulating tumour DNA) which is derived from tumor cell. Mutational analysis from the main tumour was performed using Ion PGM™ Sequencer following library preparation with Ampliseq CHPver.2 (Thermo Fisher Scientific). Each mutant fragment in ccfDNA was quantified using digital PCR (QuantStudio 3D® digital PCR system).

Results: We enrolled 30 patients (22 SEMS and 8 TDT). CcfDNA levels on day7 was significantly increased in the SEMS group (before; 623ng/ml, day7; 1455ng/ml, p=0.006) but TDT group. Sequencing result revealed that the average number of mutation per tumor was 3.7 (e.g. APC, TP53, and KRAS) out of 50 genes. Mutant fragments (ctDNA) were detected in the ccfDNA in all cases. Mutant fragment also increased after decompression in SEMS group(before; 6.2copies/μl, day3; 22.6copies/μl, p=0.03)but in TDT group.

Conclusion: SEMS insertions increased plasma levels of not only ccfDNA but also ctDNA in patients with MLBO. This indicated that SEMS would induce massive cancer cell death. This tumor cell death can drain various mediators, including DAMPs, into blood flow and may worsen prognosis of patients with MLBO. Conversely, TDT may not induce massive tumor cell death.

Citation Format: Goro Takahashi, Takeshi Yamada, Takuma Iwai, Kohki Takeda, Michihiro Koizumi, Seiichi Shinji, Yasuyuki Yokoyama, Keisuke Hara, Hiroyasu Furuki, Atsushi Watanabe, Keiichro Ohta, Eiji Uchida. Circulating tumour DNA following decompression using selfexpandable metallic stent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5682. doi:10.1158/1538-7445.AM2017-5682

Emergence of KRAS mutations and acquisition of resistance to EGFR blockade

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Background: Epidermal growth factor receptor (EGFR) blockade can effectively shrink tumors in patients with metastatic colorectal cancer (CRC). However, most patients who benefit from EGFR blockade acquire resistance. Although RAS mutation is established as a main cause of primary resistance, the mechanisms of this acquired resistance remain unclear. Here, we aimed to identify the mechanisms underlying acquired resistance to EGFR blockade by using circulating cell-free (ccf)DNA to track emerging KRAS, BRAF and S492R mutations during chemotherapy. Methods: We enrolled 33 patients with metastatic CRC and no RAS mutations in their primary tumors. Patients were treated with first-line systemic chemotherapy that included EGFR blockade. We obtained ccfDNA from each patient before they started chemotherapy, and every 2–3 months during chemotherapy until disease progression. We detected KRAS (codons 12, 13, 61, and 146), BRAF (V600E) and S492R mutations using digital polymerase chain reaction. Results: KRAS mutations were detected in the ccfDNA of 4 of the 33 patients (12%) before chemotherapy. The response rate was 88% (29/33); all four non-responders had KRAS mutations in their ccfDNA and one of the four had both KRAS and BRAF mutations before starting chemotherapy. A response was detected in all patients (29/29) with no KRAS or BRAF mutations in their ccfDNA before chemotherapy. Of the 29 initial responders, 14 (48%) acquired resistance. Emerging KRAS mutations were detected in the ccfDNA of 13 of these 14 patients (93%); eight of these patients had multiple mutations (e.g. G12D and G12V; G13D and Q61H). BRAF mutations were also detected in six patients (43%); none of the patients had solo BRAF mutations. Six patients (43%) had S492R mutations; none of the patients had solo S492R mutations. Only one patient had no KRAS, BRAF or S492R mutations. Conclusions: Emergence of KRAS, BRAF or S492R mutations that were undetectable before the start of chemotherapy may be a mechanism underlying acquisition of resistance to EGFR blockade. Notably, emerging KRAS mutations were detected in most of the patients (93%) who acquired resistance. This indicates that KRAS mutation emergence may play a major role in the acquisition of resistance to EGFR blockade.

Tracking emerging KRAS, BRAF and EGFR mutations through ccfDNA in colorectal cancers treated with EGFR blockade

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Background: Epidermal growth factor receptor (EGFR) blockade can achieve considerable tumor shrinkage in patients with metastatic colorectal cancer (CRC). However, most patients who benefit from EGFR blockade acquire resistance within a year through emerging KRAS, BRAF or EGFR ( S492R) mutations. We have shown that patients with KRAS or BRAF mutations in circulating cell-free DNA (ccfDNA) do not respond favorably to EGFR blockade. In this study, we aimed to detect acquired resistance to EGFR blockade early by using ccfDNA to track emerging KRAS, BRAF and S492R mutations during chemotherapy. Methods: We enrolled 24 patients with metastatic CRC and no KRAS mutations in their primary tumors who were to be treated with systemic chemotherapy that included EGFR blockade. We purified ccfDNA from 1 mL of serum from each patient before they started chemotherapy. We also extracted ccfDNA from these patients every 2–3 months until disease progression. We detected nine KRAS, BRAF (V600E) and S492R mutations using digital polymerase chain reaction. Results: We detected KRAS mutations in ccfDNA of three patients before chemotherapy (12.5%; 3/24). The response rate was 83% (20/24); the four non-responders comprised the three with KRAS mutations and the other with BRAF mutations in their ccfDNA before chemotherapy. All patients with no KRAS or BRAF mutations in their ccfDNA before chemotherapy responded to the chemotherapy (20/20). Of these 20 initially responsive patients, 12 (60%) acquired resistance. We detected emerging KRAS mutations in the ccfDNA of eight of these 12 patients (67%) prior to relapse, six of them having multiple mutations. Five of these patients had mutations in codon 61 and one had solo codon 61 mutations. We also detected BRAF mutations in five patients; none had solo BRAF mutations. Four patients had S492R mutations; none had solo S492R mutations. Conclusions: If KRAS or BRAF mutation do not detected in primary tumor, EGFR blockade has no beneficial effect in patients with KRAS or BRAF mutations in their ccfDNA prior to commencing chemotherapy. Emerging KRAS, BRAF or S492R mutations that were undetectable before starting chemotherapy are associated with acquired resistance to EGFR blockade.

The effect of Daikenchuto on postoperative intestinal motility in patients with right-side colon cancer

PURPOSE

Daikenchuto (DKT) has a stimulant effect on intestinal motility and reportedly has a positive effect on postoperative intestinal motility in patients with sigmoid colon cancer. In this study, we investigated the effects of DKT in patients with right-side colon cancer.

METHODS

This retrospective study included 88 patients with right-side colon cancer. We orally administered 7.5 g of DKT in the DKT group and did not administer any DKT to patients in the no-DKT group. All patients ingested radiopaque markers 2 h before surgery, which were used to assess intestinal motility. The postoperative intestinal motility was radiologically assessed by counting the numbers of residual markers in the large and small intestines.

RESULTS

The DKT and no-DKT groups showed no marked differences in the total number of residual markers or number of residual markers in the small intestine. However, in the elderly subgroup, the total number of residual markers in the DKT group was significantly less than in the no-DKT group.

CONCLUSION

Although DKT had some small effect on the postoperative intestinal motility for most patients, it may have positive effects in elderly patients.

A case of repeated small bowel perforations in a short period in a patient with cholesterol crystal embolism

We report a case of jejunal perforation related to cholesterol crystal embolism (CCE) in a woman in her seventies. The jejunum was partially resected;histological examination of the resected tissue revealed that the perforation was caused by CCE. On postoperative day 12, computed tomography (CT) showed free air in the abdomen. We then performed a second operation to alleviate the anastomotic leakage. Subsequently, 26 days after the second surgery, CT again showed free air in the abdomen. A third operation was performed, and multiple perforations of the jejunum were detected. She died of multiple organ failure 43 days after the first surgery. The prognosis of CCE with gastrointestinal perforation is reported to beextremely poor, and there is a high rate of anastomotic leakage. Partial resection of the intestine and ileostomy might be useful for removing the intestinal perforations caused by a CCE. Steroid administration should be continued, however, because discontinuation may worsen the problem.

Abstract 3135: Prediction of acquired resistance in colorectal cancer patients treated with EGFR blockade by detection of a new KRAS mutation in ccfDNA

Background: Oncogenic KRAS mutations can be used to predict a lack of response to epidermal growth factor receptor (EGFR) blockade. KRAS status is usually determined by biopsy from the primary site of colorectal cancer (CRC). However, the genomic profiles of primary tumors and metastases are not always concordant because of intrinsic molecular heterogeneity. Furthermore, chemotherapeutic agents and targeted drugs can alter the tumor molecular landscape. We exploited circulating tumor DNA (ctDNA) to genotype colorectal tumors and track clonal evolution during treatment involving EGFR blockade. To account for these spatial and temporal changes, the genomic profiles of patients with CRC can be repeatedly evaluated during the course of therapy. In this study, we evaluated the utility of KRAS mutation detection using ctDNA before and during chemotherapy.

Method: Experiment 1: We enrolled 46 metastatic colorectal cancer patients. Before starting chemotherapy, ctDNA was purified from 1 mL serum using the QIAamp circulating nucleic acid kit. We detected nine KRAS (G12A, G12R, G12D, G12C, G12S, G12V, G13D, Q61H, and Q61R) mutations using the Invader method and digital PCR. Experiment 2: Fifteen patients were treated with systemic chemotherapy including EGFR blockade. ctDNA was extracted from these patients every 2 months until disease progression, and the KRAS mutation was detected in nine.

Results: Experiment 1: KRAS mutations in circulating tumor DNA were detected in 88% (14/16) of patients with KRAS mutations in their primary tumor, but in 10% (10/30) of patients without KRAS mutations in their primary tumors. Experiment 2: The response rate was 87% (13/15). In two non-responders, KRAS mutations in ctDNA were detected before chemotherapy. Disease progression was identified in five patients and KRAS mutations in ctDNA were detected in all patients; the five patients with disease progression included the two non-responders in whom KRAS mutations in ctDNA were detected before chemotherapy. However, the genotypes detected after disease progression were different from those detected before chemotherapy (G13D to G12C and Q61R to Q61H). New KRAS mutations occurred in codon 12 in the other three patients in whom no KRAS mutations in ctDNA were detected before chemotherapy. New KRAS mutations in codon 61 disappeared during chemotherapy and disease progression was not detected at that time in two patients.

Discussion: It has been reported in a retrospective study that new KRAS mutations were detected in patients who acquired resistance to EFGR blockade, and many of them were in codon 61. However, new KRAS mutations in codon61 can disappear during treatment involving EGFR blockade. This phenomenon may indicate that new KRAS mutations in ctDNA do not always indicate acquired resistance to chemotherapy involving EGFR blockade.

Citation Format: Takeshi Yamada, Hayato Kan, Takuma Iwai, Goro Takahashi, Michihiro Koizumi, Akihisa Matsuda, Seiichi Shinji, Yasuyuki Yokoyama, Atsushi Tatsguchi, Tetsuro Kawagoe, Shiro Kitano, Masato Nakayama, Satoshi Matsumoto, Keiichiro Ohta, Eiji Uchida. Prediction of acquired resistance in colorectal cancer patients treated with EGFR blockade by detection of a new KRAS mutation in ccfDNA. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3135.

Abstract 3134: Prediction of early recurrence after resection of metastatic liver tumors from colorectal cancer using circulating cell-free DNA

Background: We have reported that the amount of total circulating cell-free DNA (ccfDNA) increases with tumor growth and decreases upon tumor shrinkage. However, adverse effects of drugs and surgical stress can increase total ccfDNA because ccfDNA is derived from both normal and cancer cells. Thus, the ability to determine how much ccfDNA is derived from cancer cells is a critical issue. It has been reported that the length of ccfDNA derived from cancer cells is greater than 200 bp while that from normal cells undergoing apoptosis is less than 200 bp. Furthermore, the ratio of ccfDNA to β-globin reflects the amount of mitochondrial DNA derived from normal cells undergoing stress-induced apoptosis. We developed a new biomarker readout, the LINE-1 long fragment (longer than 200 bp) to β-globin ratio (LBR), based on this principle. In this study, we evaluated the clinical utility of the LBR to detect early recurrence of liver metastasis from colorectal cancer after liver resection.

Methods: We enrolled 20 patients who underwent curative liver resection of metastatic liver tumors from colorectal cancer. Total ccfDNA and LBR were measured pre-surgery, and at 1 week and 1 month post-surgery. ccfDNA was purified from 1 mL serum using the QIAamp Circulating Nucleic Acid Kit. Total ccfDNA was measured using Qubit Fluorometer. LINE-1 long fragment and β-globin in ccfDNA were measured using real time PCR. The Ethics Review Committee of our institution approved the study protocol. Written informed consent was obtained from each patient.

Results: We completed 1-year follow-up in 13 of 20 patients. Recurrence was detected in 7 patients and no signs of recurrence were detected in the other 6. Total ccfDNA increased 1 week after surgery in all 13 patients, which could have been caused by surgical stress. Total ccfDNA 1 month after surgery increased in 5 of 7 patients with recurrence. Total ccfDNA 1 month after surgery increased in 3 of 6 patients without recurrence. The 3 patients with increased ccfDNA had post-operative complications or drug-induced liver dysfunction. Notably, LBR increased in the 7 patients with recurrence and decreased in the 6 patients without recurrence 1 month post-surgery.

Conclusion: LBR has potential as a novel biomarker readout for early detection of recurrence after liver resection of metastatic liver tumors from colorectal cancer.

Citation Format: Takuma Iwai, Takeshi Yamada, Hayato Kan, Michihiro Koizumi, Seiichi Shinji, Yasuyuki Yokoyama, Goro Takahashi, Shiro Kitano, Masato Nakayama, Zenya Naito, Keiichiro Ohta, Eiji Uchida. Prediction of early recurrence after resection of metastatic liver tumors from colorectal cancer using circulating cell-free DNA. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3134.

Utility of KRAS mutation detection using circulating cell-free DNA from patients with colorectal cancer

In this study, we evaluated the clinical utility of detecting KRAS mutations in circulating cell-free (ccf)DNA of metastatic colorectal cancer patients. We prospectively recruited 94 metastatic colorectal cancer patients. Circulating cell-free DNA was extracted from plasma samples and analyzed for the presence of seven KRAS point mutations. Using the Invader Plus assay with peptide nucleic acid clamping method and digital PCR, KRAS mutations were detected in the ccfDNA in 35 of 39 patients previously determined to have primary tumors containing KRAS mutations using the Luminex method, and in 5 of 55 patients with tumors containing wild-type KRAS. Curative resection was undertaken in 7 of 34 patients with primary and ccfDNA KRAS mutations, resulting in the disappearance of the mutation from the cell-free DNA in five of seven patients. Three of these patients had tumor recurrence and KRAS mutations in their ccfDNA reappeared. Epidermal growth factor receptor blockade was administered to 24 of the KRAS tumor wild-type patients. Of the 24 patients with wild-type KRAS in their primary tumors, three patients had KRAS mutations in their ccfDNA and did not respond to treatment with epidermal growth factor receptor (EGFR) blockade. We also detected a new KRAS mutation in five patients during chemotherapy with EGFR blockade, before disease progression was detectable with imaging. The detection of KRAS mutations in ccfDNA is an attractive approach for predicting both treatment response and acquired resistance to EGFR blockade, and for detecting disease recurrence.

Rechallenge with 5-fluorouracil in a patient who developed encephalopathy caused by 5-fluorouracil for colon cancer

We report a case involving a patient with colon cancer who underwent 5-fluorouracil (5-FU) rechallenge and maintained an oncological effect for a long period after encephalopathy caused by 5-FU. Our patient was a 61-year-old man who was diagnosed with adenocarcinoma of the ascending colon with direct liver invasion. He underwent right hemicolectomy with partial liver resection followed by adjuvant chemotherapy with modified FOLFOX6 (mFOLFOX6). Ten months after completion of mFOLFOX6, his carcinoembryonic antigen concentration increased, and ascites was revealed by computed tomography 2 months later. We started FOLFIRI, and he was taken to our hospital by ambulance because of loss of consciousness 10 days after the start of the third cycle of FOLFIRI. Laboratory investigations showed hyperammonemia and elevations of his serum creatinine and blood urea nitrogen concentrations. Brain computed tomography demonstrated no abnormalities. Transfusion of 1500 ml of crystalloid fluid resulted in gradual recovery over the next 12 h. His ammonia concentration decreased to a normal level. Twelve days after onset of the encephalopathy, we restarted FOLFIRI, but the dose of continuous 5-FU was decreased by 20 %. The patient's carcinoembryonic antigen concentration considerably decreased from 376.5 to 19.9 ng/ml, and his ascites disappeared. Nineteen months after the resumption of FOLFIRI, he underwent 34 courses of FOLFIRI and maintained stable disease. The encephalopathy did not recur.

[Skeletal Mass Depletion Is a Negative Prognostic Factor in Gastrointestinal Cancer Patients in the Terminal Stage]

BACKGROUND

Skeletal mass depletion has been reported to be a prognostic factor for cancer patients. However, special and expensive devices are required to measure skeletal mass, and this is a major reason why skeletal mass is not used extensively for prognostic marker in clinical settings. We developed a new method to measure skeletal mass for use as a prognostic marker using CT images without special and expensive devices. In this study, we evaluated the usefulness of skeletal mass as measured by this new method as a prognostic marker for gastrointestinal cancer patients.

METHOD

Patients who died from gastrointestinal cancer between March 2010 and October 2013 were included. We measured the right-sided maximum psoas muscle cross sectional area (MPCA) by using CT images before surgery and after the patients developed a terminal condition. The maximum psoas muscle cross sectional area ratio (MPCA-R) was defined as follows: MPCA-R=MPCA before surgery/MPCA after developing a terminal condition. We evaluated the correlation between MPCA-R and survival.

RESULT

Fifty-nine patients were included. The median survival was 44 days, and MPCA-R was significantly correlated with survival (p=0.001). On receiver operating characteristic (ROC) analysis, the area under the curve (AUC) to predict 30-day and 90-day survival was 0.710 and 0.748, respectively.

CONCLUSION

MPCA-R is a new and novel prognostic marker for gastrointestinal cancer patients in terminal condition.

A Case of Portal Venous Gas after Rectal Surgery without Anastomotic Leakage or Bowel Necrosis

Portal venous gas has traditionally been considered an indicator of a poor prognosis due to bowel necrosis. Portal venous gas has recently been detected in patients with various clinical conditions, such as Crohn's disease, chemotherapy, and blunt abdominal injury without bowel necrosis. We herein report the first case of a patient with rectal cancer in whom portal venous gas developed after low anterior resection without anastomotic leakage or bowel necrosis. A 66-year-old man who had undergone low anterior resection started having severe diarrhea the day after the operation. A fever was present for 2 days after the operation but resolved on postoperative day 3. The patient complained of abdominal pain 5 days postoperatively. Computed tomography showed portal venous gas. Emergency open laparotomy was performed, but only limited ascites fluid without leakage or bowel necrosis was found. We irrigated the abdominal cavity and performed an ileostomy with insertion of a drainage tube in the rectovesical pouch. Only serous ascites was discharged through the drainage tube. The portal venous gas disappeared 3 days after the second operation. The patient was discharged in good condition 21 days after the first operation. Portal venous gas can develop after rectal surgery without anastomotic leakage or bowel necrosis. Conservative treatment is reasonable for patients without signs of bowel necrosis or panperitonitis. However, patients with portal venous gas must be carefully observed because portal venous gas may be life threatening.