Role of carcinoembryonic antigen and liver function tests in the detection of recurrent colorectal carcinoma

The optimal laboratory evaluation for the early detection of liver metastases from colorectal cancer is controversial. This investigation was undertaken to compare the efficacy of liver function tests (LFTs) with that of carcinoembryonic antigen (CEA) levels for the early detection of liver metastases. Patients who developed liver metastases after potentially curative resections of adenocarcinoma of the colorectum between 1974 and 1988 were reviewed. The following laboratory tests were serially evaluated during the follow-up period: CEA., alkaline phosphatase (AP), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and lactic dehydrogenase (LDH). These values were retrospectively assessed from the time of documented liver metastases to identify which lab value (s) were elevated initially. Ninety-two patients were available for study. Average time for the occurrence of liver metastases was 20 months (range, 3–72 months). The incidence of elevation of individual tests at the time of suspicion of liver metastasis was: CEA, 94.6 percent (P <0.25, chisquared); AP, 18.5 percent; SGOT, 12.0 percent; SGPT, 5.4 percent; and LDH, 29.3 percent. When comparing CEA with a battery of LFTs at the time of suspicion of liver metastasis, CEA was elevated with normal LFTs in 64.1 percent (P <0.05, chi-squared), the most frequent occurrence. At least one LFT was elevated with a normal CEA in only 2.2 percent; CEA and at least one LFT were increased in 30.4 percent; and both tests were normal in only 3.3 percent. These results indicate that, of the individual laboratory tests performed, CEA elevation heralds liver metastases significantly more frequently. LDH is the liver function test most frequently elevated when liver metastases are first suspected. When CEA is directly compared with a battery of LFTs, CEA is statistically significantly more frequently elevated. In fact, suspicion of liver metastases would have been delayed by the omission of LFTs in only 2.2 percent of patients. Therefore, we conclude that LFTs should be deleted from the follow-up of colorectal cancer patients, decreasing costs without significantly decreasing accuracy.     

Usefulness of carcinoembryonic antigen monitoring despite normal preoperative values in node-positive colon cancer patients

PURPOSE: The aim of our study was to determine to what extent serial carcinoembryonic antigen (CEA) monitoring is helpful in detecting colorectal cancer recurrence in patients if their preoperative serum CEA is normal. Additional major objectives of this study were to correlate CEA immunohistochemical features of the primary tumor with serum CEA levels at the time of tumor recurrence in node-positive colorectal cancer patients with low preoperative CEA values. METHODS: One hundred fourteen node-positive colorectal cancer patients with preoperative serum CEA levels of <5.0 ng/ml undergoing clinically curative operations were studied. Primary tumors were evaluated for tissue CEA using the same monoclonal antibody as used for serum CEA determinations utilizing the avidin-biotin-peroxidase immunohistochemical technique. RESULTS: The exact preoperative serum CEA value did not correlate with tumor grade, immunohistochemical CEA intensity or pattern. In the 32 patients who developed recurrent cancer, the serum CEA at recurrence was greater than 5 ng/ml in 44 percent. All such patients had CEA present in their primary tumor. There was no correlation with the exact preoperative serum CEA, the intensity of the primary tissue CEA, or the localization of such CEA and subsequent serum elevation at recurrence. CONCLUSION: Serum CEA is a useful marker in the detection of recurrent colorectal cancer despite normal preoperative values.     

Value of carcinoembryonic antigen monitoring in curative surgery for recurrent colorectal carcinoma

PURPOSE: This study is designed to review a carcinoembryonic antigen (CEA)-driven postoperative protocol designed to identify patients suitable for curative reresection when recurrent colorectal cancer is identified. METHODS: A total of 285 patients who were operated on for colon or rectal carcinoma between 1981 and 1985 were evaluated (with CEA levels) every two months for the first two years, every three months for the third year, every six months for years 4 and 5, and annually thereafter. CEA levels above 5 g were considered abnormal and were evaluated with diagnostic imaging and/or endoscopy. RESULTS: Follow-up was available for 280 patients (98.2 percent). Distribution of patients by Astler-Coller was: A, 14 percent; B₁ 20 percent; B₂, 39 percent; C₁, 5 percent; C₂, 21 percent. There were 62 of 280 patients (22 percent) who developed elevated CEA levels, with 44 patients who demonstrated clinical or radiographic evidence of recurrence. Eleven patients were selected for surgery with curative intent (4 hepatic resections, 1 pulmonary wedge resection, 2 abdominoperineal resections, 2 segmental bowel resections, and 2 cranial metastasectomies). Three of 11 patients (27 percent) benefited and have disease-free survivals greater than 60 months. Of the 223 patients without elevated CEA, 22 (9.9 percent) had recurrent cancer without any survivors. Overall, 3 of 285 patients (1.1 percent) were cured as a result of CEA follow-up. CONCLUSION: CEA-driven surgery is useful in selected patients and can produce long-term survivors.Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.     

Role of carcinoembryonic antigen in predicting resectability of recurrent colorectal cancer

The reported low resectability rate for patients with recurrent colorectal cancer who have carcinoembryonic antigen (CEA) levels >11 has led us to perform this study. One hundred twenty-four patients who underwent Radioimmunoguided Surgery ^® (RIGS ^®)procedures for recurrent colorectal cancer from 1986 to the present were studied. In surgery, all patients underwent a traditional exploration followed by survey with a hand-held, gamma-detecting probe to detect preinjected radiolabeled monoclonal antibodies attached to cancer cells. Sites of metastases included: 72 liver (58.1 percent), 23 pelvis (18.5 percent), 15 distant lymph nodes (12.1 percent), 2 anastomotic (1.6 percent), and 12 other sites (9.7 percent). The resectability rate was 43.5 percent (54 patients). The mean preoperative CEA level for patients with resectable disease was significantly lower than for patients with unresectable disease (P=0.017): unresectable—mean, 87.1; SD, 141.0; minimum, 0.3; maximum, 501; resectable—mean, 36.6; SD, 59.3; minimum, 0.3; maximum, 329. The CEA level for patients with liver metastasis did not vary significantly from those patients without metastasis: 70 vs. 58.2 (P=0.58). Those patients with resectable liver tumors had lower mean CEA levels than those with unresectable liver, approaching significance: 41.6 vs. 91.9 (P=0.065). Other metastatic sites had a mean CEA level of: pelvic, 72.6; distant lymph nodes, 47.8; anastomotic, 2.7; and other sites, 53.8. These data suggest that there is a significant difference between the preoperative CEA level of the resectable and unresectable recurrent colorectal cancer patients, but the large standard deviation does not justify abandonment of exploration for any CEA level.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

Immunohistochemical localization of carcinoembryonic antigen as a predictor of lymph node status in submucosa-invasive colorectal carcinoma

PURPOSE: Submucosa-invasive colorectal carcinoma is a colorectal carcinoma extending only into the submucosal layer. To clarify the metastatic potential of submucosa-invasive colorectal carcinoma, we studied the relationship between the immunohistochemical staining pattern of carcinoembryonic antigen (CEA) and that of lymphatic invasion/ lymph node metastasis. METHODS: We investigated 49 submucosa-invasive colorectal carcinomas resected surgically or endoscopically. CEA distribution patterns of the neoplastic tissues were divided into three patterns: Pattern 1 = luminal type; Pattern 2 = apical cytoplasmic type; and Pattern 3 = diffuse cytoplasmic type. We also observed the submucosal stromal staining of CEA. RESULTS: Lymphatic invasion and lymph node metastasis were found in 48.8 percent (21/43) and 11.6 percent (5/43) of the Pattern 2/Pattern 3 cases, whereas these were seen in none (0/6) of Pattern 1 cases. Lymphatic invasion and lymph node metastasis were found in 63.3 percent (19/30) (chi-squared =21.94;P <0.001) and 16.7 percent (5/30) of the positive stromal CEA cases, whereas these were seen in 10.5 percent (2/19) and none (0/14) of the negative stromal CEA cases, respectively. CONCLUSION: Pattern 2/Pattern 3 and stromal CEA can be predictors of the lymph node metastasis with 11.6 percent and 16.7 percent risks.Read at the meeting of the Japanese Society of Gastroenterological Surgery, Tokyo, Japan, February 24 to 25, 1994.     

Xanthogranulomatous cystitis as a cause of elevated carcinoembryonic antigen mimicking recurrent colorectal cancer

We report a case of xanthogranulomatous cystitis that developed in a patient with a history of colon cancer. While undergoing adjuvant chemotherapy with fluorouracil and levamisole, rising carcinoembryonic antigen (CEA) levels and the appearance of a pelvic mass, suspicious for recurrent cancer, were identified. Exploratory laparotomy demonstrated the presence of a benign condition of the bladder, xanthogranulomatous cystitis, which was resected by partial cystectomy. CEA levels have normalized. This is the first reported case of xanthogranulomatous cystitis producing an elevated CEA level.     

Level of serum gastrin as a predictor of liver metastasis from colorectal cancer

There have been no reports on the relationship between serum gastrin level and liver metastasis in human colorectal cancer. One hundred forty patients who underwent surgery for colorectal cancer (T2 or more) were enrolled in this study. Fasting serum gastrin level was determined prior to the surgery. Incidence of liver metastasis was significantly (P<0.01) higher in patients with a serum gastrin level of 150 pg/ml (37 percent; 14/38) than in those with a serum gastrin level of <150 pg/ml (12 percent; 12/102). As for the tumors with venous invasion, liver metastasis was detected in 11 of 55 patients (20 percent) with a serum gastrin level of <150 pg/ml; however, it was detected in 11 of 19 patients (58 percent) with a serum gastrin level of 150 pg/ml (P<0.01). These results suggest that serum gastrin serves as a useful predictor of liver metastasis from colorectal cancer and that the predictability of liver metastasis can be improved when both serum gastrin level and venous invasion are considered.     

Second-look operation for recurrent colorectal cancer based on carcinoembryonic antigen and imaging techniques

PURPOSE: The usefulness of postoperative carcinoembryonic antigen (CEA) monitoring and improvements in imaging techniques have renewed enthusiasm for second-look operations (SLO) as the most effective treatment for recurrent colorectal cancer by reresection following early detection. The aim of our study is to evaluate the role of CEA and imaging techniques-directed SLO. METHODS: Seven hundred fifty-six patients with Dukes Stages B and C, who had undergone curative resection, were monitored postoperatively using CEA and imaging techniques. An SLO was performed on any potentially resectable recurrence, and in addition, an SLO was done when a persistently rising CEA value was detected. RESULTS: Recurrence developed in 18.8 percent (142/756) of patients, and 90.8 percent (129/ 142) of the recurrences were detected within the first three years following curative resection. When comparing carcinomas of the colon with that of the rectum, the former were associated with significantly more hepatic and intra-abdominal recurrences, whereas the latter had significantly more locoregional and pulmonary recurrences. Seventy-two patients underwent SLO. Of these patients, 54.2 percent (39/72) had all of their disease resected, and 1.4 percent (1/72) had no detectable disease at the SLO. Among the 142 patients with recurrence, 71 (50 percent) patients underwent SLO. The resectable group at SLO carried a significantly better survival than the unresectable recurrence group (41.3 vs. 5.2 percent;P <0.01). CONCLUSIONS: Complete removal of colorectal cancer recurrences by SLO, on the basis of postoperative, follow-up CEA and imaging technique findings, results in improved survival.Supported, in part, by a grant-in-aid for Cancer Research from the Japanese Ministry of Health and Welfare and Scientific Research from the Japanese Ministry of Education, Culture and Science.     

Expandable metal stent application in obstructing carcinoma of the proximal colon

PURPOSE: The increased mortality of emergency vs. elective colonic surgery applies equally to the right and left colon. Recent interest has surrounded the application of expandable metal stenting in acute obstruction but has been confined to the left colon. We describe successful application of stenting in the right colon, allowing postponement of a particularly high-risk laparotomy. METHODS: A patient with acute bilateral iliofemoral thromboses simultaneously developed complete obstruction of the proximal transverse colon. After heparinization and under fluoroscopic control, a 10-cm-long, self-expanding Wallstent ^® (Schneider, Bulach, Switzerland), 22 mm in diameter, was manipulated across the obstruction. RESULTS: Immediate decompression with symptomatic relief ensued. The stent prevented obstruction during a 10-week period of anticoagulation, and repeat duplex scanning showed resolution of iliac thrombus. An elective right hemicolectomy was then performed. Postoperative course was uncomplicated, and histopathology confirmed a Dukes B carcinoma. CONCLUSIONS: This case, in which a potentially hazardous laparotomy was delayed until the operative risk improved, defines a new role for stenting in colonic obstruction and demonstrates an extension of its applicability to the right colon. Literature review found no other report of stent application in the right colon.     

Value of carcinoembryonic antigen in the management of colorectal cancer

PURPOSE: The practical value of carcinoembryonic antigen (CEA) assay in the management of colorectal cancer after surgery is controversial. The value of CEA in the management of colorectal cancer was reviewed and discussed to justify the use of CEA assay in the management of colorectal cancer. METHODS: A retrospective study was performed on 318 patients who underwent resection by one surgeon (JYW) between 1981 and 1986 and who were followed for a minimum of 5 years or until death. RESULTS: The incidence of preoperative CEA levels >5 ng/ml in Dukes Stages A, B, C, and D were 0, 32, 48, and 79 percent, respectively. Five-year survival rates for groups with CEA levels 5 ng/ml and >5 ng/ml were 85 percent and 55 percent (P < 0.05), respectively, in Dukes Stage B patients and 64 percent and 37 percent (P < 0.05) in Stage C patients. The sensitivity and specificity of postoperative CEA monitoring in detecting recurrent diseases were 66 percent and 94 percent, respectively, for patients with a preoperative CEA value 5 ng/ml and 97 percent and 88 percent for patients with a higher preoperative CEA value. CONCLUSION: CEA is still the best tumor marker available to be used as an independent prognostic factor and as a monitor for recurrence of disease after primary tumor resection.     

Primary signet-ring cell carcinoma of the colon and rectum

PURPOSE: Colorectal signet-ring cell carcinoma (SRCC) is uncommon; discordant data have been previously reported about clinicopathologic features. Thirty-four cases of primary colorectal SRCC were retrospectively reviewed to clarify controversies. METHODS: Primary colorectal SRCC was diagnosed when the following criteria were satisfied: 1) the tumor was primary; 2) histologic material was adequate; 3) signet-ring cell represented more than 50 percent of the cancer. RESULTS: We identified 34 cases (1.1 percent) of 2,995 consecutive large bowel cancers collected at the Institute of Anatomic Pathology of Florence between 1985 and 1993. Patients ranged in age from 31 to 89 (mean, 63.5; median, 65) years; 19 were male, and 15 were female (male:female=1.31). Fifteen tumors were located in the proximal colon, 11 in the rectum, and 8 in the distal colon. The gross shape was infiltrative in 24 cases and exophytic in 10; only 6 cases (17.6 percent) showed features of linitis plastica. Most cancers (61.8 percent) were Stage C, 29.4 percent were Stage B, and distant metastases were present in only three cases (8.8 percent). No Stage A case was found. Prognosis was extremely poor, and overall five-year survival rate was 9.1 percent. Survival was influenced significantly by tumor stage (P <0.01). CONCLUSIONS: Comparison of our data with the literature showed many differences that could be related to different applied diagnostic criteria. We underlined the importance of histology as reproducible criterion for diagnosis of primary colorectal SRCC.     

Involvement of carbohydrate antigen sialyl Lewisx in colorectal cancer metastasis

PURPOSE: Recognition of metastatic tumor cells with distinct biochemical phenotypes predominant in the primary tumors should be useful not only for establishment of new therapeutic approaches but also for identification of highrisk or low-risk patients for relapse. We examined whether carbohydrate antigens, sialyl Lewis^x (sLe^x) and sialyl Lewis^a (sLe^a) are involved in colorectal cancer metastasis. METHODS: Metastatic abilities of human colon cancer cell variants that were selected for their high or low cell surface levels of sLe^x (KM12-HX and KM12-LX, respectively) were analyzed. Also, immunohistochemical expressions of sLe^x and sLe^a in 159 primary colorectal cancers were examined to determine the clinical significance of increased expression of these antigens. RESULTS: KM12-HX cells adhered more readily to tumor necrosis factor- activated endothelial cells than did KM12-LX cells. Increased adhesion of KM12-HX cells to activated endothelial cells was inhibited by antibodies against E-selectin and sLe^x and by modification of cell surface carbohydrates. KM12-HX cells showed more invasive ability in vitro and more metastatic potential in the liver of nude mice than KM12-LX cells. Although no difference was seen in the expression of six messenger ribonucleic acids corresponding to progression or metastasis of colorectal cancer, expression of fucosyltransferase was found to be responsible for the higher expression of sLe^x in KM12-HX cells. Clinical records of patients showed that disease-free survival rate of patients with sLe^x-positive tumors was significantly poorer than that of those with sLe^x-negative tumors. Cox's multivariate analysis revealed that the sLe^x status was an independent predictive factor for disease recurrence (P = 0.004), depth of invasion (P = 0.0005), and histologic type> (P = 0.037), but sLe^a status, age, gender, tumor location, N stage, and vessel invasion were not. CONCLUSION: Increased expression of sLe^x could be involved in establishment of colorectal cancer metastasis. It appears that examining sLe^x expression may serve as a potent marker of the recurrence in patients with colorectal cancer.Supported in part by a Grant-in-Aid from the Ministry of Health and Welfare for a New 10-Year Strategy for Cancer Control, Japan. Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.     

Flow cytometric examination of p53 protein in primary tumors and metastases to the liver and lymph nodes of colorectal cancer

PURPOSE AND METHODS: To confirm prognostic significance of overexpression of p53 in cases of colorectal cancer, expression of p53 protein was examined by flow cytometry in 113 cases of colorectal cancer and its metastasis to the liver and lymph nodes. RESULTS: Overexpression of p53 was found in 44 (39 percent) of the 113 primary tumors. There were no significant correlations among the level of p53 protein in the primary tumor, clinicopathologic features, and prognosis of colorectal cancer. Overexpression of p53 protein was detected in 72 percent (18/25) of liver metastases and in 40 percent (10/25) of lymph node métastases. Frequency of samples that were positive for p53 was significantly higher for liver metastases than for primary tumors and lymph node metastases (P<0.01). By comparing overexpression of p53 in primary tumors with that in corresponding secondary tumors, a decrease of more than 5 percent in the fluorescence index, compared with primary tumor, was not found in liver metastasis but was found in 20 percent of lymph node metastases. Incidence of cases with lower level expression of p53, compared with primary tumor, was significantly higher in lymph node metastases (32 percent) than in liver metastases (8 percent;P<0.05). CONCLUSIONS: From these results, it seems possible that overexpression of p53 may not be a good prognostic indicator of colorectal cancer and may be influenced by environments of the tumor.Presented at the meeting of the Japanese Gastroenterological Surgery, Fukui City, Japan, July 20 and 21, 1995.     

Assessment of “squamous cell carcinoma antigen” (SCC) as a marker of epidermoid carcinoma of the anal canal

We measured squamous cell carcinoma antigen (SCC) in epidermoid carcinoma of the anal canal in 66 patients. Samples were taken at diagnosis, before treatment, and during follow-up; 353 samples were analyzed. The positive threshold was taken as 2 ng/ml. At diagnosis, the sensitivity of the marker was 44 percent and its specificity 92 percent. In our series, the pretherapeutic level of SCC does not correlate with T as in Papillons' Clinical Staging System, but it does correlate with nodal invasion (P<0.05). It is of no prognostic value at the time of diagnosis. During follow-up, at relapse the level of SCC is 20.3 ±43 ng/ml. This increase is significant (P<0.01); the sensitivity of the marker is 77 percent. In patients who have relapsed, development of the illness correlates with the level of SCC, which is of prognostic value (P<0.01). In conclusion, the level of SCC should be associated with the clinical follow-up of patients with epidermoid carcinoma of the anal canal.     

The risk of lymph node metastasis in colorectal polyps with invasive adenocarcinoma

One hundred fifty-one patients with colorectal polyps containing invasive adenocarcinoma treated by resection were studied to determine the incidence of lymph node metastasis and whether lymph node metastasis was related to the depth of invasion. Other variables evaluated included size and configuration of the polyp, grade of adenocarcinoma, presence or absence of lymphovascular invasion, and degree of differentiation. In patients with sessile polyps, the incidence of lymph node metastasis was 10 percent. Eighty percent of these lesions had lymphovascular invasion. For pedunculated polyps, the overall incidence of lymph node metastasis was 6 percent. However, there was no incidence of lymph node metastasis when the depth of invasion was limited to the head, neck, and stalk of the polyp (Levels 1, 2, and 3). Only when the depth of invasion reached to the base of the stalk (Level 4) was the risk of lymph node metastasis high (27 percent). The other risk factors were not associated with lymph node metastasis. We concluded that the most significant risk factor for lymph node metastasis in patients with invasive carcinoma in a polyp was invasion into the submucosa of the bowel wall (Level 4).Presented in part at the Tripartite Meeting, Birmingham, United Kingdom, June 19–21, 1989.     

Growth suppression of human colorectal carcinoma in nude mice by monoclonal antibody C27-abrin A chain conjugate

PURPOSE: The aim of this study was to assess an immunotoxin, monoclonal antibody C27-abrin A chain conjugate (MAAC), that might be effective in the treatment of colorectal carcinoma. METHODS: The immunotoxin was prepared by a specific monoclonal antibody against carcinoembryonic antigen (CEA), monoclonal antibody C27, linked toN-succinimidyl-3-(2-pyridyldithio)propionate and then coupled covalently to the toxic abrin-A chain to synthesize MAAC. The therapeutic role of this immunotoxin in suppressing thein vitro andin vivo growth of CEA-secreting human colorectal cancer cells (LS174T) was assayed by methods of protein biosynthesis inhibition, cell colony proliferation, and treatment of tumor cells before and after inoculation in nude mice. RESULTS: We found that MAAC effectively suppressed the growth of LS174T in culture medium and completely eradicated cells in inoculated nude mice. In contrast, irrelevant immunotoxin antiferritin-abrin A chain conjugate and isotype-matched monoclonal immunoglobin (MOPC21IgG1)-abrin A chain conjugate did not cause such effects. Thein vitro toxicity was highly specific because the conjugate (MAAC) inhibitedde novo protein biosynthesis, impeded growth, and caused death of cells possessing surface CEA determinants. The 50 percent inhibition dose values of the conjugate for colonogenic survival and for protein biosynthesis in LS174T cells were 0.09 g/ml and 0.06 g/ml, respectively. Colony survival was inhibited 96.3 percent after prolonged MAAC treatment. MAAC showed selective cytotoxicity; the inhibitory effect of MAAC to the CEA-secreting LS174T cells over the CEA-nonsecreting human embryonic kidney cells was 16-fold. CONCLUSION: These results indicate that MAAC may be of benefit in therapy during or soon after resection of colorectal carcinoma or in patients who have micrometastasis.Supported by a grant from the National Science Council and the Veterans General Hospital-Taipei, Taipei, Taiwan.     

Immunoperoxidase staining of carcinoembryonic antigen as a prognostic indicator in colorectal carcinoma

Immunoperoxidase staining for carcinoembryonic antigen (CEA) was performed on 192 colorectal carcinomas to determine: whether tissue staining can be substituted for preoperative serum CEA levels, and whether patient survival can be predicted by these parameters. The overall incidence of positive tissue staining was 75 percent, which was similar to the elevated serum level percentage of 73 percent. Both the serum CEA level and the CEA tissue stain correlated with patient survival in Dukes' stage C patients. There was no correlation between tissue CEA stain and tumor differentiation. Positive tissue stain and elevated preoperative serum CEA identified patients with poor prognosis in Dukes' stage D only. This study shows that tissue staining with immunoperoxidase may be substituted for preoperative serum levels for CEA. The combination of these two parameters, however, does not identify patients at greater risk for recurrence than either procedure alone. Supported by a grant from the Veterans Administration.     

Solitary colonic metastasis from renal-cell carcinoma 17 years after nephrectomy

Late recurrence of renal-cell carcinoma can present many years after nephrectomy. To the best of our knowledge, we are reporting the first known case of solitary metastatic renal-cell carcinoma to the colon occurring 17 years after nephrectomy.     

Possible effect of pneumoperitoneum on the spreading of colon cancer tumor cells

PURPOSE: By using a murine hepatic metastatic model, we tried to investigate the possible influence of gas insufflation in colon cancer cells spreading from the portal system to the liver. METHODS: After transducing the human placental ALP gene into murine colon cancer cell line CT26, we successfully selected a clone of CT26/DAP that would yield a specific color following histochemical staining. Fifty mice were assigned into two groups, receiving either an intrasplenic injection of 10 ⁶ CT26/DAP cells alone or the cells followed by intra-abdominal helium insufflation with the pressure of 15 cm H ₂ O for ten minutes. Five mice in each group were used to observe their survival and the other mice were killed at four different time periods: 10 minutes, 24 hours, 48 hours, and 72 hours following cell injection. The livers and spleens were removed for histochemical staining. By counting the numbers of specific dark reddish spots of CT26/DAP cells, we could estimate the number of tumor cells on the hepatic surface. RESULTS: At the very beginning following tumor cell injection, we found a significantly greater number of tumor cells on the hepatic surface in mice with gas insufflation (6354±1072 vs.2133±223, respectively;P=0.012). But the difference of these two groups became smaller and smaller as time went by. The number of tumor cells on the hepatic surface would reach the lowest level at postoperative 48 hours, and the tumor foci then began to grow both in size and number. The above patterns of dynamic change in tumor cell distribution were similar in mice both with and without gas insufflation. Average survival was slightly shorter in mice with gas insufflation, but the difference was not statistically significant. CONCLUSION: Pneumoperitoneum caused by gas insufflation may increase tumor cell spread from the portal system to the liver at the very beginning stage; however, there was no significant difference in long-term survival between mice with and without gas insufflation in this murine animal model.Mice colon cancer cell lines CT-26 were provided by Dr. I. J. Fidler, M.D. Anderson Cancer Center, Huston, Texas, and pDAP plasmid was provided by Dr. R. Mulligan, Massachusetts Institute of Technology, Cambridge, Massachusetts.Paper presentation at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.     

Initial results of a new procedure for treatment of malignant obstruction of the left colon

PURPOSE: This study was undertaken to analyze the results obtained in 38 unselected patients using a new and original procedure for treatment of malignant obstructions of the left colon. METHOD: This procedure involves three phases: 1) resolution of the obstruction by means of a stem placed at the site of the tumor; 2) recovery of the general state of the patient, study of the extent of disease, and mechanical preparation of the colon; 3) regulated and final surgery (if this is not suitable, the stent may be used as definitive palliative treatment). RESULTS: In 35 patients (92 percent), the obstruction was resolved with the stent. In 22 patients the three phases were completed, and in 13 patients the stent constituted definitive palliative treatment. Only one patient (2.6 percent) died after resection of the tumor. CONCLUSION: This procedure offers a new, safe, and efficacious option for treatment of neoplastic colorectal obstructions.