Decrease In Carcinoembryonic Antigen Research Articles

Successful long-term management of a patient with late-stage metastatic colorectal cancer treated with panitumumab

Recent approval and introduction into clinical practice of epidermal growth factor receptor inhibitors such as the chimeric monoclonal antibody cetuximab and the fully human monoclonal antibody panitumumab have provided new treatment options for chemotherapy-refractory patients. Here, we report a case of a 47-year-old man with metastatic, chemotherapy-refractory colorectal cancer who achieved long-term partial remission during panitumumab therapy. A 41-year-old male patient presented with a 24-hour history of abdominal pain and fever. A computed tomography (CT) scan revealed a voluminous and perforated abscess with a suspected tumour lesion in the sigmoid colon. The patient underwent sigmoidectomy and was diagnosed with a poorly differentiated necrotic carcinoma of the sigmoid colon with invasion in 13 of 19 tested lymph nodes. A colonoscopy revealed multiple tubular adenomas and a positron emission tomography CT scan showed multiple and bilateral hyperfixating lumbar-aortic lymph nodes leading to a final tumour classification of T4N2M1. Carcinoembryonic antigen (CEA) was elevated. The patient achieved a partial response following six cycles of FOLFIRI (irinotecan, 5-fluorouracil, leucovorin), then progressed and was enrolled in a trial where he received treatment with FOLFOX4 (oxaliplatin, leucovorin and 5-fluorouracil) with or without a vascular endothelial growth factor inhibitor (PTK787/ZK 222584 [valatinib]). Eight months later he progressed again and was included in a panitumumab (6mg/kg every 2 weeks) monotherapy trial. A partial response was noted after 8 weeks of therapy along with a rapid CEA reduction and decrease in lymph node size. The patient is continuing panitumumab treatment and is still in partial remission after 65 months' treatment. He has non-mutated KRAS and no human-anti-human antibodies have been detected. During treatment the patient has on occasion experienced grade 1-2 diarrhoea as well as folliculitis and acne-like rash up to grade 3 in severity. Cutaneous toxicity was managed with a combination dose interruption/reduction and the use of topical agents. No eye or nail toxicities occurred. This case shows that long-term responses are possible during panitumumab therapy and that this agent may be an effective long-term treatment option for selected patients with metastatic colorectal cancer. The associated skin toxicities can be successfully managed.

A Herpes Oncolytic Virus Can Be Delivered Via the Vasculature to Produce Biologic Changes in Human Colorectal Cancer

Genetically engineered herpes simplex viruses (HSVs) can selectively infect and replicate in cancer cells, and are candidates for use as oncolytic therapy. This long-term report of a phase I trial examines vascular administration of HSV as therapy for cancer. Twelve subjects with metastatic colorectal cancer within the liver failing first-line chemotherapy were treated in four cohorts with a single dose (3 x 10(6) to 1 x 10(8) particles) of NV1020, a multimutated, replication-competent HSV. After hepatic arterial administration, subjects were observed for 4 weeks before starting intra-arterial chemotherapy. All patients exhibited progression of disease before HSV injection. During observation, levels of the tumor marker carcinoembryonic antigen (CEA) decreased (median % drop = 24%; range 13-74%; P < 0.02). One of three individuals at the 10(8) level showed a 39% radiologic decrease in tumor size by cross-section and 75% by volume. HSV infection was documented from liver tumor biopsies. After beginning regional chemotherapy, all patients demonstrated a further decrease in CEA (median 96%; range 50-98%; P < 0.008) and a radiologic partial response. Median survival for this group was 25 months. During follow-up, no signs of virus reactivation were found. Multimutated HSV can be delivered safely into the human bloodstream to produce selective infection of tumor tissues and biologic effects.

Mutations of the Epidermal Growth Factor Receptor Gene Predict Prolonged Survival After Gefitinib Treatment in Patients With Non–Small-Cell Lung Cancer With Postoperative Recurrence

To evaluate the relationship between mutations of the epidermal growth factor receptor (EGFR) gene and the effectiveness of gefitinib treatment in patients with recurrent lung cancer after pulmonary resection. We sequenced exons 18-21 of the EGFR gene using total RNA extracted from 59 patients with lung cancer who were treated with gefitinib for recurrent lung cancer. Gefitinib effectiveness was evaluated by both imaging studies and change in serum carcinoembryonic antigen (CEA) levels. EGFR mutations were found in 33 patients (56%). Of these mutations, 17 were deletions around codons 746-750 and 15 were point mutations (12 at codon 858, three at other codons), and one was an insertion. EGFR mutations were significantly more prevalent in females, adenocarcinoma, and never-smokers. Gefitinib treatment resulted in tumor shrinkage and/or CEA decrease to less than half of the baseline level in 26 patients, tumor growth and/or CEA elevation in 24 patients, and gefitinib effect was not assessable in nine patients. Female, never-smoking patients with adenocarcinoma tended to respond better to gefitinib treatment. Gefitinib was effective in 24 of 29 patients with EGFR mutations, compared with two of 21 patients without mutations (P < .0001). Of note, del746-750 might be superior to L858R mutations for prediction of gefitinib response. Patients with EGFR mutations survived for a longer period than those without the mutations after initiation of gefitinib treatment (P = .0053). EGFR mutations were a good predictor of clinical benefit of gefitinib in this setting.

Salivary carcinoembryonic antigen as an inflammatory marker

In this study we examined concentration of carcinoembryonic antigen (CEA) in paired saliva and serum samples from healthy individuals and patients with periodontal disease. CEA concentration was determined immunoradiometrically using highly specific anti-CEA antibodies. The salivas from periodontally healthy subjects revealed CEA concentrations with median value of 62 mg/L. Distribution of salivary CEA concentrations in patients with periodontal diseases were very broad with median values: 74 mg/L (stage I), 84 mg/L (stage II), 240 mg/L (stage III) and 412 mg/L (necrotizing ulcerative periodontitis-NUP). Analysis of the obtained values indicated statistically significant increase in salivary CEA, in subjects with periodontal diseases. Metronisadole treatment in patients with NUP leads to statistically significant decrease in salivary CEA. The results obtained suggested salivary CEA as a potential marker of the alterations of periodontium.

Echogenicity of liver metastases from colorectal carcinoma is an independent prognostic factor in patients treated with regional chemotherapy

Echogenicity of liver metastases was found to be a predictive biologic factor influencing long-term outcome after curative liver resection. The current analysis focuses on the influence of echogenicity on survival in patients treated with intraarterial chemotherapy for unresectable colorectal carcinoma liver metastases. A retrospective analysis of prospectively collected data at the Department of Surgery at the University of New South Wales-affiliated St. George Hospital was performed. Two hundred twelve consecutive patients with unresectable hepatic metastases from colorectal carcinoma treated between May 1992 and September 2000 were analyzed. Echogenicity of metastases was measured intraoperatively using a 5 MHz probe. Overall survival difference was compared between hyper- and hypoechoic metastases on an intention-to-treat basis. At a median followup of 15.1 months, 47 patients (22%) were alive and 165 (78%) had died. A significant survival benefit was observed in patients having hyperechoic lesions (median survival 16.2 months, 95% confidence interval [CI] 13.9-18.5) compared to hypoechoic lesions (median survival 11.6 months, 95% CI 8-15.2), P < 0.01. Other prognostic factors were differentiation of the primary tumor (P < 0.02), percentage hepatic replacement (P < 0.05) and carcinoembryonic antigen decrease (P < 0.03). Echogenicity was identified as an independent prognostic factor in multivariate analysis (P < 0.009). Echogenicity is an important prognostic survival parameter.

Immunotherapy for medullary thyroid carcinoma by dendritic cell vaccination.

Recent studies suggest that immunization with autologeous dendritic cells (DCs) pulsed with tumor antigen result in protective immunity and rejection of established tumors in various human malignancies. The objective of this study was to develop a DC vaccination therapy in patients with metastasized medullary thyroid carcinoma (MTC). Mature DCs were generated from peripheral blood monocytes in the presence of granulocyte macrophage colony-stimulating factor, IL-4, and TNFalpha. After loading with calcitonin and carcinoembryonic antigen (CEA) peptide, 2-5 x 10(6) DCs were repeatedly delivered by sc injections. During follow-up (mean, 13.1 months) all patients developed a strong delayed-type hypersensitivity skin reaction caused by perivascular and epidermal infiltration with CD4+ memory T cells and CD8+ cytotoxic T cells. Clinical responses with a decrease of serum calcitonin and CEA were initially documented in three of seven patients. One of these patients had a complete regression of detectable liver metastases and a significant reduction of pulmonary lesions. T-cell response in this patient revealed a calcitonin- and CEA-specific immunreactivity. Our data indicate that vaccination with calcitonin and/or CEA peptide-pulsed DC results in the induction of a cellular, antigen-specific immune response in patients with MTC, leading to clinical response in some patients. Our approach may represent the basis for the development of new therapeutic strategies not only in MTC but also in other endocrine malignancies.

Pilot Study of Albendazole in Patients with Advanced Malignancy

Our preclinical studies have shown that the widely used antiparasitic drug albendazole has potent antiproliferative activity against colorectal cancer (CRC) and hepatocellular carcinoma (HCC). This trial was designed to evaluate albendazole in a small number of patients (n = 7) with either HCC or CRC and hepatic metastases refractory to other forms of therapy. Albendazole was given at 10 mg/kg/day orally in two divided doses for a period of 28 days. To follow the effect of treatment, tumor markers, carcinoembryonic antigen (CEA) or α-feto protein (AFP), were measured routinely in these patients. A range of hematological and biochemical indices were also serially measured to monitor bone marrow, kidney or liver toxicity. Albendazole therapy resulted in a decrease in CEA in 2 patients. In the remaining 5 with measurable tumor markers, serum CEA or AFP was stabilized in 3 patients, while in the other 2, after an initial stabilization (5–10 days), the markers began to increase. In the 7 patients completing the trial, albendazole was well tolerated and there were no significant changes in any hematological, kidney or liver function tests, but 3 patients were withdrawn for severe neutropenia which was probably contributory to the death of 1 patient. These data support our previous experimental results demonstrating that albendazole has antitumor effects.

The utility of monitoring carcinoembyronic antigen during systemic therapy for advanced colorectal cancer.

To determine if pre-treatment serum carcinoembryonic antigen (CEA) levels or changes in CEA values during treatment have prognostic value, we reviewed five prior fluorouracil/leucovorin-based trials and identified 125 colorectal cancer patients with no prior chemotherapy for metastatic disease in whom CEA values were available. Although pre-treatment serum CEA values did not predict for clinical response or time to progression, serial monitoring of CEA appeared to be useful in patients with an elevated pre-treatment CEA, particularly when a decrease in CEA occurred in concert with radiographic evidence of disease response. The CEA nadir was a strong prognostic variable with respect to time to disease progression. A consistent rise in CEA values over the minimum value signals the need for radiographic re-assessment of the patient's disease status to rule out disease progression.

CT findings after hepatic chemoembolization.

Hepatic arterial chemoembolization (CE) with a mixture of particulate collagen and chemotherapeutic agents was evaluated as therapy for hepatic metastases from colorectal carcinoma. This article describes the characteristics sequential pattern of change seen on liver CT scans following CE. Thirty CT scans were performed on seven patients who had undergone a total of 11 CE procedures. All patients had baseline, immediate postprocedural, and follow-up CT exams at 1 to 2 month intervals following CE. Immediate post-procedural CT scans mapped the area of embolization owing to the density of the contrast mixed with the CE agents. Some lesions seen easily on baseline were more difficult to see as they became isodense with normal liver. Reflux of embolic material into the cystic artery and gallbladder wall was also observed on postprocedural scans in three patients. In all patients, early follow-up scans (1 month after CE) demonstrated changes in lesions seen on baseline scans consistent with tumor necrosis. This was corroborated by a decrease in carcinoembryonic antigen (CEA) levels. In three patients, however, low attenuation regions developed in areas in which there had been no lesion before. The significance of these is uncertain, but the low CEA values and the subsequent evolution in appearance of these sites on CT suggest that they were regions of hepatic ischemia/infarction as opposed to heretofore unidentifiable metastases, now "unmasked." Intermediate follow-up scans (2-3 months) revealed maximal effect on tumor volume, with a decrease of > or = 25% in five of seven patients (71%). Late follow-up scans (> or = 3 months after the last CE) confirmed recurrent disease and new lesions in all cases.

Continuous intrahepatic infusion of floxuridine and leucovorin through an implantable pump for the treatment of hepatic metastases from colorectal carcinoma

Based on laboratory studies showing enhanced cytotoxicity of floxuridine (FUDR) when used with high doses of leucovorin (LV), a pilot study of FUDR and LV through an implantable pump was initiated for the treatment of hepatic metastases from colorectal cancer. The highest dose of LV that could be administered, taking into account the constraints of the capacity of the pump and the solubility of LV, was 120 mg/m2/d. Due to the possibility of added toxicity, 25% of this dose was initially used. Twenty-four patients were treated at three dose levels. Eight patients were treated with the combination of LV (30 mg/m2/d) and FUDR (0.3 mg/kg/d) for a 14-day infusion through the pump, alternating with 2 weeks of saline. All eight patients had a greater than 50% decrease in measurable disease (PR) and a greater than 50% decrease in carcinoembryonic antigen (CEA) value; however, sclerosing cholangitis developed in two of these patients within 4 months. The next seven patients were treated with a lower dose of FUDR (0.2 mg/kg/d) and the same dose of LV, both for 14 days. Four of seven patients had a PR, and toxicity was decreased with no biliary sclerosis. A third regimen explored the combination of FUDR (0.3 mg/kg/d) and LV (30 mg/m2/d) for 7 days, alternating with 1 week of saline, to evaluate a shorter interval of treatment with the same overall dose intensity. Six of nine patients had a PR and all patients had a greater than 50% decrease in CEA value; sclerosing cholangitis developed in three of these patients. The overall response rate was 72%, with 18 of 25 patients alive after 1 year. The median survival time has not been determined, but it is greater than 27 months. FUDR with LV appeared to be effective in the treatment of hepatic metastases from colorectal carcinoma, but hepatic toxicity appeared to be greater than that previously reported with FUDR alone.

Immunotherapy using freund’s adjuvant and recombinant interleukin-2 combined with transarterial chemoembolization for hepatocellular carcinoma

A new immunotherapy for hepatocellular carcinoma (HCC) using Freund's adjuvant and recombinant interleukin-2 (IL-2) combined with conventional transarterial chemoembolization therapy was performed. In 16 patients with HCC and one patient with metastatic liver cancer receiving this therapy, decrease and suppression of reelevation of alpha-fetoprotein after therapy was observed. Disappearance of tumor thrombi of HCC in the main portal vein was observed in a patient, and decrease of carcinoembryonic antigen was also observed in a patient with metastatic liver cancer. The present therapy using Freund's adjuvant and IL-2 is likely to open a new avenue for the treatment of patients with advanced liver cancer.

A phase I study of intraarterial iododeoxyuridine in patients with colorectal liver metastases.

Regional delivery of iododeoxyuridine (IdUrd) to patients with colorectal liver metastases was examined in a phase I study. The maximum-tolerated intraarterial (IA) dose (MTD) was 1,333 mg/m2/d administered continuously for 14 days. The dose-limiting toxicity was thrombocytopenia. Thrombocytopenia and leukopenia were correlated with the amount of IdUrd incorporated into DNA of peripheral granulocytes. In contrast to our experience with 5-fluorodeoxyuridine, there was no evidence of hepatobiliary toxicity. In 11 patients who received IA IdUrd alone, seven had a greater than or equal to 50% decrease in carcinoembryonic antigen (CEA) levels, with five having tumor volume reductions of 65%, 48%, 46%, 44%, and 27%. Thus, IA IdUrd alone has antitumor efficacy. Patients subsequently received IdUrd in combination with external beam radiation to a total dose of 2,400 cGy without acute local toxicity. In addition to these favorable clinical findings, we have previously shown that IdUrd is selectively incorporated into tumor DNA compared with normal liver in these patients. Further phase II evaluations of this approach are warranted.

Assessment of serial carcinoembryonic antigen: determinations to monitor the therapeutic progress and prognosis of metastatic liver disease treated by regional chemotherapy.

It is difficult, time-consuming, and expensive to evaluate the therapeutic efficacy of regional chemotherapy of metastatic liver disease by means of imaging procedures. Therefore it was the aim of this study to find out whether serial carcinoembryonic antigen (CEA) determinations yield reliable data on the therapeutic progress and the individual prognosis of these patients. Since there exists no generally accepted modality to assess CEA curves of patients receiving chemotherapy, we developed our own criterion and tested it in a group of 35 patients. For each patient an individual reference level (CEA-means) was fixed which was obtained as the arithmetical mean of serial CEA values taken during the first three courses of chemotherapy (reference time). On the basis of CEA-means the marker curves of the 35 patients could be divided into two groups. After the reference time the CEA values of group 1 (12 patients) never decreased below CEA-means. Survival of these patients was significantly (P = 0.00001) shorter than that of the 23 patients (group 2) who showed a decrease in their CEA curves below CEA-means after the reference time. Beyond this it could be observed that the improvement in survival was significantly greater in those patients who showed a CEA decrease below CEA-means for a prolonged period (3 months). This difference in prognosis is not an artefact due to different pretherapeutic conditions but is a sign of different responses to therapy. The decrease in CEA values below the individual reference level (CEA-means) is a certain sign of the efficacy of the chosen chemotherapy. A continuous rise of the CEA curve above CEA-means signifies an ineffective intrahepatic chemotherapy or extrahepatic tumor manifestation. In this case an intensive diagnostic workup of the patient and possibly a modification of the therapy are indicated.

Is there any clinical relevance of serial determinations of serum carcinoembryonic antigen in small cell lung cancer patients?

Carcinoembryonic antigen (CEA) serum concentrations were serially determined by an enzyme immunoassay before, during, and after chemotherapy and radiotherapy in 129 male patients with small cell lung cancer (SCLC). Pretherapeutic CEA concentrations were as follows: 2.5 ng/ml or less for 37% of the patients; greater than 2.5 but less than or equal to 5 for 27%; and greater than 5 for 36%. Before therapy, CEA levels in patients with extensive disease (median value, 5.8 ng/ml) were higher than those in patients with limited disease (3.0 ng/ml; P less than 0.01). Median survival in patients with pretherapeutic CEA titers of 5 ng/ml or less (median survival, 14.3 months) was significantly longer than in patients with CEA levels greater than 5 but less than or equal to 10 and CEA levels greater than 10, respectively (8.3 and 9.7 months; P less than 0.01). Patients with pretherapeutic CEA levels greater than 10 ng/ml showed a significant decrease (P less than 0.01) of CEA while reaching partial remission (PR) or complete remission (CR). In five of 16 evaluable patients, a continuous increase of CEA titers was seen starting at least 3 months before relapse could be defined by clinical, radiologic, or endoscopic means. However, the number of patients for whom CEA serum determinations reliably indicate stage of disease and outcome of therapy is small (at best, 10% of all SCLC patients), and pretherapeutic CEA level cannot be used for individual prognosis. Moreover, it is still uncertain whether earlier detection of relapse in SCLC can improve the therapeutic results. So far, the clinical relevance of serial CEA serum determinations in SCLC patients is rather low.

Phase I study and pharmacokinetics of caracemide (NSC-253272) administered as a short infusion.

A Phase I study of caracemide evaluating a short intravenous infusion repeated every 21 days is presented. Patients were entered at 85 mg/m2 with subsequent escalation levels of 170, 425, 595, and 795 mg/m2. Mild to moderate nausea and vomiting occurred at all dose levels. An apparent allergic reaction was observed at the 425 mg/m2 level. A "burning pain" originating in the mucosal areas of the head and neck, progressing to the chest and abdomen, was noted at the 425 mg/m2 level. Because of this observation, the infusion time was extended to 4 h. At the 795 mg/m2, this toxicity precluded completion of the 4 h infusion. Pharmacokinetic evaluation disclosed blood levels of 0.74-2.31 microgram/ml at the 425 mg/m2 during the 0.5 h infusion. At the same dose for a 4 h infusion time, blood levels were 0.15-0.18 microgram/ml. At 595 mg/m2 administered as a 4 h infusion, blood levels increased to 0.33 +/- 0.14 microgram/ml. The drug was cleared rapidly from the blood compartment with a half-life of 2.5 min and a total body clearance of 11.51/min/m2. No partial or complete response was observed. However, an advanced colon carcinoma patient experienced subjective pain relief with a decrease in carcinoembryonic antigen. The dose-limiting toxicity of caracemide using the 4 h infusion was an intolerable "burning pain" with a maximum tolerated dose of 795 mg/m2. Further characterization of this dose-limiting toxicity is required prior to further clinical evaluation of caracemide.

Hepatic arterial infusion with floxuridine and cisplatin: overriding importance of antitumor effect versus degree of tumor burden as determinants of survival among patients with colorectal cancer.

Cisplatin (CDDP) was combined with floxuridine (FUDR) and delivered into the hepatic arteries of 29 patients as induction therapy for colorectal cancer metastatic to the liver. Mitomycin C and FUDR combination was substituted after progression or when response had peaked. Chemotherapy was delivered with an Infusaid pump (Infusaid Corp; Norwood, Mass; 14 patients), Medtronic programmable drug administration device (Medtronic, Inc, Minneapolis; two patients), or percutaneously placed catheters (13 patients). Complete disappearance of liver metastases was observed in four patients and 11 additional patients had a partial remission as determined by computed tomography (CT) scan and substantiated at times by angiography, for a total response rate of 52%. Response as determined by imaging techniques coincided with a concurrent decrease in carcinoembryonic antigen (CEA) and improvement in performance status. The severity of tumor burden was correlated with the response to therapy and survival. Among those patients who responded to arterial chemotherapy, differences in disease severity did not significantly influence survival. Median survival among responders with greater than 25% liver replacement by tumor was 14 months (P = .28), compared with 28 months for those patients with less than 25% liver replacement. In contrast, differences in tumor burden significantly affected survival among patients who failed to respond to chemotherapy; median survival among nonresponding patients with greater than 25% liver replacement was 4 months, compared with 8 months for those who had less than 25% liver replacement (P = .01). The presence of minimal extrahepatic disease at the time of initiation of intraarterial treatment did not seem to have a significant detrimental effect on survival. The study suggests that hepatic tumor response to arterial administration of CDDP and FUDR and mitomycin C and FUDR is clinically significant because it overrides the effect of tumor burden on survival among patients who have colorectal cancer with liver metastases and may offer effective palliation.

Hepatic artery ligation and portal vein infusion for liver metastases from colon cancer.

Localized treatment of liver metastases from colon cancer has yielded better results than has systemic therapy. We report 19 patients with metastatic colon cancer whose bulk disease was limited to the liver, but was not amenable to surgical resection. Many of these patients had poor prognostic features: 14 had greater than 30% replacement of the liver, five had poorly differentiated tumor, and five had previously failed to respond to systemic chemotherapy. All were treated with hepatic artery ligation and portal vein infusion of chemotherapy (mitomycin C and 5-fluorouracil). Two patients (10%) died within one month postoperatively. The remaining 17 patients all improved clinically and demonstrated a marked decrease in carcinoembryonic antigen (CEA) levels. Based on follow-up physical exam, liver function tests, computed tomographic scan, and/or laparotomy, there were two complete responses, ten partial responses, four improved, and one indeterminate, for an objective response rate of 63%. Median survival of all patients was 13 months after hepatic artery ligation, and 14 months after diagnosis of liver metastases, with four patients still alive at 13+, 16+, 41+, and 61+ months after hepatic artery ligation. We believe that this form of therapy is an effective, well-tolerated alternative for patients with unresectable liver metastases.

Concomitant hepatic radiation and intraarterial fluorinated pyrimidine therapy: correlation of liver scan, liver function tests, and plasma CEA with tumor response.

Sixteen patients with metastatic disease to the liver (12 colorectal and four unknown primary tumors) were treated in a pilot study of hepatic irradiation (2500-3000 rads in 10-12 fractions) delivered concomitantly with continuous short-term intraarterial infusion of 5-fluorouracil (1 g/d) or FUDR (0.5 mg/kg/d) via a percutaneously placed hepatic artery catheter. Abnormal liver function tests, including SGOT, LDH, and alkaline phosphatase, decreased in all patients by day 7-10 of treatment, and other metabolic factors, including serum cholesterol, calcium, albumin, phosphorous, and uric acid, also decreased, often to subnormal levels by termination of treatment (day 15-20). These chemical alterations did not correlate with tumor response in that the identical pattern was observed in responders (ten patients) as well as nonresponders (six patients). Objective determinants of response were assessed by serial monitoring of the plasma carcinoembryonic antigen (CEA) and liver scan. In 14 patients with elevated CEA levels, tumor response (nine patients), nonresponse (four patients), and relapse (five patients) was predicted and confirmed by sequential monitoring of CEA. In one patient, a paradoxical decrease in plasma CEA was associated with progressive disease. The liver scan identified all responding patients but was difficult to quantitate and was delayed for months following subjective clinical response and changes in plasma CEA levels.

The value of serial carcinoembryonic antigen (CEA) in predicting response rate and survival of patients with gastrointestinal cancer treated with chemotherapy.

Elevated serum levels of carcinoembryonic antigen (CEA) were found in 70% of 141 patients with advanced gastrointestinal (GI) cancers. Serial CEA measurements were performed on 70 patients before and during chemotherapy. The majority were treated with 5-FU and Methyl-CCNU (33 patients), 5-FU (19 patients), or 5-FU and mitomycin-C (8 patients). In 49 patients with colorectal carcinoma who had elevated serum CEA prior to chemotherapy, 18 had objective partial tumor remission, 16/18 (89%) showed definite decrease in CEA level, one had no change, and one had an increase CEA titer. Thirty-one patients had either stable disease (10 patients) or increasing disease (21 patients) while on chemotherapy. Of these patients four showed decrease in CEA, eight had no change, and 19 had increase in CEA levels as compared to pretreatment value. The survival of patients with a decrease in CEA during chemotherapy was statistically significant (p = .03) as compared to survival of those with no change or increasing CEA levels. In 21 patients with other GI cancers, the correlation between the clinical response and change in CEA level observed was not as definite as in patients with colorectal carcinoma.

Plasma carcinoembryonic antigen versus plasma calcitonin in the diagnosis of medullary carcinoma of the thyroid

The value of carcinoembryonic antigen (CEA) assay for diagnosis and follow-up in patients suffering from medullary carcinoma of the thyroid (MCT) was investigated in a large sample (106 cases). High levels of CEA were found in 84% of patients suffering from either the sporadic or the familial form of the disease. Levels of CEA and calcitonin (CT) are significantly and positively correlated. Removal of tumoral tissue is followed by a decrease in both CEA and CT levels. High levels of CEA were also observed in the parents of patients suffering from the familial form of MCT. These patients were operated on and MCT was confirmed histologically. The limitations of the use of CEA assay in the diagnosis of MCT are discussed.