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Biomedical subjects

A M Cohen

Publications and source records attributed to A M Cohen.

At least 55 records · Page 3Linked to original sources
PubMed2000

Evaluation of myocardial viability in asymptomatic patients early after infarction with perfusion/metabolism single-photon-emission computed tomographic imaging and dobutamine echocardiography.

OBJECTIVE: To study the impact of detection of viability of myocardium in asymptomatic patients early (3-10 days) after Q-wave myocardial infarction on segmental recovery of left ventricular function after elective revascularization. METHODS: Patients were studied with low-dose dobutamine echocardiography (LDDE) and single photon-emission computed tomography with 99mTc sestamibi and [18F]-fluorodeoxyglucose (FDG) imaging. Viability of myocardium was defined as detection of improvement in segmental thickening of left ventricle by LDDE (versus baseline echocardiographic data), uptake of 99mTc sestamibi > 50% of maximum counts, uptake of [18F]-FDG > 50% of maximum normal, combined uptake of 99mTc sestamibi or [18F]-FDG > 50% of normal maximum, uptake of [18F]-FDG > 50% or mismatched pattern (uptake of [18F]-FDG greater than that of 99mTc sestamibi). Functional recovery was defined as improvement of segmental thickening of left ventricle detected at follow-up 8 weeks after infarction (versus baseline resting echocardiographic data). Interpretation of the tests was blinded with respect to the angiographic data and the results of the alternative method. RESULTS: In total 18 patients with 133 left-ventricle segments with abnormal contractile function at baseline were analysed; 29% were hypocontractile and 71% were noncontractile. Examination with LDDE showed that 18% of the segments had normal contractility and 26% were hypocontractile; the respective percentages were 29 and 28% according to follow-up resting echocardiography. Radionuclide tests for viability of myocardium gave positive results in 57% (uptake of [18F]-FDG > 50%) and 62% (uptake of 99mTc sestamibi > 50%) of cases. With respect to segmental analysis, there was a 25-27% positive concordance, a 24-27% negative concordance, and a 48-50% discordance between the LDDE and the radionuclide definitions of viability of myocardium. Additionally, there was no significant difference among sensitivities and specificities for the definitions of viability. The sensitivity was 69% for the uptake of 99mTc sestamibi > 50% criterion, and the highest specificity was 66% for the LDDE. Incorporation of imaging with [18F]-FDG into the analysis yielded a marginally higher sensitivity of 71% for the criterion of uptake of [18F]-FDG or 99mTc sestamibi > 50%, versus imaging with the 99mTc sestamibi alone. CONCLUSION: LDDE was more specific and radionuclide imaging more sensitive for detection of viability of myocardium in asymptomatic patients early after infarction. Possibly defective myocardial metabolization of glucose in the period early after infarction and the specific LDDE protocol applied account for the limited benefit of these studies in terms of facilitating prediction of segmental functional recovery after revascularization in this clinical setting.

Cardiotonic Agents↗
PubMed2000

Oral contraceptives can cause falsely low vitamin B(12) levels.

Serum vitamin B(12) radioimmunoassays may give falsely low results in patients with folate deficiency, multiple myeloma, megadose of vitamin C and following radioisotope organ scan. We evaluated 10 consecutive healthy women on oral contraceptives (OC) who had falsely low vitamin B(12) levels, as reflected by normal urine methylmalonic acid and plasma homocysteine. After 1-month cessation of OCs, vitamin B(12) returned to the normal range in all women. Transcobalamin I (TCI) blood level was decreased in 60% of patients. OCs may cause temporary low vitamin B(12) blood levels of no clinical significance that can be associated with low TCI levels

Adult↗
PubMed2000

Recombinant human erythropoietin reduces allogeneic blood transfusion requirements in patients undergoing major orthopedic surgery.

Blood loss is a significant problem encountered in patients undergoing total joint arthroplasty, and is considered to be one of the factors affecting the outcome of the operation. Traditionally these patients have been treated with blood transfusions. The introduction of recombinant human erythropoietin (rHuEpo) into clinical practice enabled assessment of its effectiveness to decrease the allogeneic blood transfusion requirement (BTR), thus avoiding or minimizing transfusion-related complications. Fifteen patients undergoing total hip replacement (THR, 10 patients) and total knee replacement (TKR, 5 patients) in our institute (from January-April 1997), were studied. After signing an informed consent they received daily s.c. rHuEpo (100 IU/kg for those with hemoglobin (Hb) > 13 g/dl, 300 IU/kg for Hb < 13) during the 10 days prior to surgery and the 4 days following the operation. Allogeneic red blood cell (RBC) transfusions were given as needed. Hb levels were measured on days -10, 0, +1.3 and 7 of the procedure and the BTR was recorded. The results were compared with those of previous patients operated on from January-December 1996. Patients who were eligible for the study but refused to participate served as controls. The mean Hb level in the study group prior to rHuEpo administration (day -10) was 13.41 g/dl, similar to those of the control group (13.47 g/dl on day 0). However, the mean Hb levels in the rHuEpo treated patients on days 0, 1, 3 and 7 were 14.37, 11.09, 10.99, and 11.2 g/dl, respectively. This way compared with the levels of 13.47 (p = 0.016), 9.88 (p = 0.024), 9.60 (p = 0.004) and 9.97 g/dl (p = 0.007) in the control patients. The difference between the rHuEpo treated patients and the control patients was more significant among the THR patients than among the TKR patients. Of the 10 rHuEpo-treated THR patients, only a single patient required one allogeneic blood unit, as compared with 23 units transfused to the 30 control patients. None of the rHuEpo-treated TKR patients required blood transfusion as opposed to 4 units needed by the 11 control patients. In total, only one allogeneic blood unit was required by the study group which way calculated to an average consumption of 0.066 blood unit per person, compared with 27 blood units used by the 41 controls, i.e. 0.66 blood units per person (p < 0.001). In the patients treated, rHuEpo was very well tolerated with no adverse effects.

Adult↗
PubMed2000

The incidence of pseudothrombocytopenia in automatic blood analyzers.

UNLABELLED: The aim of the present work was to undertake an assessment of the incidence of pseudothrombocytopenia (PTCP) in patients referred for evaluation of thrombocytopenia in an outpatient hematology clinic. METHODS: Prospective assessment of 60 consecutive cases with platelet count < 100 x 10(9)/l in a hematology clinic during a 2-year period. RESULTS: PTCP was the second most common cause for low platelet count, with an incidence of 17%. Platelet count of patients with PTCP at presentation was 42 +/- 22 x 10(9)/l, and when re-analyzed on fresh samples, 208 +/- 39 x 10(9)/l. The relatively high prevalence of pseudothrombocytopenia in our series was due to a lack of microscopic inspection of the blood smear in the primary care laboratories and considerable delay in sample processing. CONCLUSIONS: PTCP should be considered in the assessment of low platelet count. While decreasing the transfer time of blood specimens may decrease PTCP incidence, microscopic inspection of the blood smear may avoid erroneous diagnosis of thrombocytopenia.

Adult↗
PubMed2000

Phase I/II trial of recombinant methionyl human tumor necrosis factor binding protein PEGylated dimer in patients with active refractory rheumatoid arthritis.

OBJECTIVE: To evaluate the safety, immunogenicity, pharmacokinetics, and efficacy of intravenous administration of tumor necrosis factor binding protein (TNFbp) dimer in patients with rheumatoid arthritis (RA). METHODS: This phase I/II study was a multicenter, randomized, double blind, placebo controlled, ascending dose study evaluating TNFbp dimer administered by i.v. infusion. Thirty-three patients with RA divided into 3 cohorts received TNFbp dimer (30, 100, 300 microg/kg) or placebo during a 5 min infusion at baseline and at 3 and 6 weeks; patients were followed at routine intervals after each infusion through 77 days postinfusion. Pharmacokinetics were analyzed using a log-linear regimen and comparisons were made between half-life after first, 2nd, and 3rd doses. Plasma TNFbp dimer concentrations and serum antibody levels were used in the measurement of pharmacokinetics. RESULTS: Administration of 30 microg/kg of TNFbp dimer was generally well tolerated; the maximum tolerated dose was 100 microg/kg. No serious adverse events were reported. A significant antibody response affected the half-life and clearance of TNFbp dimer at each dose group. Anti-TNFbp antibodies were noncytotoxic and nonagonistic. Clinical evaluations provided evidence of in vivo activity of TNFbp dimer in these patients. CONCLUSION: TNFbp dimer administered to patients with long standing RA resulted in significant antibody production to the study drug. This effect reduced the half-life and clearance of the TNFbp. This TNFbp will not be a viable option for treating patients with RA secondary to immunogenicity.

Adult↗
PubMed2000

Pravastatin: an antithrombotic effect independent of the cholesterol-lowering effect.

Lipid-lowering with statins reduces blood thrombogenicity. However, it is unknown whether this is purely due to LDL-cholesterol reduction, or it is related to a statin or agent specific effect. We investigated the relationship between reduction in blood thrombogenicity and the magnitude of low-density lipoprotein cholesterol (LDL-C) during pravastatin therapy. We prospectively followed for 6 months 57 hyperlipidemic patients who initiated therapy with pravastatin, and 36 patients who were randomized into placebo plus diet. Pravastatin-treated patients were grouped according to the LDL-C reduction at 6 months; (i) "adequate LDL-C reduction": LDL-C reduction >30% from baseline or LDL-C<125 mg/dl (n = 38; LDL-C reduction 74 +/- 4 mg/dl; 6-month LDL-C 119 +/- 5 mg/dl); (ii) "inadequate LDL-C reduction": neither of the above criteria (n = 19; LDL-C reduction 31 +/- 5 mg/dl; 6-month LDL-C 158 +/- 6 mg/dl). Placebo patients were divided into those "with LDL-C reduction" (n = 17, mean reduction 21 +/- 5 mg/dl) and those "without LDL reduction" (n = 19). The following parameters were altered at 6 months in both patients with "adequate" and "inadequate" LDL-C reduction: (1) tissue plasminogen activator decreased by 1.4 +/- 0.4 and 1.5 +/- 0.5 ng/ml respectively (p = NS); (2) plasminogen activator inhibitor-1 decreased by 8.7 +/- 2.0 and 10.1 +/- 2.7 ng/ml respectively (p = NS); (3) thrombus formation under dynamic flow conditions decreased by 3.5 +/- 0.9 and 2.8 +/- 1.2 microm2 x 10(3) respectively (p = NS). In contrast, no significant changes from baseline were noted in placebo-treated patients, regardless of their LDL-C reduction category, and multivariate analysis eliminated LDL-C reduction as an independent predictor of reduction in thrombogenicity. Therefore, the reduction in thrombogenicity was not proportional to the magnitude of LDL-C reduction suggesting that a class or agent specific property is primarily responsible for the pro-fibrinolytic/antithrombotic effects observed.

Aged↗
PubMed2000

Radical surgery for rectal cancer: why we fail and rationale for current clinical trials of adjuvant therapy.

The major goals in the treatment of patients with rectal cancer are overall cure, maximizing local control, and maintaining quality of life. Quality of life issues include avoidance of a permanent stoma and maintaining adequate bowel, sexual, and urinary function. Optimizing the surgical technique with a more selective application of adjuvant therapy will meet these goals. This article describes the likely explanations for local and distant recurrence and delineates current clinical trials of adjuvant therapy directed toward minimizing failure despite potentially curative surgical resection.

Chemotherapy, Adjuvant↗
PubMed2000

NCCN Practice Guidelines for Colorectal Cancer.

The NCCN Colorectal Cancer Guidelines panel believes that a multidisciplinary approach is necessary for the management of the patient with colorectal cancer. The panel endorses the concept that treatment of patients in a clinical trial has priority over standard or accepted therapy. The recommended surgical procedure for resectable colon cancer is an en bloc resection; laparoscopic surgery should be done only in the context of a clinical trial. For patients with stage III disease, 5-FU-based adjuvant therapy is recommended. A patient who has metastatic disease in the liver or lung should be considered for surgical resection if he or she is a candidate for surgery and if surgery can extend survival. Surgery should be followed by adjuvant chemotherapy. The panel advocates a conservative post-treatment surveillance program for colon and rectal carcinoma patients. Serial CEA determinations are appropriate if the patient is a candidate for aggressive surgical resection, should recurrence be detected. Abdominal and pelvic CT scans should be utilized only when there are clinical indications of possible recurrence. Patients whose disease progresses during 5-FU-based therapy should be treated with irinotecan or encouraged to participate in a phase I or phase II clinical trial.

Colorectal Neoplasms↗
PubMed1999

Hepatic arterial infusion of chemotherapy after resection of hepatic metastases from colorectal cancer.

BACKGROUND: Two years after undergoing resection of liver metastases from colorectal cancer, about 65 percent of patients are alive and 25 percent are free of detectable disease. We tried to improve these outcomes by treating patients with hepatic arterial infusion of floxuridine plus systemic fluorouracil after liver resection. METHODS: We randomly assigned 156 patients at the time of resection of hepatic metastases from colorectal cancer to receive six cycles of hepatic arterial infusion with floxuridine and dexamethasone plus intravenous fluorouracil, with or without leucovorin, or six weeks of similar systemic therapy alone. Patients were stratified according to previous treatment and the number of liver metastases identified at operation. The study end points were overall survival, survival without recurrence of hepatic metastases, and survival without any metastases at two years. RESULTS: The actuarial rate of overall survival at two years was 86 percent in the group treated with local plus systemic chemotherapy and 72 percent in the group given systemic therapy alone (P=0.03). The median survival was 72.2 months in the combined-therapy group and 59.3 months in the monotherapy group, with a median follow-up of 62.7 months. After two years, the rates of survival free of hepatic recurrence were 90 percent in the monotherapy group and 60 percent in the monotherapy group (P<0.001), and the respective rates of progression-free survival were 57 percent and 42 percent (P=0.07). At two years, the risk ratio for death was 2.34 among patients treated with systemic therapy alone, as compared with patients who received combined therapy (95 percent confidence interval, 1.10 to 4.98; P=0.027), after adjustment for important variables. The rates of adverse effects of at least moderate severity were similar in the two groups, except for a higher frequency of diarrhea and hepatic effects in the combined-therapy group. CONCLUSIONS: For patients who undergo resection of liver metastases from colorectal cancer, postoperative treatment with a combination of hepatic arterial infusion of floxuridine and intravenous fluorouracil improves the outcome at two years.

Adenocarcinoma↗
PubMed1999

Gender differences in blood thrombogenicity in hyperlipidemic patients and response to pravastatin.

Thrombotic risk in hyperlipidemic women and its response to lipid therapy is unknown. We prospectively studied 28 men and 29 women with high low-density lipoprotein (LDL) cholesterol during 6 months of therapy with pravastatin. Women had significantly higher high-density lipoprotein (HDL) cholesterol (54.2 +/- 1.7 vs 39.5 +/- 2.2 mg/dl, p <0.01), lower prevalence of coronary artery disease (41% vs 67%, p = 0.04), and otherwise similar baseline characteristics compared with men. Both genders achieved a 33% reduction in LDL at 6 weeks (188 +/- 6 to 133 +/- 5 mg/dl) and maintained similar LDL levels throughout the study. Systemic hemostatic markers and thrombus formation under dynamic flow conditions were evaluated at baseline, and at 3 and 6 months of follow-up. Prothrombin fragment F1.2, a marker of thrombin generation, was higher in women versus men at baseline (2.4 +/- 0.2 vs 1.4 +/- 0.3 nmol/L, p = 0.02). The levels decreased in women to 2.0 +/- 0.3 nmol/L at 3 months and to 1.6 +/- 0.2 nmol/L at 6 months (p <0.045, analysis of variance), whereas it remained unchanged in men. Plasminogen activator inhibitor-I significantly decreased at 3 and 6 months of follow-up: by 12.6% and 18.7%, respectively, in women, and by 18.8% and 23.5%, respectively, in men. Similarly, tissue plasminogen activator decreased significantly by 7.4% in women and 11.8% in men at 6 months compared with baseline. Fibrinogen showed an increase in both genders at follow-up. Thrombus formation was similar at baseline between the 2 genders, and decreased at 3 and 6 months compared with baseline by 12.5% and 29.5% in women, and by 18.6% and 19.4% in men (p <0.04 at 6 months vs baseline in both men and women). Other markers, including C-reactive protein, fibrinopeptide A, D-dimer, and factor VIIa, did not differ between genders and did not change with therapy. Thus, despite higher HDL, and lower incidence of coronary disease, women with high LDL had a comparable thrombotic and/or fibrinolytic profile to men and even evidence of increased thrombin generation at baseline. Blood thrombogenicity was reduced with pravastatin in both genders; in addition, thrombin generation was gradually reduced in women to a level similar to that of men by 6 months of follow-up.

Aged↗
PubMed1999

Conservative management of rectal cancer with local excision and postoperative adjuvant therapy.

BACKGROUND: To determine the local control, survival, and functional outcome of local excision plus postoperative therapy for patients with rectal cancer. METHODS: A total of 39 patients underwent a local excision (2 with snare excision of a T1 polyp and 37 with full-thickness local excision) followed by postoperative radiation therapy +/- 5-FU-based chemotherapy. The median follow-up was 41 months, and 11 patients had positive margins. RESULTS: The 5-year actuarial colostomy-free survival was 87% and overall survival was 70%. Crude local failure increased with T stage: 0% T1, 24% T2, and 25% T3. Of the 8 patients (21%) who developed local failure, 5 underwent salvage APR and were locally controlled. Actuarial local failure at 5 years was 31% for T2 disease and 27% for the total patient group. In the 32 patients with an intact sphincter, 94% had good to excellent sphincter function. CONCLUSION: Although local failure in patients with T2 tumors has increased since our prior report, the survival, sphincter function, and local salvage rates are acceptable. Local excision and postoperative therapy remains a reasonable alternative to APR in selected patients.

Adenocarcinoma↗
PubMed1999

Production of prostanoids and nitric oxide by infarcted heart in situ and the effect of aspirin.

The production of prostacyclin (PGI2) and thromboxane A2 (TXA2) in infarcted and noninfarcted portions of the rabbit heart was studied prior to and following administration of acetylsalicylic acid (aspirin). Aspirin was administered intravenously (iv) as water-soluble Aspisol, d-lysinmono (acetylsalicylate) (Bayer, Leverkusen, Germany) into an ear vein. A branch of the left circumflex coronary artery was ligated. The animals were divided into three groups. The first group received 150 mg/kg/day of aspirin (75 mg/kg of aspirin every 12 h, n = 10). The first administration of aspirin was 1 h after ligation of the coronary artery and the last injection was 1 h before euthanasia. The second group received 5 mg/kg/day of aspirin (every 24 h, n = 10). A separate group of rabbits not receiving aspirin served as controls (n = 12). Two days following onset of ischemia, inducible form of nitric oxide synthase (iNOS) was measured in heart muscle and the oxidation products of nitric oxide (nitrite, NO-2 plus nitrate, NO-3: their sum referred to as NOx) were determined in arterial and coronary venous blood. Concentrations of both PGI2 and TXA2 were elevated in the infarcted portions of the heart compared to the noninfarcted regions. Formation of prostanoids was accompanied by increased activation of iNOS. Both doses of aspirin diminished the concentrations of PGI2 and TXA2 in infarcted heart muscle; in contrast, small doses of aspirin failed to influence myocardial iNOS activity. Apparently small doses of aspirin changed the relationship of iNOS to cyclooxygenase (COX). Coronary arterial-venous difference of NOx and myocardial iNOS activity showed parallel increases. Diminution of prostacyclin by aspirin can damage gastric mucosa and interfere with vasodilatation. Since NO counters these deficiencies, a combination of aspirin with a nitric oxide donor may be advantageous.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

30 Gy may be an adequate dose in patients with anal cancer treated with excisional biopsy followed by combined-modality therapy.

BACKGROUND AND OBJECTIVES: There are a subset of patients with invasive anal cancers who undergo an excisional biopsy either before or after combined-modality therapy (CMT). The objective of this study is to determine whether these patients can be adequately treated with a lower dose of pelvic radiation therapy. METHODS: A total of 25 patients were treated with CMT either before or after an excisional biopsy. The four subsets included 8 patients with initial excision followed by CMT with 30-34 Gy (EX/30), 6 patients with initial excision followed by CMT with 45-50.4 Gy (EX/45), 10 patients treated by CMT with 30 Gy followed by an excision (30/EX), and 1 patient by CMT with 45 Gy followed by an excision (45/EX). RESULTS: For the total group, the actuarial 5-year disease-free survival was 78%, overall survival was 86%, colostomy-free survival was 91%, and local control was 82%. When patients received CMT either before or following an excision, the actuarial local control and survival results with 30-34 Gy vs. 45-50.4 Gy were similar. In contrast to radiation dose, in patients who received 30-34 Gy, the sequence of the excision (before or after CMT) did appear to have a borderline significant impact on local control. Actuarial 5-year local control was 100% for EX/30 vs. 67% for 30/EX (P = 0.08). CONCLUSIONS: Because of the small number of patients in each group and the retrospective nature of the analysis, it is difficult to draw definitive conclusions from this study. However, our data suggest that in patients who are selected to undergo an initial excisional biopsy followed by CMT, 30 Gy may be an adequate radiation dose. Local control may be higher in patients who undergo an excisional biopsy followed by CMT compared with the converse.

Adenocarcinoma↗
PubMed1999

Sphincter preservation of leiomyosarcoma of the rectum and anus with local excision and brachytherapy.

PURPOSE: The aim of this study was to determine the outcome of patients with leiomyosarcoma of the rectum or anus treated with local excision and brachytherapy. METHODS: Eight patients with leiomyosarcoma of the rectum (7 patients) or anus (1 patient) were treated with a transanal excision followed by a temporary iridium-192 interstitial implant to 4,500 cGy. Median tumor size was 4.2 (range, 1.5-5) cm. Margins were positive in six patients, negative in one patient, and close in one patient. RESULTS: With a median follow-up of 53 months, median survival time was 53 months and the three-year actuarial survival rate was 71 percent. The cumulative incidence of failure as a component of failure for local was 25 percent (2/8), for abdominal was 0 percent (0/8), and for distant was 25 percent (2/8). Four patients eligible for functional analysis all had excellent sphincter function (1-2 bowel movements per day, no soilage). CONCLUSION: In selected patients the use of conservative surgery followed by brachytherapy is a reasonable alternative to an abdominoperineal resection. However, more experience and longer follow-up are needed before this approach can be recommended routinely.

Anal Canal↗
PubMed1999

Varying features of early age-of-onset "sporadic" and hereditary nonpolyposis colorectal cancer patients.

PURPOSE: Although the criteria for clinical diagnosis of hereditary nonpolyposis colorectal cancer are not fully agreed on, young age seems to be a common trait. The purpose of this study is to identify clinicopathologic features of hereditary nonpolyposis colorectal cancer in early age-of-onset colorectal cancer patients stratified as a function of family cancer history. METHODS: Two hundred thirty consecutive colorectal cancer patients 40 years or older at time of diagnosis were registered into an ongoing database during a ten-year period. Accurate family history was obtained via medical records, telephone calls, and questionnaires on 146 patients. According to extent of family history of cancer, patients were stratified into seven groups: 1) fulfilling Amsterdam criteria, 2) fulfilling less strict criteria, 3) having at least one first-degree relative with colorectal cancer, 4) having at least one distant relative with colorectal cancer, 5) having at least one first-degree relative with any cancer, 6) having at least one distant relative with any cancer, 7) having no family history of cancer. RESULTS: Twenty-two of 146 patients fulfilled Amsterdam and less strict hereditary nonpolyposis colorectal cancer criteria (15 percent). These hereditary nonpolyposis colorectal cancer patients were significantly younger (31 vs. 35 years; P = 0.0003) and had more metachronous colorectal cancer (27 percent vs. 2 percent; P = 0.007) and less colorectal cancer with nodal or metastatic spread than the non-hereditary nonpolyposis colorectal cancer patients (35 percent vs. 65 percent; P = 0.01). CONCLUSION: Precise familial cancer assessment in early age-of-onset colorectal cancer increases the yield of hereditary nonpolyposis colorectal cancer diagnosis. Because of the frequent development of metachronous colorectal cancer and favorable prognosis, extensive rather than segmental surgery should be considered in early age-of-onset colorectal cancer patients belonging to hereditary nonpolyposis colorectal cancer families.

Adolescent↗
PubMed1999

All patients with small intramural rectal cancers are at risk for lymph node metastasis.

PURPOSE: Although local excision can be curative in patients with early-stage rectal cancer, approximately 20 percent of patients will develop local recurrence, many as a result of unrecognized and unresected regional lymph node metastases. Our objective was to determine if standard pathologic factors can predict lymph node metastases in small intramural rectal cancers and provide a basis for patient selection for nonradical surgery. METHODS: Between June 1986 and September 1996, 318 patients with T1 or T2 rectal cancers underwent radical resection at our institution. Of these, 159 patients (48 T1 and 111 T2) were potentially eligible for curative local excision (< or =4 cm in size, < or =10 cm from the anal verge, no synchronous metastases), and the prevalence of lymph node metastases based on T stage and other pathologic factors was analyzed in this group. RESULTS: The overall frequency of lymph node metastasis was 15 percent (24/159 patients). T stage (T1, 10 percent; T2, 17 percent), differentiation (well-differentiated or moderately differentiated, 14 percent and poorly differentiated, 30 percent), and lymphatic vessel invasion (lymphatic vessel invasion-negative, 14 percent and lymphatic vessel invasion-positive, 33 percent) influenced the risk of lymph node metastasis. However, only blood vessel invasion (blood vessel invasion-negative, 13 percent and blood vessel invasion-positive, 33 percent) reached statistical significance as a single predictive factor (P=0.04). Tumors with no adverse pathologic features (low-risk group) had a lower overall frequency of lymph node metastasis (11 percent) compared with the remaining tumors (high-risk group, 31 percent; P=0.008). However, even in the most favorable group (T1 cancers with no adverse pathologic features) lymph node metastases were present in 7 percent of patients. CONCLUSION: In rectal cancer patients potentially eligible for local excision, the overall risk of undetected and untreated lymph node metastases is considerable (15 percent). The use of pathologic factors alone after local excision does not reliably assure the absence of lymph node metastases.

Adenocarcinoma↗
PubMed1999

Signet-ring cell carcinoma of the colon and rectum: a matched control study.

PURPOSE: There is little information comparing signet-ring cell carcinoma to common non-signet-ring cell colon and rectal cancers. The aim of this study was to better define the clinicopathologic differences between these two distinct entities. METHODS: Using a prospective database of 5,350 surgical patients with rectal cancers operated on at Memorial Sloan-Kettering Cancer Center between 1986 and 1997, 46 patients with signet-ring cell carcinoma were identified. Signet-ring cell carcinoma lesions were those in which signet-ring cells constituted more then 50 percent of the tumor. Six patients who presented with recurrent disease were excluded from the study. Control patients were matched for age, gender, TNM stage, primary site, procedure, and adjuvant therapy. Age, primary site of the tumor, stage at presentation, and survival times of patients with signet-ring cell carcinoma were also compared with 3,371 patients with primary non-signet-ring cell rectal cancers. Survival was calculated using Kaplan-Meier survival estimates. RESULTS: Mean age of the signet-ring cell carcinoma group was 59 +/- 12 years and median age was 61 (range, 20-91) years. Male-to-female ratio was 1.1:1. Lymphatic and peritoneal spread was more common among the signet-ring cell carcinoma group. Approximately one-third of signet-ring cell carcinoma patients presented with metastatic disease. Mean survival time of the signet-ring cell carcinoma group was 45.4 months (95 percent confidence interval, 26.9-63.8) compared with 78.5 months (95 percent confidence interval, 62.0-94.9) for the control patients group; P = 0.02 by the log-rank test. The cumulative survival curve of patients with signet-ring cell carcinoma resembles that of patients with poorly differentiated rectal cancers. CONCLUSIONS: Patients with signet-ring cell carcinoma of the colon and rectum have a worse prognosis compared with matched controls with the same stage of disease.

Adult↗