Growing colorectal tumors: minimizing microbial and stromal competition and assessing in vitro selection pressures.

Development of primary colorectal cancer cell lines ishampered by contamination from regional microbes, overgrowthof stromal cells, and purported genetic drift from selectionpressures in vitro. We initiated 32 primaryadenocarcinomas, 3 recurrences and 6 distant metastases incell culture. Twelve cell lines from eleven tumors weregenerated (26.8%) overall. Nine of 32 primary tumorsyielded 10 cell lines, 5 were lost to contamination, 13 wereoverwhelmed by stromal cells, and 5 demonstrated no growth.Addition of isobutyl methyl xanthine (IBMX) to culturelimited fibroblastoid growth. There was no associationbetween tumor location (p = 0.535, mid-P), degree ofdifferentiation (p = 0.850, mid-P) or clinicopathologic stage(p = 0.400, mid-P), and the ability of cells to becomeestablished in culture. The majority of cell lines hadsimilar nuclear DNA content and expression of cell-surfaceantigens compared with their parent tumors. Microbialcontamination and stromal cell overgrowth present thegreatest obstacle to capturing a representative bank ofcolon tumors in vitro.

Evidence for tumor-host cooperation in regulating MMP-2 expression in human colon cancer.

Matrix metalloproteinase 2 (MMP-2) facilitates tumor growth and metastasis in colon cancer. Although tumor cells may produce MMP-2, stromal cells, such as macrophages and fibroblasts, contribute significantly to MMP-2 synthesis in human tumors. We characterized four human colon cancer cell lines with differing biological behavior for MMP-2 expression. While the parent tumors from which the cell lines were derived all expressed MMP-2 mRNA, MMP-2 transcripts were detected in only one cell line, TF-17C, which is nontumorigenic in a nude mouse tumor model. TF-43C, which is tumorigenic and metastatic in the same tumor model, did not produce MMP-2, yet the tumors which arose from it after injection into nude mice did contain MMP-2 mRNA, suggesting a contribution from stromal cells. Co-culturing TF-43C with fibroblasts resulted in an increase in MMP-2 protein, whereas co-culturing with the nontumorigenic cell line TF-13Cm did not alter constitutive fibroblast MMP-2 secretion. Conditioned medium from TF-43C cells also stimulated fibroblast MMP-2 production. These data suggest that a soluble factor from TF-43C cells can stimulate fibroblast MMP-2 production and support the hypothesis that colon cancer cell interactions with stromal fibroblasts may be important determinants of tumor behavior in vivo.

The significance of allelic deletions and aneuploidy in colorectal carcinoma. Results of a 5-year follow-up study.

BACKGROUND: A prospective study was initiated to analyze the prognostic value of both the deletion of candidate tumor suppressor genes and the DNA content in colorectal carcinoma specimens. METHODS: A prospective study was initiated in 1988, into which 104 patients from the Brooklyn VA Medical Center were accrued through March 1992. DNA restriction endonuclease digests, obtained by the Southern blot technique, were examined for allelic deletions by cDNA probes pnm23-H1 (17q21) YNZ 22.1 (17p13), and p15-65 (18q21). DNA content was measured by image analysis cytometry of Feulgen-stained tumor imprints. Median follow-up was 5.5 years (range, 4-8.5 years). RESULTS: Patients with nm23-H1 allelic deletions were 3 times as likely to develop distant metastases as patients without nm23-H1 deletions (relative risk [RR], 3.89; 95% confidence interval [CI], 1.39, 10.89). This connection was even stronger after adjustment for TNM stage and site of primary tumor (RR, 5.27; 95% CI, 1.67, 16.68). No significant association of 17p or 18q deletions or ploidy with either distant metastases or overall survival was noted. In multivariate analysis, clinicopathologic variables associated with decreased survival included intracellular mucin production, nuclear grade, TNM stage, and nerve invasion. CONCLUSIONS: A combination of clinicopathologic and molecular biologic variables may identify patients at high risk for death from disseminated colorectal carcinoma.

Moose-motor vehicle collisions. An increasing hazard in northern New England.

OBJECTIVE: To analyze the epidemiology and epizootiology of moose-motor vehicle collisions (MMVC) and outcomes in severely injured patients to identify variables that might be modified to reduce the impact of this mutually deleterious interspecies interaction. DESIGN: Wildlife and Traffic Safety databases permitted retrospective, population-based assessment of MMVC epidemiology. A case series compiled from hospital trauma registries characterized morbidity and mortality from MMVC. SETTING: New Hampshire and Maine area. PATIENTS: All victims of MMVC (1980 through 1991) were included in population-based analyses. Twenty-three patients hospitalized at three rural trauma centers (January 1990 through June 1994) were included in the case series. MAIN OUTCOME MEASURES: Location, time of day and seasonal occurrence of MMVC were determined. Injury patterns and Injury Severity Scores were analyzed in 23 representative patients. Maine's 1991 traffic and medical data were linked, and factors predictive of injury from MMVC were identified using multivariate logistics. RESULTS: Most MMVC occur from April through October after dark. Of 23 subjects, 70% sustained head and/or face injuries and 26%, cervical spine injuries. Mortality was 9%. Mean Injury Severity Score was 15.7 (SD=9.0). Safety belt use, rear seat location, and light truck occupancy were associated with reduced injury (p<.05). CONCLUSIONS: Moose-motor vehicle collisions are increasing in rural regions. Prevention programs should emphasize defensive driving and seat belt use, especially during high-risk periods. Injury patterns in MMVC suggest a need for automobile design modifications that better protect the passenger compartment form direct impact.

Adenocarcinoma arising within a colonic diverticulum: report of two cases and review of the literature.

The first reported cases of colonic carcinoma arising within a diverticulum are documented. Although colonic diverticulitis and cancer are common diseases in patients over 60 years of age, cancer arising within a diverticulum is rare. Only close histopathologic scrutiny can differentiate inflammatory changes from neoplasia. Because colonic diverticula are characteristically thin-walled, cancers arising within diverticula may easily penetrate the serosa and first be diagnosed at an advanced stage despite their small size.

Association of nm23-H1 allelic deletions with distant metastases in colorectal carcinoma.

A prospective study analysed the prognostic value of nm23-H1 allelic deletions in colorectal cancer. Of 21 patients with no evidence of distant metastases at initial operation, 11 showed nm23-H1 allelic deletions (including 1 homozygous deletion); 10 had no nm23-H1 deletions. After median follow-up of 25 months, distant metastases had developed in 8 of 11 (73%) patients with nm23-H1 deletions but in only 2 of 10 (20%) without nm23-H1 deletions (p less than 0.03). Tests with probe YNZ 22.1, near p53, showed no significant association with distant metastases. nm23-H1 may be, or may be located near, a late-acting suppressor gene in colorectal carcinoma, in which deletions may have prognostic value.

Tumor metastasis and nm23: current concepts.

Reduced expression and/or somatic allelic deletion of nm23 is associated with high metastatic potential in several types of rodent tumors and human breast and colorectal carcinomas. Transfection of murine nm23-1 cDNA into highly metastatic murine K-1735 TK melanoma cells results in a reduced incidence of primary tumor formation, significant reduction in tumor metastatic potential, and altered responsiveness to the cytokine, transforming growth factor beta. Here we discuss emerging concepts concerning nm23, such as its varied pattern of alteration/expression in tumor metastasis, its effect on tumorigenesis, and its possible biochemical functions.

Localization of radioiodinated monoclonal antibody in colorectal cancer. Initial dosimetry results.

HT-29-15 is an IgG1 monoclonal antibody reacting with a neuraminidase-sensitive determinant on a cell-surface antigen (molecular weight, 200,000 daltons) present on the colon cancer cell line HT-29. HT-29-15 was selected for a tumor localization study because the antigen was shown to be present, by immunohistochemical staining, in a high percentage of primary and metastatic colorectal cancers. HT-29-15 labeled with iodine 131 was given intravenously over a dose range of 0.2 to 10.0 mg to 23 patients with colorectal cancer. No significant toxicity was seen. Imaging of hepatic metastases was successful from days 5 to 7. Analysis of tissue radioactivity by biopsy showed that the tumor-liver ratio increased from day 1 to day 7, suggesting more rapid clearance of antibody from normal tissue than from tumor. Thus, tissue biopsy specimens and scintigraphy have shown that imaging of metastatic colorectal cancer is possible with monoclonal antibody HT-29-15. Tissue biopsy specimens are essential for demonstrating specificity of localization. Scans alone provide insufficient evidence of specific localization by monoclonal antibodies. Simultaneous infusion of a nonreactive control antibody would be necessary for specific localization to be demonstrated unequivocally.

Biologic considerations and operative strategy in papillary thyroid carcinoma: arguments against the routine performance of total thyroidectomy.

Reasons cited for the routine performance of total thyroidectomy in patients with papillary thyroid carcinoma include: fear of multicentric neoplastic foci causing local recurrence and death; risk of anaplastic transformation of unresected multifocal microscopic carcinoma; toxicity of high-dose radioactive iodine to ablate normal thyroid remnants; and lack of reliable criteria for grading malignancy and identifying patients at high risk. However, autopsy studies have detected microscopic foci of papillary thyroid cancer as incidental findings in up to 24% of patients dead of other diseases. The prevalence of anaplastic transformation of papillary thyroid carcinoma as determined from reports in the literature is less than 1%. A retrospective investigation of 90 patients with papillary thyroid carcinoma derived from the Swedish National Cancer Registry showed no complications from radioiodine ablation of postoperative thyroid remnants in 45 patients. Retrospective analysis of the DNA content of tumors at the time of the initial operation showed a significant difference between a group of 10 patients who died of recurrent and metastatic papillary thyroid carcinoma and a group of 16 patients alive at least 10 years after operation despite distant metastases or recurrent cancer in the thyroid bed and/or cervical lymph nodes. The risk of permanent hypoparathyroidism is higher in patients after total thyroidectomy without apparent improvement in survival rates when compared with less extensive resections. Therefore it is proposed that the criteria for total thyroidectomy in patients with papillary thyroid carcinoma be limited to: tumors that clinically involve both lobes of the thyroid gland, extracapsular spread of cancer requiring enbloc resection, and reoperations where scarring prevents accurate delineation of the extent of the tumor. By differentiating patients at high risk for death from papillary thyroid carcinoma from patients at low risk, the measurement of DNA content may decrease the need for routine total thyroidectomy.

Lessons of parathyroid reoperations.

The case histories of the 23 patients in this series demonstrate the importance of a systematic approach to parathyroid surgery. Ligation of the superior thyroid vessels and mobilization of the upper pole of the thyroid are often necessary to find the superior parathyroid glands that are located on the posterior surface of the thyroid. Devascularization of the thyroid gland does not occur with this maneuver because of abundant collateral circulation from the inferior thyroid artery and tracheal vessels. Normal appearing parathyroid glands should not be resected because this procedure does not treat hypercalcemia and may leave the patient with insufficient parathyroid tissue if an adenoma is found at a later date. Bilateral cervical exploration [35,36] is performed before resection of any abnormal appearing parathyroid tissue. Patients may also have supernumerary parathyroid glands [16], especially in the inferior cervical and superior mediastinal areas that are associated with the thymus [37,38].

Thermal-energy dissipation: a laboratory study to assess patency in blood vessels.

Surgeons involved in the repair of small blood vessels could benefit from a postoperative monitoring system that would allow vessel-patency determination. These experiments have confirmed that thermal-energy dissipation, measured electrically by direct vascular thermocouple application, is a sensitive and accurate indicator of regional arterial perfusion. Occlusion of arteries 1 to 2 mm in diameter produced a significant temperature decrease in direct artery measurements in the rat and island-flap artery assessments in rats and rabbits. Early recognition of vessel occlusion could allow for rapid intervention and increase the likelihood of tissue salvage. While this technology need not replace existing methodology, it does alleviate many of the problems seen with other vessel- and tissue-monitoring methods and thus may deserve further investigation.

Chemotherapy from an insider's perspective.

This paper is based on my experience of receiving chemotherapy from November, 1980, to July, 1981. I was well until Oct. 15, 1980, when I discovered a 3 cm mass in my left mid-neck. Apart from intermittent pruritus and an intertriginous fungus infection at the end of August, 1980, I had had no symptoms. I had not noticed any masses before Oct. 15, and I had not lost weight or experienced night sweats. A sonogram showed the mass to be cystic. With the preoperative diagnosis of cystic hygroma, I underwent a cervical exploration on Oct. 20, 1980, and was informed in the recovery room that the frozen section was malignant. Because of a normal bone-marrow aspiration, as well as a negative computerised tomographic scan of the abdomen and pelvis, I was designated stage IA, diffuse undifferentiated lymphoma. After sperm-banking had been completed I began, on Nov. 17, 1980, a 37-week course of chemotherapy (including bleomycin, adriamycin, cyclophosphamide, oncovin, dexamethasone, methotrexate, and citrovorum).

KIE: Problems confronting physicians who become patients are discussed by a resident who underwent chemotherapy for lymphoma. Stresses induced by side effects of the drugs, the unexpected termination of therapy, and physical debilitation are enumerated. Oncologists are urged to address the emotional problems associated with chemotherapy.