Serum glutathione transferase does not respond to indole-3-carbinol: A pilot study

Background:

Despite the well recognized protective effect of cruciferous vegetables against various cancers, including human colorectal cancers, little is known about how this effect is conferred. It is thought that some phytochemicals found only in these vegetables confer the protection. These compounds include the glucosinolates, of which indole-3-carbinol is one. They are known to induce carcinogen-metabolizing (phase II) enzymes, including the glutathione S-transferase (GST) family. Other effects in humans are not well documented. We wished to assess the effect of indole-3-carbinol on GST enzymes.

Methods:

We carried out a placebo-controlled human volunteer study. All patients were given 400 mg daily of indole-3-carbinol for three months, followed by placebo. Serum samples were tested for the GSTM1 genotype by polymerase chain reaction. Serum GST levels were assessed using enzyme-linked immunosorbent assay and Western Blot methodologies.

Results:

Forty-nine volunteers completed the study. GSTM1 genotypes were obtained for all but two volunteers. A slightly greater proportion of volunteers were GSTM1-positive, in keeping with the general population. GST was detected in all patients. Total GST level was not affected by indole-3-carbinol dosing compared with placebo. Although not statistically significant, the GSTM1 genotype affected the serum GST level response to indole-3-carbinol.

Conclusion:

Indole-3-carbinol does not alter total serum GST levels during prolonged dosing.

An audit of pre-operative skin preparative methods

INTRODUCTION

A study into how pre-operative skin preparation varies between surgical units and surgeons.

MATERIALS AND METHODS

A postal audit of general, vascular and thoracic surgeons in Northern Ireland was conducted together with a literature review to establish best practice.

RESULTS

Overall, 73 surgeons were contacted, and 63 (86.3%) responded. There was marked variation in shaving of the operative site. A wide range of solutions was used, and 14 different sequences were employed. All surgeons used a swab or sponge to apply the solutions. Several drying methods were employed.

CONCLUSIONS

There is variation in the method of skin preparation employed between surgical units and surgeons. There is limited evidence-based research on this topic. Recommendations are made as to best practice.

Surgeon and hospital volume and the management of colorectal cancer patients in Australia

BACKGROUND

The evidence for a relationship between patient outcomes and clinician and hospital volume is increasing. The National Colorectal Cancer Care Survey was undertaken to determine the management patterns in Australia for individuals newly diagnosed with colorectal cancer in a 3 month period in the year 2000.

METHODS

All new cases of colorectal cancer registered at each Australian State Cancer Registry were entered into the survey. This generated a questionnaire that was sent to the treating surgeon. Chi-squared tests and logistic regression analyses were used to determine levels of statistical significance.

RESULTS

Of 2,383 surgical questionnaires generated, 2,015 (85%) were completed. The majority (58%) of surgeons treated one or two patients with colorectal cancer over the 3 months of the survey. There was variation across surgeon cohorts for preoperative measures including the use of deep vein thrombosis prophylaxis. Patients seen by low volume surgeons were most likely to be given a permanent stoma (P < 0.0001). Patients with rectal cancer who were operated on by high volume surgeons were significantly more likely to receive a colonic pouch (P < 0.0001).

CONCLUSION

This nationwide population-based survey of the treatment of colorectal cancer patients suggests that the delivery of care by surgeons (the majority) who treat patients with rectal cancer infrequently should be evaluated.

In the beginning there was colectomy: current surgical options in familial adenomatous polyposis

Multiple colonic polyps, almost guaranteed colorectal cancer by the age of forty-five and an increased risk of non-colonic cancers characterise the autosomal dominant condition Familial Adenomatous Polyposis (FAP) [1]. The patients and families faced with such a diagnosis present many difficult management challenges, both surgical and non-surgical. We discuss the current surgical options for treatment of the more significant manifestations of FAP arising in the colorectum and duodenum as well as desmoid disease

Management of colorectal cancer patients in Australia: the National Colorectal Cancer Care Survey

BACKGROUND

The National Colorectal Cancer Care Survey was undertaken to determine the management patterns for individuals newly diagnosed with colorectal cancer in Australia.

METHODS

Between 1 February and 30 April 2000, all new cases of colorectal cancer registered at each Cancer Registry within Australia were entered into the survey. This generated a questionnaire that was sent to the treating surgeons. Chi-squared and logistic regression analyses were used to determine levels of statistical significance for the various comparisons of interest.

RESULTS

Of 2383 surgical questionnaires generated, 2015 (85%) were completed. A total of 1911 patients (95% of those who responded to the questionnaire) had an operation. Of the 86 guidelines for the management of colorectal cancer published by the National Health and Medical Research Council, the survey allowed for comparison between 18 of these, which covered a spectrum of surgical management. Thromboembolic prophylaxis was given to 1843 patients (96.4%) undergoing surgery. Prophylactic antibiotics were commonly used, but there appear to be issues regarding the best regimen to use. Curative resections were carried out in 1563 patients (81.8%), with anterior resections being the most commonly performed procedure. Adjuvant therapy was regularly used, but not all eligible patients were offered such treatment.

CONCLUSION

With the considerable resources required to develop clinical practice guidelines, studies like this are essential to monitor the impact of the guidelines. To ensure that the guidelines are in line with current evidence, regular reviews of the guideline recommendations are required.

Sulforaphane inhibits growth of a colon cancer cell line

OBJECTIVE

The consumption of cruciferous vegetables has a protective effect on the development of colorectal cancer. The phytochemical Sulforaphane is an isothiocyanate found almost exclusively in cruciferous vegetables. We have studied the effect of Sulforaphane on cell proliferation of an HT-29 colon cancer cell line.

MATERIALS AND METHODS

HT-29 colon cancer cells were cultured in 96-well microtitre plates. Sulforaphane (in concentrations ranging from 0.01 to 0.1 mmol) were added to the wells. Cell proliferation was measured using the colourimetric assay technique.

RESULTS

The proliferation of colon cancer cells was significantly reduced by Sulforaphane at concentrations of >/=0.02 mmol.

CONCLUSION

These findings may help explain the epidemiologically proven protective effect of vegetables against colon cancer.

Preventive measures in Peutz-Jeghers syndrome

Peutz-Jeghers syndrome is a rare genetic disorder characterized by mucocutaneous melanin deposition, intestinal polyposis and an increased risk of cancer, both intestinal and extra-intestinal. We describe the current status of diagnosis and the methods by which the consequences of this condition can be minimized. A surveillance program for those diagnosed is also included.

The variable effect on proliferation of a colon cancer cell line by the citrus fruit flavonoid Naringenin

OBJECTIVE

Naringenin, a naturally occurring flavonoid found in citrus fruits, is known to have anticarcinogenic properties. We have examined the effect of Naringenin on cell proliferation of an HT-29 colon cancer cell line.

METHODS

HT-29 colon cancer cells were cultured in 96-well tissue culture plates. Naringenin concentrations ranging from 0.02 to 2.85 mmol were added to the wells of the Test group. The Control group contained all the elements present in the Test group with the exception of Naringenin. Cell proliferation was measured by colourimetric assay using the 2% WST-1 cell proliferation kit.

RESULTS

Significant inhibition of cell proliferation was observed in HT29 colon cancer cells exposed to Naringenin at doses greater than 0.71 mmol.

CONCLUSIONS

These results suggest a potential role for citrus fruits as a source of chemoprotective agents for colon cancer.

The effect of indole-3-carbinol and sulforaphane on a prostate cancer cell line

BACKGROUND

Cruciferous vegetable consumption is inversely related to the incidence of prostate cancer. We examined the effect of indole-3-carbinol (I3C) and of sulforaphane (constituents of cruciferous vegetables) on cell proliferation of a PC-3 prostate cancer cell line, in order to observe if an inhibitory effect might be detected in vitro.

METHODS

PC-3 prostate cancer cells were cultured in 96-well microtitre plates. Indole-3-carbinol concentrations ranging from 0.1 mmol/L to 0.8 mmol/L or sulforaphane concentrations ranging from 0.01 mmol/L to 0.06 mmol/L were added to the wells. Cell proliferation was measured by colorimetric assay and results were based on the mean value of triplicate experiments. Data are -presented as medians and interquartile ranges and were analysed using the Mann-Whitney U-test.

RESULTS

Cell proliferation in PC-3 prostate cancer cells was significantly inhibited by I3C and sulforaphane at media concentrations of 0.2 mmol/L and 0.02 mmol/L, respectively.

CONCLUSION

Both compounds inhibited the proliferation of prostate cancer cells in a dose-dependent manner. These findings may help explain the observed protective effect of cruciferous vegetables in relation to prostate cancer.

Hereditary colorectal cancer: keeping it in the family--the bowel cancer story

Up to 20% of colorectal cancers are thought to have a genetic component. Several familial syndromes are known to confer an increased risk for colorectal cancer. Advances in our understanding of these syndromes has improved the care delivered to, and the overall survival of, these patients. Genetic testing has great potential to further improve detection and direct subsequent preventative measures. The diagnosis, management and surveillance issues relating to some of the more commonly encountered syndromes - in particular Familial Adenomatous Polyposis and Hereditary Non-Polyposis Colorectal Cancer - are reviewed.