Colorectal cancer mass screening event utilising quantitative faecal occult blood test

INTRODUCTION

Colorectal cancer (CRC) is a leading cause of morbidity and mortality with human and financial costs. Screening by faecal occult blood test (FOBT) has proven to be effective in decreasing mortality from CRC in both randomised trials and case-control studies. We report on the results of a CRC screening event using quantitative FOBT (QFOBT) held in Singapore.

METHODS

The mass screening event was held over two days, and participants 40 years or older without prior screening performed in the preceding year were eligible. Those with significant symptoms or medical comorbidities were excluded. Stool sampling was done with two issued immunochemical QFOBT kits, and participants with positive stool samples with equal or greater than 100 ng haemoglobin/ml sample solution in any two samples were advised to have a colonoscopy screening conducted.

RESULTS

A total of 1,048 participants took part in the screening event. 222 (21 percent) of the participants claimed to have some abdominal symptoms prior to screening. 49 participants (26 males, 23 females) tested positive for QFOBT and 47 were evaluated. 10 (21 percent) had polyps and one case of colorectal cancer was detected. Seven of these cases had significant neoplasia (lesions 1 cm or larger) and were treated. Two patients required surgery.

CONCLUSION

Our study demonstrates wide variation in the attitudes of participants who turned up for screening. In addition, the number of significant colorectal neoplasia patients (14 percent) in those with positive QFOBT provides further evidence of the importance of screening with a potential reduction in CRC mortality. Continuous education of the public in events such as this, is essential to improving attitudes towards screening.

Two Cases of Chickenpox Complicating Pregnancy and an Update on Management

Susceptible pregnant women with chickenpox exposure are uncommon but are medical emergency conditions. Chickenpox infection in the first trimester is associated with the congenital varicella syndrome and in the third trimester is associated with fatal complications and the neonatal varicella syndrome. In this article, two cases and the management of chickenpox during pregnancy are discussed.

A 6-year review of surgical morbidity and oncological outcome after high anterior resection for colorectal malignancy with and without splenic flexure mobilization

OBJECTIVE

High anterior resection (HAR) for colorectal cancer is traditionally performed with routine mobilization of the splenic flexure. This is a retrospective review of mortality and morbidity following HAR in which the splenic flexure has been preserved.

METHOD

From a prospective database, all patients who had undergone elective HAR for colorectal cancer between 1999 and 2005 were identified. Morbidity, mortality, pathology and survival data for patients having HAR with and without splenic flexure mobilization were analysed.

RESULTS

A total of 707 patients were identified. Five hundred and thirty-one had HAR with preservation of the splenic flexure. In these patients outcome was: anastomotic leak (0.4%), wound infection (3.6%), anastomotic stricture (0.4%) and 30-day mortality (0.9%). No statistical significant difference was found for postoperative morbidity (P = 0.1926), 30-day mortality (P =0.3285), lymph node harvest (P = 0.2127) or survival (P = 0.1457) compared with patients in whom the splenic flexure was mobilized. Longitudinal resection margins were greater following HAR with splenic flexure mobilization (P < 0.0001).

CONCLUSION

No morbidity, oncological or survival disadvantage in performing splenic flexure preserving HAR was found.

Meta-analysis of randomized clinical trials comparing drainage alone vs primary sphincter-cutting procedures for anorectal abscess-fistula

BACKGROUND AND AIM

Concurrent definitive treatment of underlying fistulas from infected anal glands at the time when the anorectal abscesses are drained is controversial as this is associated with a higher incidence of faecal incontinence, failure and recurrence. This meta-analysis was conducted to determine the merits of drainage alone vs primary sphincter-cutting procedures (which includes fistulotomy and fistulectomy) for anorectal abscess-fistula.

METHODS

Medline, Embase and Cochrane Central Register of Controlled Trials database searches identified all randomized controlled trials using the keywords: anorectal abscess, anal sepsis, drainage, fistulotomy, fistulectomy or surgery from 1966 to 2004. The outcome variables analysed were recurrence, faecal continence and wound-healing times.

RESULTS

Five trials were considered suitable for the meta-analysis, with a total of 405 patients. Sphincter-cutting procedures for anorectal abscesses resulted in 83% reduction in recurrence rate [relative risk (RR) 0.17, 95% confidence interval (CI) 0.09-0.32, p<0.001]. However, there was a tendency to a higher risk of faecal incontinence to flatus and soiling when primary sphincter-cutting procedure was performed (RR 2.46, 95% CI 0.75-8.06, p=0.140).

CONCLUSION

There is no conclusive evidence if simple drainage or sphincter-cutting procedure is better in the treatment of anorectal abscess-fistula.

PPH03 stapled hemorrhoidopexy: our experience

BACKGROUND

Stapled hemorrhoidopexy is an established treatment for hemorrhoidal disease. We evaluated our experience with stapled hemorrhoidopexy using the new Procedure for Prolapse and Hemorrhoids (PPH03) Proximate HCS hemorrhoidal circular stapler (Ethicon Endo-Surgery).

METHODS

We retrospectively reviewed clinical data for 238 patients who had undergone stapled hemorrhoidopexy in our department over a 2-month period. Patients were followed-up for a median of 3.5 weeks (range, 1-11 weeks) and were analyzed for complications and resolution of symptoms.

RESULTS

The hemorrhoids treated were third- and fourth-degree, as well as second degree (after failure of other therapies). Mean duration of surgery was 12.7 minutes (range, 5-20 minutes) and the majority of patients was treated with an ambulatory procedure. Most patients were discharged within 6 hours after surgery. On follow-up, 3.7% of patients had minor complaints after surgery. Technically, the new PPH03 stapler device has a quickclose knob, which allows rapid opening and closing. The closed staple height of 0.75 mm increases staple line compression on tissue and key blood vessels, hence minimizing bleeding. Prior to this, stapled hemorrhoidopexy was done using the PPH01 device.

CONCLUSIONS

Stapled hemorrhoidopexy using the new PPH03 stapler is a safe, short and effective procedure in the management of hemorrhoids. It can be done in the ambulatory setting and patients have few postoperative complications.

False positive F-18 fluorodeoxyglucose combined PET/CT scans from suture granuloma and chronic inflammation: report of two cases and review of literature

INTRODUCTION

F-18 fluorodeoxyglucose (FDG) combined positron emission tomography (PET)/ computed tomography (CT) imaging is often used in the surveillance of recurrent colorectal cancers after curative resections. We report 2 patients where FDG combined PET/CT imaging produced false positive results due to chronic inflammation and suture granuloma.

CLINICAL PICTURE

Case 1 is a patient with a curative anterior resection done 10 months ago. Serial surveillance carcinoembryonic antigen (CEA) showed a marginal elevation. A solitary "hot spot" on combined PET/CT imaging was seen at the level of the previously resected inferior mesenteric vein. Case 2 is a patient with a positive solitary lesion on combined PET/CT imaging 16 months after a curative right hemicolectomy for colorectal cancer. The serum CEA was within normal limits.

TREATMENT

Both patients had undergone exploratory laparotomy with complete resection of the solitary lesions.

OUTCOME

The histology of Case 1 was reported as a suture granuloma while the histology of Case 2 was reported as an inflammatory nodule related to the previous suture pedicle, both with no malignant tissues identified.

CONCLUSIONS

False positives on combined PET/CT imaging may result from inflammatory granulomas months after surgery.

High-sensitivity and specificity of laser-induced autofluorescence spectra for detection of colorectal cancer with an artificial neural network

An artificial neural network (ANN) has been used in various clinical research for the prediction and classification of data in cancer disease. Previous research in this direction focused on the correlation between various input parameters such as age, antigen, and size of tumor growth. Recently, laser-induced autofluorescence (LIAF) techniques have been shown to be a useful noninvasive early diagnostic tool for various cancer diseases. We report on a successful application of ANN to in vitro LIAF spectra. We show that classification of tumor samples with ANN can be done with high sensitivity, specificity, and accuracy. Thus a combination of LIAF techniques and ANN can provide a robust method for clinical diagnosis.

Which colorectal cancers are missed by double contrast barium enema?

BACKGROUND

The relative merits of either barium enema or colonoscopy for investigating lower gastrointestinal tract symptoms is still unclear. We studied the value of double contrast barium enema (DCBE) as the initial evaluation modality. We reviewed our 10-year experience of double contrast enemas as read by consultant radiologists. The study also aimed to identify which lesions are usually missed.

PATIENTS AND METHODS

We reviewed clinical data for all patients who underwent DCBE within the 6 months prior to surgical resection of colorectal cancer between April 1989 and April 1999. Patient demographics and tumour characteristics were analysed for their effects on the likelihood of the lesions being missed at DCBE.

RESULTS

There were 706 patients included in the study, 54.2% were male and the mean age was 63.7 years (SEM=0.5 years). The site along the colon and rectum of tumours missed by DCBE corresponded with the frequency of tumour occurrence at each site. The overall rate of missed lesions was 4.1% (29 of 706 patients); these patients were found on subsequent endoscopy to harbour cancer. Tumours less than 3 cm in length and with lesser extent of circumferential involvement were more likely missed at DCBE (p=0.05 and p=0.01, respectively). Age, sex, and tumour grade and stage were not significant predictors of the likelihood of missed lesions. Of the 29 patients with missed lesions, 77.2% had a serum concentration of carcinoembryonic antigen (CEA) above the normal range (3.5 microg/l). The mean follow-up was 65.3 months (SEM=1.8 months). The overall survival for this series was 60.1%. The inaccuracy of the initial DCBE was not found to cause statistically significant differences in the stage of the tumour at diagnosis nor the overall survival of the patients in our series.

CONCLUSIONS

Smaller cancers without circumferential involvement may be missed when DCBE is performed to evaluate lower gastrointestinal symptoms. Further evaluation by colonoscopy must be recommended when symptoms persist, especially in the context of a raised CEA level.

Minilaparotomy left iliac fossa skin crease incision vs. midline incision for left-sided colorectal cancer

BACKGROUND

Midline laparotomies offer excellent exposure but are associated with increased postoperative pain and longer recovery. A minilaparotomy resection of leftsided colorectal cancers was studied as an alternative approach.

PATIENTS AND METHODS

We performed a case-control retrospective review of 280 randomly selected patients (140 midline incisions; 140 left skin crease incisions) who underwent elective, curative resection of left-sided colorectal cancers.

RESULTS

Patients in both groups were of comparable age and sex. The left skin crease incision was shorter (median length, 13.5 cm) than the midline incision (median length, 20.0 cm). Median operation time was less in the left skin crease group (75 min) than in the midline incision group (105 min). Similar types of operations were performed, including left hemicolectomies, sigmoid colectomies, anterior resections and ultra-low anterior resections. Adequacy of resection was confirmed by histological analysis, with no involvement of margins. The median numbers of lymph nodes removed were comparable: 10 for the skin crease incision group and 12 for the midline incision group. Postoperative parameters for the skin crease incision group showed that feeding, ambulation, narcotic use and hospital stay were significantly better than the parameters in the midline group. Complications of intestinal obstruction were also reduced in the skin crease incision group.

CONCLUSIONS

The limited left skin crease incision provides adequate margins of clearance in colorectal cancers when compared to the midline incision, but has advantages of shorter operation time, earlier feeding and ambulation, and earlier discharge from hospital.

Distance and angular dependence of intensity ratios in laser-induced autofluorescence techniques

Laser-induced autofluorescence techniques have the potential to be used for the detection of preinvasive human cancer cells. For colorectal and gastrointestinal cancer cells, the light is introduced in vivo through endoscopic means and the probe tip is brought gently into contact with the tissue under investigation. However, it is often assumed that there is no distance or angular dependence in the intensity of the light collected from the probes. We performed an in vitro experiment in which we showed that there was indeed no angular dependence provided the angle of inclination of the probe to normal incidence is small. However, we find substantial fluctuation in the intensities of peaks for changing distances. These fluctuations can be eliminated by considering the ratio of the intensities from two spectral lines.

Chemoprevention of colorectal cancer--experimental approach and clinical applications

INTRODUCTION

The holy grail of cancer treatment is prevention. Chemoprevention is the use of specific agents to prevent, inhibit or reverse the process of cancer formation before malignancy. This review aims to explore the clinical approaches to investigation for chemoprevention and to discuss the more promising agents that have proceeded on to clinical trials.

METHODS

A Medline search was done using the words colorectal cancer, chemoprevention, models, surrogate markers and prevention clinical trials.

RESULTS

Research into chemopreventive agents is highly dependent on an effective model in which studies may be performed and from which results may be extrapolated into the human or clinical setting. As carcinogenesis is a prolonged biological event, intermediate surrogate markers that will reliably predict future cancer risk are usually studied. Various models are used with varying impact. Among some of the more recent agents being explored, the COX-2 inhibitors are emerging as strong potential agents. However, there are significant side-effects that need to be overcome first before routine use may be considered.

CONCLUSIONS

Although there is presently no agent available for the safe, widespread use for the chemoprevention of colorectal cancer, research into this area is rapidly progressing and may in the future change the paradigm of cancer treatment.

Prospective randomized study of bacteraemia in diathermy and stapled haemorrhoidectomy

BACKGROUND

The incidence and consequences of bacteraemia associated with diathermy and stapled haemorrhoidectomy have not been studied previously.

METHODS

Two hundred and five healthy patients randomized to stapled haemorrhoidectomy or diathermy haemorrhoidectomy had perioperative blood cultures taken. The clinical sequelae of bacteraemia and complications of surgery were assessed prospectively.

RESULTS

Six patients were excluded for protocol violations. Eleven (11 per cent) of 101 patients with stapled and five (5 per cent) of 98 who had diathermy haemorrhoidectomy had positive blood cultures for organisms after haemorrhoidectomy, predominantly anaerobes commonly found within the bacterial flora of the anorectum (P = 0.19). Transient postoperative pyrexia in several patients did not correlate with detected bacteraemia and settled spontaneously without treatment. There were no serious complications from either operative technique, and no clinical consequences from proven bacteraemia.

CONCLUSION

Transient bacteraemia may complicate surgical haemorrhoidectomy but has no serious clinical consequences for healthy adults.

A novel indicator for surveillance colonoscopy following colorectal cancer resection

INTRODUCTION

Current surveillance for recurrent intraluminal or metachronous colorectal cancer following resection is largely undertaken by colonoscopic examination of the remaining colon. The burden on colonoscopic services is high and the procedure is expensive. Immunological faecal occult blood testing (FOBT) is a sensitive and specific test for detecting colorectal cancer, and may fine tune the need for timely surveillance colonoscopy.

METHODS

Consecutive patients due for surveillance colonoscopy following colonic resection for cancer were prospectively studied. Each patient had a single faecal sample obtained at per rectal examination on a gloved examining finger. This was subjected to immunological FOBT in the clinic, and patients were categorized as FOBT positive or negative, according to the result. Colonoscopy as well as ultrasound or CT of the liver were performed within eight weeks of FOBT.

RESULTS

Six hundred and eleven patients had both FOBT and colonoscopy. Fifty-nine (13.6%) were categorized as FOBT-positive. Of these, nine had biopsy-proven recurrent or metachronous cancer, 12 patients had one, or more adenomatous polyps, one patient had radiation proctitis and two patients had pan-colonic mucositis following chemotherapy. In the remaining 552 FOBT-negative patients, no cancers were found. Thirty-eight patients had polyps that were removed. The sensitivity and specificity for detecting cancer by immunological FOBT was 100% sensitivity for detecting adenomatous polyps was 24% but specificity was 93%.

CONCLUSION

The immunological faecal occult blood test provides sensitive detection of metachronous and recurrent cancer in postoperative surveillance. Routine application may be used to reduce the frequency of colonoscopic surveillance, as a negative FOBT may be taken as a sign that colonoscopy may be deferred safely.

Optical orientation and femtosecond relaxation of spin-polarized holes in GaAs

Optical orientation of spin-polarized heavy and light holes followed by relaxation to other valence subband states has been observed unambiguously in undoped bulk GaAs in spite of the extremely short spin relaxation time. The measured relaxation time for the heavy holes is 110 fs +/-10%. The results are relevant for applications such as interpretation of spin-polarized transport in semiconductors as well as the assessment of feasibility of hole-based spin-transport devices which relies on precise knowledge of the hole-spin relaxation time.

Prospective, randomized trial comparing sigmoid vs. descending colonic J-pouch after total rectal excision

PURPOSE

The aim of this study was to compare the bowel function of sigmoid vs. descending colonic J-pouches after ultralow anterior resection for rectal cancer.

METHODS

A prospective, randomized trial was conducted from March 1998 to September 1999. Ninety-two consecutive patients undergoing ultralow anterior resection for cancers arising from 3 to 10 cm from the anal verge were recruited. Forty-eight patients were males; the mean ages (standard error of the mean) for patients with sigmoid and descending colon pouches, respectively, were 65.2 (3.1) years and 62.3 (3.1) years. A total of 46 patients were randomly assigned to each group. Two patients from each group were excluded; abdominoperineal resection was performed for two patients in the sigmoid pouch group and one patient in the descending pouch group. One patient in the descending pouch group had a transanal resection of a benign polyp. Dukes staging and use of postoperative chemoradiotherapy were statistically similar in both groups. All patients underwent a standardized ultralow anterior resection. A defunctioning loop ileostomy was used routinely. Anorectal physiology and bowel function questionnaires were performed at six weeks after ileostomy closure and again at 6 and 12 months after surgery.

RESULTS

Median follow-up was 12 (range, 7 to 25) and 12 (range, 6 to 25) months, respectively, for sigmoid and descending pouch groups. Median tumor and anastomotic heights, time to ileostomy closure, operative time, and postoperative stay were statistically similar in both groups. There were no significant differences in stool frequency, incontinence, urgency, use of pads and antidiarrheals, sensation of incomplete evacuation, and anorectal physiology results between groups (P > 0.05).

CONCLUSION

Pouches made from sigmoid or descending colon give similar bowel function after ultralow anterior resection for rectal cancers.

Prospective randomised trial comparing ayurvedic cutting seton and fistulotomy for low fistula-in-ano

The aim of this study was to evaluate the role of ayurvedic setons in the treatment of low fistula-in-ano. One hundred and eight patients were randomised into either conventional fistulotomy (F) or ayurvedic cutting seton insertion (C). Endpoints investigated included time to wound healing and complications of surgery. Post-operative pain scores were measured daily using a visual analog scale. Anal function was compared using a continence score. Pre- and postoperative manometry and ultrasound were also performed. After exclusions, there were 54 patients in group F and 46 in group C. There were no differences in age, sex or follow-up duration between the two groups. Healing time was similar between the groups. Group C reported more pain following operation and on the first 2-4 postoperative days, but both groups experienced the same amount of pain subsequently. In conclusion, chemical seton was more painful than conventional fistulotomy in the first few days following surgery. However, there was no difference in time to wound healing, complications or functional outcome.

A prospective randomised study of drains in infra-peritoneal rectal anastomoses

Although increasing evidence suggests that prophylactic drainage after intra-peritoneal colorectal anastomoses is unnecessary, drains for infra-peritoneal rectal anastomoses, where the leak rate is higher, are widely employed still. The aim of this study was to assess the effect of prophylactic drainage after anastomosis below the peritoneal reflection. All patients attending one specialist unit over an 8-month period for elective rectal cancer resection with an infra-peritoneal anastomosis were randomised to drainage or no drainage. The incidence of anastomotic leak and complications specific to the drain as well as other complications were compared. Fifty-nine patients were analysed (31 with drain). Twenty-five of the drained and 16 of the no-drain patients had a defunctioning stoma (p=ns). The groups were comparable for demographic data, operation and anastomotic height from the anal verge. There were three leaks (10%) in the drain group and five leaks (18%) in the no-drain group (p=ns). There were 2 (7%) patients in each group with a clinical leak. There were no specific drain complications and the incidence of other complications was similar in both groups. In conclusion, this study supports the contention that there is no difference in morbidity with or without the use of a drain for infra-peritoneal anastomoses.

Mutation-tolerant protein identification by mass spectrometry

Database search in tandem mass spectrometry is a powerful tool for protein identification. High-throughput spectral acquisition raises the problem of dealing with genetic variation and peptide modifications within a population of related proteins. A method that cross-correlates and clusters related spectra in large collections of uncharacterized spectra (i.e., from normal and diseased individuals) would be very valuable in functional proteomics. This problem is far from being simple since very similar peptides may have very different spectra. We introduce a new notion of spectral similarity that allows one to identify related spectra even if the corresponding peptides have multiple modifications/mutations. Based on this notion, we developed a new algorithm for mutation-tolerant database search as well as a method for cross-correlating related uncharacterized spectra.

Randomized clinical trial of the effect of open versus laparoscopically assisted colectomy on systemic immunity in patients with colorectal cancer

BACKGROUND

Laparoscopic surgery is believed to produce an attenuated metabolic stress response and to have a less dampening effect on the immune response than open surgery. To date, the effect has not been studied in a randomized clinical trial of colorectal cancer.

METHODS

The study was a two-armed randomized prospective trial conducted in parallel with the UK Medical Research Council's Conventional versus Laparoscopic-Assisted Surgery in Colorectal Cancer (CLASICC) trial comparing laparoscopically assisted colorectal surgery for left-sided tumours with conventional open surgery. Systemic immunity was assessed by determining the T- and B-cell counts, the CD4 : CD8 ratio, the natural killer cell counts, the immunoglobulin (Ig) G, IgM and IgA levels, and C3 and C4 levels. The white cell phagocytic activity (nitroblue tetrazolium test) was studied before operation and on the third postoperative day.

RESULTS

A total of 236 patients were randomized in the immune study between 11 March 1997 and 14 August 1999; 161 had complete preoperative and postoperative assays for the analysis of results. There was no difference in mean response between the two surgical groups for each of the immune parameters studied. The unadjusted difference for the primary endpoint, T-cell count, 3 days after operation was - 1.6 per cent (95 per cent confidence interval - 5.0 to 1.8 per cent).

CONCLUSION

There is no difference in the systemic immune response in patients having laparoscopically assisted colectomy compared with those undergoing conventional open surgery for colorectal cancer.