Carcinoembryonic antigen screening: how far should we go?

INTRODUCTION

The role of carcinoembryonic antigen (CEA) in screening has been previously investigated and found to be inefficient because of its low sensitivity and specificity. Nevertheless, it is still used as a tumour marker in health screening packages, often for asymptomatic patients. We aimed to review all asymptomatic patients who were referred to our department for raised CEA, to determine if this was indeed associated with significant pathology, and to what extent the asymptomatic patients should be investigated.

METHODS

All patients with no gastrointestinal symptoms, and whose only indication for endoscopy was a raised CEA level, were entered into the study group. All the investigations were retrospectively reviewed and any pathology was noted.

RESULTS

There were 217 asymptomatic patients who presented for endoscopy and further evaluation due to raised CEA, from December 1998 to August 2004. After the initial investigations, a total of 20 primary and eight metastatic cancers were found. The malignancies detected included 11 colorectal cancers, two stomach cancers, five lung cancers, one periampullary carcinoma and one ovarian teratoma. There were two cases of metastasis in the lungs and six with liver metastasis. In the subsequent median follow-up period of 13 (range 6-97) months, an additional 16 (7.4 percent) primary cancers were detected.

CONCLUSION

Asymptomatic average-risk patients who present with raised CEA should be investigated endoscopically and radiologically for commonly-associated cancers, and thereafter followed up for at least two years, as up to 7.4 percent present with a subsequent malignancy.

Increased susceptibility in Hp knockout mice during acute hemolysis

Haptoglobin, a conserved plasma glycoprotein, forms very stable soluble complexes with free plasma hemoglobin. Hemoglobin binding by haptoglobin is thought to be important in the rapid hepatic clearance of hemoglobin from the plasma and in the inhibition of glomerular filtration of hemoglobin. To evaluate these functions, Haptoglobin knockout (-/-) mice were created. These mice were viable but had a small, significant reduction in postnatal viability. Contrary to popular belief, the lack of haptoglobin did not impair clearance of free plasma hemoglobin in -/- mice. Induction of severe hemolysis by phenylhydrazine caused extensive hemoglobin precipitation in the renal tubular cells of both -/- and +/+ mice, with death occurring in 55% of -/- mice and in 18% of +/+ mice. In general, phenylhydrazine-treated -/- mice suffered greater tissue damage, as evidenced by the induction of hepatic acute phase response resulting in increased plasma alpha 1-acid glycoprotein (AGP) levels. Among -/- and +/+ mice that survived, -/- mice tend to suffer greater oxidative damage and failed to repair or regenerate damaged renal tissues, as indicated by their higher plasma malonaldehyde (MDA) and 4-hydroxy-2(E)-nonenal (HNE) levels and lower mitotic indices in their kidneys, respectively. This study suggested that a physiologically important role of hemoglobin-haptoglobin complex formation is the amelioration of tissue damages by hemoglobin-driven lipid peroxidation.

Cervical screening in foreign domestic workers in Singapore

INTRODUCTION

Globally, cervical cancer is the fourth most common cancer in women, with about 85% occurring in low-middle income countries (LMIC) and an age-standardised incidence rate of more than 15 per 100,000. It is largely preventable through HPV vaccination and cervical cancer screening. In Singapore, 18% of the foreign domestic workforce hail from Indonesia, the Philippines, Myanmar, and India. However, there is no data on preinvasive cervical disease and cervical cancer in foreign domestic workers (FDWs) and the aim of this pilot programme is to determine the baseline screen positive rate of high-grade intraepithelial in this population.

METHODS

A total of 322 FDWs were offered HPV screening through the Helping Our Helper (HOH) pilot programme. Data from this pilot programme were analysed and reported using simple descriptive statistics.

RESULTS

Out of the 322 FDWs who registered for HPV screening, 68.6% participated. There was a 22.2% screen-positive rate; 10% of those who screened positive for high-risk HPV had histologically confirmed high-grade cervical intraepithelial neoplasia. This result is similar to other data on cervical cancer screening in Singaporeans. This pilot project screened less than 1% of the eligible FDWs in Singapore.

DISCUSSION

The findings of this pilot programme suggest that there is public health value in providing cervical cancer screening to FDWs. Improving cervical cancer screening by increasing awareness and including routine cervical cancer screening as part of the employment medical examination should be studied.

Development of a TaqMan minor groove binding probe-based quantitative reverse transcription polymerase chain reaction for the detection and quantification of Zika virus

Zika virus (ZIKV) infection has emerged as a global health concern following epidemic outbreaks of severe neurological disorders reported in Pacific and Americas since 2016. Therefore, a rapid, sensitive and specific diagnostic test for ZIKV infection is critical for the appropriate patient management and the control of disease spread. A TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the conserved sequence regions of 463 ZIKV NS2B genes. The designed ZIKV qRT-PCR assay was evaluated for its detection limit, strain coverage and cross-reactivity. We further assessed the clinical applicability of qRT-PCR assay for ZIKV RNA detection using a total 18 simulated clinical specimens. The detection limit of the qRT-PCR assay was 11.276 ZIKV RNA copies at the 95% probability level (probit analysis, p<= 0.05). Both Asian and African ZIKV strains were detected by the qRT-PCR assay without cross-reacting with DENV-1, DENV-2, DENV-3, DENV-4, CHIKV, JEV, LGTV, GETV and SINV. The qRT-PCR assay demonstrated a perfect agreement (k = 1.000, P < 0.001) with the reference assay; the sensitivity and specificity of the qRT-PCR assay were 100% (95% CI= 79.6-100) and 100% (95% CI= 43.9-100) respectively. The qRT-PCR assay developed in this study is a useful diagnostic tool for the broad coverage detection and quantification of both the Asian and African ZIKV strains.

Robotic-assisted surgery for low rectal dissection: from better views to better outcome

INTRODUCTION

The use of robotics in colorectal surgery is relatively new. The first few cases of colonic surgery using da Vinci Surgical System were reported in 2002. Since then, several centres had reported on their experience, with favourable outcomes. Our department started to embark on robotics in colorectal surgery in December 2007. The aim of our paper was to share our early experience with robotics in colorectal surgery and provide an update on the current status of robotics.

METHODS

Preparations included formal training with the da Vinci Surgical System, certification of the surgeons, and obtaining Hospital Ethics committee approval. We used a hybrid technique of laparoscopic and robotic assistance in the resection of mid- to low-rectal cancer (total mesorectal excision). Laparoscopic approach was used to isolate the inferior mesenteric artery and for mobilisation of the left colon. The da Vinci robot was used in the dissection of the rectum down to the pelvic floor. We reviewed the outcomes of our early experience with emphasis on feasibility and safety.

RESULTS

Over a period of three months, we performed eight cases of robotic-assisted colorectal surgery for cancer. The median age of the patients was 55 (range 42-80) years. The median operating time was 192.5 (range 145-250) minutes. There were no intraoperative or postoperative complications related to the use of robotics. The median length of hospital stay was five (range 4-30) days.

CONCLUSION

Robotic-assisted laparoscopic colorectal surgery is a safe and feasible procedure.

Mucosal vaccination against influenza: protection of pigs immunized with inactivated virus and ether-split vaccine

Effective vaccinations against swine influenza reduce the economic loss of pig industries, and also may minimize the possibility of emergence of new pandemic viruses, since pigs are intermediate hosts to generate reassortant viruses among avian and mammalian influenza viruses. In this study, we showed that intranasal immunization of pigs with formalin-inactivated or ether-split influenza vaccine (A/Aichi/2/68) induced virus-specific IgG, IgM, and IgA antibodies in their nasal secretions and sera, resulting in complete protection from virus challenge. Antibody response to the challenge virus was not observed in the immunized pigs, suggesting that the replication of the virus in the primary targets, respiratory epithelial cells, was inhibited. The present results indicate that intranasal immunization of pigs with inactivated vaccines is effective to control swine influenza, and also provide a good model, as well as a mouse model, to evaluate an intranasal application of influenza vaccine for humans.

Lagophthalmos surgery in leprosy: findings from a population-based survey in Korea

Lagophthalmos continues to be a serious problem in cured leprosy patients. We conducted a population-based survey of lagophthalmos surgical coverage (LSC), barriers to lagophthalmos surgery and outcome of lagophthalmos surgery in leprosy patients in South Korea. In our survey, there were 60 patients with lagophthalmos who had needed surgery (> 5 mm gap), 34 of whom had received surgery, resulting in a lagophthalmos surgery coverage of 57%. Among the 34 patients who had received lagophthalmos surgery, 18 needed further surgery. Among those who had never had surgery, none of the demographic indicators predicted surgical uptake; the primary reason given for failure to have surgery was lack of knowledge about it. Outcome of surgery (by eye) showed that 29% of eyes still had a gap of 5 mm or more. The frequency of symptoms (tearing, blurring of vision, pain, etc.) was high. Even in settings with a good eye care infrastructure, such as Korea, uptake of surgery can still be low and results may not be satisfactory to patients. There is a need for practical guidelines for leprosy control programmes in the areas of (a) patient recognition, (b) patient education, (c) monitoring the uptake of surgery, and (d) monitoring the outcome of surgery to ensure the best possible outcome.