Update on the Recommendations on Breast Cancer Screening by the Cancer Expert Working Group on Cancer Prevention and Screening.

Breast cancer (BC) is the most common cancer among women in Hong Kong. The Food and Health Bureau commissioned The University of Hong Kong (HKU) to conduct the Hong Kong Breast Cancer Study (HKBCS) with the aim of identifying relevant risk factors for BC in Hong Kong and developing a locally validated BC risk assessment tool for Hong Kong Chinese women. After consideration of the most recent international and local scientific evidence including findings of the HKBCS, the Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) has reviewed and updated its BC screening recommendations. Existing recommendations were preserved for women at high risk and slightly changed for women at moderate risk. The following major updates have been made concerning recommendations for other women in the general population: Women aged 44 to 69 with certain combinations of personalised risk factors (including presence of history of BC among first-degree relative, a prior diagnosis of benign breast disease, nulliparity and late age of first live birth, early age of menarche, high body mass index and physical inactivity) putting them at increased risk of BC are recommended to consider mammography screening every 2 years. They should discuss with their doctors on the potential benefits and harms before undergoing mammography screening. A risk assessment tool for local women (eg, one developed by HKU) is recommended to be used for estimating the risk of developing BC with regard to the personalised risk factors described above.

Recommendations on prevention and screening for colorectal cancer in Hong Kong.

Colorectal cancer is the commonest cancer in Hong Kong. The Cancer Expert Working Group on Cancer Prevention and Screening was established in 2002 under the Cancer Coordinating Committee to review local and international scientific evidence, assess and formulate local recommendations on cancer prevention and screening. At present, the Cancer Expert Working Group recommends that average-risk individuals aged 50 to 75 years and without significant family history consult their doctors to consider screening by: (1) annual or biennial faecal occult blood test, (2) sigmoidoscopy every 5 years, or (3) colonoscopy every 10 years. Increased-risk individuals with significant family history such as those with a first-degree relative diagnosed with colorectal cancer at age ≤60 years; those who have more than one first-degree relative diagnosed with colorectal cancer irrespective of age at diagnosis; or carriers of genetic mutations associated with familial adenomatous polyposis or Lynch syndrome should start colonoscopy screening earlier in life and repeat it at shorter intervals.

Recommendations on prevention and screening for breast cancer in Hong Kong.

In Hong Kong, breast cancer is the most common cancer among women and poses a significant health care burden. The Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) was set up in 2002 by the Cancer Coordinating Committee to review and assess local and international scientific evidence, and to formulate recommendations for cancer prevention and screening. After considering the local epidemiology, emerging scientific evidence, and local and overseas screening practices, the CEWG concluded that it was unclear whether population-based breast cancer screening did more harm than good in local asymptomatic women at average risk. The CEWG considers that there is insufficient evidence to recommend for or against population-based mammography screening for such individuals. Women who consider breast cancer screening should be adequately informed about the benefits and harms. The CEWG recommends that all women adopt primary preventive measures, be breast aware, and seek timely medical attention for suspicious symptoms. For women at high risk of breast cancer, such as carriers of confirmed BRCA1/2 deleterious mutations and those with a family history of breast cancer, the CEWG recommends that they seek doctor's advice for annual mammography screening and the age at which the process should commence. Additional annual screening by magnetic resonance imaging is recommended for confirmed BRCA1/2 mutation carriers or women who have undergone radiation therapy to the chest between the age of 10 and 30 years. Women at moderate risk of breast cancer should discuss with doctors the pros and cons of breast cancer screening before making an informed decision about mammography screening every 2 to 3 years.

Best practices to prevent transmission and control outbreaks of hand, foot, and mouth disease in childcare facilities: a systematic review.

INTRODUCTION: Hand, foot, and mouth disease continues to cause seasonal epidemics in the Asia-Pacific Region. Since the current Enterovirus 71 vaccines do not provide cross-protection for all Enterovirus species that cause hand, foot, and mouth disease, there is an urgent need to identify appropriate detection tools and best practice to prevent its transmission and to effectively control its outbreaks. This systematic review aimed to identify characteristics of outbreak and assess the impact and effectiveness of detection tools and public health preventive measures to interrupt transmission. The findings will be used to recommend policy on the most effective responses and interventions in Hong Kong to effectively minimise and contain the spread of the disease within childcare facilities. METHODS: We searched the following databases for primary studies written in Chinese or English: MEDLINE, EMBASE, Global Health, WHO Western Pacific Region Index Medicus database, China National Knowledge Infrastructure Databases, and Chinese Scientific Journals Database. Studies conducted during or retrospective to outbreaks of hand, foot, and mouth disease caused by Enterovirus 71 from 1980 to 2012 within childcare facilities and with a study population of 0 to 6 years old were included. RESULTS: Sixteen studies conducted on outbreaks in China showed that hand, foot, and mouth disease spread rapidly within the facility, with an outbreak length of 4 to 46 days, especially in those with delayed notification (after 24 hours) of clustered outbreak (with five or more cases discovered within the facility) to the local Center for Disease Control and Prevention and delayed implementation of a control response. The number of classes affected ranged from 1 to 13, and the attack rate for children ranged from 0.97% to 28.18%. CONCLUSIONS: Communication between key stakeholders about outbreak confirmation, risk assessment, and surveillance should be improved. Effective communication facilitates timely notification (within 24 hours) of clustered outbreaks to a local Center for Disease Control and Prevention. Timely implementation of a control response is effective in minimising incidence and length of an outbreak in childcare facilities. The government should provide incentives for childcare facilities to train infection control specialists who can serve as the first contact, knowledge, and communication points, as well as facilitate exchange of information and provision of support across stakeholders during a communicable disease epidemic.

Speedup of doping fronts in organic semiconductors through plasma instability.

The dynamics of doping transformation fronts in organic semiconductor plasma is studied for application in light-emitting electrochemical cells. We show that new fundamental effects of the plasma dynamics can significantly improve the device performance. We obtain an electrodynamic instability, which distorts the doping fronts and increases the transformation rate considerably. We explain the physical mechanism of the instability, develop theory, provide experimental evidence, perform numerical simulations, and demonstrate how the instability strength may be amplified technologically. The electrodynamic plasma instability obtained also shows interesting similarity to the hydrodynamic Darrieus-Landau instability in combustion, laser ablation, and astrophysics.

The contribution of charcoal burning to the rise and decline of suicides in Hong Kong from 1997-2007.

BACKGROUND: There has been scant research exploring the relationship between choice of method (means) of self-inflicted death, and broader social or contextual factors. The recent emergence and growth of suicide using carbon monoxide poisoning resulting from burning charcoal in an enclosed space (hereafter, "charcoal burning") was related to an increase in the overall suicide rate in Hong Kong. The growth of this method coincided with changing economic conditions. This paper expands upon previous work to explore possible relationships further. PURPOSE: This study aims to discern the role of charcoal burning in overall suicide rate transition during times of both economic recession and expansion, as captured in the unemployment rate of Hong Kong, and to examine whether there was evidence of an effect from means-substitution. METHODS: Age and gender specific suicide rates in Hong Kong by suicide methods from 1997 to 2007 were calculated. To model the transition of suicide rate by different methods, Poisson regression analyses were employed. RESULTS: Charcoal burning constituted 18.3% of all suicides, 88% of which involved individuals drawn from the middle years (25-59) of life. During both periods of rising and declining unemployment, charcoal burning played an important role in the changing suicide rates, and this effect was most prominent among for those in their middle years. Means-substitution was found among the married women during the period of rate advancement (1997-2003). CONCLUSIONS: Compared to others, working-age adults preferentially selected carbon monoxide poisoning from charcoal burning.

Restricting the means of suicide by charcoal burning.

We conducted an exploratory controlled trial to examine the efficacy of restricting access to charcoal in preventing suicides from carbon monoxide poisoning by charcoal burning in Hong Kong. All charcoal packs were removed from the open shelves of major retail outlets in the intervention region for 12 months; in the control region, charcoal packs were displayed as usual. The suicide rate from charcoal burning was reduced by a statistically significant margin in the intervention region (P<0.05) but not in the control region. We observed no significant change in the suicide rate using other methods in either location.

Years of life lost from suicide in China, 1990-2000.

Suicide is an important public health problem in China: It is the fifth leading cause of death in China, and suicide in China accounts for over 30% of the world's overall suicide deaths. The substantial burden due to suicide has not been well recognized. This study aims to provide an estimate of the socioeconomic burden of the suicide problem in China in terms of years of life lost (YLL) and to discuss its implications. Suicide rates and the related YLL by age, gender, and region (urban/rural) from 1990 to 2000 were estimated using the most recent data from the Ministry of Health of China. The suicide rate in rural China was three times higher than that in urban areas. Suicide completers in rural areas shared 90% of total YLL. Rural women aged 25-39 years contributed the largest share of YLL. Our results show that some population subgroups contributed a disproportionate share to the disease burden of suicide. National strategies for suicide prevention should include targeted programs in catering the need of these specified subgroups in China.

Suicidal ideation and suicidal attempts in a population-based study of Chinese people: risk attributable to hopelessness, depression, and social factors.

BACKGROUND: The population attributable fraction of hopelessness, depression and other risk factors for suicidal ideation and suicidal attempts in Asian population is unknown. Social support is often said to be a buffer against the effect of hopelessness and depression. METHODS: Suicidal ideation, suicidal attempts as well as demographic and psychometric data were delineated in a random and representative population sample of 2,219 Chinese people in Hong Kong. The population attributable fraction was used to determine the contribution of hopelessness, depression and other risk factors to suicidal ideation and attempts. RESULTS: Multivariate modelling shows that about 40% of suicidal ideation and attempts was attributable to depression and about 20% was attributable to hopelessness. Drug abuse and marital dissolution were also significant contributors to suicidality. The impact of hopelessness and depression was not affected by social support. LIMITATIONS: Suicidality was self-reported. CONCLUSIONS: Suicidal ideation and suicidal attempts were to a large extent attributable to depression and hopelessness, and, to a lesser extent, drug abuse and marital dissolution. Social support appeared to play little role as a buffer.

Social and economic burden of suicides in Hong Kong SAR: a year of life lost perspective.

The paper proposes to use the years-of-life-lost method (YLL) in assessing the social and economic burden of suicides in Hong Kong SAR. The YLL from suicide by age group in 1981-2002 is calculated based on the standard set by World Health Organization (WHO). It shows that the middle age group (25-39) contributed most to the burden of disease in Hong Kong. The proportion of older adults' suicides is about 25% of the total number of suicides but its disease burden is less than 6% in terms of the YLL. Though the group aged 25-39 contributed disproportionately to the total YLL from suicide, the prevention effort for this particular group has been very much neglected and needs to be strengthened. It illustrates that use of YLL could provide a new viewpoint for setting up public health policies.

In-depth evaluation of the AJCC/UICC 1997 staging system of nasopharyngeal carcinoma: prognostic homogeneity and proposed refinements.

PURPOSE: To critically evaluate the American Joint Commission on Cancer (AJCC)/International Union Against Cancer (UICC) 1997 staging system and look back on its achievements by comparing it with the AJCC/UICC 1992 and Ho 1978 staging systems. To identify areas for additional refinement, we analyzed the prognostic heterogeneity within each stage in depth, which provided important clues for the addition or better categorization of the different defining criteria. METHODS AND MATERIALS: We performed a retrospective review of the data from 1294 consecutive biopsy-proven nonmetastatic nasopharyngeal carcinoma patients and staged the extent of disease according to the defining criteria of the three staging systems. All patients had undergone detailed pretreatment assessment by fiberoptic endoscopy and CT. Radical-intent radiotherapy was given using the Ho technique according to our standard protocol. RESULTS: The AJCC/UICC 1997 staging system was superior to the other two staging systems, because it assigned patients to more uniform-size stage groupings and correlated better with prognosis. Parapharyngeal space involvement was not an independent predictor for survival, local control, or metastasis. On the other hand, carotid space involvement correlated with a greater likelihood of metastasis. Prognostic heterogeneity was found. Those with orbit, cranial nerve, or intracranial involvement fared worse within Stage T4; those with a maximal lymph node size >3 cm fared worse within Stage N2; and those with bilateral lymph node metastasis fared worse within Stage N3. CONCLUSION: The prognostic accuracy of the AJCC/UICC 1997 staging system can be improved further by recategorization of the T, N, and group stage criteria.

Clinical role of circulating Epstein-Barr virus DNA as a tumor marker in lymphoepithelioma-like carcinoma of the lung.

Nineteen Chinese patients with lymphoepithelioma-like carcinoma (LELC) of the lung were tested for Epstein-Barr virus (EBV) DNA in their serum samples by a quantitative polymerase chain reaction (PCR) technique. There was prospective serial monitoring of the serum in seven patients with advanced inoperable or relapsing disease. Five other patients at first diagnosis and two patients at relapse had only a single serum sample available. Serum samples were also taken from three other patients who had prior curative surgery and two patients with prolonged disease remission. Measurable levels of EBV DNA were detected in 11 of 12 patients with a pre-therapy serum sample and a clinically evident tumor. A low level of EBV DNA was also detectable in one of the two other patients whose first serum samples were obtained after some chemotherapy. There was no detectable EBV DNA in the five patients without evidence of tumor. The longitudinal serum EBV DNA profile of seven patients showed consistent correlation with response to therapy and clinical outcome. Patients with a pre-therapy serum EBV DNA >10,000 copies/mL had significantly inferior overall survival. This study suggests that circulating serum EBV DNA can be used as a tumor marker in the clinical management of patients with LELC of the lung.

Reactive hemophagocytic syndrome: a study of 7 fatal cases.

Reactive hemophagocytic syndrome is a clinico-pathologic entity characterized by systemic proliferation of non-neoplastic histiocytes showing phagocytosis of hemopoietic cells, resulting in blood cytopenia. It is best known to be associated with virus infection, but other associated diseases have also been implicated. The clinical and pathological findings of 7 fatal cases are described. The syndrome affected both sexes of a wide age range, and all patients had fever. Significant laboratory findings were blood cytopenia, abrupt drop in the blood cell counts, deranged liver function tests and abnormal coagulation profile. The associated diseases were diverse: two patients had bacterial infection; two had peripheral T-cell lymphoma; one had disseminated undifferentiated carcinoma of the ovary; one had both tuberculosis and disseminated nasopharyngeal carcinoma, and one had no obvious underlying disease. It is postulated that lymphokines secreted by lymphoid cells or tumor cells may be responsible for the systemic activation of histiocytes. The differential diagnosis from malignant histiocytosis is discussed.

Nasopharyngeal carcinoma with bone marrow metastasis.

Five of 23 patients with recurrent nasopharyngeal carcinoma (NPC) were diagnosed to have bone marrow metastasis. They all had advanced local-regional disease, and were treated with neoadjuvant chemotherapy and definitive radiotherapy after the initial diagnosis. Bone marrow metastasis developed 4-24 months later. The clinical features were anemia (5 of 5), leukopenia (3 of 5), thrombocytopenia (4 of 5), sepsis (3 of 5), tenderness of the sternum (3 of 5), and fever (4 of 5). Patients frequently had elevation of serum lactic dehydrogenase (LDH), alkaline phosphatase (ALK-P), and IgG and IgA antibody titers to Epstein-Barr viral capsid antigen when bone marrow involvement was diagnosed. However, clinical manifestations and laboratory tests were not specific. It is important that three patients had normal bone scans. All five patients had a rapid downhill course; four patients died within 23 days, and the fifth 3 months after the diagnosis of bone marrow metastasis. We concluded that bone marrow was a common metastatic site in NPC patients. Bone marrow metastasis adversely affected patients' survival and required a high index of suspicion for diagnosis. We suggested that bone marrow biopsy should be considered as a routine staging procedure in NPC patients and indicated especially when patients presented with abnormal blood counts, sepsis, bone pain, or tenderness of the sternum. It may be positive in the face of a normal bone scan.

Staging of nasopharyngeal carcinoma: evaluation of N-staging by Ho and UICC/AJCC systems. Union Internationale Contre le Cancer. American Joint Committee for Cancer.

To evaluate the prognostic accuracy of N-staging by Ho's and the UICC/AJCC systems, 5020 patients with undifferentiated or poorly differentiated squamous cell carcinoma of the nasopharynx treated at the Queen Elizabeth Hospital, Hong Kong in the period 1976-1985 were analysed retrospectively. They were initially staged with Ho's system, but detailed records of nodal involvement allowed accurate retrospective restaging with the UICC/ AJCC (1988) system. Staging assessment depended almost entirely on physical examination; only 14% of patients had additional investigations with computed tomography. To evaluate the independent significance of different nodal parameters, T-stage adjusted analyses of the 4730 patients presenting without distant metastases were performed. Both N-staging systems showed a strongly significant overall correlation with distant failures and cancer-specific deaths. A significant trend was also shown for nodal failures in node-positive patients. Ho's system was superior in predicting distant failures, while the UICC/AJCC system was superior for nodal failures. However, even with due adjustment for level, the independent significance of nodal size, laterality and fixity could be demonstrated. After adjustment for UICC/AJCC N-stage, both level and fixity were also significant. Furthermore, when adjusted for all other meaningful parameters, there were no significant differences between ipsilateral and contralateral involvement, upper and mid-level extent, and nodal size < or = 3 cm or > 3- < or = 6 cm. N-staging can be further optimized by a newly proposed system incorporating fixity (movable versus fixed), level (upper-mid versus lower), size (greatest diameter < or = 6 cm versus > 6 cm), and laterality (unilateral versus bilateral) as staging criteria.

N-staging of nasopharyngeal carcinoma: discrepancy between UICC/AJCC and Ho systems. Union Internationale Contre le Cancer. American Joint Committee for Cancer.

To enable clinicians to have a better understanding of the limitations of the UICC/AJCC and Ho N-staging systems for nasopharyngeal carcinoma, 4730 patients without distant metastases at diagnosis were retrospectively analysed. The two systems agreed in 54% (1867/3451) of node-positive patients, and their treatment results were taken as the reference for comparison. To identify the most appropriate N-stage for the discrepant groups, their outcomes were measured against the respective reference. All patients with single, ipsilateral and small nodes, irrespective of their relative position in the upper-mid neck should be classified as N1, while those with multiple, bilateral/contralateral or medium-sized node(s) are effectively N2, even if nodal involvement is confined to the upper neck. All patients with extension to the supraclavicular fossa (irrespective of size) and those with nodes larger than 6 cm at the greatest diameter (irrespective of level) should be classified and treated as N3, especially as, in this group, half of the patients died of distant metastases and trials of adjuvant systemic therapy have to be considered. Areas of inaccurate prognostication by the respective system should be noted to avoid misguiding treatment strategy. The present analyses support our previous suggestions that both the level of extent and the bulk of nodal deposits are important prognostic factors. While supraclavicular involvement is a significant demarcation, there is little justification for further division into upper and mid-levels. The merits of both systems should be duly recognized and combined for the further improvement of prognostic accuracy.

Treatment of trichlorophenol by catalytic oxidation process.

The oxidation of 2,4,6-trichlorophenol (TCP) by ferrous-catalyzed hydrogen peroxide was quantified and modeled in the study. TCP was effectively degraded by hydroxyl radicals that were generated by Fe(II)/H(2)O(2) in the oxidation process. The oxidation capacity (OC) of the process depends on the concentrations of oxidant (hydrogen peroxide) and oxidative catalyst (ferrous ion). Up to 99.6% of TCP removal can be achieved in the process, provided the doses of Fe(II) and H(2)O(2) are selected correctly. The OC of the process was successfully predicted through a kinetic approach in a two-stage model with some simple and measurable parameters, which makes the model useful for predicting, controlling and optimizing the catalyzed oxidation process in the degradation of TCP.

Norms and alcohol consumption: Japanese in Japan, Hawaii and California.

The study compared age/sex norms and alcohol consumption of a sample of Japanese from Japan and Japanese Americans in Hawaii and California. Age norms included acceptable drinking levels for the following age groups: 16, 21, 40 and 60, both male and female. There were significant differences in norms across the sites with the Japanese in Japan holding the most tolerant views of heavier drinking for men, followed by California and Hawaii. The Japanese-American samples were more tolerant of female drinking than were the Japanese. There was a high degree of similarity between Hawaii and California, whereas Japanese respondents in Japan differed in their responses. A correlation between drinking and norms by site indicated a high degree of congruence between drinking and more tolerant norms for drinking in all of the samples: Those who drank the most also had the most permissive norms toward drinking. The differences in norms between Japanese in Japan and Japanese Americans were explained in terms of enculturation and acculturation.

Viability of the health protection account in Hong Kong.

OBJECTIVE: To evaluate the viability of the Health Protection Account proposed by the Hong Kong Special Administrative Region Government. DESIGN: Retrospective study. SETTING: The Hospital Authority of Hong Kong. MATERIALS AND METHODS: Data were obtained from hospital and specialist out-patient clinic admissions. The expected health cost for each patient from the age of 65 years to the average age of life expectancy (83 years) was estimated, as was the contribution to these health costs from the Health Protection Account. RESULTS: If individuals contribute 1% of their salary to the Health Protection Account from age 40 to 65 years, the Account can only cover 4% of the actual health costs. CONCLUSION: The Health Protection Account, as proposed, does not ease the financial burden of increasing health care costs in the elderly. Increasing the contribution rate or reducing the age at which contributions to the scheme are started are possible viable options for making the scheme sustainable. However, the current economic situation is such that the public would not favour either of these alternatives. It is envisaged that the Government will need to continue to finance the health care of its citizens by taxation. A gradual increase in user charges might be the only future option for controlling government health expenditure.