Deciphering the epidemiology of hepatocellular carcinoma through the passage of time: A study of 1,401 patients across 3 decades

Hepatocellular carcinoma (HCC) is one of the most common and lethal cancers globally. With advances in therapy for chronic viral hepatitis, changing social circumstances, and increasing practice of HCC surveillance, the epidemiology of HCC is expected to change over time. We explored the temporal trends in HCC in Singapore, a multiethnic Asian country, over the last 3 decades. Patients with HCC were prospectively enrolled and stratified into two cohorts (C1, 1988‐2002; C2, 2003‐2016). Patient and tumor characteristics, management, and survival were compared between the two cohorts, and a survival census was performed on October 31, 2015. There were 1,401 patients, and the mean age at diagnosis of HCC for C1 and C2 was 60.1 and 63.5 years, respectively. Male patient preponderance decreased significantly, with the male to female ratio falling from 5.2:1 to 3.9:1 between C1 and C2. Hepatitis B, although still the predominant risk factor for HCC, showed a significant decline from C1 to C2 (76.5% to 68.2%), while the nonviral etiology increased significantly over the same period (14.4% versus 25.0%, respectively). Significantly more patients in C2 than C1 were diagnosed through surveillance (39.2% versus 11.3%, respectively) and had better physical performance (Eastern Cooperative Oncology Group 0, 62.1% versus 20.4%, respectively). While Child‐Pugh status was comparable, significantly more patients in C2 than C1 had early stage disease (Barcelona Clinic Liver Cancer 0‐A, 39.5% versus 7.4%, respectively), which translated into significantly higher median survival (18.6 months versus 3.8 months, respectively). Conclusion: Over the past 3 decades, hepatitis B‐related HCC has been decreasing while HCC due to nonviral etiology has been increasing significantly. Surveillance to diagnose early stage HCC is important in improving the outcome of HCC. (Hepatology Communications 2017;1:564–571)

Incidence, Trends and Ethnic Differences of Oropharyngeal, Anal and Cervical Cancers: Singapore, 1968-2012

In recent decades, several Western countries have reported an increase in oropharyngeal and anal cancers caused by human papillomavirus (HPV). Trends in HPV-associated cancers in Asia have not been as well described. We describe the epidemiology of potentially HPV-related cancers reported to the Singapore Cancer Registry from 1968-2012. Analysis included 998 oropharyngeal squamous cell carcinoma (OPSCC), 183 anal squamous cell carcinoma (ASCC) and 8,019 invasive cervical cancer (ICC) cases. Additionally, 368 anal non-squamous cell carcinoma (ANSCC) and 2,018 non-oropharyngeal head and neck carcinoma (non-OP HNC) cases were included as comparators. Age-standardized incidence rates (ASR) were determined by gender and ethnicity (Chinese, Malay and Indian). Joinpoint regression was used to evaluate annual percentage change (APC) in incidence. OPSCC incidence increased in both genders (men 1993-2012, APC = 1.9%, p<0.001; women 1968-2012, APC = 2.0%, p = 0.01) and was 5 times higher in men than women. In contrast, non-OP HNC incidence declined between 1968-2012 among men (APC = -1.6%, p<0.001) and women (APC = -0.4%, p = 0.06). ASCC and ANSCC were rare (ASR = 0.2 and 0.7 per 100,000 person-years, respectively) and did not change significantly over time except for increasing ANSCCs in men (APC = 2.8%, p<0.001). ICC was the most common HPV-associated cancer (ASR = 19.9 per 100,000 person-years) but declined significantly between 1968-2012 (APC = -2.4%). Incidence of each cancer varied across ethnicities. Similar to trends in Western countries, OPSCC incidence increased in recent years, while non-OP HNC decreased. ICC remains the most common HPV-related cancer in Singapore, but Pap screening programs have led to consistently decreasing incidence.

Long-term prognosis and risk heterogeneity of heart failure complicating acute myocardial infarction

The Killip classification of acute heart failure was developed decades ago to predict short-term mortality in patients with acute myocardial infarction (AMI). The aim of this study was to determine the long-term prognosis of acute heart failure graded according to the Killip classification in 15,235 unselected patients hospitalized for AMI from 2000 to 2005. Vital status for each patient was ascertained, through to March 1, 2012, from linkage with national death records. A stepwise gradient in the adjusted hazard ratio (HR) for 12-year mortality was observed with increasing Killip class: class I (n = 10,123), HR 1.00 (reference group); class II (n = 2,913), HR 1.13 (95% confidence interval [CI] 1.06 to 1.21); class III (n = 1,217) HR 1.49 (95% CI 1.37 to 1.62); and class IV (n = 898), HR 2.80 (95% CI 2.53 to 3.10). Unexpectedly, in a landmark analysis excluding deaths <30 days after admission, patients in Killip class IV had lower adjusted long-term mortality than those in class III. The adjusted HR for 12-year mortality comparing Killip class IV with Killip class III in patients <60 years of age was 1.71 (95% CI 1.33 to 2.19, p <0.001) and in patients >60 years of age was 2.30 (95% CI 2.07 to 2.56, p <0.001). In conclusion, on the basis of simple clinical features, the Killip classification robustly predicted 12-year mortality after AMI. The heterogeneity in early versus late risk in patients with Killip class IV heart failure underscores the importance of appropriate early treatment in cardiogenic shock.

Assessing risk of breast cancer in an ethnically South-East Asia population (results of a multiple ethnic groups study)

BACKGROUND

Gail and others developed a model (GAIL) using age-at-menarche, age-at-birth of first live child, number of previous benign breast biopsy examinations, and number of first-degree-relatives with breast cancer as well as baseline age-specific breast cancer risks for predicting the 5-year risk of invasive breast cancer for Caucasian women. However, the validity of the model for projecting risk in South-East Asian women is uncertain. We evaluated GAIL and attempted to improve its performance for Singapore women of Chinese, Malay and Indian origins.

METHODS

Data from the Singapore Breast Screening Programme (SBSP) are used. Motivated by lower breast cancer incidence in many Asian countries, we utilised race-specific invasive breast cancer and other cause mortality rates for Singapore women to produce GAIL-SBSP. By using risk factor information from a nested case-control study within SBSP, alternative models incorporating fewer then additional risk factors were determined. Their accuracy was assessed by comparing the expected cases (E) with the observed (O) by the ratio (E/O) and 95% confidence interval (CI) and the respective concordance statistics estimated.

RESULTS

From 28,883 women, GAIL-SBSP predicted 241.83 cases during the 5-year follow-up while 241 were reported (E/O=1.00, CI=0.88 to 1.14). Except for women who had two or more first-degree-relatives with breast cancer, satisfactory prediction was present in almost all risk categories. This agreement was reflected in Chinese and Malay, but not in Indian women. We also found that a simplified model (S-GAIL-SBSP) including only age-at-menarche, age-at-birth of first live child and number of first-degree-relatives performed similarly with associated concordance statistics of 0.5997. Taking account of body mass index and parity did not improve the calibration of S-GAIL-SBSP.

CONCLUSIONS

GAIL can be refined by using national race-specific invasive breast cancer rates and mortality rates for causes other than breast cancer. A revised model containing only three variables (S-GAIL-SBSP) provides a simpler approach for projecting absolute risk of invasive breast cancer in South-East Asia women. Nevertheless its role in counseling the individual women regarding their risk of breast cancer remains problematical and needs to be validated in independent data.

Singapore cancer trends in the last decade

In this review, we examine the trends in cancer incidence, mortality and survival in the last decade, using published data from the Singapore Cancer Registry in the period 1998 to 2009. While overall cancer incidences have remained stable, overall cancer mortality rates have declined for both genders. Thus, it is not surprising that there was an improvement in cancer survival. A steady decrease in lung cancer among males and females was observed, thereby leading to a drop in its cancer ranking. In the last five years, the most frequently occurring cancer was colorectal cancer among the male population and breast cancer among females. Survival for both cancers remained relatively optimistic. There is good reason to pay special attention to colorectal cancer due to its high frequency of occurrence among the Singapore population and because it is amenable to early detection via screening.

Effect of childbirth after treatment on long-term survival from breast cancer

Background

This study quantified long-term absolute and relative mortality risks of survivors of breast cancer with subsequent childbirth.

Methods

The Singapore Birth Register (n = 319 437), Swedish Multi-Generation Register (n = 11 million) and population-based cancer registries were linked to identify 492 women with childbirth after breast cancer. For these women, cumulative mortality risks and standardized mortality ratios (SMRs) were calculated and compared with those of 8529 women aged less than 40 years with breast cancer without subsequent childbirth, and with those predicted by Adjuvant! Online.

Results

Women with subsequent childbirth had a lower 15-year cumulative overall mortality rate than other women with breast cancer (16·8 (95 per cent confidence interval (c.i.) 13·3 to 20·9) versus 40·7 (39·5 to 41·9) per cent), but a higher relative mortality risk than the background population (SMR 13·6, 95 per cent c.i. 10·6 to 17·3). Mortality risks decreased significantly with increasing interval between diagnosis and subsequent childbirth. Mean 10-year cumulative mortality risks of women with subsequent childbirth were within the range of 10-year mortality predicted by Adjuvant! Online for women with T1 N0 tumours in otherwise perfect health.

Conclusion

This study reinforced the view that pregnancy after breast cancer is not detrimental to survival. However, women who gave birth after this diagnosis had substantially higher mortality risks than young women in the general population. This information may be a valuable addition to routine mortality estimates.

Prevalence of Adolescent Idiopathic Scoliosis among Female School Children in Singapore

Introduction: Screening for scoliosis started in Singapore schools in 1982 and is currently being done for both boys and girls, as part of the annual school-based health screening programme in all primary and secondary schools. The screening levels in the current protocol were based on the 1997 prevalence study by Wong et al. In the study, it appeared that there was a significant increase in prevalence rates between 9- and 11-year-old girls (i.e. between Primary 4 and Primary 6) but there was no data on the prevalence rates of scoliosis in 10-year-old girls (Primary 5) and in 12-year-old girls (Secondary 1). In order to decide on whether to make changes to the screening levels, a review was conducted to determine the prevalence of scoliosis among the 10-year-old girls (in Primary 5) and 12-year-old girls (in Secondary 1). Materials and Methods: A total of 93,626 female students, aged between 9 and 13 years old were screened. The study covered all of the 183 primary schools and only 83 of the 165 secondary schools due to a disruption of health screening in schools during the outbreak of SARS (severe acute respiratory syndrome). In mid-2003, schools in Singapore were closed because Singapore was one of the countries af-fected by SARS. Scoliosis screening was done for all female students in the Primary 4, 5 and 6 levels as well as in the Secondary 1 and 2 levels. Male students were routinely screened for scoliosis in the Primary 6 and Secondary 2 levels. Scoliosis screening was done by measuring the angle of trunk rotation (ATR) using a scoliometer. All students with ATR ≥5° were referred to the Student Health Centre (SHC) where second-tier screening was done. At SHC, if ATR ≥5°, postero-anterior radiograph of the spine was done. Of the 3186 female students in the primary level, aged between 9 and 13 years old who were referred to SHC for the second-tier screen-ing, 2438 attended, and for secondary students aged between 12 and 13 years old, 1587 out of 1720 students attended. Results: The prevalence rates of idiopathic adolescent scoliosis for the 9- to 13-year-old female students were 0.27%, 0.64%, 1.58%, 2.22% and 2.49%, respectively, which showed an increasing trend in the prevalence rates with increasing age. There was a significant increase in the prevalence rates of adolescent idiopathic scoliosis (AIS) in the 10- to 11-year-old females compared to the 9-year-old females (OR, 1.7; 95% CI, 1.1-2.4; P = 0.010). There was also a significant increase in the prevalence rates in the 12- to 13-year-old females (OR, 2.2; 95% CI, 1.4-3.3; P = 0.001). Conclusions: The study showed a significant increase in the prevalence rates of scoliosis in the 10- to 11-year-old female students and again a significant increase in the prevalence rates in the 12- to 13-year-old female students. Since the prevalence rate for the 9-year-old females was quite low (0.27%), and there was a significant increase in the prevalence rates in the 10- to 11-year-old and 12- to 13-year-old females, it was recommended that screening for females be performed every year commencing at 10 years old (Primary 5) until 13 years old (Secondary 2).

Prevalence of adolescent idiopathic scoliosis among female school children in Singapore

INTRODUCTION

Screening for scoliosis started in Singapore schools in 1982 and is currently being done for both boys and girls, as part of the annual school-based health screening programme in all primary and secondary schools. The screening levels in the current protocol were based on the 1997 prevalence study by Wong et al. In the study, it appeared that there was a significant increase in prevalence rates between 9- and 11-year-old girls (i.e. between Primary 4 and Primary 6) but there was no data on the prevalence rates of scoliosis in 10-year-old girls (Primary 5) and in 12-year-old girls (Secondary 1). In order to decide on whether to make changes to the screening levels, a review was conducted to determine the prevalence of scoliosis among the 10-year-old girls (in Primary 5) and 12-year-old girls (in Secondary 1).

MATERIALS AND METHODS

A total of 93,626 female students, aged between 9 and 13 years old were screened. The study covered all of the 183 primary schools and only 83 of the 165 secondary schools due to a disruption of health screening in schools during the outbreak of SARS (severe acute respiratory syndrome). In mid-2003, schools in Singapore were closed because Singapore was one of the countries affected by SARS. Scoliosis screening was done for all female students in the Primary 4, 5 and 6 levels as well as in the Secondary 1 and 2 levels. Male students were routinely screened for scoliosis in the Primary 6 and Secondary 2 levels. Scoliosis screening was done by measuring the angle of trunk rotation (ATR) using a scoliometer. All students with ATR >or=5 degrees were referred to the Student Health Centre (SHC) where second-tier screening was done. At SHC, if ATR >or=5 degrees , postero-anterior radiograph of the spine was done. Of the 3186 female students in the primary level, aged between 9 and 13 years old who were referred to SHC for the second-tier screening, 2438 attended, and for secondary students aged between 12 and 13 years old, 1587 out of 1720 students attended.

RESULTS

The prevalence rates of idiopathic adolescent scoliosis for the 9- to 13-year-old female students were 0.27%, 0.64%, 1.58%, 2.22% and 2.49%, respectively, which showed an increasing trend in the prevalence rates with increasing age. There was a significant increase in the prevalence rates of adolescent idiopathic scoliosis (AIS) in the 10- to 11-year-old females compared to the 9-year-old females (OR, 1.7; 95% CI, 1.1-2.4; P = 0.010). There was also a significant increase in the prevalence rates in the 12- to 13-year-old females (OR, 2.2; 95% CI, 1.4-3.3; P = 0.001).

CONCLUSIONS

The study showed a significant increase in the prevalence rates of scoliosis in the 10- to 11-year-old female students and again a significant increase in the prevalence rates in the 12- to 13-year-old female students. Since the prevalence rate for the 9-year-old females was quite low (0.27%), and there was a significant increase in the prevalence rates in the 10- to 11-year-old and 12- to 13-year-old females, it was recommended that screening for females be performed every year commencing at 10 years old (Primary 5) until 13 years old (Secondary 2).

Trends in long-term cancer survival in Singapore: 1968-2002

INTRODUCTION

The life expectancy of cancer patients has increased in recent decades due to better diagnostic and screening tools as well as better treatment modalities. Hence, it becomes increasingly important to study trends in long-term cancer patient survival in order to document that medical progress has conveyed benefit at the population level. In this paper, we assessed the long-term survival experience of all incident cancer patients in Singapore.

MATERIALS AND METHODS

The study population consisted of patients diagnosed with single primary invasive cancer from 1 January 1968 to 31 December 2002, and passively followed up to 31 December 2005. The data was derived from the Singapore Cancer Registry, which has been in existence since 1968. Relative survival via the period approach was used to provide a more up-to-date estimate by looking at recent cohorts of patients. Sex- and stage-specific survival was compared for each cancer.

RESULTS

The overall age-standardised 10-year relative survival ratios for the calendar years of 1998 to 2002 were 30.5% in males and 44.2% in females. A steady improvement in overall long-term cancer survival was observed over the study period. This upward trend in survival was observed in localised tumours and cancers with a favourable prognosis such as breast, cervical and colorectal cancers. In contrast, survival of cancers with poor prognosis such as lung, liver and pancreas remained low.

CONCLUSIONS

Although factors such as changes in diagnostic criteria could influence the trend in survival, we believed that the improvement in survival predominantly reflected real progress in cancer control in Singapore.

SARS coronavirus and apoptosis

1. The adenovirus-mediated overexpression of SARS coronavirus (SARS-CoV) spike protein (S) and its C-terminal domain (S2) induce apoptosis in Vero E6 cells. 2. Such apoptosis in Vero E6 cells is time- and dose-dependent. 3. The adenovirus-mediated overexpression of SARS-CoV N-terminal domain (S1) and other structural proteins, including E,M and N protein, do not induce apoptosis.

Measurable predictive factors for progression to AIDS among HIV-infected patients in Singapore

INTRODUCTION

This study identifies measurable factors at the time of diagnosis that predict the progression to Acquired Immunodeficiency Syndrome (AIDS) among Human Immunodeficiency Virus (HIV)-infected patients in Singapore.

MATERIALS AND METHODS

We carried out a retrospective study of 790 HIV-infected patients from 16 May 1985 to 31 December 2001. The end-point was the onset of AIDS-defining illness listed in the 1987 and 1991 revised Centers for Disease Control and Prevention criteria, but excluded CD4 cell counts as a criterion. Using the Kaplan-Meier method, AIDS-free survival curves were plotted for age groups at diagnosis, baseline CD4 counts and periods for utilisation of antiretroviral treatment. A Cox regression model was constructed to determine independent predictors of disease progression.

RESULTS

Univariate analysis showed that patients of older age at diagnosis had a significantly higher risk of progression compared to younger patients, and patients with higher baseline CD4 cell counts had a lower risk of progression to AIDS. Adjusting for the simultaneous influence of several covariates on the rate of HIV progression to AIDS, multivariate analysis using the Cox model showed a significantly higher risk of progression for older patients at diagnosis, and the progressive lowering of risk with increasing baseline CD4 cell counts.

CONCLUSIONS

This study found older age at diagnosis and baseline CD4 cell counts to be measurable predictors for HIV progression to AIDS at time of diagnosis. Identification of these risk factors enables physicians to provide counselling and advice, and to start appropriate treatment early. This could lower the risk of progression and improve survival.

Discrimination of an infected brain tumor from a cerebral abscess by combined MR perfusion and diffusion imaging

The aim of this study was to investigate the signal characteristics of the abscess wall and tumor wall on diffusion-weighted and perfusion-weighted images and thus to evaluate the feasibility of using combined MR diffusion and perfusion imaging to differentiate pyogenic cerebral abscess from infected brain tumor. The tumor wall of various types of cystic or necrotic brain tumor was significantly hyperintense relative to that of cerebral abscess wall on both diffusion-weighted images and regional cerebral blood volume maps. Sixteen patients who had cerebral masses with large cystic or necrotic cavities were imaged to generate diffusion-weighted images and regional cerebral blood volume maps using single-shot echoplanar imaging (EPI) pulse sequences. Apart from qualitative analysis, apparent diffusion coefficients (ADC) as well as regional cerebral blood volume (rCBV) ratios were calculated from the abscess wall and peripheral tumor wall and comparison was made by using Student's t-test. The tumor wall of various types of cystic or necrotic brain tumor had significantly lower ADCs relative to those of the abscess wall (P<0.005) and thus appeared relatively hyperintense on diffusion-weighted images. The mean rCBV ratio relative to normal white matter (2.90+/-0.62) of the peripheral tumor wall of various types of cystic or necrotic brain tumor were significantly larger than the mean rCBV ratio (0.45+/-0.11) of the pyogenic cerebral abscess wall (P<0.001) by Student's t-test. It is concluded that the combined MR diffusion and perfusion imaging might be capable of differentiating an infected brain tumor from a pyogenic cerebral abscess.

Does enhanced sympathetic tone contribute to angiotensin II hypertension in rats?

To determine whether enhanced sympathetic tone contributes to the maintenance of chronic angiotensin II (A II, 10 ng/min i.v. for 10 days) hypertension in rats, sympathetic activity was assessed in hypertensive and control rats by measuring norepinephrine (NE) turnover (alpha-methyl-p-tyrosine) in peripheral organs and by measuring depressor responses to ganglionic blockade in conscious rats. Pressor responses to methoxamine (1-8 micrograms/min) and arginine vasopressin (0.5-4 ng/min) were also obtained in rats with ganglionic blockade. Chronic A II infusion produced significant hypertension (mean +/- S.E. tail cuff pressure: 176 +/- 5 vs. 134 +/- 2 mm Hg in controls; n = 23 each group) but there were no significant differences in NE turnover in heart, kidney, skeletal muscle, or intestine in hypertensive rats compared with controls. Ganglionic blockade produced a significantly larger decrease in mean arterial pressure in A II-treated rats when compared with controls (73 +/- 7 vs. 38 +/- 2 mm Hg, n = 18 for each group). Dose-response curves for methoxamine and vasopressin were not significantly different between groups. The results suggest that the maintenance of chronic A II hypertension does not involve postsynaptic interactions between A II and the sympathetic system. The NE turnover data do not support the hypothesis that rats with chronic A II hypertension have enhanced sympathetic tone.

Bites by the white-lipped pit viper (Trimeresurus albolabris) and other species in Hong Kong. A survey of 4 years' experience at the Prince of Wales Hospital

The case records of 242 snake bite victims admitted to the Prince of Wales Hospital in Hong Kong between September 1984 and October 1988 were studied retrospectively. When the snake was identified, the White-lipped pit viper (Trimeresurus albolabris) was by far the commonest species involved. In addition to local oedema and inflammation, evidence of a significant blood clotting disturbance was present in at least 10% of cases, defibrination and thrombocytopenia being the commonest findings. Since such abnormality was not always sought the true figure is likely to be higher. Three fatalities occurred, one of which was secondary to a probable White-lipped pit viper bite, one to a bite by Chinese cobra and one to a bite by Russell's viper.

Effect of short-term administration of vasopressin on arterial pressure and norepinephrine turnover in Long-Evans rats

Vasopressin (AVP) in acute experiments has been shown to influence cardiovascular reflexes, but the effect of a more prolonged administration of AVP on the sympathetic nervous system has not been investigated. Long-Evans rats were treated for 7 days with AVP (Pitressin tannate in oil, with single daily doses of 100 or 500 mU.100 g-1, s.c.) to determine whether AVP alters norepinephrine (NE) turnover in kidney, intestine, or skeletal muscle. Control rats were given equal doses of peanut oil daily. NE turnover was determined by measuring the decline in tissue levels of NE for 8 h after inhibition of tyrosine hydroxylase with alpha-methyl-p-tyrosine (300 mg.kg-1, i.p. every 4 h). Measurements of water intake, urine output, and urine osmolality showed that chronic administration of the high dose, but not the low dose, of AVP produced maintained increases in urine osmolality and decreases in water intake and urine output. Body weight, plasma osmolality, plasma electrolytes, and hematocrit were not significantly altered by AVP treatment, but mean arterial pressure was elevated significantly (control, 105 +/- 3 mmHg versus AVP, 119 +/- 4 mmHg, p less than 0.05) (1 mmHg = 133.3 Pa) in the high dose group. Plasma renin activity was decreased slightly, but significantly in rats treated with the high dose of AVP. Compared with results in control animals, there were no statistically significant changes in NE turnover after chronic administration of either the low or the high dose of AVP. The results indicate that administration of AVP for 7 days to rats in normal fluid balance does not result in a decrease in NE turnover in peripheral organs.