Population-based survival analysis of colorectal cancer patients in Singapore, 1968-1992

Survival of colorectal cancer patients in Brunei Darussalam: comparison between 2002-09 and 2010-17

Background

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. It is the second leading cause of cancer death in men and women in Brunei Darussalam in 2017, posing a major burden on society.

Methods

This retrospective cohort study (n = 1035 patients diagnosed with CRC in Brunei Darussalam from 1st January 2002 until 31st December 2017) aims to compare the overall survival rates of CRC patients (2002–2017), to compare survival rates between two study periods (2002–2009 and 2010–2017) and to identify prognostic factors of CRC. Kaplan-Meier estimator and log-rank tests were performed to analyse the overall survival rates of CRC patients. Multiple Cox regression was performed to determine the prognostic factors of CRC with adjusted hazard ratios (Adj. HRs) reported.

Results

The 1-, 3- and 5-year survival rates of CRC patients are 78.6, 62.5, and 56.0% respectively from 2002 to 2017. The 1-, 3-, and 5-year survival rates of CRC patients for 2002–2009 are 82.2, 69.6, and 64.7%; 77.0, 59.1, and 51.3% for 2010–2017 respectively. A significant difference in CRC patients’ survival rate was observed between the two study periods, age groups, ethnic groups, cancer stages, and sites of cancer (p < 0.05). The Adjusted Hazard Ratios (Adj. HRs) were significantly higher in the 2010–17 period (Adj. HR = 1.78, p < 0.001), older age group ( ≥ 60 years) (Adj. HR = 1.93, p = 0.005), distant cancer (Adj. HR = 4.69, p < 0.010), tumor at transverse colon and splenic flexure of colon (Adj. HR = 2.44, p = 0.009), and lower in the Chinese(Adj. HR = 0.63, p = 0.003).

Conclusion

This study highlights the lower survival rates of CRC patients in 2010–2017, Malays, older patients, distant cancer, and tumors located at the latter half of the proximal colon (transverse colon), and predominantly LCRC (splenic flexure, descending colon, sigmoid colon, overlapping lesion colon and colon (NOS), as well as the rectosigmoid junction and rectum (NOS)). Age, ethnicity, cancer stage, and tumor location are significant prognostic factors for CRC. These findings underscore the importance of public health policies and programmes to enhance awareness on CRC from screening to developing strategies for early detection and management, to reduce CRC-associated mortality.

Survival Rates and Associated Factors of Colorectal Cancer Patients in Brunei Darussalam

Background:

Colorectal cancer (CRC) is the third most common cancer in both men and women. In most Asian countries, both the incidence and mortality rates of CRC are gradually increasing. In Brunei Darussalam, CRC ranks first and second in lifetime risk among men and women respectively. This study aims to report the overall survival rates and associated factors of CRC in Brunei Darussalam.

Methods:

This is a retrospective study examining CRC data for the period 2007 to 2017 retrieved from a population based cancer registry in Brunei Darussalam. A total of 728 patients were included in the analysis. Kaplan Meier method was used to estimate survival rates. Univariate analysis using log-rank test was used to examine the differences in survival between groups. Multivariate analysis using Cox PH regression was used to estimate hazard of death and obtain significant predictors that influence CRC patients’ survival.

Results:

The median survival time for colorectal, colon and rectal cancer patients were 57.0, 85.8 and 40.0 months respectively. The overall 1-, 3- and 5- year survival rates for CRC patients were 78.0%, 57.7% and 49.6% respectively. In univariate analysis, age at diagnosis, ethnicity, cancer stage, tumour location and histology were found to have significant difference in CRC patients’ survival. In the Cox PH analysis, older age (≥70 years), cancer stage, ethnicity and other histological type were determined as associated factors of CRC patients’ survival.

Conclusion:

This study found the overall 5-year survival rate of CRC in Brunei Darussalam is similar to that in some Asian countries such as Singapore and Malaysia. However, more efforts need to be carried out in order to raise awareness of CRC and improve the survival of CRC patients.

Survival rates and predictors of survival among colorectal cancer patients in a Malaysian tertiary hospital

Background

Colorectal cancer is the third most commonly diagnosed malignancy and the fourth leading cause of cancer-related death globally. It is the second most common cancer among both males and females in Malaysia. The economic burden of colorectal cancer is likely to increase over time owing to its current trend and aging population. Cancer survival analysis is an essential indicator for early detection and improvement in cancer treatment. However, there was a scarcity of studies concerning survival of colorectal cancer patients as well as its predictors. Therefore, we aimed to determine the 1-, 3- and 5-year survival rates, compare survival rates among ethnic groups and determine the predictors of survival among colorectal cancer patients.

Methods

This was an ambidirectional cohort study conducted at the University Malaya Medical Centre (UMMC) in Kuala Lumpur, Malaysia. All Malaysian citizens or permanent residents with histologically confirmed diagnosis of colorectal cancer seen at UMMC from 1 January 2001 to 31 December 2010 were included in the study. Demographic and clinical characteristics were extracted from the medical records. Patients were followed-up until death or censored at the end of the study (31st December 2010). Censored patients’ vital status (whether alive or dead) were cross checked with the National Registration Department. Survival analyses at 1-, 3- and 5-year intervals were performed using the Kaplan-Meier method. Log-rank test was used to compare the survival rates, while Cox proportional hazard regression analysis was carried out to determine the predictors of 5-year colorectal cancer survival.

Results

Among 1212 patients, the median survival for colorectal, colon and rectal cancers were 42.0, 42.0 and 41.0 months respectively; while the 1-, 3-, and 5-year relative survival rates ranged from 73.8 to 76.0%, 52.1 to 53.7% and 40.4 to 45.4% respectively. The Chinese patients had the lowest 5-year survival compared to Malay and Indian patients. Based on the 814 patients with data on their Duke’s staging, independent predictors of poor colorectal cancer (5-year) survival were male sex (Hazard Ratio [HR]: 1.41; 95% CI: 1.12, 1.76), Chinese ethnicity (HR: 1.41; 95% CI: 1.07,1.85), elevated (≥ 5.1 ng/ml) pre-operative carcino-embryonic antigen (CEA) level (HR: 2.13; 95% CI: 1.60, 2.83), Duke’s stage C (HR: 1.68; 95% CI: 1.28, 2.21), Duke’s stage D (HR: 4.61; 95% CI: 3.39, 6.28) and emergency surgery (HR: 1.52; 95% CI: 1.07, 2.15).

Conclusions

The survival rates of colorectal cancer among our patients were comparable with those of some Asian countries but lower than those found in more developed countries. Males and patients from the Chinese ethnic group had lower survival rates compared to their counterparts. More advanced staging and late presentation were important predictors of colorectal cancer survival. Health education programs targeting high risk groups and emphasizing the importance of screening and early diagnosis, as well as the recognition of symptoms and risk factors should be implemented. A nationwide colorectal cancer screening program should be designed and implemented to increase early detection and improve survival outcomes.

Prognostic Variables in 1814 Sporadic Colon Cancers: A Review of Experience from a Single Institution from 1999–2005

Introduction:

Singapore has one of the highest age-standardized incidence rates for colorectal cancer (CRC) at 35.1% in men and 29.9% in women which is almost double that of our neighboring Southeast Asian countries. Surgery is presently the mainstay in treatment of this cancer. This present study evaluates the clinical and prognostic characteristics of sporadic cancers treated by surgical resection in a single institution in an Asian population.

Methods:

1814 consecutive patients with CRC from 1999–2005 treated in the Department of Colorectal Surgery in Singapore General Hospital were reviewed. The clinciopathological characteristics of these patients were collected from a prospectively collected database maintained in the department since 1987. Univariate analysis was performed, and survival curves were constructed using the Kaplan-Meier method. Multivariate analysis was carried out on independent prognostic factors that were positive on univariate analysis.

Results:

All patients had a minimum follow up duration of 5 years unless they were lost to follow up. There were 921 (50.8%) males and 893 (49.2%) females with a median age of 67 years (interquartile range 22–99). The predominant location of the tumour was left-sided ie distal to (and including) the splenic flexure (n=1272, 70%), and the majority presented at an advanced AJCC stage III and IV (n=1018, 56%). The most common site for solitary metastasis is in the liver (n=194, 49%) followed by the lungs (6%). Locoregional recurrence is low at 2.6% (n=46) and distant recurrence is noted at 16.8% (n=297). Disease recurrence are 5.7%, 18.1%, and 27.5% for Stages I, II and III respectively. The median five-year Cancer Specific Survival (CSS) is 58.7 % (95% CI 56.2%–61.2%). On multivariate analysis, a high pre-operative CEA, poorly-differentiated tumour grade, signet ring cell tumours, high tumour stage (T3/T4), nodal disease (N1/N2), presence of both perineural invasion and vascular emboli were all significant factors that worsened CSS.

Conclusion:

Our dataset confirms the current favourable survival of colonic cancers in our country which is comparable to data from the West. Future challenges in management of patients involve improving staging, selection of high risk of recurrence of patients for closer monitoring and further adjuvant treatment to improve survival and reduce locoregional recurrence.

Trends in prevalence of prognostic factors and survival in lung cancer patients from 1985 to 2004 at a tertiary care center

BACKGROUND

After a prolonged period of increasing rates of lung cancer incidence and mortality for both men and women, incidence and mortality rates are decreasing in men and stabilizing in women. The goal of this study was to assess changes over 20 years in the prevalence of known risk factors for lung cancer and to elucidate possible predictors associated with lung cancer survival.

METHODS

The study included a total of 908 patients with primary lung cancer referred to The University of Texas M.D. Anderson Cancer Center over three study periods 1985-1989 (N=392), 1993-1997 (N=216), and 2000-2004 (N=300). Detailed questionnaires were used to collect information from the patients. Hazard ratios were estimated by fitting a Cox proportional hazards model. Using the Kaplan-Meier method, survival in months was calculated up to 2 years from the date of diagnosis to achieve comparability in the three groups.

RESULTS

We observed a decrease in the proportion of patients who are current cigarette smokers and an increase in the proportion of patients who present with adenocarcinoma of the lung, are obese and patients who present with localized disease. We also found an increase in the number of patients who report a family history of lung cancer. The overall median survival duration has increased over the years from 12.0 months in 1985-1989 to 17.5 months in 2000-2004. Also, the probability of survival of patients who were alive at 2 years after diagnosis has also increased (26.5% in 1985-1989 to 40.8% in 2000-2004). Overall, women had a better median survival than men.

CONCLUSIONS

The results show that the demographic, histologic, clinical, and outcome variables of patients with lung cancer have changed over the past 20 years. Most important, the survival of patients with lung cancer has improved.

Rise of colorectal cancer in Singapore: an epidemiological review

BACKGROUND

Over the past three decades, Singapore has seen a dramatic increase in the incidence of colorectal cancer and this is now the most frequent cancer when both genders are combined.

METHODS

In light of this alarming trend, a review of colorectal cancer in Singapore was conducted, using data from the Singapore Cancer Registry from 1968 to 2002. Our research has shown that among Southeast Asian countries, Singapore has the highest age-standardized incidence rates, 35.1% in men and 29.9% in women, more than twice that of the next country; these rates have been increasing at a startling average annual rate of approximately 2.6 and 2.35%, for men and women, respectively.

RESULTS

Between 1998 and 2002, deaths from colorectal cancer constituted 19% of all cancer mortalities in men and 14% in women, accounting for the second highest cause of cancer mortality in both genders. In the same period, more than three quarters (75.6%) of colorectal cancers occurred in the distal colon (including splenic flexure, descending, sigmoid colon and rectum), with the predominant histological subtype being adenocarcinoma (approximately 90%). The age-specific rates for colorectal cancer begin to increase sharply in the 40- to 45-year age group. It remains the most common primary site of cancer in men aged between 35 and 64 years but lies a distant second after breast cancer in women. In individuals aged 65 years and above, colorectal cancer remains prominent in both genders.

CONCLUSION

Despite the dramatic increase in incidence of colorectal cancer in Singapore, there has also been significant progress in survival of colorectal cancer patients with localized disease (limited to large bowel), with 5-year, age-standardized relative survival improving from 36 to 66% in men and 32 to 71% in women; in rectal cancer, improvements from 25 to 66% in men and 23 to 66% in women were also observed. Similar improvements were noted in patients with regional disease (lymph node involvement) but not with distant metastases. This has paralleled the dramatic national development in socioeconomic and health-care services.

Trends in survival and excess risk of death after diagnosis of cancer in 1980-1996 in New South Wales, Australia

Survival from almost all cancers has improved during the last 30 years. There is debate over the reasons for the improvement. We examined trends in survival for 28 cancers from 1980 to 1996 in New South Wales (NSW), Australia, with adjustment for disease spread at diagnosis. NSW Central Cancer Registry data were used to estimate 5-year relative survival and relative excess risk of death for patients diagnosed in 1980-84, 1985-88, 1989-92 and 1993-96. Statistical significance of variation in excess deaths between periods of diagnosis was assessed using Poisson regression, with adjustment for age, sex, duration of follow-up, histology and spread of disease at diagnosis. There were statistically significant falls in excess deaths for 20 of the cancers with a 25% fall for all cancers combined. Cancers of the prostate, liver, thyroid, breast, gallbladder, body of uterus, rectum, cervix and ovary had falls of >30%. The falls varied by spread of disease; the largest being in localised and regionally spread tumours. Overall survival, when unadjusted for spread of cancer, generally fell in parallel with that in the specific categories of spread, which implies that stage migration did not contribute importantly to survival trends. While acknowledging the limitations of incomplete data on stage of cancer at diagnosis, we conclude that falls in excess deaths in NSW from 1980 to 1996 are unlikely, for many cancers, to be attributed to earlier diagnosis or stage migration; thus advances in cancer treatment have almost certainly contributed to them.

Proteomic Analysis of Colorectal Cancer Reveals Alterations in Metabolic Pathways

Colorectal cancer is the second leading killer cancer worldwide and presently the most common cancer among males in Singapore. The study aimed to detect changes of protein profiles associated with the process of colorectal tumorigenesis to identify specific protein markers for early colorectal cancer detection and diagnosis or as potential therapeutic targets. Seven pairs of colorectal cancer tissues and adjacent normal mucosa were examined by two-dimensional gel electrophoresis at basic pH range (pH 7-10). Intensity changes of 34 spots were detected with statistical significance. 16 of the 34 spots were identified by MALDI-TOF/TOF tandem mass spectrometry. Changes in protein expression levels revealed a significantly enhanced glycolytic pathway (Warburg effect), a decreased gluconeogenesis, a suppressed glucuronic acid pathway, and an impaired tricarboxylic acid cycle. Observed changes in protein abundance were verified by two-dimensional DIGE. These changes reveal an underlying mechanism of colorectal tumorigenesis in which the roles of impaired tricarboxylic acid cycle and the Warburg effect may be critical.

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.

Characterization of lectins and their specificity in carcinomas-An appraisal

Lectins, a group of specific glycoproteins present in animal as well as plant cells, are used as differentiating markers to study cancers and metastatic cell lines. This property of lectins depends on the process of cellular glycosylation. Glycosylation of some of the extracellular membrane proteins and lipids maintains the cell/cell and cell/matrix interactions. Chemical alterations in glycosylation play an important role in the metastatic behavior of tumor cells. Carbohydrate residues of the membrane glycoproteins can be detected using lectins due to their binding specificity to carbohydrates. Lectins, therefore have gained an importance in the field of cancer research. Galectins, a specialized group of lectin like proteins that are Ca+ independent and galactoside binding, are also considered as differentiation markers in some specific cancers like the carcinomas of thyroid.Thus the use of lectins and galectins to identify specific carbohydrates present on cell surface help in invasion and metastasis processes.