The spectrum of cancer in Papua New Guinea. An analysis based on the Cancer Registry 1979-1988

Leading causes of deaths in the mortality transition in Papua New Guinea: evidence from the Comprehensive Health and Epidemiological Surveillance System

Background

Changing causes of deaths in the mortality transition in Papua New Guinea (PNG) are poorly understood. This study analysed community-level data to identify leading causes of death in the population and variations across age groups and sexes, urban-rural sectors and provinces.

Method

Mortality surveillance data were collected from 2018–20 as part of the Comprehensive Health and Epidemiological Surveillance System (CHESS), using the World Health Organization 2016 verbal autopsy (VA) instrument. Data from 926 VA interviews were analysed, using the InterVA-5 cause of death analytical tool to assign specific causes of death among children (0–14 years), those of working age (15–64 years) and the elderly (65+ years).

Result

Nearly 50% of the total deaths were attributed to non-communicable diseases (NCDs), followed by infectious and parasitic diseases (35%), injuries and external causes (11%) and maternal and neonatal deaths (4%). Leading causes of death among children were acute respiratory tract infections (ARTIs) and diarrhoeal diseases, each contributing to 13% of total deaths. Among the working population, tuberculosis (TB) contributed to 12% of total deaths, followed by HIV/AIDS (11%). TB- and HIV/AIDS-attributed deaths were highest in the age group 25–34 years, at 20% and 18%, respectively. These diseases killed more females of working age (n = 79, 15%) than males (n = 52, 8%). Among the elderly, the leading causes of death were ARTIs (13%) followed by digestive neoplasms (10%) and acute cardiac diseases (9%).

Conclusion

The variations in leading causes of death across the populations in PNG suggest diversity in mortality transition. This requires different strategies to address specific causes of death in particular populations.

Prevalence of non-communicable diseases and their risk factors in Papua New Guinea: A systematic review

INTRODUCTION

The mortality associated with non-communicable diseases has increased significantly in most countries in the World Health Organization Western Pacific Region over the last 20 years, as have the underlying risk factors. This study aimed to collate evidence on the prevalence of four major non-communicable diseases and their risk factors in Papua New Guinea in order to inform appropriate policy for their prevention and management.

METHODS

We performed a systematic review of Papua New Guinea-based population prevalence studies of cardiovascular diseases, type 2 diabetes mellitus, chronic respiratory diseases, and cancers, as well as non-communicable disease risk factors published before 2016. Five online databases were searched and screened against eligibility criteria according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

A total of 57 articles were included in this review, most of which (n = 48) were published prior to 2000. Eleven articles reported on diabetes, six reported on chronic lung disease/asthma, two reported on cardiovascular diseases, and two reported cancer as the primary outcome, while the remaining 36 papers reported non-communicable disease risk factors.

CONCLUSION

This review demonstrated variations in the prevalence of non-communicable diseases (0%-19%) and their risk factors (0%-80.6%) attributed to the lifestyle and genetic diversity of the Papua New Guinea population. There is a strong suggestion that the prevalence of non-communicable diseases (particularly type 2 diabetes mellitus) and key non-communicable disease risk factors (hypertension, overweight, and obesity) has increased, but there is a lack of recent data. As such, there is an urgent need for new and up-to-date data in all areas of Papua New Guinea.

Oral cancer in Papua New Guinea: looking back and looking forward

Oral diseases, including cancers, affect 3.5 billion people globally and remain largely untreated in low- to middle-income countries because of lack of resources. In Papua New Guinea (PNG), oral cancer has, for many decades, been identified as the most common cancer in men, but as the GLOBOCAN 2018 data are estimates extrapolated from surrounding countries, the real prevalence of this disease is not known. The PNG National Health Plan (2011-2020) highlights the need to improve health care, but oral health is not identified as a priority. Alcohol, tobacco, and areca nut/betel quid, which are the social and commercial determinants of oral cancer, are common risk factors, and there are robust data linking these risk factors to oral cancer in PNG. Our recent Global Challenges Research Fund Workshop on Oral Cancer, held in Port Moresby, PNG, brought together a number of researchers in oral cancer epidemiology and translational science with clinicians from PNG to assess the current situation and plan ways to move forward. In this article, we will review the literature on oral cancer in PNG, and make suggestions as to how, collaboratively, we can address the issues identified, ultimately, for the benefit of the people of PNG.

The epidemiological transition in Papua New Guinea: new evidence from verbal autopsy studies

BACKGROUND

Recent economic growth in Papua New Guinea (PNG) would suggest that the country may be experiencing an epidemiological transition, characterized by a reduction in infectious diseases and a growing burden from non-communicable diseases (NCDs). However, data on cause-specific mortality in PNG are very sparse, and the extent of the transition within the country is poorly understood.

METHODS

Mortality surveillance was established in four small populations across PNG: West Hiri in Central Province, Asaro Valley in Eastern Highlands Province, Hides in Hela Province and Karkar Island in Madang Province. Verbal autopsies (VAs) were conducted on all deaths identified, and causes of death were assigned by SmartVA and classified into five broad disease categories: endemic NCDs; emerging NCDs; endemic infections; emerging infections; and injuries. Results from previous PNG VA studies, using different VA methods and spanning the years 1970 to 2001, are also presented here.

RESULTS

A total of 868 deaths among adolescents and adults were identified and assigned a cause of death. NCDs made up the majority of all deaths (40.4%), with the endemic NCD of chronic respiratory disease responsible for the largest proportion of deaths (10.5%), followed by the emerging NCD of diabetes (6.2%). Emerging infectious diseases outnumbered endemic infectious diseases (11.9% versus 9.5%). The distribution of causes of death differed across the four sites, with emerging NCDs and emerging infections highest at the site that is most socioeconomically developed, West Hiri. Comparing the 1970-2001 VA series with the present study suggests a large decrease in endemic infections.

CONCLUSIONS

Our results indicate immediate priorities for health service planning and for strengthening of vital registration systems, to more usefully serve the needs of health priority setting.

Estimating the pattern of causes of death in Papua New Guinea

Background

Papua New Guinea (PNG) is a diverse country with high mortality and evidence of increased prevalence of non-communicable diseases (NCDs), but there is no reliable cause of death (COD) data because civil registration is insufficient and routine health data comprise only a small proportion of deaths. This study aims to estimate cause-specific mortality fractions (CSMFs) for five broad groups of causes (endemic infections, emerging infections, endemic NCDs, emerging NCDs and injuries), by sex for each of PNG’s provinces.

Methods

CSMFs are calculated as the average of estimates obtained from: (1) Empirical cause method: Utilising available Verbal Autopsy (VA) data and Discharge Health Information System (DHIS) data, and applying statistical models of community versus facility CODs; and (2) Expected cause patterns method: Utilising existing estimates of mortality levels in each province and statistical models of the relationship between all-cause and cause-specific mortality using Global Burden of Disease (GBD) data.

Results

An estimated 41% of male and 49% of female deaths in PNG are due to infectious, maternal (female only), neonatal and nutritional causes. Furthermore, 45% of male and 42% of female deaths arise from NCDs. Infectious diseases, maternal, neonatal and nutritional conditions account for more than half the deaths in a number of provinces, including lower socioeconomic status provinces of Gulf and Sandaun, while provinces with higher CSMFs from emerging NCDs (e.g. ischemic heart disease, stroke) tend to be those where socioeconomic status is comparatively high (e.g. National Capital District, Western Highlands Province, Manus Province, New Ireland Province and East New Britain Province). Provinces with the highest estimated proportion of deaths from emerging infectious diseases are readily accessible by road and have the highest rates of sexually transmitted infections (STIs), while provinces with the highest CSMFs from endemic infectious, maternal, neonatal and nutritional causes are geographically isolated, have high malaria and high all-cause mortality.

Conclusions

Infectious, maternal, neonatal and nutritional causes continue to be an important COD in PNG, and are likely to be higher than what is estimated by the GBD. Nonetheless, there is evidence of the emergence of NCDs in provinces with higher socioeconomic status. The introduction of routine VA for non-facility deaths should improve COD data quality to support health policy and planning to control both infectious and NCDs.

Rising incidence of breast cancer in Papua New Guinea

BACKGROUND

Three previous reports have shown the incidence of breast cancer in Papua New Guinea (PNG) to have risen in the 30 years between 1958 and 1987. In the present report the incidence and pathology of breast cancer in the decade 1989-1998 are described.

METHODS

This was a retrospective review of all histopathology specimens in PNG from 1989 to 1998. During this period the female population grew from 1 640 000 to more than 2 000 000.

RESULTS

There were 790 cases of breast cancer. The age of the patient was not known in 221 cases (26%). The age-standardized incidence was 6.9 per 100 000. The incidence of breast cancer has been steadily rising in the 40 years since cancers were recorded in PNG. The incidence has risen in all four regions, most notably in the islands. The peak incidence was in the 45-54-year-old age group (18.4/100 000); 83.9% of women with breast cancer were aged 54 or less. Fifteen per cent were under 35 years old and 55.7% were under 45. The incidence fell in the elderly. The tumours tended to be advanced. The actual size was recorded in only 163 cases (20.7%) but there were only three T1 tumours in this group. Clinical signs of advanced breast cancer were recorded in 206 cases: ulceration of skin (91 cases), peau d' orange (69 cases), nipple retraction (43 cases) and lymphoedema of the upper extremity (three cases). Axillary nodes were positive in 185 of 247 patients (75%) in whom they were sampled.

CONCLUSIONS

The incidence of breast cancer in PNG women has steadily risen over the past 40 years and the highest age-specific incidence occurs in the 35-54 age group. Tumours present late at an advanced stage. Clinical information on pathology request forms is poor and a prospective clinical audit is needed. Strategies need to be developed to detect breast cancer earlier in this population of women.

The epidemiology of mouth cancer: a review of global incidence

Mouth cancer (143-145 ICD-9) is a major health problem in many parts of the world. While its incidence is relatively low in most western countries there are some important exceptions to this trend: on the Indian subcontinent and in other parts of Asia it remains one of the most common forms of cancer. This review article summarises the global incidence of mouth cancer using cancer maps. Data have been compiled from the latest edition of Cancer Incidence in Five Continents and recent studies from various locations around the world. Significant geographic variation is noted in the incidence of mouth cancer, with high rates reported for the Indian subcontinent and parts of Asia (male incidence rates in excess of 10 per 100,000 per annum). It is also noted that as with other forms of oral cancer, the majority of population-based data for mouth cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. Mouth cancer remains a serious health problem in many parts of the world with many regions reporting increasing incidence rates particularly in males. Ongoing research into the aetiologic risk factors associated with this disease must remain a very high priority if the causes of mouth cancer are to be established and disease control protocols introduced widely.

The epidemiology of tongue cancer: a review of global incidence

The tongue (141 ICD-9) is the most common intraoral site for cancer in most countries, however its global epidemiology shows significant geographic variation. This review paper summarises the global incidence of cancer of the tongue using cancer maps and references to recent studies from various locations. Tongue cancer remains a serious health problem in many countries including India (male incidence rates up to 6.5 per 100,000 per annum) and parts of Europe (male incidence rates in France up to 8.0 per 100,000 per annum). It is noted that as with other forms of oral cancer the majority of population-based data for tongue cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. The tongue remains the most common intraoral site for oral cancer worldwide and in a number of countries it is a serious public health problem with significant morbidity and mortality. While the incidence of tongue cancer appears to be stable or falling in some regions of the world, in other areas it is rising, particularly among younger people.

Adult head and neck lymphomas in Papua New Guinea: a retrospective study of 70 cases

BACKGROUND

During a 10-year period (1986-95), 70 adult Papua New Guineans with head and neck lymphomas were seen in the 18 years-and-above age group.

METHODS

The clinical information was obtained from the medical records section of the Port Moresby General Hospital. Relevant treatment modalities and the follow-up data were acquired from the National Cancer Centre, Angau Memorial Hospital, Lae.

RESULTS

Of a total of 227 adult lymphomas recorded in a 10-year period, 70 cases were seen in the head and neck region. Non-Hodgkin's lymphoma constituted 56 cases, which included seven cases of adult Burkitt's-like lymphoma. Fourteen cases of Hodgkin's lymphoma were recorded.

CONCLUSIONS

In Papua New Guinea, malignant lymphomas primarily affecting the head and neck region were seen in 30.8% of all lymphomas. This constitues 2.8% of all malignancies in this region. These lymphomas appear to be more aggressive at this site. Proper tissue diagnosis and combination chemoradiotherapy are the key factors in its management.

Incidence of haematological malignancies in French Polynesia between 1990 and 1995

To determine the incidence of haematological malignancies in French Polynesia from 1990 to 1995, we collected cases from the local cancer registry, sanitary evacuation files and all the histopathology and clinical biology laboratories. All leukaemias, non Hodgkin's lymphomas, and multiple myelomas incidence was slightly lower among French Polynesians than among Maoris from New-Zealand and Hawaiians of Hawaii. Standardised Incidence Ratio (SIR) for Hodgkin's disease among females was 0.08 when comparing to Hawaiians and 0.33 when comparing to Maoris. Other salient features were a high proportion of high grade and Burkitt's lymphoma, the absence of Hodgkin's disease after 40 years of age, a low incidence of chronic lymphoid leukaemia, and a high non lymphoblastic/lymphoblastic acute leukaemia ratio in childhood. This study stresses the peculiar incidence of some haematological malignancies in this south pacific area.

Malignant tumours of the nasal cavity and the paranasal sinuses in a Melanesian population

Malignant tumours of the nasal cavity and paranasal sinuses are usually associated with poor prognosis. From 1986 to 1995, 50 such tumours were managed in Papua New Guinea. Twenty-nine of these arose in the maxillary sinus, 15 in the nasal cavity, four in the ethmoid sinus and two in the frontal sinus. Males were more frequently affected than females. No specific carcinogenic factor was apparent in these patients who were uniformly distributed all over the country. Advanced local disease with multiple symptoms and signs was common during presentation. Systemic and neck node metastases were infrequent. Histopathologically, squamous cell carcinoma was the commonest type of tumour. Satisfactory results were obtained by combination therapy consisting of surgery, irradiation, and systemic chemotherapeutics agents. Better health consciousness and health care delivery system are essential for early diagnosis, regular posttreatment follow-up and improved survival of these patients.

The future of surgery in Papua New Guinea and the South Pacific

Surgery in the South Pacific is different in many respects from surgery in Australia and New Zealand. It is primarily the surgery of trauma, infection, advanced malignancy, hollow-tube obstruction and congenital abnormalities. Specific tropical infections such as tuberculosis, typhoid, pigbel and amoebiasis occur regularly but constitute only a small proportion of all cases. The patients tend to be young, rural and poor, and often present late because access to surgical services is limited. The treatment patients receive is also compromised by a lack of resources--the result of underfunding and inefficient administration. Standards for appropriate surgical practice should be determined in-country and based at least on surgical audit and clinical studies. Even though Western diseases are emerging in the tropics, the best management may sometimes be different. Training of national surgeons is a priority if a sustainable surgical service is to be established. Such training is more effectively carried out in the home country, or at least in one with similar pathology and problems, rather than overseas. Project aid should support these schemes and encourage regional co-operation through the Fiji and Papua New Guinea medical schools. There remains an important role for visiting surgical specialists, but they need to ensure that they transfer skills and encourage the professional development of promising local doctors rather than simply focusing on treating patients.