Emmanuel Oga

Cancer Incidence in Nigeria: A Report from Population-based Cancer Registries

INTRODUCTION Cancer has become a major source of morbidity and mortality globally. Despite the threat that cancer poses to public health in sub-Saharan Africa (SSA), few countries in this region have data on cancer incidence. In this paper, we present estimates of cancer incidence in Nigeria based on data from 2 population-based cancer registries (PBCR) that are part of the Nigerian national cancer registry program. MATERIALS AND METHODS We analyzed data from 2 population based cancer registries in Nigeria, the Ibadan Population Based Cancer Registry (IBCR) and the Abuja Population Based Cancer Registry (ABCR) covering a 2 year period 2009-2010. Data are reported by registry, gender and in age groups. We present data on the age specific incidence rates of all invasive cancers and report age standardized rates of the most common cancers stratified by gender in both registries. RESULTS The age standardized incidence rate for all invasive cancers from the IBCR was 66.4 per 100000 men and 130.6 per 100000 women. In ABCR it was 58.3 per 100000 for men and 138.6 per 100000 for women. A total of 3393 cancer cases were reported by the IBCR. Of these cases, 34% (1155) were seen among males and 66% (2238) in females. In Abuja over the same period, 1128 invasive cancers were reported. 33.6% (389) of these cases were in males and 66.4% (768) in females. Mean age of diagnosis of all cancers in men for Ibadan and Abuja were 51.1 and 49.9 years respectively. For women, mean age of diagnosis of all cancers in Ibadan and Abuja were 49.1 and 45.4 respectively. Breast and cervical cancer were the commonest cancers among women and prostate cancer the most common among men. Breast cancer age standardized incidence rate (ASR) at the IBCR was 52.0 per 100000 in IBCR and 64.6 per 100000 in ABCR. Cervical cancer ASR at the IBCR was 36.0 per 100000 and 30.3 per 100000 at the ABCR. The observed differences in incidence rates of breast, cervical and prostate cancer between Ibadan and Abuja, were not statistically significant. CONCLUSION Cancer incidence data from two population based cancer registries in Nigeria suggests substantial increase in incidence of breast cancer in recent times. This paper highlights the need for high quality regional cancer registries in Nigeria and other SSA countries.

The role of hospital-based cancer registries in low and middle income countries—The Nigerian Case Study

BACKGROUND The incidence of cancer continues to rise all over the world and current projections show that there will be 1.27 million new cases and almost 1 million deaths by 2030. In view of the rising incidence of cancer in sub-Saharan Africa, urgent steps are needed to guide appropriate policy, health sector investment and resource allocation. We posit that hospital based cancer registries (HBCR) are fundamental sources of information on the frequent cancer sites in limited resource regions where population level data is often unavailable. In regions where population based cancer registries are not in existence, HBCR are beneficial for policy and planning. MATERIALS AND METHODS Nineteen of twenty-one cancer registries in Nigeria met the definition of HBCR, and from these registries, we requested data on cancer cases recorded from January 2009 to December 2010. 16 of the 19 registries (84%) responded. Data on year hospital was established; year cancer registry was established, no. of pathologists and types of oncology services available in each tertiary health facility were shown. Analysis of relative frequency of cancers in each HBCR, the basis of diagnosis recorded in the HBCR and the total number of cases recorded by gender was carried out. RESULTS The total number of cancers registered in these 11 hospital based cancer registries in 2009 and 2010 was 6484. The number of new cancer cases recorded annually in these hospital based cancer registries on average was 117 cases in males and I77 cases in females. Breast and cervical cancer were the most common cancers seen in women while prostate cancer was the commonest among men seen in these tertiary hospitals. CONCLUSION Information provided by HBCR is beneficial and can be utilized for the improvement of cancer care delivery systems in low and middle income countries where there are no population based cancer registries.

Developing National Cancer Registration in Developing Countries - Case Study of the Nigerian National System of Cancer Registries.

The epidemiological transition in sub-Saharan Africa (SSA) has given rise to a concomitant increase in the incidence of non-communicable diseases including cancers. Worldwide, cancer registries have been shown to be critical for the determination of cancer burden, conduct of research, and in the planning and implementation of cancer control measures. Cancer registration though vital is often neglected in SSA owing to competing demands for resources for healthcare. We report the implementation of a system for representative nation-wide cancer registration in Nigeria – the Nigerian National System of Cancer Registries (NSCR). The NSCR coordinates the activities of cancer registries in Nigeria, strengthens existing registries, establishes new registries, complies and analyses data, and makes these freely available to researchers and policy makers. We highlight the key challenges encountered in implementing this strategy and how they were overcome. This report serves as a guide for other low- and middle-income countries (LMIC) wishing to expand cancer registration coverage in their countries and highlights the training, mentoring, scientific and logistic support, and advocacy that are crucial to sustaining cancer registration programs in LMIC.

Paucity of HPV-Related Head and Neck Cancers (HNC) in Nigeria

Introduction The burden of HPV-related Head and Neck Cancers (HNC) has been rising in the U.S. and other developed countries but this trend has not been reported in Africa. Objective of study was to evaluate the prevalence of HPV infection in HNC cancer cases seen between 1990 and 2011 at the tertiary health care institutions in Nigeria. Methods We retrieved 149 head and neck cancer formalin fixed, paraffin embedded tumor specimens diagnosed between 1990 and 2011 from four teaching hospitals in Nigeria. One hundred and twenty-three blocks (83%) contained appropriate HNC for analysis while DNA extraction was successful in 60% (90/149). PCR amplification was successful in 33% (49/149) and Linear Array genotyping for HPV was successful in 11% (17/149) of these cases. These were in tumors from the larynx (6), cervical lymph nodes (3), nasal cavity (2), parotid (1), palate (1), maxillary sinus (1) and mandible (1). Two cases were non-specific and none were from the oropharynx. Histologically, 41% (7/17) of the successfully genotyped blocks were squamous cell carcinomas (larynx 6, maxillary sinus 1). Results and Conclusion We were unable to detect HPV in any of the HNC samples in our study. Our result may suggest that there is a low prevalence of HPV-related HNC among the adult population in Nigeria. Our results provide a benchmark to compare future incidence of HPV -related HNC in this community in future. We had significant analytical challenges from possible poor tissue processing and urge that future studies should prospectively collect samples and ensure high quality sample processing.

Comparison and validation of screening tools for substance use in pregnancy: a cross-sectional study conducted in Maryland prenatal clinics

Introduction Prescription-drug use in the USA has increased by more than 60% in the last three decades. Prevalence of prescription-drug use among pregnant women is currently estimated around 50%. Prevalence of illicit drug use in the USA is 14.6% among pregnant adolescents, 8.6% among pregnant young adults and 3.2% among pregnant adults. The first step in identifying problematic drug use during pregnancy is screening; however, no specific substance-use screener has been universally recommended for use with pregnant women to identify illicit or prescription-drug use. This study compares and validates three existing substance-use screeners for pregnancy—4 P’s Plus, National Institute on Drug Abuse (NIDA) Quick Screen/Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST) and the Substance Use Risk Profile-Pregnancy (SURP-P) scale. Methods and analysis This is a cross-sectional study designed to evaluate the sensitivity, specificity and usability of existing substance-use screeners. Recruitment occurs at two obstetrics clinics in Baltimore, Maryland, USA. We are recruiting 500 participants to complete a demographic questionnaire, NIDA Quick Screen/ASSIST, 4 P’s Plus and SURP-P (ordered randomly) during their regularly scheduled prenatal appointment, then again 1 week later by telephone. Participants consent to multidrug urine testing, hair drug testing and allowing access to prescription drug and birth outcome data from electronic medical records. For each screener, reliability and validity will be assessed. Test–retest reliability analysis will be conducted by examining the results of repeated screener administrations within 1 week of original screener administrations for consistency via correlation analysis. Furthermore, we will assess if there are differences in the validity of each screener by age, race and trimester. Ethics and dissemination This study is approved by the Institutional Review Board of the University of Maryland (HP-00072042), Baltimore, and Battelle Memorial Institute (0619–100106433). All participants are required to give their informed consent prior to any study procedure.

Burden of Cancers Attributable to Infectious Agents in Nigeria: 2012–2014

Introduction Infections by certain viruses, bacteria, and parasites have been identified as risk factors for some cancers. In Nigeria, like many other developing countries, infections remain a leading cause of morbidity and mortality. While there are data on the incidence of different cancers in Nigeria, there has been no study of cancers attributable to infections. This study was carried out to determine the burden of cancers attributable to infections using data from two population-based cancer registries (PBCRs) in Nigeria. Methods We obtained data on cancers associated with EBV, human papillomavirus (HPV), hepatitis B and C, HIV, HHV8, Helicobacter pylori, and Schistosoma spp. from the databases of Abuja and Enugu cancer registries in Nigeria. We used population-attributable fraction for infections-associated cancers in developing countries that are based on prevalence data and relative risk estimates from previous studies. Results The PBCRs reported 4,336 incident cancer cases [age standardized incidence rate (ASR) 113.9 per 100,000] from 2012 to 2014, of which 1,627 (37.5%) were in males and 2,709 (62.5%) were in females. Some 1,030 (23.8%) of these cancers were associated with infections (ASR 44.4 per 100,000), while 951 (22.0%) were attributable to infections (ASR 41.6 per 100,000). Cancers of the cervix (n = 392, ASR 28.3 per 100,000) and liver (n = 145, ASR 3.4 per 100,000); and non-Hodgkin’s lymphoma (n = 110, ASR 2.5 per 100,000) were the commonest infections-associated cancers overall. The commonest infectious agents associated with cancers in this population were HPV, EBV, hepatitis B and C, HIV, and HHV8. Conclusion Our results suggest that 23.8% of incident cancer cases in this population were associated with infections, while 22.0% were attributable to infections. The infections attributable cancers are potentially preventable with strategies, such as vaccination, risk factor modification, or anti-infective treatment.

Comparability, diagnostic validity and completeness of Nigerian cancer registries.

BACKGROUND Like many countries in Africa, Nigeria is improving the quality and coverage of its cancer surveillance. This work is essential to address this growing category of chronic diseases, but is made difficult by economic, geographic and other challenges. PURPOSE To evaluate the completeness, comparability and diagnostic validity of Nigerias cancer registries. METHODS Completeness was measured using childrens age-specific incidence (ASI) and an established metric based on a modified Poisson distribution with regional comparisons. We used a registry questionnaire as well as percentages of death-certificate-only cases, morphologically verified cases, and case registration errors to examine comparability and diagnostic validity. RESULTS Among the childrens results, we found that over half of all cancers were non-Hodgkin lymphoma. There was also evidence of incompleteness. Considering the regional completeness comparisons, we found potential evidence of cancer-specific general incompleteness as well as what appears to be incompleteness due to inability to diagnose specific cancers. We found that registration was generally comparable, with some exceptions. Since autopsies are not common across Nigeria, coding for both them and death-certificate-only cases was also rare. With one exception, registries in our study had high rates of morphological verification of female breast, cervical and prostate cancers. CONCLUSIONS Nigerias registration procedures were generally comparable to each other and to international standards, and we found high rates of morphological verification, suggesting high diagnostic validity. There was, however, evidence of incompleteness.

Creating a nationwide cancer registration system to support AIDS-cancer match studies in Nigeria

Results The commonest cancer at all sites is Prostate in men and Breast in women. There was a gradient in the incidence that paralleled the socio-economic development of the regions of the country. The ASR for breast cancer ranged from 101.1 in Abuja to 7.5 in less cosmopolitan areas. For Prostate the ASR ranged from 73 in Abuja to 1.7. The other common cancers were Kaposi Sarcoma and Colo-Rectal in men, and cervix in women. Additional data collection and analysis is ongoing.

Cigarette Smoking Status and Substance Use in Pregnancy

Objectives Substance use during pregnancy is a significant public health issue. Prenatal substance use increased in the past decade while prenatal cigarette smoking has remained stable. Co-use of tobacco and other drugs is a concern because of potential additive risks. This study aims to describe the prevalence rates of substance use among pregnant women and examine the association between smoking status (nonsmoker, recent quitter and current smoker) and other drug use. Methods In this cross-sectional study, pregnant women (n = 500) were recruited from two obstetric practices to complete three substance use screeners and have their urine tested for 12 different drug classes, including cannabis, opioids and cocaine. Participants were divided into three groups based on survey responses: nonsmokers, recent quitters (smoked in the month prior to pregnancy but not past month) and current smokers (past-month). Results Approximately 29% of participants reported smoking in the month before pregnancy. During pregnancy, 17, 12 and 71% were current smokers, recent quitters and nonsmokers respectively. Overall prevalence of illicit or prescription drug use in pregnancy was 27%. Cannabis was the most common drug used in pregnancy with prevalence of 22%, followed by opioids (4%), cocaine (1%), tricyclic antidepressants (TCAs) (1%), amphetamines (1%), and benzodiazepines (1%). On multivariable logistic regression, smoking in pregnancy was associated with a positive urine drug screen; with adjusted odds ratio (aOR) 4.7 (95% CI 2.6–8.3) for current smokers and 1.6 (95% CI 0.8–3.3) for recent quitters. Factors negatively associated with positive drug screen were second and third trimester pregnancies, 0.5 (0.3–0.9) and 0.3 (0.2–0.6) respectively; and employment, 0.5 (0.3–0.8). Conclusions for Practice Co-use of tobacco and illicit drugs, particularly cannabis, is relatively high during pregnancy. Additional research is needed to understand the health implications of co-use versus use of tobacco only. Given the strong association between smoking and other drug use, clinicians should routinely assess for illicit drug use in women who smoke during pregnancy.

Cancers Attributable to Alcohol Consumption in Nigeria: 2012-2014.

Introduction Alcohol consumption has been identified as a risk factor for many cancers but less attention has been paid to the fraction of those cancers that are attributable to alcohol consumption. In this study, we evaluated the incidence and population attributable fraction (PAF) of cancers associated with alcohol consumption in Nigeria. Methods We obtained data on incidence of cancers from two population-based cancer registries (PBCRs) in Nigeria and identified cancer sites for which there is strong evidence of an association with alcohol consumption based on the International Agency for Research on Cancer Monograph 100E. We computed the PAF for each cancer site by age and sex, using prevalence and relative risk estimates from previous studies. Results Between 2012 and 2014 study period, the PBCRs reported 4,336 cancer cases of which 1,627 occurred in males, and 2,709 occurred in females. Of these, a total of 1,808 cancer cases, 339 in males and 1,469 in females, were associated with alcohol intake. The age standardized incidence rate (ASR) of alcohol associated cancers was 77.3 per 100,000. Only 4.3% (186/4,336) of all cancer cases or 10.3% (186/1,808) of alcohol associated cancers were attributable to alcohol consumption. Some 42.5% (79/186) of these cancers occurred in males while 57.5% (107/186) occurred in females. The ASR of cancers attributable to alcohol in this population was 7.2 per 100,000. The commonest cancers attributable to alcohol consumption were cancers of the oral cavity and pharynx in men and cancer of the breast in women. Conclusion Our study shows that 4.3% of incident cancers in Nigeria can be prevented by avoiding alcohol consumption. While the incidence of cancers associated with alcohol intake is high, the proportion attributable to alcohol consumption is much lower suggesting that the number of cancers that may be prevented by eliminating alcohol intake in this population is relatively low.