Heavy Metal Pollution in Sub-Saharan Africa and Possible Implications in Cancer Epidemiology

The increasing scourge of cancer epidemiology is a global concern. With WHO emphasizing that 40% of allcancer cases are preventable, exposure to known and suspected carcinogens must be discouraged. The battlewith communicable diseases and other third world challenges has greatly de-emphasized anti-cancer campaignsin sub-Saharan Africa. The abundant deposit of mineral resources in sub-Saharan Africa has attracted highmining activity with its negative environmental aftermath. Poor regulatory mechanisms have led to environmentalcontamination by products of mining including heavy metals. In addition to poor urban planning, the springingup of settlements in industrial areas has led to generation and exposure to more hazardous wastes consequenton poor disposal systems. Studies establishing close association between exposure to heavy metals and cancerepidemiology in sub-Saharan Africa are increasing. The current review assesses the level of environmentalpollution by heavy metals in sub-Saharan Africa, and brings to the fore available evidence implicating such inthe increasing cancer epidemiology in the sub-continent.     

Impact of Detection Method and Age on Survival Outcomes in Triple-Negative Breast Cancer: A Population-Based Cohort Analysis

Background

Most investigations have compared triple-negative breast cancer (TNBC) to non-TNBC to elucidate clinical or epidemiologic differences between subtypes. We examined a contemporary cohort of patients with primary TNBC by detection and age at diagnosis within a population-based breast screening program to examine survival outcomes.

Review of the Cervical Cancer Burden and Population-Based Cervical Cancer Screening in China

Cervical cancer continues to be a serious public health problem in the developing world, including China. Because of its large population with geographical and socioeconomic inequities, China has a high burden of cervical cancer and important disparities among different regions. In this review, we first present an overview of the cervical cancer incidence and mortality over time, and focus on diversity and disparity in access to care for various subpopulations across geographical regions and socioeconomic strata in China. Then, we describe population-based cervical cancer screening in China, and in particular implementation of the National Cervical Cancer Screening Program in Rural Areas (NACCSPRA) and the challenges that this program faces. These include low screening coverage, shortage of qualified health care personnel and limited funds. To improve prevention of cervical cancer and obtain better cancer outcomes, the Chinese government needs to urgently consider the following key factors: reducing disparities in health care access, collecting accurate and broadly representative data in cancer registries, expanding target population size and increasing allocation of government funding for training of personnel, improving health education for women, enhancing quality control of screening services and improving a system to increase follow up for women with positive results.     

Primary Care Continuity and Wait Times to Receiving Breast Cancer Chemotherapy: A Population-Based Retrospective Cohort Study Using CanIMPACT Data

(1) Background: Wait times to chemotherapy are associated with morbidity and mortality in breast cancer patients; however, it is unclear how primary care physician (PCP) continuity impacts these wait times, or whether this association is different in immigrants, who experience cancer care inequities. We assessed the association between PCP continuity and the contact-to-chemotherapy interval (wait time from when a patient first presents to healthcare to the first day of receiving breast cancer chemotherapy), with a specific look at the immigrant population. (2) Methods: Population-based, retrospective cohort study of women who were diagnosed with stage I–III breast cancer in Ontario who received surgery and adjuvant chemotherapy. We used quantile regression at the median and 90th percentile to quantify the effect of PCP continuity on the contact-to-chemotherapy interval, performing a separate analysis on the immigrant population. (3) Results: Among 12,781 breast cancer patients, including 1706 immigrants, the median contact-to-chemotherapy interval (126 days) was 3.21 days shorter (95% confidence interval (CI) 0.47–5.96) in symptom-detected patients with low PCP continuity, 10.68 days shorter (95% CI 5.36–16.00) in symptom-detected patients with no baseline PCP visits and 17.43 days longer (95% CI 0.90–34.76) in screen-detected immigrants with low PCP continuity compared to the same groups with high PCP continuity. (4) Conclusions: Higher PCP continuity was not associated with a change in the contact-to-chemotherapy interval for most of our study population, but was associated with a marginally longer interval in our symptom-detected population and a shorter contact-to-chemotherapy interval in screen-detected immigrants. This highlights the importance of PCP continuity among immigrants with positive screening results. Additionally, having no PCP visits at baseline was associated with a shorter contact-to-chemotherapy interval in symptom-detected patients.     

Survival Analysis of Cervical Cancer Patients: A Case Study of Bhutan

Objective: The purpose of the study is to identify the risk factors such as age, the stage of patients based on the International Federation of Gynecology and Obstetrics system (FIGO stage) and treatment type, and their effect on the survival of cervical cancer patients receiving treatments at Jigme Dorji Wangchuck National Referral Hospital (JDWNRH) in Bhutan between January 2014 and December 2019. Methods: In this retrospective study, all 357 women diagnosed with cervical cancer were included. Kaplan-Meier model was applied to estimate survival, and the log-rank test was performed to compare survival distributions between subgroups stratified by each of the risk factors. Baseline demographics, cervical cancer stages, and treatment options were analyzed as factors and predictors of survival by Cox proportional hazards model. Results: The overall estimated 1- to 5-year survival rates are 82.1% (95% CI: 77.8-86.7), 75.6% (70.4-81.1), 65.2% (58.2-73.0), 62.3% (54.7-70.9) and 55.4% (44.9-68.3). The results reveal that age group, FIGO stage, treatment, and frequency of hospital visits are significant factors affecting the survival of cervical cancer patients in Bhutan. Patients aged >45 years increases the risk of dying (HR: 2.1, 95% CI: 1.2-3.9) compared to the young age group (≤45 years). Treatment types other than surgery only are significantly associated with an increased risk of mortality in patients with cervical cancers. The more frequency of hospital visits also reduces the risk of dying (HR: 0.1, 95% CI: 0-0.3). FIGO stage IV is the most significant risk factor for mortality with a hazard ratio of 6 (95% CI: 2.1-17.6). Conclusion: The five-year survival rate of cervical cancer patients in this study was low. Late diagnosis of cervical cancer appears to be mainly associated with a higher risk of dying. The results provide valuable information for further research and policymaking in the prevention and management of cervical cancer.     

Second Primary Cancers Following Female Breast Cancer in Osaka, Japan--A Population-Based Cohort Study

Using the data accumulated in the Osaka Cancer Registry, a cohortstudy was conducted on the occurrence of second primary cancersfollowing the first breast cancer in females. Of the 9, 503breast cancer patients newly diagnosed in the period 1965–1982who were followed up until the end of 1983 (average follow-upperiod, 5.7 years), 344 developed second cancers, whereas theexpected number had been 211 (relative risk (RR) = 1.6; 95%confidence interval (CI) = 1.5–1.8). The increased riskwas observed throughout the observation period, and was higherin patients of less than 45 years of age at diagnosis than inolder women. Significant excess risks were found for secondcancers of the opposite breast (RR = 4.2; 95% CI = 3.4–5.2),buccal cavity (RR = 3.6; 95% CI = 1.6–7.2), stomach (RR= 1.4; 95% CI = 1.2–1.8), colon (RR = 1.8; 95% CI = 1.1–2.1)and thyroid gland (RR = 3.2; 95% CI % 1.5–6.1). The effectsof chemo- and radiotherapy administered for initial breast canceron the increased risk of the above mentioned second cancerswere also examined. These therapeutic measures were found notlikely to be related to the excess risks for cancers of thebuccal cavity, stomach and colon. For second cancer of the oppositebreast, however, both chemotherapy and radiotherapy remainedas possible risk factors. The effect of radiation was proposedas being a likely explanation for the excess risk of secondthyroid cancer.     

Quality of End-of-Life Care for People with Advanced Non-Small Cell Lung Cancer in Ontario: A Population-Based Study

Ensuring high quality end of life (EOL) care is necessary for people with advanced non-small-cell lung cancer (NSCLC), given its high incidence, mortality and symptom burden. Aggressive EOL care can adversely affect the quality of life of NSCLC patients without providing meaningful oncologic benefit. Objectives: (1) To describe EOL health services quality indicators and timing of palliative care consultation provided to patients dying of NSCLC. (2) To examine associations between aggressive and supportive care and patient, disease and treatment characteristics. Methods: This retrospective population-based cohort study describes those who died of NSCLC in Ontario, Canada from 2009–2017. Socio-demographic, patient, disease and treatment characteristics as well as EOL health service quality and use of palliative care consultation were investigated. Multivariable logistic regression models examined factors associated with receiving aggressive or supportive care. Results: Aggressive care quality indicators were present in 50.3% and supportive care indicators in 60.3% of the cohort (N = 37,203). Aggressive care indicators decreased between 2009 and 2017 (57.4% to 45.3%) and increased for supportive care (54.2% to 67.5%). Benchmarks were not met by 2017 in 3 of 4 cases. Male sex and greater comorbidity were associated with more aggressive EOL care and less supportive care. Older age was negatively associated and rurality positively associated with aggressive care. No palliative care consultation occurred in 56.0%. Conclusions: While improvements in the use of supportive rather than aggressive care were noted, established Canadian benchmarks were not met. Moreover, there is variation in EOL quality between groups and use of earlier palliative care must improve.     

Access to Cancer Specialist Care and Treatment in Patients With Advanced Stage Lung Cancer

Background

Access to specialty care is critical for patients with advanced stage lung cancer. This study assessed access to cancer specialists and cancer treatment in a broad population of patients with advanced stage lung cancer.

Time from Self-Detection of Symptoms to Seeking Definitive Care among Cervical Cancer Patients

Background: India had the burden of 97,000 new cases of cervical cancer with 60,000 deaths accounting nearly one-third of global cervical cancer deaths during the year 2018. Cervical cancer is the leading cause of cancer mortality in India. The present study aims to estimate the time interval between self-detection of cervical cancer symptoms and seeking care and different barriers for the possible time lag in seeking care. Methods: A cross-sectional study was undertaken from April 2017 to September 2017 in a regional cancer centre in the south of India. The centre has both a population and a hospital-based cancer registry. Cervical cancer cases (N= 210) with histological confirmation were interviewed at the hospital using a pre-tested semi-structured questionnaire. Results: The median time interval between the self-detection of cervical cancer symptoms and first contact with the general physician was 80 [IQR 45-150] days. The overall median time interval between the self-detection of symptoms to the initiation of primary treatment was 123[IQR 83-205] days. The major perceived reason for not seeking medical care was a lack of awareness in identifying cervical cancer symptoms in 183(92.9%) women. Conclusion: The median time of 80 days was observed from the self-detection of cervical cancer symptoms to the first contact with a general physician. Lack of awareness of patients pertaining to cancer symptoms was the major concern in seeking cancer care.     

A Narrative Synthesis of Literature on the Barriers to Timely Diagnosis and Treatment of Cancer in Sub-Saharan Africa

Poor cancer survival outcomes in sub-Saharan Africa (SSA) have been linked to delays in diagnosis and treatment. Here we present a detailed overview of the qualitative literature evaluating the barriers to receiving timely diagnosis and treatment of cancer in SSA. The PubMed, EMBASE, CINAHL, PsycINFO databases were searched to identify qualitative studies reporting on barriers to timely diagnosis of cancer in SSA published between 1995 and 2020. A systematic review methodology was applied, including quality assessment and narrative data synthesis. We identified 39 studies, of which 24 focused on breast or cervical cancer. Only one study focused on prostate cancer and one on lung cancer. When exploring factors contributing to delays, six key themes emerged from the data. The first theme was health service barriers, which included: (i) inadequate numbers of trained specialists; (ii) limited knowledge of cancer among healthcare providers; (iii) poor co-ordination of care; (iv) inadequately resourced health facilities; (v) negative attitudes of healthcare providers towards patients; (vi) high cost of diagnostic and treatment services. The second key theme was patient preference for complementary and alternative medicine; the third was the limited understanding of cancer among the population. The fourth barrier was a patient's personal and family obligations; the fifth was the perceived impact of cancer and its treatment on sexuality, body image and relationships. Finally, the sixth was the stigma and discrimination faced by patients following a diagnosis of cancer. In conclusion, health system, patient level and societal factors all influence the likelihood of timely diagnosis and treatment for cancer in SSA. The results provide a focus for targeting health system interventions, particular with regards to awareness and understanding of cancer in the region.     

The Impact of Human Papillomavirus Infection on Skin Cancer: A Population-Based Cohort Study

Background

This study investigated the correlation between a history of human papillomavirus (HPV) infection and skin cancer risk.

Materials and Methods

The study cohort comprised 26,919 patients with newly diagnosed HPV infection between 2000 and 2012; with the use of computer-generated numbers, patients without previous HPV infection were randomly selected as the comparison cohort. The patients in the HPV infection cohort were matched to comparison individuals at a 1:4 ratio by demographic characteristics and comorbidities. All study individuals were followed up until they developed skin cancer, withdrew from the National Health Insurance program, were lost to follow-up, or until the end of 2013. The primary outcome was subsequent skin cancer development. Cox proportional hazards regression analysis was used to analyze the risk of skin cancer with hazard ratios (HRs) and 95% confidence intervals (CIs) between the HPV and control cohort.

Results

The adjusted HR of skin cancer for patients with HPV relative to controls was 2.45 after adjusting sex, age and comorbidities. (95% CI, 1.44–4.18, p < .01). The subgroup analysis indicated that a patient with HPV infection had a significantly greater risk of skin cancer if they were aged >40 years. Notably, a risk of skin cancer was found in the group diagnosed with HPV within the first 5 years after the index date (adjusted HR, 3.12; with 95% CI, 1.58–5.54). Sensitivity analysis by propensity score, matching with balanced sex, age, and comorbidities, showed consistent results.

Conclusion

A history of HPV infection is associated with the development of subsequent skin cancer in Taiwanese subjects, and the risk wanes 5 years later.

Implications for Practice

In this Taiwan nationwide cohort study, there was a 2.45-fold increased risk of developing new-onset skin cancers for patients with incident human papillomavirus (HPV) infection, compared with the matched controls. Furthermore, the risk was noticeably significant among patients aged >40 years. A prominent risk of skin cancers was found in the group diagnosed with HPV within the first 5 years after the index date in this study. The results of this analysis may raise consensus on the effect of HPV infection on the risk of skin cancers. Clinicians are encouraged to implement prudently on the differential diagnosis of skin cancers and HPV prevention and treatment, especially in older patients.