Factors associated with carcinoma of the oesophagus at Mulago Hospital, Uganda

Systematic review and meta-analysis of esophageal cancer in Africa: Epidemiology, risk factors, management and outcomes

BACKGROUND

Esophageal cancer (EC) is associated with a poor prognosis, particularly so in Africa where an alarmingly high mortality to incidence ratio prevails for this disease.

AIM

To provide further understanding of EC in the context of the unique cultural and genetic diversity, and socio-economic challenges faced on the African continent.

METHODS

We performed a systematic review of studies from Africa to obtain data on epidemiology, risk factors, management and outcomes of EC. A non-systematic review was used to obtain incidence data from the International Agency for Research on Cancer, and the Cancer in Sub-Saharan reports. We searched EMBASE, PubMed, Web of Science, and Cochrane Central from inception to March 2019 and reviewed the list of articles retrieved. Random effects meta-analyses were used to assess heterogeneity between studies and to obtain odds ratio (OR) of the associations between EC and risk factors; and incidence rate ratios for EC between sexes with their respective 95% confidence intervals (CI).

RESULTS

The incidence of EC is higher in males than females, except in North Africa where it is similar for both sexes. The highest age-standardized rate is from Malawi (30.3 and 19.4 cases/year/100000 population for males and females, respectively) followed by Kenya (28.7 cases/year/100000 population for both sexes). The incidence of EC rises sharply after the age of 40 years and reaches a peak at 75 years old. Meta-analysis shows a strong association with tobacco (OR 3.15, 95%CI: 2.83-3.50). There was significant heterogeneity between studies on alcohol consumption (OR 2.28, 95%CI: 1.94-2.65) and on low socioeconomic status (OR 139, 95%CI: 1.25-1.54) as risk factors, but these could also contribute to increasing the incidence of EC. The best treatment outcomes were with esophagectomy with survival rates of 76.6% at 3 years, and chemo-radiotherapy with an overall combined survival time of 267.50 d.

CONCLUSION

Africa has high incidence and mortality rates of EC, with preventable and non-modifiable risk factors. Men in this setting are at increased risk due to their higher prevalence of tobacco and alcohol consumption. Management requires a multidisciplinary approach, and survival is significantly improved in the setting of esophagectomy and chemoradiation therapy.

Clinical trial design and selected drug safety issues for antibiotics used to treat community-acquired pneumonia

High-quality evaluations of both efficacy and safety are essential to characterize the risk-benefit profile of antibiotics. The current US Food and Drug Administration guidelines on trial design for community-acquired pneumonia have several weaknesses, including the failure to insist on the use of double blinding and intention-to-treat analysis. A primary difficulty with noninferiority designs is that poorly conducted studies, which increase noise, are biased toward the conclusion of noninferiority even in the presence of important differences between the test drug and the control drug. Additionally, results of noninferiority trials, in the absence of a well-established anchor, may be difficult to interpret. The US Food and Drug Administration drug-evaluation process includes preclinical studies to assess toxicity and a series of clinical studies involving humans to define efficacy and to identify potential safety problems. When signals are apparent, as they were for telithromycin (liver toxicity in rats, dogs, and monkeys) or for sparfloxacin (prolongation of the QT interval in dogs), it is nonetheless essential that these signals are fully and fairly evaluated in human studies with adequate power. Risks of antibiotic use, such as prolongation of the corrected QT interval and sudden death, may be acceptable in the presence of convincing benefits for patients with severe, life-threatening infections; however, the risk-benefit profile derived from severe infections cannot necessarily be generalized to mild or self-limited infections, for which the same serious drug-associated risks are likely to exceed the benefits. Complete and proper evaluation of both safety and efficacy in specific situations is essential to define the risk-benefit profiles of all drugs, including antibiotics.