Cancer in Rwanda

Data are presented on the frequency of malignant tumours registered at the population-based cancer registry in the southern prefecture of Butare, Rwanda, from May 1991 until 2 months before the outbreak of civil war in April 1994. Beginning in 1992, subjects were also interviewed about socio-demographic and life-style factors that have been associated with cancer risk in the West. The distribution of cancer in Rwanda is similar to that in other countries in sub-Saharan Africa. The most frequent cancers are those with possible infectious aetiologies: liver cancer (12%), cervical cancer (12%) and stomach cancer (9%). In addition, cancers known to be associated with HIV infection are relatively frequent (Kaposi's sarcoma [6%] and non-Hodgkin's lymphoma [3%]). Chronic infection, including infection with HIV, high parity and multiple sexual partners are important determinants of cancer incidence in this population. Tobacco consumption is low in Rwanda and there are few tobacco-related tumours, such as lung and laryngeal cancer. Other tumours believed to be associated with aspects of Western life-style, such as colorectal and breast cancer, are also relatively infrequent. © 1996 Wiley-Liss, Inc.     

Relationship of Height to Site‐Specific Fracture Risk in Postmenopausal Women

Height has been associated with increased risk of fracture of the neck of femur. However, information on the association of height with fractures at other sites is limited and conflicting. A total of 796,081 postmenopausal women, who reported on health and lifestyle factors including a history of previous fractures and osteoporosis, were followed for 8 years for incident fracture at various sites by record linkage to National Health Service hospital admission data. Adjusted relative risks of fracture at different sites per 10‐cm increase in height were estimated using Cox regression. Numbers with site‐specific fractures were: humerus (3036 cases), radius and/or ulna (1775), wrist (9684), neck of femur (5734), femur (not neck) (713), patella (649), tibia and/or fibula (1811), ankle (5523), and clavicle/spine/rib (2174). The risk of fracture of the neck of femur increased with increasing height (relative risk [RR] = 1.48 per 10‐cm increase, 99% confidence interval [CI] 1.39–1.57) and the proportional increase in risk was significantly greater than for all other fracture sites (p_{heterogeneity} < 0.001). For the other sites, fracture risk also increased with height (RR = 1.15 per 10 cm, CI 1.12–1.18), but there was only very weak evidence of a possible difference in risk between the sites (p_{heterogeneity} = 0.03). In conclusion, taller women are at increased risk of fracture, especially of the neck of femur. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).     

In vivo characterization of emerging white matter microstructure in the fetal brain in the third trimester

The third trimester of pregnancy is a period of rapid development of fiber bundles in the fetal white matter. Using a recently developed motion‐tracked slice‐to‐volume registration (MT‐SVR) method, we aimed to quantify tract‐specific developmental changes in apparent diffusion coefficient (ADC), fractional anisotropy (FA), and volume in third trimester healthy fetuses. To this end, we reconstructed diffusion tensor images from motion corrected fetal diffusion magnetic resonance imaging data. With an approved protocol, fetal MRI exams were performed on healthy pregnant women at 3 Tesla and included multiple (2–8) diffusion scans of the fetal head (1–2 b = 0 s/mm² images and 12 diffusion‐sensitized images at b = 500 s/mm²). Diffusion data from 32 fetuses (13 females) with median gestational age (GA) of 33 weeks 4 days were processed with MT‐SVR and deterministic tractography seeded by regions of interest corresponding to 12 major fiber tracts. Multivariable regression analysis was used to evaluate the association of GA with volume, FA, and ADC for each tract. For all tracts, the volume and FA increased, and the ADC decreased with GA. Associations reached statistical significance for: FA and ADC of the forceps major; volume and ADC for the forceps minor; FA, ADC, and volume for the cingulum; ADC, FA, and volume for the uncinate fasciculi; ADC of the inferior fronto‐occipital fasciculi, ADC of the inferior longitudinal fasciculi; and FA and ADC for the corticospinal tracts. These quantitative results demonstrate the complex pattern and rates of tract‐specific, GA‐related microstructural changes of the developing white matter in human fetal brain.     

Spatiotemporal changes in diffusivity and anisotropy in fetal brain tractography

Population averaged diffusion atlases can be utilized to characterize complex microstructural changes with less bias than data from individual subjects. In this study, a fetal diffusion tensor imaging (DTI) atlas was used to investigate tract‐based changes in anisotropy and diffusivity in vivo from 23 to 38 weeks of gestational age (GA). Healthy pregnant volunteers with typically developing fetuses were imaged at 3 T. Acquisition included structural images processed with a super‐resolution algorithm and DTI images processed with a motion‐tracked slice‐to‐volume registration algorithm. The DTI from individual subjects were used to generate 16 templates, each specific to a week of GA; this was accomplished by means of a tensor‐to‐tensor diffeomorphic deformable registration method integrated with kernel regression in age. Deterministic tractography was performed to outline the forceps major, forceps minor, bilateral corticospinal tracts (CST), bilateral inferior fronto‐occipital fasciculus (IFOF), bilateral inferior longitudinal fasciculus (ILF), and bilateral uncinate fasciculus (UF). The mean fractional anisotropy (FA) and mean diffusivity (MD) was recorded for all tracts. For a subset of tracts (forceps major, CST, and IFOF) we manually divided the tractograms into anatomy conforming segments to evaluate within‐tract changes. We found tract‐specific, nonlinear, age related changes in FA and MD. Early in gestation, these trends appear to be dominated by cytoarchitectonic changes in the transient white matter fetal zones while later in gestation, trends conforming to the progression of myelination were observed. We also observed significant (local) heterogeneity in within‐tract developmental trajectories for the CST, IFOF, and forceps major.     

Correlation of neutrophil/lymphocyte and platelet/lymphocyte ratio with visual acuity and macular thickness in age-related macular degeneration

AIM: To investigate the place of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in the diagnosis of and prognosis for neovascular age-related macular degeneration (AMD). METHODS: One hundred AMD patients and 100 healthy controls were included in the study. Blood samples were obtained from the venous blood, which is used for routine analysis, and these samples were subjected to complete blood count. NLR was defined as the neutrophil count divided by the number of lymphocytes, and PLR was defined as the platelet count divided by the number of lymphocytes. RESULTS: No statistically significant difference was observed between the two groups under consideration in terms of demographic features (P>0.05). The average NLR in the patient group was found to be significantly higher than that in the healthy control group (P<0.05). The average PLR was significantly higher in the patient group as compared to the control group (P<0.05). As best corrected visual acuity (BCVA) increased, both NLR and PLR decreased (significant negative correlations at 49.8% and 63.0%, respectively), whereas as central macular thickness (CMT) increased, both NLR and PLR increased (significant positive correlations at 59.3% and 70.0%, respectively). CONCLUSION: NLR and PLR levels are higher among neovascular AMD patients as compared to healthy control group. NLR and PLR levels were found to be inversely proportional to BCVA and directly proportional to CMT.     

Obstetric outcome of in vitro fertilization pregnancies compared with normally conceived pregnancies.

OBJECTIVE: To compare the obstetric outcome of in vitro fertilization pregnancies with normally conceived pregnancies. STUDY DESIGN: The obstetric outcome of in vitro fertilization pregnancies achieved in 763 British residents at two in vitro fertilization clinics resulting in the births of 961 babies were compared by means of the relative risk statistic with a control group of naturally conceived primiparous pregnancies matched by maternal age and multiplicity of pregnancy. RESULTS: Twenty-five percent of in vitro fertilization pregnancies were multiple pregnancies. The incidence of singleton term breech presentation was similar to that among controls. As compared with controls there was an increased incidence among in vitro fertilization pregnancies of vaginal bleeding and hypertension requiring hospitalization (p less than 0.001) and cesarean births (p less than 0.001) and, among in vitro fertilization singleton pregnancies, an increased incidence of intrauterine growth retardation (p less than 0.05), placenta previa (p less than 0.05), and preterm delivery (p less than 0.001). The congenital malformation, stillbirth, and perinatal mortality rates were comparable with maternal age-standardized national rates. CONCLUSIONS: Although the majority of in vitro fertilization pregnancies have a satisfactory obstetric outcome, there are a number of increased obstetric risks that may reflect the history of infertility, the relatively high incidence of poor obstetric history, and the lower threshold for obstetric intervention in in vitro fertilization patients.     

Is the apparent rise in cancer mortality in the elderly real? analysis of changes in certification and coding of cause of death in England and Wales, 1970–1990

The effect of changes in recording and coding of cause of death on trends in cancer mortality in England and Wales in persons aged 45 and over during 1970–1990 is reviewed. During this period, all-cancer mortality rates increased only at ages over 75 in males and over 55 in females. Rises in cancer mortality were largely due to increases in cancer of lung, prostate and unspecified site in men, and of lung, breast and unspecified site in women. Death coding and certification artefacts were much larger in older persons. In those aged 75–84, a change in the position of recording cancer on the death certificate could potentially account for 46% of the recorded increase in prostate-cancer mortality and 28% of the increase in breast-cancer mortality. The decrease in recorded mortality from ill-defined terminal events was far greater than the increase in cancer mortality in this age group. The rise in all-cancer mortality in the elderly was partly due to an increase in lung-cancer mortality, and data artefacts explained a large proportion of the increase in the other common specified cancers in those aged 75–84. The use of routine mortality statistics to chart progress against cancer lacks validity at older ages because of imprecision in certification of cause of death.     

Association between human immunodeficiency virus type 1 infection and cancer in the black population of Johannesburg and Soweto, South Africa.

A case-control study of 913 black cancer patients (aged 15-50 years) was undertaken to measure the association between human immunodeficiency (HIV) infection and cancers believed to have an infective aetiology. Controls were patients with cancers believed not to be infective in origin. The prevalence of HIV in the controls of 7.3% (24 of 325) was similar to the background HIV seropositivity in this population. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, year of diagnosis, marital status and sex were calculated. There was a strong association between HIV infection and Kaposi''s sarcoma (KS), with 27 of 33 cases being HIV seropositive, OR = 61.8 (95% CI 19.7-194.2) and an elevated association with non-Hodgkin''s lymphoma (NHL), with 27 of 40 cases being HIV seropositive [OR = 4.8 (95% CI 1.5-14.8)]. The elevated odds ratio for KS associated with HIV infection accords with the observed increases in the incidence of KS in several sub-Saharan African countries where the prevalence of HIV is high. The odds ratio for NHL associated with HIV infection was lower than that reported in developed countries, and the reason for this is not clear. No other cancers, including cervical and liver cancers, showed significantly elevated odds ratios associated with HIV infection.     

Local excision of rectal cancer: review of literature

In selected patients, local excision of rectal cancer may be an alternative to radical surgery such as abdominoperineal excision of the rectum or anterior resection. Local excision carries lower mortality and morbidity, without the functional disturbance or alteration in body image that can be associated with radical surgery. There are several techniques of local therapy for rectal cancer, with most experience being available in transanal excision. Transanal endoscopic microsurgery is also used but experience with this newer technique is limited. Patient selection is the most important factor in successful local excision, however specific criteria for selecting patients have not been universally accepted. Review of the published literature is difficult because of the variation in adjuvant therapy regimes and follow-up strategies, as well as results reported in terms of local recurrence and survival rates. There is increasing evidence to suggest that local excision should be restricted to patients with T1 stage rectal cancer without high-risk factors. The place for local excision in patients with T2 or high-risk T1 tumours requires prospective, randomised multi-centre trials comparing radical surgery with local excision, with or without adjuvant therapy.