The association of plasma fatty acids with prostate cancer risk in Nigerians.

PURPOSE: To investigate the role of fatty acids (FAs) in prostate cancer (PCa) risk in Nigeria, a country in transition to westernized diet high in animal fats, and currently experiencing rising rates of prostate cancer. METHODS: Men > or =40 years were recruited from surgery/urology clinics, University of Benin Teaching Hospital and from 2 rural and 2 urban communities. Personal information, urological symptom history and anthropometrics were recorded, digital rectal examination performed, and 30 mLs of fasting blood collected for prostatic specific antigen and fatty acid (FA) analysis. Odds ratio (OR) of PCa risk was determined by unconditional logistic regression with the plasma FA 1st quartile as reference, controlling for age, education, waist-to-hip ratio, and family history. RESULTS: Mean ages for 66 (22.6%) cases and 226 (77.4%) controls were 71.9+/-11.47 and 56.7+/-12.69 years, P<.001, and median (25th, 75th percentile) fasting plasma FA were 2,447 (2,087, 3,024) and 2,373 (2,014, 2,751) microg/mL, respectively. PCa risk trend was observed for total omega-6 FA, adjusted ORQ3vs.Q1 2.33 (95% CI, 0.77-7.07), P<0.05. Unadjusted ORQ4vs.Q1 for behenic and nervonic acids were 2.79 (95% CI, 1.27-6.10) and 2.40 (95% CI, 1.19-4.85), and unadjusted ORQ2vs.Q1 for erucic and arachidonic acids were 4.20 (95% CI, 1.79-9.82) and 3.81 (95% CI, 1.50-9.70) respectively. Unadjusted ORQ2vs.Q1 for omega-3 FAs eicosapentaenoic (EPA) and docosapentaenoic (DPA) were 0.39 (95% CI, 0.18-0.85) and 0.79 (95% CI, 0.35-1.79) respectively. CONCLUSIONS: In this population with high total plasma omega-3, we observed modest positive PCa risk trend with total plasma omega-6 (2.3), inverse risk reduction with EPA (0.4), and strong positive risk associations with behenic (2.8), erucic (4.2), and nervonic (2.4) acids. Total plasma omega-6 is highest in the educated high-income group. These findings should be confirmed in a larger study because of the potential serious implication of dietary transition particularly in a region designated as low-incidence for PCa.

Knowledge, attitude and practice of Nigerian women towards breast cancer: a cross-sectional study.

BACKGROUND: Late presentation of patients at advanced stages when little or no benefit can be derived from any form of therapy is the hallmark of breast cancer in Nigerian women. Recent global cancer statistics indicate rising global incidence of breast cancer and the increase is occurring at a faster rate in populations of the developing countries that hitherto enjoyed low incidence of the disease. Worried by this prevailing situation and with recent data suggesting that health behavior may be influenced by level of awareness about breast cancer, a cross-sectional study was designed to assess the knowledge, attitude and practices of community-dwelling women in Nigeria towards breast cancer. METHODS: One thousand community-dwelling women from a semi-urban neighborhood in Nigeria were recruited for the study in January and February 2000 using interviewer-administered questionnaires designed to elicit sociodemographic information and knowledge, attitude and practices of these women towards breast cancer. Data analysis was carried out using Statistical Analysis Software (SAS) version 8.2. RESULTS: Study participants had poor knowledge of breast cancer. Mean knowledge score was 42.3% and only 214 participants (21.4%) knew that breast cancer presents commonly as a painless breast lump. Practice of breast self examination (BSE) was low; only 432 participants (43.2%) admitted to carrying out the procedure in the past year. Only 91 study participants (9.1%) had clinical breast examination (CBE) in the past year. Women with higher level of education (X2 = 80.66, p < 0.0001) and those employed in professional jobs (X2 = 47.11, p < 0.0001) were significantly more knowledgeable about breast cancer. Participants with higher level of education were 3.6 times more likely to practice BSE (Odds ratio [OR] = 3.56, 95% Confidence interval [CI] 2.58-4.92). CONCLUSION: The results of this study suggest that community-dwelling women in Nigeria have poor knowledge of breast cancer and minority practice BSE and CBE. In addition, education appears to be the major determinant of level of knowledge and health behavior among the study participants. We recommend the establishment and sustenance of institutional framework and policy guidelines that will enhance adequate and urgent dissemination of information about breast cancer to all women in Nigeria.

The association of plasma fatty acids with prostate cancer risk in African Americans and Africans.

Higher risk for prostate cancer (PCa) among African Americans is partly associated with exposure to dietary fatty-acids, the carcinogenic effects of which remain controversial. Odds ratio of PCa risk was determined by unconditional logistic regression comparing highest with lowest quartiles of plasma fatty-acids in a case-control design. Mean age for 173 African Americans and 340 Nigerians was 56.9 +/- 9.8 and 60.1 +/- 14.0, p<.006, median (25th, 75th percentile) plasma fatty-acid was 2598 (2306, 3035) microg/ml and 2420 (2064, 2795) microg/ml, p<.001, with 48 (27.7%) and 66 (19.4%) PCa cases, respectively. African Americans recorded higher total, omega-6, and trans, but lower saturated and omega-3 fatty-acids, with non-significant PCa risk association for total, omega-6 and trans fatty acids. Positive PCa risk trend was observed in both populations with nervonic, erucic, and arachidonic acids, with docosahexaenoic acid (DHA) among African Americans, and with behenic and stearic acids in Nigerians. Non-significant negative PCa risk trend was observed with ecosapentaenoic acid (EPA) in Nigerians only. These preliminary findings need to be further explored in a larger study that will include risk analysis of fatty-acid ratios to clarify their combined impact on PCa risk.

Cytochrome P450 1B1 Val432Leu polymorphism and breast cancer risk in Nigerian women: a case control study.

BACKGROUND: Cytochrome P450 1B1 (CYP1B1) is active in the metabolism of estrogens to reactive catechols and of different procarcinogens. Several studies have investigated the relationship between genetic polymorphisms of CYP1B1 and breast cancer risk with inconsistent results. A G --> C transversion polymorphism in the heme-binding region in codon 432 of the gene results in amino acid change (Val --> Leu); the Leu allele display increased catalytic efficiency for 4-hydroxylation of estradiol in some experimental systems. METHODS: In this study, we utilized a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay to assess the relationship between this polymorphism and breast cancer risk in a case control study including 250 women with breast cancer and 250 controls from four University Teaching Hospitals in Southern Nigeria. RESULTS: Heterozygosity for the CYP1B1 M1 genotype (CYP1B1 M1 [Val/Leu]) was associated with a significant 59% increased risk of breast cancer (OR = 1.59, 95% CI 1.01-2.58) while homozygosity for the genotype (CYP1B1 M1 [Leu/Leu]) conferred a non-significant 51% increased risk of breast cancer. These risk profiles were modified in subgroup analysis. In premenopausal women, harboring at least one CYP1B1 (Leu) allele conferred a significant two-fold increased risk of breast cancer (OR = 2.04, 95% CI 1.10-3.78). No significant association was observed in postmenopausal women (OR = 1.08, 95% CI 0.57-2.04). CONCLUSION: Our results suggest that the codon 432 polymorphism of the CYP1B1 gene is associated with increased risk of breast cancer and is particularly involved in breast cancer risk in premenopausal women of African descent.

Anthropometry and breast cancer risk in Nigerian women.

The recent upsurge in global obesity and the recognition of the role of metabolic syndrome and other correlates of obesity in the etiology of breast cancer and other chronic diseases has created the impetus for renewed interest in the role of anthropometric measures in breast cancer risk. This case-control study was designed to evaluate the role of anthropometric variables in breast cancer susceptibility in an indigenous sub-Saharan African population drawn from midwestern and southeastern Nigeria, a population grossly underreported in the global epidemiologic literature. Study participants were 250 women with breast cancer who were receiving treatment in the surgical outpatient clinics and surgical wards of four university teaching hospitals located in midwestern and southeastern Nigeria, while the controls were 250 age-matched women without breast cancer or other malignant diseases being treated for other surgical diseases in the same institutions between September 2002 and April 2004. Waist:hip ratio (WHR) was associated with a significant 2.5-fold increased risk of premenopausal breast cancer (odds ratio [OR] = 2.56, 95% confidence interval [CI] 1.48-4.41] and a 2-fold increased risk of postmenopausal breast cancer (OR = 2.00, 95% CI 1.04-2.53). Increasing height conferred a modestly nonsignificant increased risk of premenopausal breast cancer (OR = 1.59, 95% CI 0.98-2.58). The study showed that WHR is a significant predictor of breast cancer risk in Nigerian women and measures to sustain increased physical activity and ensure healthy dietary practices are recommended to reduce the burden of obesity in the population.

Prevalence of elevated serum prostate-specific antigen in rural Nigeria.

BACKGROUND: Recent hospital and cancer registry data show increasing prostate cancer incidence in Nigeria, which was previously regarded as a low incidence region. This study investigates the prevalence of prostate cancer risk in a previously unscreened cohort of rural Nigerians. METHODS: Rural Nigerian men, 40 years and older, were screened by serum prostate-specific antigen (PSA) and digital rectal examination (DRE) and those with PSA >/= 4 ng/mL and/or abnormal DRE were referred for prostate biopsy. RESULTS: Of 200 consecutive men invited, 151 (75.5%) presented for screening, the mean age was 56.45 + 15.1 and 95 (61.6%) were >/= 50 years of age. Of the 140 who consented to a blood test, PSA correlated with age (r = 0.3, P < 0.01), 14 (10.0%) had abnormal PSA >/= 4 ng/mL, increasing from 3 (3.6%) in men < 60 years to 4 (50%) in men >/= 80 years. The rate was 13 (15.7%) for men >/= 50 years and there was no evidence of increased incidence of prostatitis in the community. Mean (median) PSA in ng/mL increased from 1.17 (0.60) in the youngest to 13.75 (4.45) in the oldest cohort. Of those who accepted DRE, 38 (29.0%) had an enlarged prostate, including two who had nodular prostate, one-third with symptoms, increasing from 4 (5.4%) in those < 50 years to 6 (75.0%) in men >/= 80 years. The proportion of men with PSA >/= 4 ng/mL among those with enlarged vs normal prostate is 27.0 to 3.4%, P < 0.001, and the pattern was similar for men >/= 60 years and those < 60 years of age. The 40 (32.0%) men referred for prostate biopsy defaulted mainly because they did not fully understand the need for further investigation because they were symptom free or afraid of the possible side-effects of the procedure or diagnosis of cancer. CONCLUSION: The proportion of men with PSA >/= 4 ng/mL is comparable to that of previously unscreened populations with high incidence of prostate cancer such as African-American men. A larger study is required to confirm these findings and intensify efforts to determine the prostate cancer detection rate by biopsy in this population. A prostate cancer awareness and education campaign will be useful in this community.