Evidence for an association of human papillomavirus infection and colorectal cancer.

AIM: To investigate the presence of human papillomavirus (HPV) in colorectal carcinomas and the correlation of the viral infection with prognostic factors for the disease outcome. METHODS: Seventy-two patients with primary colorectal adenocarcinoma were studied. From each patient two tissue samples were collected: one sample of the tumor and one sample of normal colorectal tissue from an area located 15 cm away from the tumor. Samples of colorectal mucosa obtained from 30 individuals without malignant disease were also studied as control group. Tissues were initially analyzed through MY/GP nested polymerase chain reaction (PCR) and through GP5+/GP6+ auto-nested PCR. Specific primer sets targeting the E6/E7 region of the HPVs 6, 11, 16, 18, 31, 33, 45 were used for typing. Direct DNA sequencing was conducted to confirm positive PCR results. RESULTS: HPV DNA was detected in colorectal specimens of 60 patients with cancer (83.3%), but in none of the tissues from the non-malignant control group (p<0.001). Twenty-three cancer patients had HPV DNA detected in both the tumor and the matched normal tissue, 23 had HPV only in the tumor, and 14 had HPV only in the normal colorectal tissue. HPV16 was the viral type most frequently detected, being present in 41 out of 60 positive cases (68.3%). No correlation between the presence of the virus and specific prognostic predictors for the disease outcome was observed. CONCLUSION: HPV is present in the colon and rectum of most patients with colorectal adenocarcinoma, suggesting that this virus may be related to the pathogenesis of colorectal cancer.

[Evolution of breastfeeding pattern]. / Evolução do padrão de aleitamento materno.

OBJECTIVE: To follow the evolution of the breastfeeding practice among women in a childbirth clinic and evaluate the actions for its promotion. METHODS: Two cohorts of children born in an school hospital of Porto Alegre, Brazil, in different periods of time were compared regarding the prevalence of breastfeeding during the first six months of life, and the percentage of early cessation of breastfeeding. Both were prospective studies, including 202 children in the cohort of 1987, and 187 children in the cohort of 1994. All participants were healthy children, with birth weight of 2500g or more, were being breastfed and their parents were living in the same house. The 1987 study children were followed up through mail, and the 1994 study ones by home visits. RESULTS: Survival analysis showed similar frequencies of breastfeeding in the two cohorts. The prevalence of exclusive breastfeeding, although for a short period in both groups, was higher in the population studied in 1994, especially among children whose mothers were better educated. There was no rate difference of early cessation of breastfeeding between the two cohorts (36% for the 1987 cohort and 39% for the 1994 cohort). CONCLUSIONS: The results revealed a certain degree of apathy in regard of the promotion of breastfeeding during the studied period, giving support to actions to promote breastfeeding, especially among poor families.