Increased risk of laryngeal and pharyngeal cancer after gastrectomy for ulcer disease in a population-based cohort study.

BACKGROUND: Gastrectomy has been indicated as a risk factor for laryngeal cancer, and possibly also for pharyngeal cancer, but few studies are available. The postulated mechanism is increased bile reflux following gastrectomy. METHODS: This was a population-based cohort study of patients who underwent gastrectomy for peptic ulcer disease between 1964 and 2008 in Sweden. Follow-up data for cancer was obtained from the Swedish Cancer Register. Relative risk was calculated as standardised incidence ratios (SIRs) with 95% confidence intervals (CIs). RESULTS: The gastrectomy cohort comprises 19 767 patients, contributing 348 231 person-years at risk. The observed number of patients with laryngeal (n=56) and pharyngeal cancer (n=28) was two-fold higher than the expected (SIR: 2.0, 95% CI: 1.5-2.6 and SIR: 2.4, 95% CI: 1.6-3.5, respectively). After exclusion of 5536 cohort members with tobacco- or alcohol-related disease, the point SIRs remained increased (SIR: 1.6, 95% CI: 1.1-2.2 and SIR: 1.7, 95% CI: 0.9-2.8, respectively). The SIRs of laryngeal and pharyngeal cancer increased with time after gastrectomy (P for trend <0.0001), and were particularly increased 30 years after gastrectomy (SIR: 4.8, 95% CI: 2.1-9.5 and SIR: 10.2, 95% CI: 3.7-22.3, respectively). CONCLUSION: Gastrectomy for peptic ulcer disease might entail a long-term increased risk of laryngeal and pharyngeal cancer.

Malignancies among women who gave birth after in vitro fertilization.

BACKGROUND: Relatively few studies published to date have investigated IVF and cancer risk. In this study we compared the occurrence of cancer in women who gave birth after IVF with all other women who gave birth in the study period. METHODS: All women who were treated with IVF and gave birth during the years 1982-2006 in Sweden were identified from all IVF clinics, and the occurrence of cancer in these women was identified by linkage with the nationwide Swedish cancer register. Comparison was made with Mantel-Haenszel odds ratios (ORs), adjusting for year of delivery and maternal age, parity and smoking. Cancer before IVF was only studied in first parity women. Specific cancer forms were also studied. RESULTS: Among 24058 women who had been treated with IVF, 1279 appeared in the cancer register. The total number of women studied in the population was 1 394 061, and 95 775 of these were registered in the cancer register. The risk for cancer before IVF was increased [OR 1.37, 95% confidence interval (CI) 1.27-1.48] and was especially high for ovarian cancer (3.93). The risk for cancer after IVF was significantly lower (OR 0.74, 95% CI 0.67-0.82), mainly due to a lower than expected risk for breast and cervical cancer. The risk for ovarian cancer was increased but lower than the risk before IVF (2.13). CONCLUSIONS: Cancer or cancer treatment may increase the risk for infertility leading to IVF. After IVF, in most cases with treatment with fertility hormones, a significantly low cancer risk was found. Ovarian cancer showed an increased risk, although lower than before IVF. One possible reason is ovarian pathology causing both infertility and an increased cancer risk.

Trends in delivery and neonatal outcome after in vitro fertilization in Sweden: data for 25 years.

BACKGROUND: Marked changes have occurred in in vitro fertilization (IVF) methodology during the past 25 years but also in characteristics of couples undergoing treatment. METHODS: This study was based on 27 386 women undergoing IVF treatment from 1982 to 2006 and giving birth to 31 850 infants. Outcomes of deliveries were studied using Swedish health registers. Comparisons were made with all deliveries in the population (n = 2 603 601). Adjusted odds ratios were calculated when important changes in background rates had occurred. RESULTS: There was a substantial increase in the use of intracytoplasmatic sperm injection (ICSI) and the transfer of cryopreserved embryos. Among all ICSI cases, the proportion using epididymal or testicular sperm varied between 5 and 10%. Maternal characteristics changed during the observation period but the median age remained relatively constant in spite of the increasing maternal age in the population. There was a decline in the rate of some maternal pregnancy diagnoses (notably pre-eclampsia, premature rupture of membranes) and some neonatal diagnoses (notably preterm births, low birthweight, cerebral hemorrhage, respiratory diagnoses, use of continuous positive airway pressure and mechanical ventilation, sepsis/pneumonia). Up till 1992, the twinning rate increased to a maximum of about 30% and then declined to 5% towards the end of the period whereas higher order multiples nearly disappeared. The total rate of infants with congenital malformations changed only little. CONCLUSIONS: The decrease in unwanted outcomes can, to a large extent, be explained by the reduced rate of multiple births but was seen also among singletons. Other explanations can be sought in changes in the characteristics of patients undergoing IVF.

Selected neonatal outcomes in dizygotic twins after IVF versus non-IVF pregnancies.

OBJECTIVE: To compare neonatal outcome among twins conceived after in vitro fertilisation (IVF) with that of spontaneously conceived twins. DESIGN: Comparison of different-sex (dizygotic) twins born after IVF with non-IVF dizygotic twins. SETTING: National health registers in Sweden. POPULATION: All births in Sweden during the period 1982-2007. METHODS: We studied gestational duration, lowest birthweight and birthweight difference in the twin pair, presence of one or two twins with a respiratory complication, and with jaundice in one or both twins. Risk estimates were calculated as odds ratios with adjustments for year of birth, maternal age, parity and smoking in pregnancy. MAIN OUTCOME MEASURES: Gestational duration, birth weight, respiratory complications, jaundice. RESULTS: We studied 1545 pairs of dizygotic twins born after IVF, and 8675 pairs of dizygotic twins where IVF was not known to have occurred. The risk for preterm delivery before 32 weeks of gestation was significantly increased among dizygotic twin pairs born after IVF compared with non-IVF dizygotic twin pairs. No significant difference in low birthweight or birthweight difference within twin pairs was seen. There was an increased occurrence of twin pairs with respiratory problems or jaundice, but only the latter diagnosis occurred in a statistically significant excess. CONCLUSIONS: The study confirms recent findings that IVF is associated with an increased risk for some neonatal complications, not only among singletons but also among twins.