Neoplasms in neurofibromatosis 1 are related to gender but not to family history of cancer

The risk of malignancies among persons with neurofibromatosis 1 (NF1) is higher than in the general population, but the excess risk has not been precisely estimated. The effects of gender and inheritance pattern on cancer risk are unclear. Therefore, we conducted a historical cohort study to determine cancer risk factors by contacting 138 Caucasian NF1 patients originally seen at Baylor College of Medicine (BCM) in Houston between 1978 and 1984. A total of 304 patients of all ethnic groups were evaluated at BCM during this period. We successfully located 173 patients, 138 of who were Caucasian. We computed standardized incidence ratios (SIRs) with the age-, gender-, and time period-specific rates from the Connecticut Tumor Registry for 2,094 person-years of observation (median follow-up = 16 years). Eleven incident tumors were reported. Females were at much higher risk of cancer than males (SIR = 5.6, 95% confidence interval (CI) 2.7-10.3 and SIR = 0.6; 95% CI, 0.0-3.0, respectively). We found no elevated cancer risk in unaffected first-degree relatives, regardless of whether the proband had cancer or not (SIR = 1.1 95% CI, 0.6-1.8 and SIR = 1.0, 95% CI, 0.6-1.5, respectively). Our results suggest that malignancy in the proband is not the result of a modifying gene that has a significant impact on general cancer risk.

Artificial neural networks and logistic regression as tools for prediction of survival in patients with Stages I and II non-small cell lung cancer

The prognosis of patients with Stage I and II non-small cell lung cancer (NSCLC) can be estimated but cannot be definitively ascertained by use of current clinicopathologic criteria and tumor marker studies. The potential value of probabilistic neural networks (NNs) with genetic algorithms and multivariate logistic regression to predict the survival of NSCLC patients has not been previously evaluated. Multiple prognostic factors (age, sex, cell type, stage, tumor grade, smoking history, and immunoreactivity to c-erbB-3, bcl-2, Glut1, Glut3, retinoblastoma gene and p53 were correlated with 5-year survival in 63 patients with Stage I or II NSCLC, treated solely by surgical excision at Baylor Medical College, Houston, Texas. Several probabilistic NNs with genetic algorithm models were developed using the prognostic features as input neurons and survival at 5 years (free of disease/dead of disease) as output neurons. The probabilistic NN yielded excellent classification rates for dependent variable survival. The best model was trained with 52 cases and classified all 11 "unknown" test cases correctly. Several statistically significant logistic regression models were fitted using 50 cases to build the models and 13 cases as "hold-out" test cases. These multivariate statistical models provide various cutoff values that predict/classify the probability of survival at 5 years. In conclusion, probabilistic NNs and logistic regression models can be useful in estimating the prognosis of patients with Stage I and II NSCLC using multiple clinicopathologic and molecular variables. These multivariate predictive models need to be validated with much larger groups of patients to assess their potential clinical value.

The effect of passive smoking and tobacco exposure through breast milk on sudden infant death syndrome

OBJECTIVE

To examine the relationship between sudden infant death syndrome (SIDS) and smoking during pregnancy; postnatal tobacco smoke exposure from the mother, father, live-in-adults, and day care providers; and postnatal smoke exposure from breast-feeding.

DESIGN

Case-control study.

SETTING

Five counties in Southern California.

PARTICIPANTS

A total of 200 white, African-American, Hispanic, and Asian parents of infants who died of SIDS between 1989 and 1992 were compared with 200 control parents who delivered healthy infants. Case infants were matched to control infants on the basis of birth hospital, birth date, gender, and race. All information was obtained from a detailed telephone interview and validated with medical records.

MAIN OUTCOME MEASURES

Risk of SIDS associated with passive smoking by the mother, father, live-in adults, and day care providers; smoking in the same room as the infant; total number of cigarettes smoked by all adults; and maternal smoking during the time period of breast-feeding.

RESULTS

Conditional logistic regression resulted in overall adjusted odds ratios (ORs) for SIDS associated with passive smoke from the mother of 2.28, the father of 3.46, other live-in adults of 2.18, and all sources of 3.50 (95% confidence interval, 1.81 to 6.75), while simultaneously adjusting for birth weight, sleep position, prenatal care, medical conditions at birth, breast-feeding, and maternal smoking during pregnancy. A dose-response effect was noted for SIDS associated with increasing numbers of cigarettes, as well as total number of smokers. Breast-feeding was protective for SIDS among nonsmokers (OR = 0.37) but not smokers (OR = 1.38), when adjusting for potential confounders.

CONCLUSIONS

Passive smoking in the same room as the infant increases the risk for SIDS. Physicians should educate new and prospective parents about the risk of tobacco smoke exposure during pregnancy and the first year of the infant's life.