Terri M. King

Accuracy of family history of cancer as reported by men with prostate cancer

OBJECTIVES To report on the accuracy of probands providing information on specific cancer types in their families and the ability of investigators to document these reports. Accurate information on the health status of family members is critical when studying familial patterns of diseases. However, collecting these data require significant resources. METHODS We identified 143 patients with prostate cancer from the University of Texas M. D. Anderson Cancer Center who had reported at least 1 first-degree relative with cancer. There were 263 first-degree relatives identified, for whom we confirmed diagnoses using medical records, death certificates, and verbal confirmation. The data are reported in summary statistics and compared with chi-square analysis. RESULTS We documented 78% of the reports, with an accuracy rate of 81.6%. We found that accuracy was highly related to the site reported. Accuracy and documentation levels were not related to the age or income of the proband. The education level was significantly associated with the ability to document cancer, but not with the accuracy of the report. The accuracy and documentation differed by the relationship of the first-degree relative to the proband. CONCLUSIONS Proband reporting of cancer in first-degree relatives varies widely by site, with common metastatic sites the most inaccurate. No reliable demographic factors were found that would reasonably predict the ability to document the accuracy of the report. We found a significant proportion of proband-reported prostate cancer was, in reality, benign prostatic hyperplasia. We propose a strategy of targeting male relatives and reports of cancer in common metastatic sites for aggressive follow-up.

Linked markers and age at diagnosis

This paper examines the relationship between age at diagnosis and markers linked to a disease trait using 100 replicates from Problem 2A in Genetic Analysis Workshop 10. After establishing the relationship between age and the quantitative trait used to define affection status, Q1, we evaluated the relationship between age at diagnosis and a marker which was linked with Q1. We found that the presence of an F allele at marker 15 on chromosome 5 was significantly associated with delayed age of diagnosis. When we evaluated 100 replicates, we found that the regression coefficients in the survival analyses were separated into two approximately normal distributions. The location of these distributions was solely reflective of the presence of affected individuals with the F allele in a particular replicate. In the replicates in one of the distributions, we found tremendous changes in the variance after employing survival models for dependent data. While we suggest that survival analysis of dependent data may be an important tool in investigating genotype specific alterations in age at event, the findings of this study indicate that the method used may be very sensitive to certain types of missing data.

Expression of a 65 kDa oncofetal protein in human prostatic carcinoma

The concentration of a novel 65 kDa oncofetal protein, p65, was measured in the sera of patients with prostatic malignancies using an enzyme-linked immunosorbent assay. The prostate cancer sera were positive for p65 in 40 out of 59 cases (68%), while only 7 of 79 normal sera (9%) and 12 of 61 sera from patients with benign diseases (20%) were positive. The detection system had an overall sensitivity of 68% and a specificity of 86%. Elevated p65 levels correlated positively with the pathologic stages of the prostate cancer. Using this marker in concert with PSA may increase our ability to evaluate treatment response and aid in early detection of prostate cancer.