Showing papers by "Benjamin F. Hankey published in 1992"

Second Cancers in patients With Chronic Lymphocytic Leukemia

Abstract: BACKGROUND Reports to date have provided widely divergent estimates of the risk of second malignant neoplasms in patients with chronic lymphocytic leukemia (CLL), ranging from cancer deficits to excesses of twofold to threefold. PURPOSE Our purpose was to estimate the risk of second primary cancers following CLL, utilizing population-based tumor registries, and to determine whether site-specific excesses might be associated with type of initial treatment for CLL. METHODS We analyzed data for 9456 patients diagnosed with CLL as a first primary cancer between 1973 and 1988, who were reported to one of nine tumor registries participating in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program and who survived 2 or more months. SEER files were searched for invasive primary malignancies that developed at least 2 months after the initial CLL diagnosis. RESULTS Compared with the general population, CLL patients demonstrated a significantly increased risk of developing all second cancers (840 observed; observed-to-expected ratio [O/E] = 1.28; 95% confidence interval [CI] = 1.19-1.37). Significant excesses were noted for cancers of the lung (O/E = 1.90), brain (O/E = 1.98), and eye (intraocular melanoma) (O/E = 3.97) as well as malignant melanoma (O/E = 2.79) and Hodgkin's disease (O/E = 7.69). Cancer risk, which did not vary according to initial treatment category, was also constant across all time intervals after CLL diagnosis. CONCLUSION CLL patients are at a significantly increased risk of developing a second malignant neoplasm. The pattern of cancer excesses suggests a susceptibility state permitting the development of selected second malignancies in patients with CLL, perhaps because of shared etiologic factors, immunologic impairment, and/or other influences. Although our results do not suggest a strong treatment effect, more detailed studies of second tumors in CLL are needed to investigate the role of radiation therapy and chemotherapy.

Differences Between Black and White Women With Breast Cancer in Time From Symptom Recognition to Medical Consultation

Abstract: Background Studies in the United States have reported that Black women have higher fatality rates than White women following a diagnosis of breast cancer and are more likely to be diagnosed with late-stage cancers. Purpose To evaluate reasons for these racial differences, we explored the difference between Black and White women in the length of time from symptom recognition to initial medical consultation. We also evaluated the extent to which other factors related to the length of this interval might contribute to any observed racial difference. Methods As part of a collaborative study of differences in the survival rates of Black patients and White patients with cancer, we interviewed a sample of 410 Black women and 325 White women from Atlanta, New Orleans, and San Francisco/Oakland who were newly diagnosed in 1985 or 1986 with invasive breast cancer. Retrospective data were collected on symptoms, dates of symptom recognition and initial medical consultation, and several other factors which may affect the interval between symptom recognition and medical consultation. Data were analyzed as if from a follow-up study, using product limit procedures and proportional hazards regression. Results At diagnosis, Black women with breast cancer were two times more likely to have stage IV breast cancer and one and one-half times more likely to have stage III breast cancer than White women with breast cancer and were only approximately one-half as likely to have stage I breast cancer. Similarly, Black women were almost twice as likely as White women to have tumors that were larger than 5 cm or tumors that had extensions to the chest wall or skin at presentation. However, the average rate at which Black women with breast cancer obtained an initial medical consultation lagged behind that for White women by only a slight but statistically significant difference (15%). The median time between symptom recognition and medical consultation was slightly longer for Black women (16 days) than for White women (14 days) (P = .06). Adjustment for other characteristics predictive of the length of this interval had little effect on racial differences. The racial differences tended to vary somewhat by age and metropolitan area, suggesting that the results may not apply equally to all demographic subgroups and regions in the United States. Conclusion This small difference in the time from symptom recognition to medical consultation is unlikely to account for the large racial differences in survival rates and in stage of disease at the time of diagnosis.

A collaborative study of differences in the survival rates of black patients and white patients with cancer

Abstract: In 1983, the National Cancer Institute began a social-epidemiologic study of possible behavioral and biologic determinants of black/white racial disparities in cancer survival The design, methodology, underlying hypotheses, and patient accrual of this study are discussed Survival differences in four organ sites are investigated: cancers of the uterine corpus, breast, bladder, and colon The first three sites were chosen because of significant observed black/white differentials in survival Although racial disparities in survival from colon cancer are less prominent, this site was included because it is a leading cause of deaths attributable to cancer, because regional variations have been observed in black/white survival disparities, and because colon data permit cross-gender comparisons Data collection centers for the study included the Georgia Center for Cancer Statistics, the Louisiana Tumor Registry, and the California Tumor Registry Probability samples of patients newly diagnosed with these cancers were drawn from the areas served by these registries Diagnostic years of eligibility were 1985 to 1986 for breast and colon cancer, and 1985 to 1987 for bladder and uterine corpus cancer Data were collected by personal interview, medical records abstract, physician records, and pathology review Analyses focus on seven main explanatory hypotheses

Graphical representation of survival curves associated with a binary non‐reversible time dependent covariate

Abstract: The use of time dependent covariates has allowed for incorporation into analysis of survival data intervening events that are binary and non-reversible (for example, heart transplant, initial response to chemotherapy). We can represent this type of intervening event as a three-state stochastic process with a starting state (S), an intervening state (I), and an absorbing state (D), which usually represents death. In this paper we present three procedures for calculating survivorship functions which attempt to display the prognostic significance of the time dependent covariate. The first method compares survival from baseline for the two possible paths through the stochastic process; the second method compares overall survival to survival with state I removed from the process; and, the third method compares survival for those already in state I at a landmark time x to those in state S at time x who will never enter state I. We develop discrete hazard estimates for the survival curves associated with the three methods. Two examples illustrate how these methods can yield different results and in which situations one might employ each of the three methods. Extensions to applications with reversible binary time dependent covariates and models with both baseline and time dependent covariates are suggested.