Reproductive factors and subtypes of breast cancer defined by hormone receptor and histology.

Reproductive factors are associated with reduced risk of breast cancer, but less is known about whether there is differential protection against subtypes of breast cancer. Assuming reproductive factors act through hormonal mechanisms they should protect predominantly against cancers expressing oestrogen (ER) and progesterone (PR) receptors. We examined the effect of reproductive factors on subgroups of tumours defined by hormone receptor status as well as histology using data from the NIHCD Women's Contraceptive and Reproductive Experiences (CARE) Study, a multicenter case-control study of breast cancer. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) as measures of relative risk using multivariate unconditional logistic regression methods. Multiparity and early age at first birth were associated with reduced relative risk of ER + PR + tumours (P for trend=0.0001 and 0.01, respectively), but not of ER - PR - tumours (P for trend=0.27 and 0.85), whereas duration of breastfeeding was associated with lower relative risk of both receptor-positive (P for trend=0.0002) and receptor-negative tumours (P=0.0004). Our results were consistent across subgroups of women based on age and ethnicity. We found few significant differences by histologic subtype, although the strongest protective effect of multiparity was seen for mixed ductolobular tumours. Our results indicate that parity and age at first birth are associated with reduced risk of receptor-positive tumours only, while lactation is associated with reduced risk of both receptor-positive and -negative tumours. This suggests that parity and lactation act through different mechanisms. This study also suggests that reproductive factors have similar protective effects on breast tumours of lobular and ductal origin.

Trends in the utilization of androgen-deprivation therapy for patients with prostate carcinoma suggest an effect on mortality.

BACKGROUND: After a surge in the incidence of prostate carcinoma in the early 1990s, diminishing rates of mortality became apparent in 1993. This decrease in mortality is unlikely to be explained entirely by treatment with curative intent alone following screen-detected cases, because the time frame between detection and mortality remains relatively brief. METHODS: This study used incidence and initial treatment data from the Detroit area SEER registry between 1973 and 1998 in addition to mortality data covering the Metropolitan Detroit area obtained from the Michigan Department of Community Health. Data for Caucasian and African-American men were analyzed. The use of androgen-deprivation therapy, which evolved during the study period, was evaluated in conjunction with mortality and incidence trend data for consideration of etiologic contributions. RESULTS: The incidence of prostate carcinoma, as noted previously in national data, increased sharply in 1988, peaking in 1992 in Southeast Michigan, whereas mortality rates began to decrease in approximately 1993, with a sustained decrease to the latest recorded data in 1998. These trends were identical in Caucasians and African Americans. A sharp increase in the use of androgen-deprivation therapy began in 1990. This use of androgen-deprivation therapy is high and sustained for patients with early-stage disease, increases for several years, and then diminishes for patients with regional disease. The use also diminished through the 1990s for patients with late-stage disease, paralleling the decrease in the incidence rate for late-stage disease. CONCLUSIONS: The pattern of androgen-deprivation therapy usage was consistent with that for hormonal monotherapy and adjuvant and neoadjuvant therapy. These findings suggest that androgen-deprivation therapy may contribute, along with advances in diagnostic techniques and curative therapy with radiation or surgery, toward decreasing prostate carcinoma mortality rates in Southeast Michigan.

Impact of race in lung cancer: analysis of temporal trends from a surveillance, epidemiology, and end results database.

STUDY OBJECTIVES: We analyzed data from a community-based cancer database over a 26-year period in order to characterize clinicopathologic differences between black and white patients with lung cancer, and to identify relevant temporal trends in incidence and survival. DESIGN, SETTING, AND PATIENTS: Data on demographics, stage, histology, and survival were obtained on all black and white patients with primary bronchogenic carcinoma registered in the community-based metropolitan Detroit Surveillance, Epidemiology, and End Results database from 1973 to 1998. RESULTS: Of 48,318 eligible patients, 23% were black. Lung cancer incidence rates decreased for men of both races from 1985 to 1998, with a greater decline occurring in black men (p < 0.0001). Although incidence rates declined over time for men of both races < 50 years of age, this decrease was greater in white men, resulting in an increase in the racial differential in younger men. Temporal trends in incidence rates were similar for women of both races. The incidence of distant-stage disease was higher among blacks throughout the study period. The incidence of local-stage disease decreased for both races, though this decline was greater in blacks. A significant racial difference in 2-year and 5-year survival rates developed during the study period, due to a distinct lack of improvement in black patients. In a multivariate model, the relative risks of death for black patients, relative to white patients, were 1.24 (p < 0.0001) for local stage, 1.14 (p < 0.0001) for regional stage, and 1.03 (p = 0.045) for distant stage. CONCLUSION: Significant racial differences exist in the incidence and survival rates for lung cancer in metropolitan Detroit. Since 1973, several disturbing trends have developed, particularly with regard to the lack of improvement in overall survival in black patients. Further study is required to determine the factors responsible for these temporal trends.

Axillary lymph node metastases associated with small invasive breast carcinomas.

BACKGROUND: Over the past 20 years the proportion of invasive breast carcinomas measuring < or = 1 cm has increased progressively. Information regarding the effect of clinical and histologic characteristics on the frequency of lymph node metastases associated with small invasive breast carcinomas is limited. METHODS: A review of Surveillance, Epidemiology, and End Results data was performed using cases diagnosed between January 1988 through December 1993. A total of 12,950 patients with invasive breast carcinomas measuring < or = 1 cm undergoing a resection of the primary tumor and an axillary lymph node dissection were included in this study. The effect of clinical and histologic characteristics on the frequency of lymph node metastases was reviewed. RESULTS: The frequency of lymph node metastases associated with T1a tumors was less than that observed from T1b tumors (9.6% vs. 14.3%; P < 0.001). Tumors with favorable histology (mucinous, papillary, and tubular carcinomas) had a lower frequency of lymph node metastases compared with all other histologic types (3.9% vs. 13.9%; P < 0.001). Increasing histologic grade was associated with an increased risk of lymph node metastases ranging from 7.8% in Grade 1 tumors to 21.0% in Grade 4 tumors (P < 0.001). Increasing patient age was associated with a progressively decreasing frequency of associated axillary lymph node metastases ranging from 22.6% in women age < 40 years to 10.2% in women age > or = 70 years (P < 0.001). CONCLUSIONS: Cases in which an axillary lymph node dissection can be avoided are those with an associated frequency of lymph node metastases < or = 5%, including T1a and T1b mucinous and tubular carcinomas, T1a papillary carcinomas, and T1a Grade 1 carcinomas.

Increasing incidence of adenocarcinomas and carcinoid tumors of the small intestine in adults.

Malignant neoplasms of the small intestine are relatively rare and have received little study. We report on trends in the age-adjusted, sex-, and race-specific incidence rates of adenocarcinomas and carcinoid tumors of the small intestine in the United States from 1973 through 1991. Data were derived from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. There were statistically significant increases in the incidence rates of both adenocarcinomas and carcinoid tumors during the time frame of the study. Rates increased most dramatically in black males, with 2- and 4-fold increases in adenocarcinomas and carcinoid tumors, respectively. The only rates that remained relatively unchanged were those of adenocarcinoma among white females. It remains to be determined if changing environmental factors are important causes of these observed trends. If environmental factors are involved in the etiology of small intestine cancers, analytic studies conducted while the disease is increasing in incidence may provide useful insights.

Increasing incidence of cancer of the prostate. The experience of black and white men in the Detroit metropolitan area.

BACKGROUND: Prostate cancer mortality and incidence rates have been gradually increasing for decades in the United States, with an accelerated increase in incidence noted in the past several years. This study explores in detail the occurrence of prostate cancer in southeast Michigan from 1973 through 1991. METHODS: Data from the National Cancer Institute Surveillance, Epidemiology, and End Results program are analyzed with emphasis on time trends by race, age, stage, and treatment. RESULTS: Population-based rates for prostate cancer increased by 70% between 1988 and 1991. Increases are most pronounced for early stage disease and among whites compared with blacks. Corresponding increases in treatment with radical prostatectomy are also observed. CONCLUSION: Increased incidence of prostate cancer is likely a result of widespread use of prostate-specific antigen.

Trends in cervical cancer incidence among young black and white women in metropolitan Detroit.

BACKGROUND: Although the overall incidence of invasive cervical cancer in the United States has declined over the past several decades, recent studies suggest that rates for both invasive and in situ cervical cancer are rising among younger women. METHODS: Trends in cervical cancer incidence among females between the ages of 15 and 39 years were evaluated using data from the Metropolitan Detroit Cancer Surveillance System, a population-based registry and founding participant in the SEER Program of the National Cancer Institute. Age-adjusted and age-specific rates for all black and white women in this age group were evaluated as well as rates for married and single women for the period 1973-1991. RESULTS: Incidence trends vary by race and marital status. A nonlinear increasing trend was evident (P < 0.01), for in situ cervical cancer among white women, with rates for single white women exhibiting the largest increase. Rates among black women for in situ cervical cancer exhibited a nonlinear decreasing trend (P < 0.01), with rates for married black women declining by 75%. Among single white women, invasive cervical cancer exhibited an increasing linear trend (P < 0.01), although the number of cases was small. CONCLUSIONS: Differences in trends among black and white women may reflect a combination of greater exposure to risk factors associated with cervical carcinoma as well as differential access to diagnostic and treatment services. Appropriate groups should be targeted for educational, screening, and follow-up services.