Improvements in observed and relative survival in follicular grade 1-2 lymphoma during 4 decades: the Stanford University experience.

Recent studies report an improvement in overall survival (OS) of patients with follicular lymphoma (FL). Previously untreated patients with grade 1 to 2 FL treated at Stanford University from 1960-2003 were identified. Four eras were considered: era 1, pre-anthracycline (1960-1975, n = 180); era 2, anthracycline (1976-1986, n = 426); era 3, aggressive chemotherapy/purine analogs (1987-1996, n = 471); and era 4, rituximab (1997-2003, n = 257). Clinical characteristics, patterns of care, and survival were assessed. Observed OS was compared with the expected OS calculated from Berkeley Mortality Database life tables derived from population matched by gender and age at the time of diagnosis. The median OS was 13.6 years. Age, gender, and stage did not differ across the eras. Although primary treatment varied, event-free survival after the first treatment did not differ between eras (P = .17). Median OS improved from 11 years in eras 1 and 2 to 18.4 years in era 3 and has not yet been reached for era 4 (P < .001), with no suggestion of a plateau in any era. These improvements in OS exceeded improvements in survival in the general population during the same period. Several factors, including better supportive care and effective therapies for relapsed disease, are likely responsible for this improvement.

Incidental extracardiac findings at coronary CT: clinical and economic impact.

OBJECTIVE: The purpose of this study was to evaluate the prevalence of incidental extracardiac findings on coronary CT, to determine the associated downstream resource utilization, and to estimate additional costs per patient related to the associated diagnostic workup. MATERIALS AND METHODS: This retrospective study examined incidental extracardiac findings in 151 consecutive adults (69.5% men and 30.5% women; mean age, 54 years) undergoing coronary CT during a 7-year period. Incidental findings were recorded, and medical records were reviewed for downstream diagnostic examinations for a follow-up period of 1 year (minimum) to 7 years (maximum). Costs of further workup were estimated using 2009 Medicare average reimbursement figures. RESULTS: There were 102 incidental extracardiac findings in 43% (65/151) of patients. Fifty-two percent (53/102) of findings were potentially clinically significant, and 81% (43/53) of these findings were newly discovered. The radiology reports made specific follow-up recommendations for 36% (19/53) of new significant findings. Only 4% (6/151) of patients actually underwent follow-up imaging or intervention for incidental findings. One patient was found to have a malignancy that was subsequently treated. The average direct costs of additional diagnostic workup were $17.42 per patient screened (95% CI, $2.84-$32.00) and $438.39 per patient with imaging follow-up (95% CI, $301.47-$575.31). CONCLUSION: Coronary CT frequently reveals potentially significant incidental extracardiac abnormalities, yet radiologists recommend further evaluation in only one-third of cases. An even smaller fraction of cases receive further workup. The failure to follow-up abnormal incidental findings may result in missed opportunities to detect early disease, but also limits the short-term attributable costs.

Modeling the transition of lung cancer from early to advanced stage.

We present a stochastic parametric model of the natural history of lung cancer that predicts the primary tumor volume at the moment the disease transits from early to advanced stage. Our model also produces estimates for the probability of symptomatic detection as a function of tumor volume and clinical stage. We estimate model parameters by likelihood maximization using data from the Mayo Lung Project (MLP), which was a clinical trial that evaluated screening for lung cancer in the 1970s. Mayo Lung Project cancer cases reported in Stage III or greater, according to the 1979 AJCC staging for lung cancer, were considered advanced stage. Our estimator distinguishes between the cases detected because of clinical symptoms and cases detected by screening. For nonsmall cell lung cancer cases detected in MLP, we estimate that the median primary tumor diameter at the onset of advanced stage disease was 4.1 cm. In addition, we estimate that the rate of patients symptomatically detected with their disease increases as their primary tumor increases in size, and for patients with a primary tumor of a given size, the rate of symptomatic detection is 12.8 times greater among patients with advanced stage disease compared to patients with early stage disease.

A stochastic simulation model of U.S. breast cancer mortality trends from 1975 to 2000.

BACKGROUND: We present a simulation model that predicts U.S. breast cancer mortality trends from 1975 to 2000 and quantifies the impact of screening mammography and adjuvant therapy on these trends. This model was developed within the Cancer Intervention and Surveillance Network (CISNET) consortium. METHOD: A Monte Carlo simulation is developed to generate the life history of individual breast cancer patients by using CISNET base case inputs that describe the secular trend in breast cancer risk, dissemination patterns for screening mammography and adjuvant treatment, and death from causes other than breast cancer. The model generates the patient's age, tumor size and stage at detection, mode of detection, age at death, and cause of death (breast cancer versus other) based in part on assumptions on the natural history of breast cancer. Outcomes from multiple birth cohorts are summarized in terms of breast cancer mortality rates by calendar year. RESULT: Predicted breast cancer mortality rates follow the general shape of U.S. breast cancer mortality rates from 1975 to 1995 but level off after 1995 as opposed to following an observed decline. Sensitivity analysis revealed that the impact adjuvant treatment may be underestimated given the lack of data on temporal variation in treatment efficacy. CONCLUSION: We developed a simulation model that uses CISNET base case inputs and closely, but not exactly, reproduces U.S. breast cancer mortality rates. Screening mammography and adjuvant therapy are shown to have both contributed to a decline in U.S. breast cancer mortality.

Cost-effectiveness of screening BRCA1/2 mutation carriers with breast magnetic resonance imaging.

CONTEXT: Women with inherited BRCA1/2 mutations are at high risk for breast cancer, which mammography often misses. Screening with contrast-enhanced breast magnetic resonance imaging (MRI) detects cancer earlier but increases costs and results in more false-positive scans. OBJECTIVE: To evaluate the cost-effectiveness of screening BRCA1/2 mutation carriers with mammography plus breast MRI compared with mammography alone. DESIGN, SETTING, AND PATIENTS: A computer model that simulates the life histories of individual BRCA1/2 mutation carriers, incorporating the effects of mammographic and MRI screening was used. The accuracy of mammography and breast MRI was estimated from published data in high-risk women. Breast cancer survival in the absence of screening was based on the Surveillance, Epidemiology and End Results database of breast cancer patients diagnosed in the prescreening period (1975-1981), adjusted for the current use of adjuvant therapy. Utilization rates and costs of diagnostic and treatment interventions were based on a combination of published literature and Medicare payments for 2005. MAIN OUTCOME MEASURES: The survival benefit, incremental costs, and cost-effectiveness of MRI screening strategies, which varied by ages of starting and stopping MRI screening, were computed separately for BRCA1 and BRCA2 mutation carriers. RESULTS: Screening strategies that incorporate annual MRI as well as annual mammography have a cost per quality-adjusted life-year (QALY) gained ranging from less than 45,000 dollars to more than 700,000 dollars, depending on the ages selected for MRI screening and the specific BRCA mutation. Relative to screening with mammography alone, the cost per QALY gained by adding MRI from ages 35 to 54 years is 55,420 dollars for BRCA1 mutation carriers, 130,695 dollars for BRCA2 mutation carriers, and 98,454 dollars for BRCA2 mutation carriers who have mammographically dense breasts. CONCLUSIONS: Breast MRI screening is more cost-effective for BRCA1 than BRCA2 mutation carriers. The cost-effectiveness of adding MRI to mammography varies greatly by age.

Ductal lavage of fluid-yielding and non-fluid-yielding ducts in BRCA1 and BRCA2 mutation carriers and other women at high inherited breast cancer risk.

OBJECTIVE: Nipple fluid production and atypical breast duct cells in women at high risk of breast cancer have been associated with further increased risk. Most publications on ductal lavage for cell collection report cannulating fluid-yielding ducts only. We report lavage of fluid-yielding and non-fluid-yielding ducts in women at high inherited breast cancer risk. METHODS: A pilot breast cancer screening study including ductal lavage was conducted in 75 women at high inherited risk, 56 (74.7%) of whom had BRCA1/2 mutations. Ductal lavage was attempted in any duct identifiable with a catheter. RESULTS: Ducts were successfully catheterized in 60 of 75 patients (80%). Successfully catheterized patients were younger (median age 41 versus 53 years, P = 0.0003) and more often premenopausal (51.7% versus 20%, P = 0.041). Thirty-one successfully catheterized patients [51.6%, 95% confidence interval (39.4-63.9%)] had non-fluid-yielding ducts only. Seventeen patients [28.3% (18.5-40.9%)] had atypical cells. Twelve of seventeen [70.6% (46.8-87.2%)] samples with atypia were from non-fluid-yielding ducts. Patients with non-fluid-yielding ducts (versus fluid-yielding ducts) were more likely to have had prior cancer (48.4% versus 17.2%, P = 0.014) or chemotherapy (45.2% versus 17.2%, P = 0.027); this was also true in patients with atypia from non-fluid-yielding ducts. CONCLUSION: Successfully lavaged women were younger and more often premenopausal. Atypical cells can be found in non-fluid-yielding ducts in patients at high inherited breast cancer risk. Non-fluid-yielding ducts, and atypia from non-fluid-yielding ducts, are more common in patients with prior cancer and chemotherapy. Larger studies are needed to identify risk factors and prognostic significance associated with atypia and non-fluid-yielding ducts in high-risk populations, and define their role as biomarkers.

A simulation model to predict the impact of prophylactic surgery and screening on the life expectancy of BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Women with inherited mutations in the BRCA1 or BRCA2 (BRCA1/2) genes are recommended to undergo a number of intensive cancer risk-reducing strategies, including prophylactic mastectomy, prophylactic oophorectomy, and screening. We estimate the impact of different risk-reducing options at various ages on life expectancy. METHODS: We apply our previously developed Monte Carlo simulation model of screening and prophylactic surgery in BRCA1/2 mutation carriers. Here, we present the mathematical formulation to compute age-specific breast cancer incidence in the absence of prophylactic oophorectomy, which is an input to the simulation model, and provide sensitivity analysis on related model parameters. RESULTS: The greatest gains in life expectancy result from conducting prophylactic mastectomy and prophylactic oophorectomy immediately after BRCA1/2 mutation testing; these gains vary with age at testing, from 6.8 to 10.3 years for BRCA1 and 3.4 to 4.4 years for BRCA2 mutation carriers. Life expectancy gains from delaying prophylactic surgery by 5 to 10 years range from 1 to 9.9 years for BRCA1 and 0.5 to 4.2 years for BRCA2 mutation carriers. Adding annual breast screening provides gains of 2.0 to 9.9 years for BRCA1 and 1.5 to 4.3 years for BRCA2. Results were most sensitive to variations in our assumptions about the magnitude and duration of breast cancer risk reduction due to prophylactic oophorectomy. CONCLUSIONS: Life expectancy gains depend on the type of BRCA mutation and age at interventions. Sensitivity analysis identifies the degree of breast cancer risk reduction due to prophylactic oophorectomy as a key determinant of life expectancy gain. IMPACT: Further study of the impact of prophylactic oophorectomy on breast cancer risk in BRCA1/2 mutation carriers is warranted.

A simulation model investigating the impact of tumor volume doubling time and mammographic tumor detectability on screening outcomes in women aged 40-49 years.

BACKGROUND: Compared with women aged 50-69 years, the lower sensitivity of mammographic screening in women aged 40-49 years is largely attributed to the lower mammographic tumor detectability and faster tumor growth in the younger women. METHODS: We used a Monte Carlo simulation model of breast cancer screening by age to estimate the median tumor size detectable on a mammogram and the mean tumor volume doubling time. The estimates were calculated by calibrating the predicted breast cancer incidence rates to the actual rates from the Surveillance, Epidemiology, and End Results (SEER) database and the predicted distributions of screen-detected tumor sizes to the actual distributions obtained from the Breast Cancer Surveillance Consortium (BCSC). The calibrated parameters were used to estimate the relative impact of lower mammographic tumor detectability vs faster tumor volume doubling time on the poorer screening outcomes in younger women compared with older women. Mammography screening outcomes included sensitivity, mean tumor size at detection, lifetime gained, and breast cancer mortality. In addition, the relationship between screening sensitivity and breast cancer mortality was investigated as a function of tumor volume doubling time, mammographic tumor detectability, and screening interval. RESULTS: Lowered mammographic tumor detectability accounted for 79% and faster tumor volume doubling time accounted for 21% of the poorer sensitivity of mammography screening in younger women compared with older women. The relative contributions were similar when the impact of screening was evaluated in terms of mean tumor size at detection, lifetime gained, and breast cancer mortality. Screening sensitivity and breast cancer mortality reduction attributable to screening were almost linearly related when comparing annual or biennial screening with no screening. However, when comparing annual with biennial screening, the greatest reduction in breast cancer mortality attributable to screening did not correspond to the greatest gain in screening sensitivity and was more strongly affected by the mammographic tumor detectability than tumor volume doubling time. CONCLUSION: The age-specific differences in mammographic tumor detection contribute more than age-specific differences in tumor growth rates to the lowered performance of mammography screening in younger women.

Survival analysis of cancer risk reduction strategies for BRCA1/2 mutation carriers.

PURPOSE: Women with BRCA1/2 mutations inherit high risks of breast and ovarian cancer; options to reduce cancer mortality include prophylactic surgery or breast screening, but their efficacy has never been empirically compared. We used decision analysis to simulate risk-reducing strategies in BRCA1/2 mutation carriers and to compare resulting survival probability and causes of death. METHODS: We developed a Monte Carlo model of breast screening with annual mammography plus magnetic resonance imaging (MRI) from ages 25 to 69 years, prophylactic mastectomy (PM) at various ages, and/or prophylactic oophorectomy (PO) at ages 40 or 50 years in 25-year-old BRCA1/2 mutation carriers. RESULTS: With no intervention, survival probability by age 70 is 53% for BRCA1 and 71% for BRCA2 mutation carriers. The most effective single intervention for BRCA1 mutation carriers is PO at age 40, yielding a 15% absolute survival gain; for BRCA2 mutation carriers, the most effective single intervention is PM, yielding a 7% survival gain if performed at age 40 years. The combination of PM and PO at age 40 improves survival more than any single intervention, yielding 24% survival gain for BRCA1 and 11% for BRCA2 mutation carriers. PM at age 25 instead of age 40 offers minimal incremental benefit (1% to 2%); substituting screening for PM yields a similarly minimal decrement in survival (2% to 3%). CONCLUSION: Although PM at age 25 plus PO at age 40 years maximizes survival probability, substituting mammography plus MRI screening for PM seems to offer comparable survival. These results may guide women with BRCA1/2 mutations in their choices between prophylactic surgery and breast screening.

A natural history model of stage progression applied to breast cancer.

Invasive breast cancer is commonly staged as local, regional or distant disease. We present a stochastic model of the natural history of invasive breast cancer that quantifies (1) the relative rate that the disease transitions from the local, regional to distant stages, (2) the tumour volume at the stage transitions and (3) the impact of symptom-prompted detection on the tumour size and stage of invasive breast cancer in a population not screened by mammography. By symptom-prompted detection, we refer to tumour detection that results when symptoms appear that prompt the patient to seek clinical care. The model assumes exponential tumour growth and volume-dependent hazard functions for the times to symptomatic detection and stage transitions. Maximum likelihood parameter estimates are obtained based on SEER data on the tumour size and stage of invasive breast cancer from patients who were symptomatically detected in the absence of screening mammography. Our results indicate that the rate of symptom-prompted detection is similar to the rate of transition from the local to regional stage and an order of magnitude larger than the rate of transition from the regional to distant stage. We demonstrate that, in the even absence of screening mammography, symptom-prompted detection has a large effect on reducing the occurrence of distant staged disease at initial diagnosis.