Naimish B. Pandya

Analysis of local control in patients receiving IMRT for resected pancreatic cancers.

PURPOSE Intensity-modulated radiotherapy (IMRT) is increasingly incorporated into therapy for pancreatic cancer. A concern regarding this technique is the potential for geographic miss and decreased local control. We analyzed patterns of first failure among patients treated with IMRT for resected pancreatic cancer. METHODS AND MATERIALS Seventy-one patients who underwent resection and adjuvant chemoradiation for pancreas cancer are included in this report. IMRT was used for all to a median dose of 50.4 Gy. Concurrent chemotherapy was 5-FU-based in 72% of patients and gemcitabine-based in 28%. RESULTS At median follow-up of 24 months, 49/71 patients (69%) had failed. The predominant failure pattern was distant metastases in 35/71 patients (49%). The most common site of metastases was the liver. Fourteen patients (19%) developed locoregional failure in the tumor bed alone in 5 patients, regional nodes in 4 patients, and concurrently with metastases in 5 patients. Median overall survival (OS) was 25 months. On univariate analysis, nodal status, margin status, postoperative CA 19-9 level, and weight loss during treatment were predictive for OS. On multivariate analysis, higher postoperative CA19-9 levels predicted for worse OS on a continuous basis (p < 0.01). A trend to worse OS was seen among patients with more weight loss during therapy (p = 0.06). Patients with positive nodes and positive margins also had significantly worse OS (HR for death 2.8, 95% CI 1.1-7.5; HR for death 2.6, 95% CI 1.1-6.2, respectively). Grade 3-4 nausea and vomiting was seen in 8% of patients. Late complication of small bowel obstruction occurred in 4 (6%) patients. CONCLUSIONS This is the first comprehensive report of patterns of failure among patients treated with adjuvant IMRT for pancreas cancer. IMRT was not associated with an increase in local recurrences in our cohort. These data support the use of IMRT in the recently activated EORTC/US Intergroup/RTOG 0848 adjuvant pancreas trial.

Trends in Disparities in Receipt of Adjuvant Therapy for Elderly Stage Iii Colon Cancer Patients: The Role of the Medical Oncologist Evaluation

Background:Race disparities in adjuvant chemotherapy for stage III colon cancer patients have been documented, and medical oncologist evaluation is a critical step in the treatment process. Recent healthcare system and environmental changes may have reduced treatment gaps. Objectives:To examine differential rates of oncologist evaluation and conditional treatment, by race, and to determine whether changing evaluation and treatment patterns reduced disparities. Research Design:Retrospective analysis of Surveillance Epidemiology and End Results-Medicare registry, enrollment, and claims data. Subjects:Patients age >65, white or African American race, diagnosed with American Joint Committee on Cancer stage III colon cancer between 1997 and 2002. N = 7176. Key Measures:Oncology specialty evaluation and management visit or chemotherapy claim; receipt of 5-fluorouracil based chemotherapy. Time periods are grouped into early (1997–1998), middle (1999–2000), and late (2001–2002). Results:Initial adjusted oncologist evaluation rates were higher for whites compared with African American patients (58.7% vs. 42.9%), but changes over time reduced the race gap substantially. We did not find significant race-time trends in treatment rates conditional on oncologist evaluation. Conclusions:Race disparities in medical oncologist evaluations diminished over time, possibly in response to increased provider supply or changing patient and provider attitudes, but there was no parallel reduction in disparities in conditional treatment rates. Projected decreases in oncologist supply suggest the need for further research on this relationship. Research on the role of supplemental medical insurance on disparities in treatment is needed, particularly as the cost of recommended adjuvant therapy increases.

Comparative Effectiveness of Different Chemotherapeutic Regimens on Survival of People Aged 66 and Older with Stage III Colon Cancer:: A Real World Analysis Using Surveillance, Epidemiology, and End Results-Medicare Data

OBJECTIVES: To compare the effectiveness and utilization trends of irinotecan (IRI)‐based and oxaliplatin (OX)‐based regimens with those of 5‐fluorouracil and leucovorin (5FU/LV) alone in people aged 66 and older with Stage III colon cancer.

Chemotherapy treatment and survival in older women with estrogen receptor-negative metastatic breast cancer: a population-based analysis.

To investigate the survival benefit associated with chemotherapy receipt in older women with estrogen receptor–negative (ER–) Stage IV breast cancer.

Comparative and cost-effectiveness of oxaliplatin-based or irinotecan-based regimens compared with 5-fluorouracil/leucovorin alone among US elderly stage IV colon cancer patients.

Clinical trials have shown a statistically significant disease‐free survival benefit of oxaliplatin‐based or irinotecan‐based combination regimens for stage IV colon cancer. Less is known regarding the comparative effectiveness and cost‐effectiveness of these agents among elderly patients. Whether the benefits of these agents justify the additional costs for elderly Medicare recipients is particularly policy relevant after US health care reform.

Validation of a claims-based predicted performance status measure in SEER-Medicare.

6085 Background: Observational studies analyzing cancer treatment and outcomes in datasets such as Surveillance, Epidemiology and End Results (SEER)-Medicare are unable to capture performance status (PS), a key determinant of treatment. In prior work we developed a multivariate regression model to predict poor PS (ECOG 3-4 versus 0-2) as a function of claims-based service use indicators. We report on initial predictive validation of our model by examining chemotherapy treatment in a cohort of metastatic breast cancer (MBC) patients. METHODS 1,519 female estrogen receptor negative MBC patients aged ≥66 were identified in 1999-2005 SEER registry data linked to Medicare Part A and B claims. We generated the predicted probability of poor PS (PredPS) by creating the set of service use indicators from Medicare Part B claims one year before diagnosis and applying coefficients from the prediction model. We examined the relationship of PredPS to age, race, socioeconomic status, and the Charlson Comorbidity Index (CCI). We also included PredPS as either a discrete (Good/ Poor) or continuous variable in multivariate logistic regressions to predict receipt of chemotherapy within 6 months following diagnosis, obtained from Medicare claims. RESULTS 258 (17%) had poor PredPS; 494 women (33%) received chemotherapy. Poor PredPS patients were less likely to receive chemotherapy (17% versus 36%; p<0.01); poor PredPS was more prevalent among non whites (31% versus 14% for whites; p<0.01), and the oldest (29% among 85+ versus 14% among patients aged 66-74 years). After adjusting for sociodemographics and CCI, MBC women with poor PredPS were 56% less likely to receive chemotherapy (OR 0.44, 95% CI 0.25, 0.77). Models with continuous PredPS showed that a 1% increase in poor predPS resulted in a 3% decrease in odds of receiving chemotherapy (OR 0.97, 95% CI 0.96, 0.99). Results were similar with alternative PredPS developed from models that included interactions with region and with Medicaid enrollment. CONCLUSIONS A predicted PS measure derived from Medicare claims was associated with receipt of chemotherapy and this effect appears to be independent of sociodemographics and CCI. Ongoing analyses will validate predPS in cancer survival models.

Comparative effectiveness of adjuvant oxaliplatin and irinotecan-based chemotherapy regimens among elderly stage III colon cancer patients completing 12 cycles.

e14069 Background: Randomized controlled trials and real world comparative effectiveness studies have suggested survival benefits with adjuvant oxaliplatin (OX)-based regimen in stage III colon can...

Oxaliplatin- or irinotecan-based combination therapy versus 5-fluorouracil/leucovorin alone in the treatment of advanced colon cancer patients age 66 and older: An analysis using SEER-Medicare data.

3613 Background: Clinical trials have demonstrated a survival benefit of oxaliplatin (OX)- or irinotecan (IRI)-based combination chemotherapy regimens for treatment of stage IV colon cancer patient...

Taxane Treatment in Women with Incident Stage IV Breast Cancer.

Introduction: The overall benefit of chemotherapy for late stage breast cancer treatment has been demonstrated in clinical trials and “real world” observational studies, but there is less data on chemotherapy use among older women. In addition, estrogen receptor status can influence treatment decisions. Our objective was to explore the clinical and demographic characteristics of women who received chemotherapy, particularly taxanes, in a large population-based cohort of older patients with incident stage IV breast cancer.Methods: Older women (age 66 and over) diagnosed with incident stage IV breast cancer from 1999 to 2005 were identified in the Surveillance, Epidemiology and End Results (SEER) cancer registries. Treatment-related data were linked from Medicare claims. We limited our analysis to ER negative (ER-) women with the assumption that these women would not be receiving tamoxifen as SEER data do not have complete information on receipt of tamoxifen. Receipt of chemotherapy was identified from claims files. Bivariate analyses were performed to compare clinical and demographic characteristics of those who received taxanes, other chemotherapy, or no chemotherapy.Results: Of 3,820 older women diagnosed with incident stage IV breast cancer, 1,518 women (40%) were identified as ER negative, of whom 247 (16%) were treated with taxanes, 312 (21%) with other chemotherapy, and the remainder received neither. Mean age was 78, 84% of the study cohort was white, 27% were married, and 91% lived in urban areas. Fifty four percent of women had HER2 assays performed. Women who received taxanes were substantially younger (Mean=74, SD=5.49) than those who did not (Mean=80, SD=7.79) and had fewer co-morbidities (measured by Charlson co-morbidity index) (bivariate [see above] p=0.0003) than any other group. Individuals who received taxanes were less likely to be married, receive radiation or undergo surgery. Only 8% of those treated with taxanes had 2 or more medical conditions compared to 18% of those receiving other chemotherapy and 74% of those with no chemotherapy. Treatment groups varied in regard to some medical conditions including CHF, cerebrovascular disease, and dementia. For example, only 8% of those receiving taxanes had CHF, compared to 13% among the 9other chemotherapy9 group and 78% among those receiving no treatment (bivariate [see above] p=0.0003). A similar trend was revealed with the other medical conditions, with taxane users consistently presenting with lower prevalence for each condition. Interestingly, no one who had dementia received any chemotherapy.Conclusion: Findings from this descriptive study showed that age and co-morbidity were the most important factors associated with receipt of taxanes as well as of other chemotherapy. However, those who received taxanes were the youngest and evidenced the least comorbidity of the 2 groups. Further study is needed to help inform clinicians in making optimum treatment recommendations for their older female patients with incident advanced breast cancer. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2068.

Chemotherapy Treatment and Survival in Estrogen Receptor Negative Metastatic Breast Cancer: A Population-Based Analysis.

Introduction: Although controlled clinical trials have demonstrated a beneficial effect of various chemotherapy regimens on survival in breast cancer (BC), little is known about treatment patterns and survival benefit in the “real world” population of elderly women with metastatic BC. Methods: We identified female Medicare beneficiaries aged ≥66 years with metastatic BC diagnosed from 1999 to 2005 in the Surveillance, Epidemiology and End Results cancer registries (SEER). Patients with a prior history of any cancer were excluded. Treatment-related data were abstracted from linked Medicare claims. Since Medicare claims have incomplete information on oral selective estrogen receptor modulators, we limited our study cohort to estrogen receptor negative (ER-) women. Chemotherapy was defined as the receipt of any chemotherapeutic regimen within 6 months after diagnosis. Initial regimens were characterized based on drugs given during the first 30 days of chemotherapy. We used a continuous-time interval-censored survival analysis to determine the effect of chemotherapy on hazard of any-cause death, controlling for sociodemographic and clinical factors, including proxy measures for performance status. Results: We identified 1518 ER(-) women diagnosed with metastatic BC in SEER. Mean age was 77.6 (SD 7.6) years, 84% were white race and 27% were married at the time of diagnosis. Of the 1518 metastatic ER(-) BC patients, 493 (32%) received chemotherapy. As compared to women who did not receive chemotherapy, women who received chemotherapy were more likely to be younger, married, have lower pre-cancer comorbidity as measured by the Charlson comorbidity index, have seen an oncology specialist and have cancer-directed surgery or radiation prior to chemotherapy. Initial regimens comprised predominantly one (31%) or two (46%) drug classes. The most common regimens were taxanes only (18%), anthracycline+alkylating agents (17%) and antimetabolite+alkylating agent (9%). Overall median followup time was 7 months; 1223 women (81%) died during followup. Median survival time was 5 months among women who did not receive chemotherapy and 15 months among women who received chemotherapy. Chemotherapy was associated with a statistically significant survival benefit (adjusted Hazard Ratio 0.61, 95% confidence interval 0.54, 0.70). Conclusion: In this population-based study of older women, there was a variety of chemotherapy regimens used for metastatic ER(-) BC. Chemotherapy received within 6 months after diagnosis was associated with a 39% reduction in hazard of death. These findings reflect chemotherapy use outside of the clinical trial setting and have important clinical and policy implications for the study of treatments among older women with advanced BC. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2064.