Annual Meeting Proceedings Part 1 - American Society of Clinical ...

386s Health Services Research
6016 Poster Discussion Session (Board #4), Tue, 8:00 AM-12:00 PM and
11:30 AM-12:30 PM
Refused versus recommended adjuvant chemotherapy in the United States: A
reason for concern. Presenting Author: Elizabeth Butzer Habermann, Department
of Surgery, University of Minnesota, Minneapolis, MN
Background: We designed this study to identify factors driving treatment
recommendations and refusal in surgically treated patients with gastrointestinal
(GI) cancers eligible for adjuvant chemotherapy. Methods: Using the 2001-2008
California Cancer Registry (CCR), we constructed a cohort of 22,469 patients
surgically treated for three GI cancers and eligible for adjuvant chemotherapy
(stage III colon cancer in patients � 80 years, Ib-IVM0 gastric cancer, or
nonmetastatic resected pancreatic adenocarcinoma). Information on chemotherapy
receipt, recommendation, and refusal was utilized to construct our
outcome measures. Multivariate logistic regression models identified predictors
of recommendation and refusal of adjuvant chemotherapy across three GI cancer
sites, adjusting for potential confounders. Results: Of those eligible for adjuvant
therapy, only 61.4% were recommended treatment and 54.3% received it.
Refusal rate was 3.5%. Persons who were older, black, publicly insured or
uninsured, or with gastric cancers were less likely to have adjuvant chemotherapy
recommended. Yet, older, Medicaid-insured, and those treated for
gastric cancer were more likely to refuse adjuvant therapies. Women were as
likely as men to be recommended adjuvant therapies but more likely to refuse
them (Table). Conclusions: Many patients eligible for adjuvant chemotherapy
after GI cancer surgery have not been so advised. Striking variations exist
between recipients of treatment recommendations versus those who refuse
them. These results demonstrate a wide implementation gap between the
recommendations arising from cancer clinical trials versus actual clinical
practice.
Age
75-79 vs. 18-64
Race
Black vs. white
Gender
Female vs. male
Insurance status
Medicaid vs. private
Medicare vs. private
Disease site
Colon vs. pancreas
Gastric vs. pancreas
Adjuvant chemotherapy
recommended vs. other
odds ratio (95% CI)
0.38
(0.34-0.41)
0.80
(0.72-0.89)
1.06
(1.00-1.12)
0.85
(0.76-0.96)
0.86
(0.80-0.92)
1.56
(1.43-1.70)
0.68
(0.62-0.75)
Adjuvant chemotherapy
refused vs. received
odds ratio (95% CI)
5.93
(4.46-7.88)
1.18
(0.82-1.70)
1.36
(1.12-1.66)
1.65
(1.13-2.42)
0.88
(0.70-1.10)
1.17
(0.84-1.62)
1.82
(1.28-2.59)
6018 Poster Discussion Session (Board #6), Tue, 8:00 AM-12:00 PM and
11:30 AM-12:30 PM
Use of palliative chemotherapy and targeted agents in elderly patients with
metastatic colorectal cancer (mCRC). Presenting Author: Matthew Chan,
British Columbia Cancer Agency, Vancouver, BC, Canada
Background: Elderly patients are increasingly diagnosed with advanced
cancers, but they are consistently underrepresented in clinical trials, which
may lead to undertreatment. Our aims were to 1) evaluate the impact of
advanced age on patterns of first-line chemotherapy and bevacizumab use
in mCRC, 2) examine the reasons for treatment choices and 3) compare
adverse events and treatment discontinuations in elderly vs young patients.
Methods: A random sample of mCRC patients diagnosed from 2006 to
2007 and referred to any 1 of 5 regional cancer centers in British
Columbia, Canada was reviewed. Summary statistics were used to describe
treatment patterns between the elderly (�/�70 years) and young (�70
years). Cox regression was used to determine the effect of systemic therapy
on overall survival, controlling for age and confounders. Results: We
identified 800 patients: 43% elderly and 57% young; 56% men; and 26 /
36/38%ECOG0/1/2�, respectively. Fewer elderly patients were given
chemotherapy (52% vs 79%, p�0.001). Among those treated, most
common first-line palliative regimens for elderly vs young included:
capecitabine (50 vs 15%), FOLFIRI (26 vs 38%), and FOLFOX (15 vs
37%) (all p�0.001). Those aged �/�70 were also less likely to receive
bevacizumab in their regimens (22 vs 50%, p�0.001). The most frequent
reasons for no systemic therapy were similar between age groups: patient
choice (31 vs 28%), poor ECOG (16 vs 17%), and significant co-morbidity
(11 vs 13%). Risk of chemotherapy (p�0.30) and bevacizumab (p�0.39)
adverse events were comparable between elderly and young as were rates of
early chemotherapy (p�0.07) and bevacizumab (p�0.79) discontinuation.
Receipt of systemic therapy �/- bevacizumab was associated with
improved survival from mCRC (HR for death 0.50, 95% CI 0.31-0.62,
p�0.001), regardless of advanced age (p interaction for age and treatment
� 0.33). Conclusions: Elderly patients with mCRC are more likely to receive
no chemotherapy, capecitabine monotherapy, or a regimen without bevacizumab.
However, in carefully selected elderly patients, adverse events,
treatment discontinuations, and overall survival benefit from treatment
appear similar to those observed for younger patients.
6017 Poster Discussion Session (Board #5), Tue, 8:00 AM-12:00 PM and
11:30 AM-12:30 PM
Endocrine therapy use among Medicaid-insured breast cancer survivors
with hormone receptor-positive tumors. Presenting Author: Racquel Elizabeth
Kohler, University of North Carolina at Chapel Hill, Chapel Hill, NC
Background: Estrogen receptor positive (ER�) and progesterone receptor
positive (PR�) cancers account for the majority of breast cancer diagnoses
and deaths. Among women with ER� or PR� breast cancers, endocrine
therapy (ET) is the cornerstone of adjuvant therapy and reduces 5-year risk
of recurrence by as much as 40%. Observational studies in Medicare and
privately-insured populations suggest that ET is underutilized. We sought
to characterize ET use in a low-income Medicaid-insured population in
North Carolina. Methods: We used Medicaid claims data matched to NC
Central Cancer Registry records for women ages 18-64 diagnosed with in
situ, stage I or II breast cancer from 2003-2007. We excluded dual
eligibles and included only cases enrolled in Medicaid for at least 12 of the
15 months following the index diagnosis. We defined our outcome as
receipt of any ET medication (tamoxifen, letrozole, exemestane, or anastroxole)
in prescription claims during the 15-month period post-diagnosis,
among women with ER� or PR� disease. In multivariate logistic regressions,
independent variables included age, race, tumor characteristics,
receipt of other breast cancer treatments, co-morbidity, rural/urban residence,
reason for Medicaid eligibility, involvement in the Breast and
Cervical Cancer Control Program (BCCCP), patient-centered medical home
enrollment, and diagnosis year. Results: Of the 269 women who met
inclusion/exclusion criteria and were ER� or PR�, only 45% filled a
prescription for ET during the study period. In multivariate analyses, being
involved in the CDC-affiliated BCCCP was significantly associated with
higher likelihood of receipt of guideline-recommended endocrine therapy
(Marginal Effect: 0.299, p�0.01), but other independent variables were
not significantly correlated with receipt of ET. Conclusions: Results suggest
that ET is substantially underutilized in this low-income, vulnerable
population and that intervention efforts to improve ET use may be
important. Qualitative research is needed to understand the more nuanced,
behavioral reasons for ET underuse, which may be related to symptom
burden, cost, and patient-provider communication.
6019 Poster Discussion Session (Board #7), Tue, 8:00 AM-12:00 PM and
11:30 AM-12:30 PM
An assessment of the collective efforts of clinical trials to provide
evidence-based practice guidelines in cancer care. Presenting Author:
Shane Lloyd, Yale University School of Medicine, New Haven, CT
Background: It is unclear how many of the recommendations in the National
Comprehensive Cancer Network (NCCN) guidelines are based Category 1
(C1: “high level evidence”), or whether current cancer research efforts are
focusing on the knowledge gap between guidelines and supporting evidence.
We defined the knowledge gap as the percent of NCCN recommendations
based on lower levels of evidence, and assessed the relation
between the knowledge gap and cancer research efforts in terms of clinical
trial enrollment. Methods: We examined the active, phase 3 randomized
controlled trials (RCTs) listed on clinicaltrials.gov for the 17 most prevalent
solid tumors. We used the NCCN guidelines to tally the percentage of C1
recommendations. We used the Pearson coefficient and linear regression to
examine whether enrollment in active phase 3 RCTs is associated with 1)
the knowledge gap and 2) measures of burden to society including
prevalence, incidence, person years life lost (PYLL) and disability adjusted
life years (DALY). Results: We identified 834 treatment recommendations
for the 17 included cancer types. Overall, 15% of the NCCN recommendations
were rated as C1, varying from 40% for hepatobiliary to 0% for
endometrial cancer. There was no association between RCT enrollment and
the proportion of C1 recommendations in univariate or multivariate
analyses. RCT enrollment positively correlated with measures of burden to
society including prevalence (p-value � 0.001), incidence (p-value 0.001),
and DALY (p-value 0.038). Breast and prostate cancers have a large
amount of RCT enrollment per PYLL and a relatively small knowledge gap.
Melanoma, ovarian, and endometrial cancers have a moderate amount of
RCT enrollment per PYLL and a relatively large knowledge gap. Lung,
esophagus, bladder and CNS cancers have a low amount of RCT enrollment
per PYLL and a moderate to large knowledge gap. Conclusions: RCT
enrollment is not correlated to the knowledge gap. Current planned
enrollment in RCTs is partially predicted by burden to society, with the
strongest correlation to incidence and prevalence. Most recommendations
in the NCCN guidelines are not based on C1 evidence.
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