UC Irvine

Background: Significant racial and socioeconomic disparities persist in the survival of

patients with select cancers in California. There are a limited number of studies that have

evaluated the association between National Comprehensive Cancer Network (NCCN)

guideline adherent care and survival across different cancer types. We aim to assess the

relationship between race/ethnicity, socioeconomic status (SES), insurance type and the

likelihood of receiving NCCN guideline adherent care and its association with cancer-specific

survival.

Objectives: To determine the relationship between NCCN guideline adherence and disease-specific survival across selected cancer types. Our secondary objective is to better understand the association of race/ethnicity, socioeconomic status, payer type, and disease characteristics with the receipt of NCCN guideline adherent care.

Methods: This was a retrospective population-based cohort study of patients with one of

eight different types of invasive cancer using the California Cancer Registry. A total of

543,198 patients were identified with invasive cancer between 2004-2017 (breast,

n=189,311; prostate, n=156,502; colon, n=80,102; rectal, n=30,118; liver, n=25,857; gastric,

n=22,066; ovary, n=22,551; and cervix, n=16,691). Adherence with NCCN guideline care was

defined by histology and stage-appropriate surgical procedures, radiation, and chemo- or

hormonal therapies. Multivariate logistic regression was used to evaluate the relationship

between the patient’s race/ethnicity, SES, insurance type, and NCCN guideline adherence.

Disease-specific survival analysis was performed using multivariate proportional hazards

model.

Results: A total of 543,198 patients were identified with invasive cancer from 2004 to 2017

(cases by disease: breast 189,311, prostate 156,502, colon 80,102, rectal 30,118, liver 25,857,

gastric 22,066, ovary 22,551, and cervix 16,691). Overall, less than half of patients (47.5%)

received guideline-adherent care and this proportion varied by disease type (30-80%). Non-

adherent treatment was associated with worse survival across all cancer types: breast (HR

1.28, 95%CI=1.23-1.33), prostate (HR 1.31, 95%CI=1.22-1.41), colon (HR 1.73, 95%CI=1.67

1.78), rectal (HR 1.52, 95%CI=1.41-1.63), liver (HR 2.52, 95%CI=2.42-2.63), ovary (HR 1.32,

95%CI=1.26-1.38), gastric (HR 2.38, 95%CI=2.28-2.49), and cervical cancer (HR 1.17,

95%CI=1.08-1.26). In multivariate models, Black patients were less likely to receive guideline

adherent care for breast (OR 0.88, 95% CI 0.84-0.92), prostate (OR 0.90, 95% CI 0.86-0.93),

colon (OR 0.86, 95% CI 0.80-0.92), and ovarian cancer (OR 0.71, 95% CI 0.62-0.82) compared

to White patients. Hispanic patients were less likely to receive guideline-adherent care for

breast (OR 0.91, 95%CI=0.88-0.93) and liver cancer (OR 0.86, 95%CI=0.80-0.91), compared to

White patients. Medicaid payer status was also associated with lower guideline

adherence for breast (OR 0.81, 95% CI 0.78-0.84), prostate (OR 0.91, 95% CI 0.86-0.97), colon (OR 0.70, 95% CI 0.65-0.75), rectal (OR 0.91, 95% CI 0.83-0.99), gastric (OR 0.69, 95% CI 0.63-0.75), and liver cancer (OR 0.66, 95% CI 0.61-0.72), compared to managed care insurance type. Patients in the lowest socioeconomic group were less likely to receive guideline adherent care across all cancer types compared to the highest SES group (breast OR 0.77, 95%CI 0.74-0.80; prostate OR 0.86, 95%CI 0.82-0.89; colon OR 0.50, 95%CI 0.46-0.53; rectal OR 0.79, 95%CI 0.72-0.86; liver OR 0.61, 95%CI 0.55-0.67; gastric OR 0.54, 95%CI 0.48-0.59; ovary OR 0.60, 95%CI 0.54-0.67; cervix OR 0.86, 95%CI 0.77-0.97).

Conclusion: Less than half of cancer patients received NCCN guideline adherent care and

non-adherence was associated with an increased disease-specific mortality. There was an

incremental relationship observed between SES and the likelihood of receiving guideline

adherent care. Individuals less likely to receive guideline adherent care also included patients

of Black or Hispanic race and those with Medicaid or Medicare insurance coverage.