Association of rurality with survival and receipt of treatment in - - PowerPoint PPT Presentation

Association of rurality with survival and receipt of treatment in early- stage non-small cell lung cancer

Charles D. Nicoli, B.S. Brian L. Sprague, Ph.D. Nataniel H. Lester-Coll, M.D.

Disclosures

• No conflicts of interest
• University of Vermont Institutional Review Board

Not Human Subjects Exemption: 18-0075

Background

• Rural populations make up ~20% of the U.S.1
• Rural areas of the U.S. are experiencing negative

population growth.2

• Recent decreasing trend of lung cancer mortality

has been less pronounced in rural areas.3-5

• Inconsistent findings of rurality’s impact on lung

cancer outcomes.3,4,7-10

• Stage I NSCLC is amenable to intervention with

established treatment paradigm (lobectomy + mediastinal LN dissection or SBRT).6

Methods: Data and Analysis

• National Cancer Data Base (NCDB): joint venture
• f American College of Surgeons, American

Cancer Society

• Captures ~70% of invasive cancers in the U.S.
• In 2005, captured estimated 82.1% of invasive

lung & bronchus cancers in the U.S.11

Survival Analysis

• Unadjusted Survival
• Log-Rank test, Kaplan-Meier method, Cox

proportional-hazards model12

• Multivariable survival modeling
• Cox proportional-hazards model.12
• Preceded by stepwise logistic regressions, included as

covariates those associated with survival at p < 0.05

Methods: Guidelines-Concordant Treatment

• Surgical: lobectomy with mediastinal lymph node

dissection.13,14

• Stereotactic Body Radiation Therapy (SBRT):
• Defined according to Corso et al., 2017:13,15
• Treatment modality: radiation therapy and

not surgery

• BED10 between 40 and 300 Gy
• < 10 fractions
• No guidelines-concordant treatment: neither

lobectomy w/LN dissection nor SBRT

Methods: Defining Rurality

• NCDB includes the USDA’s Rural-Urban Continuum Codes

(RUCC), 2013 version, in defining rurality of patient residence

Source: USDA, Economic Research Service using Data from the U.S. Census Bureau [16]

1 2 3 7 8 9 4 5 6

Figure 1: Creating a Rural Dichotomy

Methods: Defining Rurality

Source: USDA, Economic Research Service using Data from the U.S. Census Bureau [16]

1 2 3 7 8 9 4 5 6

Methods: Defining Rurality

Source: USDA, Economic Research Service using Data from the U.S. Census Bureau [16]

Rural Non-Rural

Figure 2. Exclusion Criteria

Sample Characteristics

• 81.3% Non-Rural, 18.7% Rural

Non-Rural Rural Overall n % n % n % AJCC Stage at Diagnosis Stage I 149,000 21.8 33,278 21.2 182,278 21.7 Stage II 45,972 6.7 11,842 7.5 57,814 6.9 Stage III 161,418 23.6 39,161 25.0 200,579 23.9 Stage IV 327,215 47.9 72,680 46.3 399,895 47.6

χ2 p < 0.001

Sample Characteristics

Rural patients of all stages (χ2 p < 0.001):

• More male (57.3% vs. 52.5%)
• More white (90.4% vs 79.0%)
• Lived in areas of lower median annual

income (< $38K; 38.2% vs. 17.6%)

• Lived in areas of lower education level

(>21% no H.S. diploma; 28.8% vs 17.6%)

• More often received cancer care at

community facilities (77.5% vs. 66.7%)

• Less often had private insurance payor

(24.0% vs. 30.1%)

Comorbidities

• Measured by Charlson-Deyo Comorbidities Score

(CDS)

All Stages Non- Rural Rural Overall CDS % 58.9 54.8 58.8 1 28.0 31.2 28.1 2 9.5 10.4 9.5 3+ 3.6 3.7 3.6

χ2 p < 0.001

Stage I Non- Rural Rural Overall % 52.2 48.5 51.5 32.4 34.2 32.8 11.4 13.0 11.7 4.0 4.3 4.0

χ2 p < 0.001

Receipt of Guideline-Concordant Treatment

Non-Rural Rural Total n % n % n % Lobectomy 58,522 39.3 11,917 35.8 70,439 38.7 SBRT 16,196 10.9 3,682 11.1 19,878 10.9 No Guideline- Concordant Treatment 74,247 49.8 17,669 53.1 91,916 50.4 Total 148,965 100 33,268 100 182,233 100

χ2 p < 0.001

Unadjusted Cox PH Model

Median OS (months) Non Rural-Rural

• Diff. (months)

HR (rural) LR p

All Stages Non-Rural

11.24 1.06 1.079 <0.0001

Rural

10.18

Total

11.04

Stage I Non-Rural

61.37 11.07 1.184 <0.0001

Rural

50.3

Total

59.17

Stage II Non-Rural

25.03 1.83 1.069 <0.0001

Rural

23.2

Total

24.57

Stage III Non-Rural

12.81 0.85 1.076 <0.0001

Rural

11.96

Total

12.65

Stage IV Non-Rural

5.22 0.39 1.097 <0.0001

Rural

4.83

T otal

5.16

Unadjusted Survival

Figure 3. Unadjusted Survival: Stage I

Multivariable Model: Stage I

HR 95% CI p HR 95% CI p Sex (ref: Male) Age 1.035 1.034, 1.036 <0.001 Female 0.715 0.704, 0.726 <0.001 Charlson-Deyo Score (ref: CDS = 0) Guideline-Concordant Treatment (ref: none) 1 1.097 1.079, 1.115 <0.001 Lobectomy 0.482 0.473, 0.490 <0.001 2 1.322 1.292, 1.352 <0.001 SBRT 0.950 0.927, 0.973 <0.001 3+ 1.677 1.620, 1.736 <0.001 Median Annual Income (ref: < $38,000) Insurance Payor (ref: Private) ≥ $38,000 0.935 0.915, 0.956 <0.001 Medicare 1.186 1.160, 1.212 <0.001 Education (ref: ≥ 21% lack HS diploma) Medicaid 1.566 1.504, 1.631 <0.001 < 21% Lack HS Diploma 0.919 0.898, 0.939 <0.001 Other Gov't Insur 1.237 1.159, 1.319 <0.001 Race (ref: White) Uninsured 1.387 1.302, 1.477 <0.001 Black 1.060 1.032, 1.090 <0.001 Location (ref: Northeast) Hispanic 0.794 0.751, 0.838 <0.001 Southeast 1.153 1.127, 1.180 <0.001 Asian 0.704 0.660, 0.751 <0.001 Midwest 1.164 1.137, 1.192 <0.001 Other 0.900 0.844, 0.960 0.001 West 1.117 1.085, 1.149 <0.001 Distance to Treatment Ctr 0.929 0.904, 0.955 <0.001 Pacific 1.058 1.026, 1.091 <0.001 Facility Type (ref: Community) Academic Medical Center 0.890 0.875, 0.906 <0.001 Rurality (ref: non-rural) Rural 1.085 1.062, 1.108 <0.001

Conclusions

Rural patients with Stage I NSCLC:

• 1. Have a survival disparity of 11.07 months

compared to non-rural patients

• 2. Have greater comorbidities at baseline
• 3. Less often received any form of accepted

treatment (neither lobectomy nor SBRT)

• 4. Less often underwent first-line management with

lobectomy

• 5. Rurality is an independent risk factor for

decreased survival in multivariable modeling.

Limitations

• Selection bias
• NCDB does not include data on history of:
• Tobacco use
• Alcohol and drug use
• Occupational exposures
• Diet & exercise
• Well-established difficulty in defining rurality
• Did not consider adjuvant therapy or sublobar

resections or other ablative procedures in stage I (substandard care)

Implications

• Increased provision of treatment according to

guidelines in rural patients with stage I NSCLC

• Rural public health interventions aimed at

decreasing burden of chronic health conditions ( ↓ comorbidities)

• Next steps:
• Large-database multivariable modeling

incorporating smoking as a covariate

• Temporal analysis of rural stage I survival

disparity

Acknowledgements

Mentors:

• Nataniel H. Lester-Coll, M.D.
• Brian L. Sprague, Ph.D.

References

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Questions?

Figure 3. Unadjusted Survival: All Stages

Multivariable Model: All-Stage

HR 95% CI p HR 95% CI p Median Annual Income (ref: < $38,000) Age 1.010 1.009, 1.010 <0.001 ≥ $38,000 0.951 0.939, 0.962 <0.001 Charlson-Deyo Score (ref: CDS = 0) Race (ref: White) 1 1.136 1.125, 1.147 <0.001 Black 0.921 0.908, 0.933 <0.001 2 1.265 1.247, 1.283 <0.001 Hispanic 0.759 0.740, 0.779 <0.001 3+ 1.456 1.425, 1.486 <0.001 Asian 0.671 0.653, 0.690 <0.001 Education (ref: ≥ 21% lack HS diploma) Other 0.821 0.793, 0.851 <0.001 < 21% Lack HS D1.015 1.002, 1.027 0.019 Sex (ref: Male) Insurance Payor (ref: Private) Female 0.800 0.793, 0.806 <0.001 Medicare 1.105 1.093, 1.118 <0.001 Facility Type (ref: Community) Medicaid 1.216 1.196, 1.236 <0.001 Academic Medical Center 0.886 0.878, 0.895 <0.001 Other Gov't Insur 1.041 1.008, 1.075 0.014 Distance to Treatment Ctr 0.928 0.913, 0.942 <0.001 Uninsured 1.236 1.210, 1.263 <0.001 Location (ref: Northeast) Treatment (ref: no treatment) Southeast 1.086 1.073, 1.100 <0.001 Surgery 0.264 0.258, 0.269 <0.001 Midwest 1.125 1.111, 1.139 <0.001 Radiation Therapy 0.771 0.790, 0.781 <0.001 West 0.975 0.960, 0.991 0.002 Chemotherapy 0.371 0.367, 0.375 <0.001 Pacific 1.046 1.029, 1.064 <0.001 Stage at Diagnosis (ref: Stage I) Stage II 1.878 1.840, 1.917 <0.001 Stage III 3.057 3.005, 3.110 <0.001 Stage IV 6.320 6.220, 6.422 <0.001 Rurality (ref: non-rural) Rural 1.078 1.065, 1.090 <0.001