A registry study of the association of patient's residence and age with colorectal cancer survival

Abstract

Because of limited literature from rural states of the United States like Nebraska, we evaluated the association of patient's age, Office of Management and Budget residence-county categories (rural-nonmetro, micropolitan-nonmetro, urban), and significant interactions between confounding-variables with colorectal cancer (CRC) survival. This retrospective 1998–2003 study of 6561 CRC patients from the Nebraska Cancer Registry showed median patient survival in colon and rectal cancer in urban, rural and micropolitan counties were 33, 36, and 46 months and 41, 47, 49 months, respectively. In Cox proportional-hazards analyses, after adjusting for significant demographics (age, race, marital status in colon cancer; age, insurance status in rectal cancer), cancer stage, surgery and radiation treatments; 1) no-chemotherapy urban colon cancer patients had significantly shorter survival (rural vs urban; adjusted hazard ratio, HR: 0.78 or urban vs rural HR: 1.28; micropolitan vs urban, HR: 0.78) and 2) no-surgery urban (vs rural, HR: 1.49); micropolitan (vs rural, HR: 2.01) rectal cancer patients had significantly shorter survival. Colon cancer (≥65 years) and rectal cancer (≥75 years) elderly each versus patients aged 19–64 years old had significantly shorter survival (all p < 0.01). The association of patients' age and treatment/residence-county interactions with CRC survival warrant decision-makers' attention.

Keywords::

• colorectal-cancer
• micropolitan
• Nebraska cancer registry
• Office of Management and Budget coded residence-county
• rural
• survival
• urban

Authors' contributions

All authors conceived and designed the study. J Sankaranarayanan and S Watanabe-Galloway gained ethical approval. S Watanabe-Galloway got access to the data for the study. F Qiu carried out the analysis of the data. J Sankaranarayanan, F Qiu and S Watanabe-Galloway were involved in writing the initial draft of the manuscript. All authors (J Sankaranarayanan, F Qiu and S Watanabe-Galloway) reviewed and revised the final paper for intellectual content.

Acknowledgements

The authors would like to acknowledge C Schmidt at the McGoogan Library of Medicine from the University of Nebraska Medical Center who reviewed our paper and provided editorial assistance.

Financial & competing interests disclosure

This study was funded by Nebraska Health and Human Services to investigators from the University of Nebraska Medical Center. The sponsors had no role in article preparation – study design/data analysis/statistical input/review of drafts/writing of the article/identification of papers for inclusion/any other form of input. This work was carried out when primary corresponding author was employed full time as Assistant Professor with Department of Pharmacy Practice, College of Pharmacy at the University of Nebraska Medical Center in Omaha, NE. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Colorectal cancer (CRC) is the second most frequent cause of cancer-related morbidity and mortality in the USA after lung cancer.

• Literature is limited from rural states of the USA like Nebraska on whether elderly versus younger patients, and rural versus nonrural patients have shorter survival in CRC.

• Earlier studies using the Nebraska Cancer Registry data showed that rural patients were less likely to have early stage CRC diagnosis, and elderly patients were less likely to undergo surgery, radiation and chemotherapy.

• Our 5-year retrospective study of the Nebraska Cancer Registry data showed that median CRC survival was lowest for urban county followed by rural county and was highest for micropolitan county patients.

• Using Cox proportional hazards analyses, we evaluated the association of age, three-category measure (rural, micropolitan, urban) of geographical access for patient's residence and interactions of treatment and patient residence with CRC survival.

• After adjusting for significant patient characteristics including cancer stage, our study suggests:

  • – No-chemotherapy urban colon cancer patients and no-surgery urban rectal cancer patients had significantly shorter survival compared with their rural and micropolitan counterparts, and

  • – Elderly CRC patients had significantly shorter survival compared with younger patients.

  • – Newer CRC treatments' effectiveness on survival in high-risk populations of elderly (vs young) and their effectiveness by treatment in patient residence (rural [vs nonrural]) will need further study. Future evaluations will be informative to providers, payers and policymakers to help balance cost, access and quality in the delivery of patient-centered care.