Favoriti P, Carbone G, Greco M, Pirozzi F, Pirozzi REM, Corcione F (2016) Worldwide burden of colorectal cancer: a review. Updat Surg 68(1):7–11. https://doi.org/10.1007/s13304-016-0359-y
Google Scholar
DiSario JA, Burt RW, Kendrick ML, McWhorter WP (1994) Colorectal cancers of rare histologic types compared with adenocarcinomas. Dis Colon Rectum 37(12):1277. https://doi.org/10.1007/BF02257796
Google Scholar
Zhang F, Xu B, Peng Y, Mao Z, Tong S (2023) Incidence and survival of adenocarcinoma with mixed subtypes in patients with colorectal cancer. Int J Colorectal Dis 38(1):215. https://doi.org/10.1007/s00384-023-04508-4
Google Scholar
Benesch MGK, Mathieson A (2020) Epidemiology of signet ring cell adenocarcinomas. Cancers. https://doi.org/10.3390/cancers12061544
Google Scholar
Wan Z, Huang Z, Chen L (2017) Survival predictors associated with signet ring cell carcinoma of the esophagus (SRCCE): a population-based retrospective cohort study. PLoS ONE 12(7):e0181845. https://doi.org/10.1371/journal.pone.0181845
Google Scholar
Zhu Y, Thandar M, Cheng J, Zhang X, Zhao Z, Huang S, Chi P (2023) Comparison of survival outcomes and survival prediction in patients with primary colorectal MANEC and primary colorectal SRCC: a population-based propensity-score matching study. J Cancer Res Clin Oncol 149(14):13279–13300. https://doi.org/10.1007/s00432-023-05043-z
Google Scholar
Huang A, Yang Y, Shi JY, Li YK, Xu JX, Cheng Y, Gu J (2021) Mucinous adenocarcinoma: A unique clinicopathological subtype in colorectal cancer. World J Gastrointest Surg 13(12):1567–1583. https://doi.org/10.4240/wjgs.v13.i12.1567. (PubMed PMID: 35070064; PubMed Central PMCID: PMC8727185)
Google Scholar
Hyngstrom JR, Hu CY, Xing Y, You YN, Feig BW, Skibber JM, Rodriguez-Bigas MA, Cormier JN, Chang GJ (2012) Clinicopathology and outcomes for mucinous and signet ring colorectal adenocarcinoma: analysis from the national cancer database. Ann Surg Oncol 19(9):2814–2821. https://doi.org/10.1245/s10434-012-2321-7
Google Scholar
Hugen N, van de Velde CJH, de Wilt JHW, Nagtegaal ID (2014) Metastatic pattern in colorectal cancer is strongly influenced by histological subtype. Ann Oncol 25(3):651–657. https://doi.org/10.1093/annonc/mdt591. (PubMed PMID: 24504447)
Google Scholar
Horgan D, Van den Bulcke M, Malapelle U, Normanno N, Capoluongo ED, Prelaj A, Rizzari C, Stathopoulou A, Singh J, Kozaric M, Dube F, Ottaviano M, Boccia S, Pravettoni G, Cattaneo I, Malats N, Buettner R, Lekadir K, de Lorenzo F, Alix-Panabieres C, Badreh S, Solary E, De Maria R, Hofman P (2024) Demographic analysis of cancer research priorities and treatment correlations. Curr Oncol 31(4):4. https://doi.org/10.3390/curroncol31040139
Google Scholar
Beckmann KR, Bennett A, Young GP, Cole SR, Joshi R, Adams J, Singhal N, Karapetis C, Wattchow D, Roder D (2016) Sociodemographic disparities in survival from colorectal cancer in South Australia: a population-wide data linkage study. BMC Health Serv Res 16(1):24. https://doi.org/10.1186/s12913-016-1263-3
Google Scholar
Jacobson CE, Harbaugh CM, Agbedinu K, Kwakye G (2024) Colorectal cancer outcomes: a comparative review of resource-limited settings in low- and middle-income countries and rural America. Cancers. https://doi.org/10.3390/cancers16193302
Google Scholar
Sepassi A, Li MA, Zell J, Chan A, Saunders IM, Mukamel DB (2024) Rural–urban disparities in colorectal cancer screening, diagnosis, treatment, and survivorship care: a systematic review and meta-analysis. Oncologist 29(4):e431–e446. https://doi.org/10.1093/oncolo/oyad347
Google Scholar
Carethers JM, Doubeni CA (2020) Causes of socioeconomic disparities in colorectal cancer and intervention framework and strategies. Gastroenterology 158(2):354–367. https://doi.org/10.1053/j.gastro.2019.10.029PubMedPMID:31682851;PubMedCentralPMCID:PMC6957741
Google Scholar
Gomez SL, Shariff-Marco S, DeRouen M, Keegan THM, Yen IH, Mujahid M, Satariano WA, Glaser SL (2015) The impact of neighborhood social and built environment factors across the cancer continuum: current research, methodological considerations, and future directions. Cancer 121(14):2314–2330. https://doi.org/10.1002/cncr.29345
Google Scholar
Kelly RJ, Bever K, Chao J, Ciombor KK, Eng C, Fakih M, Goyal L, Hubbard J, Iyer R, Kemberling HT, Krishnamurthi S, Ku G, Mordecai MM, Morris VK, Paulson AS, Peterson V, Shah MA, Le DT (2023) Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of gastrointestinal cancer. J Immunother Cancer 11(6):e006658. https://doi.org/10.1136/jitc-2022-006658. (PubMed PMID: 37286304; PubMed Central PMCID: PMC10254964)
Google Scholar
Shah R, Chan KKW (2021) The impact of socioeconomic status on stage at presentation, receipt of diagnostic imaging, receipt of treatment and overall survival in colorectal cancer patients. Int J Cancer 149(5):1031–1043. https://doi.org/10.1002/ijc.33622
Google Scholar
Finegan M, Firth N, Wojnarowski C, Delgadillo J (2018) Associations between socioeconomic status and psychological therapy outcomes: a systematic review and meta-analysis. Depress Anxiety 35(6):560–573. https://doi.org/10.1002/da.22765
Google Scholar
Smith RA, Fedewa S, Siegel R (2021). Chapter Three: Early colorectal cancer detection—Current and evolving challenges in evidence, guidelines, policy, and practices. In: Berger FG, Boland CR, editors. Advances in Cancer Research [Internet]. Academic Press; 2021 [cited 2025 Jun 29]. p. 69–107. (Novel Approaches to Colorectal Cancer). Available from: https://www.sciencedirect.com/science/article/pii/S0065230X21000294https://doi.org/10.1016/bs.acr.2021.03.005
Carrera PM, Kantarjian HM, Blinder VS (2018) The financial burden and distress of patients with cancer: understanding and stepping-up action on the financial toxicity of cancer treatment. CA Cancer J Clin 68(2):153–165. https://doi.org/10.3322/caac.21443
Google Scholar
Nze C, Herrera AF (2025) New strategies for enhancing enrollment of underrepresented minorities in lymphoma clinical trials. Blood Adv 9(4):774–782. https://doi.org/10.1182/bloodadvances.2024012981
Google Scholar
Wells JC, Sharma S, Del Paggio JC, Hopman WM, Gyawali B, Mukherji D, Hammad N, Pramesh CS, Aggarwal A, Sullivan R, Booth CM (2021) An analysis of contemporary oncology randomized clinical trials from low/middle-income vs high-income countries. JAMA Oncol 7(3):379–385. https://doi.org/10.1001/jamaoncol.2020.7478
Google Scholar
Sanchez JI, Shankaran V, Unger JM, Madeleine MM, Espinoza N, Thompson B (2022) Disparities in post-operative surveillance testing for metastatic recurrence among colorectal cancer survivors. J Cancer Surviv 16(3):638–649. https://doi.org/10.1007/s11764-021-01057-z
Google Scholar
Lee W, Nelson R, Mailey B, Duldulao MP, Garcia-Aguilar J, Kim J (2012) Socioeconomic factors impact colon cancer outcomes in diverse patient populations. J Gastrointest Surg 16(4):692–704. https://doi.org/10.1007/s11605-011-1809-y
Google Scholar
Liss DT, Baker DW (2014) Understanding current racial/ethnic disparities in colorectal cancer screening in the United States: the contribution of socioeconomic status and access to care. Am J Prev Med 46(3):228–236. https://doi.org/10.1016/j.amepre.2013.10.023
Google Scholar
Manser CN, Bauerfeind P (2014) Impact of socioeconomic status on incidence, mortality, and survival of colorectal cancer patients: a systematic review. Gastrointest Endosc 80(1):42-60.e9. https://doi.org/10.1016/j.gie.2014.03.011. (PubMed PMID: 24950641)
Google Scholar
Chin ZS, Ghodrati A, Foulger M, Demirkhanyan L, Gondi CS (2025) Beyond barriers: achieving true equity in cancer care. Curr Oncol 32(6):349. https://doi.org/10.3390/curroncol32060349. (PubMed PMID: 40558292; PubMed Central PMCID: PMC12191551)
Google Scholar
Ramkumar N, Colla CH, Wang Q, O’Malley AJ, Wong SL, Brooks GA (2022) Association of rurality, race and ethnicity, and socioeconomic status with the surgical management of colon cancer and postoperative outcomes among Medicare beneficiaries. JAMA Netw Open 5(8):e2229247. https://doi.org/10.1001/jamanetworkopen.2022.29247
Google Scholar
Batool DA, Lopez DA (2023) Healthcare access and regional connectivity: bridging the gap. J Reg Connect Dev 2(2):2
Bhatia S, Landier W, Paskett ED, Peters KB, Merrill JK, Phillips J, Osarogiagbon RU (2022) Rural–urban disparities in cancer outcomes: opportunities for future research. JNCI J Natl Cancer Inst 114(7):940–952. https://doi.org/10.1093/jnci/djac030
Google Scholar
Erly S, Mocha CM, Amiya RM, Glick SN (2024) Development of a rural–urban classification system for public health research that accommodates structural differences between states. Am J Epidemiol 193(12):1840–1847. https://doi.org/10.1093/aje/kwae119
Google Scholar
Burnett-Hartman AN, Powers JD, Chubak J, Corley DA, Ghai NR, McMullen CK, Pawloski PA, Sterrett AT, Feigelson HS (2019) Treatment patterns and survival differ between early-onset and late-onset colorectal cancer patients: the patient outcomes to advance learning network. Cancer Causes Control 30(7):747–755. https://doi.org/10.1007/s10552-019-01181-3
Google Scholar
Abdullah A, Liu Z, Molinari M (2025) From diagnosis to survivorship: the role of social determinants in cancer care. Cancers 17(7):1067. https://doi.org/10.3390/cancers17071067. (PubMed PMID:40227566; PubMed Central PMCID: PMC11987860)
Google Scholar
Hassan I, Chisty A, Bui T (2023) Structural and social determinants of health. In: Lu LB, Fortuna RJ, Noronha CF, Sobel HG, Tobin DG (eds) Leading an academic medical practice [Internet]. Springer International Publishing, Cham, pp 343–355
Google Scholar
Dasgupta P, Baade PD, Aitken JF, Turrell G (2012) Multilevel determinants of breast cancer survival: association with geographic remoteness and area-level socioeconomic disadvantage. Breast Cancer Res Treat 132(2):701–710. https://doi.org/10.1007/s10549-011-1899-y
Google Scholar
Wakefield DV, Carnell M, Dove APH, Edmonston DY, Garner WB, Hubler A, Makepeace L, Hanson R, Ozdenerol E, Chun SG, Spencer S, Pisu M, Martin M, Jiang B, Punglia RS, Schwartz DL (2020) Location as destiny: identifying geospatial disparities in radiation treatment interruption by neighborhood, race, and insurance. Int J Radiat Oncol Biol Phys 107(4):815–826. https://doi.org/10.1016/j.ijrobp.2020.03.016
Google Scholar
SEER [Internet]. [cited 2026 Apr 30]. SEER Incidence Data—SEER Data & Software. Available from: https://seer.cancer.gov/data/index.html
Penberthy L, Friedman S (2024) The SEER program’s evolution: supporting clinically meaningful population-level research. JNCI Monogr 2024(65):110–117. https://doi.org/10.1093/jncimonographs/lgae022
Google Scholar
Rural-Urban Continuum Codes | Economic Research Service [Internet]. [cited 2025 Nov 22]. Available from: https://www.ers.usda.gov/data-products/rural-urban-continuum-codes
SEER [Internet]. [cited 2026 Apr 30]. Time-dependent County Attributes. Available from: https://seer.cancer.gov/seerstat/variables/countyattribs/time-dependent.html
Barker LE, Kirtland KA, Gregg EW, Geiss LS, Thompson TJ (2011) Geographic distribution of diagnosed diabetes in the U.S.: a diabetes belt. Am J Prev Med 40(4):434–439. https://doi.org/10.1016/j.amepre.2010.12.019. (PubMed PMID: 21406277)
Google Scholar
Aoun N, Matsuda H, Sekiyama M (2015) Geographical accessibility to healthcare and malnutrition in Rwanda. Soc Sci Med 130:135–145. https://doi.org/10.1016/j.socscimed.2015.02.004
Google Scholar
Bureau UC. Census.gov [Internet]. [cited 2025 Aug 19]. Income in the United States: 2023. Available from: https://www.census.gov/library/publications/2024/demo/p60-282.html
The Cost of Not Getting Care: Income Disparities in the Affordability of Health Services Across High-Income Countries [Internet]. 2023 [cited 2025 Aug 19]. Available from: https://www.commonwealthfund.org/publications/surveys/2023/nov/cost-not-getting-care-income-disparities-affordability-healthhttps://doi.org/10.26099/jbe9-c870
Iragorri N, de Oliveira C, Fitzgerald N, Essue B (2021) The out-of-pocket cost burden of cancer care: a systematic literature review. Curr Oncol 28(2):1216–1248. https://doi.org/10.3390/curroncol28020117. (PubMed PMID: 33804288; PubMed Central PMCID: PMC8025828)
Google Scholar
Gallicchio L, Elena JW, Fagan S, Carter M, Hamilton AS, Hastert TA, Hunter LL, Li J, Lynch CF, Milam J, Millar MM, Modjeski D, Paddock LE, Reed AR, Moses LB, Stroup AM, Sweeney C, Trapido EJ, West MM, Wu XC, Helzlsouer KJ (2020) Utilizing SEER cancer registries for population-based cancer survivor epidemiologic studies: a feasibility study. Cancer Epidemiol Biomark Prev Publ Am Assoc Cancer Res Cosponsored Am Soc Prev Oncol 29(9):1699–1709. https://doi.org/10.1158/1055-9965.EPI-20-0153. (PubMed PMID: 32651214; PubMed Central PMCID: PMC7484198)
Google Scholar
SEER [Internet]. [cited 2025 Nov 27]. Static County Attributes—SEER Datasets. Available from: https://seer.cancer.gov/seerstat/variables/countyattribs/static.html
Siegel RL, Miller KD, Jemal A (2018) Cancer statistics, 2018. CA Cancer J Clin 68(1):7–30. https://doi.org/10.3322/caac.21442
Google Scholar
Acquah I, Hagan K, Valero-Elizondo J, Javed Z, Butt SA, Mahajan S, Taha MB, Hyder AA, Mossialos E, Cainzos-Achirica M, Nasir K (2022) Delayed medical care due to transportation barriers among adults with atherosclerotic cardiovascular disease. Am Heart J 245:60–69. https://doi.org/10.1016/j.ahj.2021.11.019
Google Scholar
George M, Smith A, Ranmuthugula G, Sabesan S (2022) Barriers to accessing, commencing and completing cancer treatment among geriatric patients in rural Australia: a qualitative perspective. Int J Gen Med. 15:1583–1594. https://doi.org/10.2147/IJGM.S338128. (PubMed PMID: 35210830)
Google Scholar
Fu MS, Pan SX, Cai XQ, Pan QC (2024) Urban vs. rural: colorectal cancer survival and prognostic disparities from 2000 to 2019. Front Public Health 12:1319977. https://doi.org/10.3389/fpubh.2024.1319977. (PubMed PMID: 38406503; PubMed Central PMCID: PMC10884167)
Google Scholar
Zhu B, Hu FH, Jia YJ, Zhao DY, Zhang WQ, Tang W, Hu SQ, Ge MW, Du W, Shen WQ, Chen HL (2023) Socioeconomic status on survival outcomes in patients with colorectal cancer: a cross-sectional study. J Cancer Res Clin Oncol 149(17):15641–15655. https://doi.org/10.1007/s00432-023-05344-3
Google Scholar
Fujii-Lau LL, Bamlet WR, Eldrige JS, Chari ST, Gleeson FC, Abu Dayyeh BK, Clain JE, Pearson RK, Petersen BT, Rajan E, Topazian MD, Vege SS, Wang KK, Wiersema MJ, Levy MJ (2015) Impact of celiac neurolysis on survival in patients with pancreatic cancer. Gastrointest Endosc 82(1):46-56.e2. https://doi.org/10.1016/j.gie.2014.12.036
Google Scholar
Wilson NW, Couper ID, De VE, Reid S, Fish T, Marais BJ (2009) A critical review of interventions to redress the inequitable distribution of healthcare professionals to rural and remote areas. Rural Remote Health 9(2):1–21. https://doi.org/10.3316/informit.496326474031125
Google Scholar
Zapka J, Taplin SH, Anhang Price R, Cranos C, Yabroff R (2010) Factors in quality care—the case of follow-up to abnormal cancer screening tests—problems in the steps and interfaces of care. JNCI Monogr 2010(40):58–71. https://doi.org/10.1093/jncimonographs/lgq009
Google Scholar
Lavasani S, Chlebowski RT, Prentice RL, Kato I, Wactawski-Wende J, Johnson KC, Young A, Rodabough R, Hubbell FA, Mahinbakht A, Simon MS (2015) Estrogen and colorectal cancer incidence and mortality. Cancer 121(18):3261–3271. https://doi.org/10.1002/cncr.29464
Google Scholar
Henley SJ (2004) Invasive cancer incidence, 2004–2013, and deaths, 2006–2015, in nonmetropolitan and metropolitan counties—United States. MMWR Surveill Summ. https://doi.org/10.15585/mmwr.ss6614a1
Google Scholar
Unger JM, Moseley AB, Cheung CK, Osarogiagbon RU, Symington B, Ramsey SD, Hershman DL (2021) Persistent disparity: socioeconomic deprivation and cancer outcomes in patients treated in clinical trials. J Clin Oncol 39(12):1339–1348. https://doi.org/10.1200/JCO.20.02602. (PubMed PMID: 33729825; PubMed Central PMCID: PMC8078474)
Google Scholar
Nicoll I, Lockwood G, Longo CJ, Loiselle CG, Fitch MI (2022) Relationships between Canadian adult cancer survivors’ annual household income and emotional/practical concerns, help-seeking and unmet needs. Health Soc Care Comm 30(4):e1290–e1301. https://doi.org/10.1111/hsc.13536
Google Scholar
Pal T, Hull PC, Koyama T, Lammers P, Martinez D, McArthy J, Schremp E, Tezak A, Washburn A, Whisenant JG, Friedman DL (2021) Enhancing cancer care of rural dwellers through telehealth and engagement (ENCORE): protocol to evaluate effectiveness of a multi-level telehealth-based intervention to improve rural cancer care delivery. BMC Cancer 21(1):1262. https://doi.org/10.1186/s12885-021-08949-4
Google Scholar
Rivers BM, Rivers DA (2022) Enhancing cancer care coordination among rural residents: a model to overcome disparities in treatment. Med Care 60(3):193–195. https://doi.org/10.1097/MLR.0000000000001691. (PubMed PMID: 35157619; PubMed Central PMCID: PMC8844695)
Google Scholar
