State Cancer Profiles

Interpretation of Incidence Rates Data

Incidence Rate Report for Montana by County

Breast (Late Stage^), 2018-2022

All Races (includes Hispanic), Female, All Ages

Sorted by Name

Explanation of Column Headers
Incidence Rate (95% Confidence Interval) - The incidence rate is based upon 100,000 people and is an annual rate (or average annual rate) based on the time period indicated. Rates are age-adjusted by 5-year age groups to the 2000 U.S. standard million population.

Percent of Cases with Late Stage - This is the number of late stages cases compared to the number of cases for all stages.

Other Notes

• Larger confidence intervals indicate less stability of the data. This is often due to low counts that are not quite low enough to be suppressed.
• Data is currently being suppressed if there are fewer than 16 counts for the time period.

Line by Line Interpretation of the Report

Montana²

• 2023 Rural-Urban Continuum Codes Φ : N/A
• Rate : The incidence rate is 43.8 with a 95% confidence interval from 41.4 to 46.3 and 286 average annual cases over 2018-2022.
• CI*Rank ⋔ : N/A

US (SEER+NPCR)¹

• 2023 Rural-Urban Continuum Codes Φ : N/A
• Rate : The incidence rate is 42.4 with a 95% confidence interval from 42.3 to 42.5 and 83,714 average annual cases over 2018-2022.
• CI*Rank ⋔ : N/A

Cascade County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 33.9 with a 95% confidence interval from 26.9 to 42.1 and 19 average annual cases over 2018-2022.
• CI*Rank ⋔ : 16 (9, 17)
• Percent of Cases with Late Stage :

Custer County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 48.8 with a 95% confidence interval from 28.2 to 79.3 and 4 average annual cases over 2018-2022.
• CI*Rank ⋔ : 6 (1, 17)
• Percent of Cases with Late Stage :

Flathead County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 42.5 with a 95% confidence interval from 35.4 to 50.6 and 29 average annual cases over 2018-2022.
• CI*Rank ⋔ : 12 (5, 16)
• Percent of Cases with Late Stage :

Gallatin County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 42.6 with a 95% confidence interval from 34.9 to 51.4 and 23 average annual cases over 2018-2022.
• CI*Rank ⋔ : 11 (4, 16)
• Percent of Cases with Late Stage :

Glacier County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 71.1 with a 95% confidence interval from 42.7 to 110.1 and 4 average annual cases over 2018-2022.
• CI*Rank ⋔ : 1 (1, 15)
• Percent of Cases with Late Stage :

Hill County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 49.1 with a 95% confidence interval from 29.3 to 77.0 and 4 average annual cases over 2018-2022.
• CI*Rank ⋔ : 5 (1, 17)
• Percent of Cases with Late Stage :

Jefferson County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 48.2 with a 95% confidence interval from 27.2 to 80.2 and 4 average annual cases over 2018-2022.
• CI*Rank ⋔ : 7 (1, 17)
• Percent of Cases with Late Stage :

Lake County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 60.1 with a 95% confidence interval from 45.1 to 78.8 and 13 average annual cases over 2018-2022.
• CI*Rank ⋔ : 2 (1, 11)
• Percent of Cases with Late Stage :

Lewis and Clark County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 39.8 with a 95% confidence interval from 31.5 to 49.8 and 18 average annual cases over 2018-2022.
• CI*Rank ⋔ : 13 (5, 17)
• Percent of Cases with Late Stage :

Lincoln County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 42.8 with a 95% confidence interval from 27.4 to 64.7 and 6 average annual cases over 2018-2022.
• CI*Rank ⋔ : 10 (2, 17)
• Percent of Cases with Late Stage :

Missoula County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 47.5 with a 95% confidence interval from 40.0 to 56.1 and 31 average annual cases over 2018-2022.
• CI*Rank ⋔ : 9 (3, 14)
• Percent of Cases with Late Stage :

Park County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 32.7 with a 95% confidence interval from 20.2 to 51.7 and 5 average annual cases over 2018-2022.
• CI*Rank ⋔ : 17 (5, 17)
• Percent of Cases with Late Stage :

Ravalli County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 57.8 with a 95% confidence interval from 44.6 to 73.9 and 16 average annual cases over 2018-2022.
• CI*Rank ⋔ : 3 (1, 12)
• Percent of Cases with Late Stage :

Sanders County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 39.2 with a 95% confidence interval from 19.6 to 71.1 and 3 average annual cases over 2018-2022.
• CI*Rank ⋔ : 14 (1, 17)
• Percent of Cases with Late Stage :

Silver Bow County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate : The incidence rate is 35.4 with a 95% confidence interval from 24.2 to 50.2 and 7 average annual cases over 2018-2022.
• CI*Rank ⋔ : 15 (5, 17)
• Percent of Cases with Late Stage :

Stillwater County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 55.2 with a 95% confidence interval from 30.2 to 94.5 and 3 average annual cases over 2018-2022.
• CI*Rank ⋔ : 4 (1, 17)
• Percent of Cases with Late Stage :

Yellowstone County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate : The incidence rate is 47.6 with a 95% confidence interval from 41.4 to 54.5 and 47 average annual cases over 2018-2022.
• CI*Rank ⋔ : 8 (3, 13)
• Percent of Cases with Late Stage :

Beaverhead County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Big Horn County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Blaine County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Broadwater County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Carbon County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Carter County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Chouteau County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Daniels County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Dawson County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Deer Lodge County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Fallon County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Fergus County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Garfield County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Golden Valley County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Granite County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Judith Basin County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Liberty County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Madison County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

McCone County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Meagher County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Mineral County²

• 2023 Rural-Urban Continuum Codes Φ : Urban
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Musselshell County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Petroleum County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Phillips County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Pondera County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Powder River County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Powell County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Prairie County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Richland County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Roosevelt County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Rosebud County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Sheridan County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Sweet Grass County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Teton County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Toole County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Treasure County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Valley County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Wheatland County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Wibaux County²

• 2023 Rural-Urban Continuum Codes Φ : Rural
• Rate :
• CI*Rank ⋔ : *
• Percent of Cases with Late Stage : *

Notes:
Created by statecancerprofiles.cancer.gov on 03/12/2026 11:33 am.

State Cancer Registries may provide more current or more local data.



† Incidence rates (cases per 100,000 population per year) are age-adjusted to the 2000 US standard population (SEER areas use 20 age groups and NPCR areas use 19 age groups). Rates are for invasive cancer only (except for bladder cancer which is invasive and in situ) or unless otherwise specified. Rates calculated using SEER*Stat. Population counts for denominators are based on Census populations as modified by NCI. The US Population Data File is used for SEER and NPCR incidence rates.

Rates are computed using cancers classified as malignant based on ICD-O-3. For more information see malignant.html.

^ Late Stage is defined as cases determined to be regional or distant. Due to changes in stage coding, Combined Summary Stage with Expanded Regional Codes (2004+) is used for data from Surveillance, Epidemiology, and End Results (SEER) databases and Merged Summary Stage is used for data from National Program of Cancer Registries databases. Due to the increased complexity with staging, other staging variables maybe used if necessary.

⋔ Results presented with the CI*Rank statistics help show the usefulness of ranks. For example, ranks for relatively rare diseases or less populated areas may be essentially meaningless because of their large variability, but ranks for more common diseases in densely populated regions can be very useful. The rates used in CI*Rank are all age-adjusted to the 2000 US standard population using 19 age groups for SEER and NPCR areas. More information about methodology can be found on the CI*Rank website.

Φ Rural–urban county classifications are based on the 2023 USDA Rural–Urban Continuum Codes (except for Connecticut Counties which use 2013 codes). State-level cancer rates for rural areas are calculated using cancer cases registered exclusively in rural counties, while state-level cancer rates for urban areas are calculated using cases registered exclusively in urban counties.

¹ Source: National Program of Cancer Registries and Surveillance, Epidemiology, and End Results SEER*Stat Database - United States Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute. Based on the 2024 submission.

² Source: National Program of Cancer Registries SEER*Stat Database - United States Department of Health and Human Services, Centers for Disease Control and Prevention (based on the 2024 submission).

* Data has been suppressed to ensure confidentiality and stability of rate estimates. Counts are suppressed if fewer than 16 records were reported in a specific area-sex-race category.

Data for United States does not include Puerto Rico.