Breast Cancer

Disease Overview

Todo

Add definition of each cancer. In particular, find data about global prevalence and disease fatal and non fatal description.

GBD 2017 Modeling Strategy

Breast cancer in GBD 2017

The GBD modelling strategy can be found in the GBD YLD Capstone Appendix [GBD-2017-YLD-Capstone-Appendix-1-Breast-Cancer].

Incidence is estimated directly from mortality using mortality to incidence ratios (MIR).

Because of long-term disability associated with mastectomy, prevalence for breast cancer is estimated beyond ten years. To estimate the disability, total prevalence for breast cancer is split into

1. Diagnosis and primary therapy

2. Controlled phase

   1. Controlled phase of breast cancer, with mastectomy

   2. Controlled phase of breast cancer, without mastectomy

3. Metastatic phase

4. Terminal phase

5. Mastectomy from breast cancer, beyond 10 years

Todo

Add more details about GBD modelling strategy of Breast cancer.

Cause Hierarchy

GBD breast cancer cause hierarchy
Cause name	GBD cause id	Level	Sequaelae
All causes	c_294	0
All NCDs	c_409	1
Neoplasms	C_410	2
Breast cancer	C_429	3	diagnosis_and_primary_therapy_phase_of_breast_cancer (s_277) metastatic_phase_of_breast_cancer (s_279) terminal_phase_of_breast_cancer (s_280) controlled_phase_of_breast_cancer_with_mastectomy (s_5486) controlled_phase_of_breast_cancer_without_mastectomy (s_5489) mastectomy_from_breast_cancer_beyond_ten_years (s_5492)

Restrictions

The following table describes any restrictions on the effects of this cause (such as being only fatal or only nonfatal), as well as restrictions on the age and sex of simulants to which different aspects of the cause model apply.

Restrictions

Restriction Type	Value	Notes
Male only	False
Female only	False
YLL only	False
YLD only	False
YLL age group start	15 to 19	GBD age group id 8
YLL age group end	95 plus	GBD age group id 235
YLD age group start	15 to 19	GBD age group id 8
YLD age group end	95 plus	GBD age group id 235

Vivarium Modeling Strategy

Scope

Todo

Add scope.

Model Assumptions and Limitations

1. Within GBD 2017, after diagnosis/ treatment if a patient survives more than 10 years, they are considered cured for calculating disability. For simulation models, this means that if the simulation is run for more than 10 years, then excess mortality rate exists due to cancer after 10 years and the number of deaths increase. But as per GBD 2017, after 10 years, the patients do not have excess mortality rate. So, this model might over estimate deaths in that scenario.

Todo

Add more assumptions and limitations.

Cause Model Diagram

Within GBD 2017 data, the remission rate is not available which makes it difficult to transition through the states. So, due to data limitations we are simplifying the model.

Note: This simpliflication might over estimate the number of deaths. See Model Assumptions and Limitations section for more information.

State and Transition Data Tables

Definitions

State	State Name	Definition
S	Susceptible	Susceptible to breast cancer
I	Infected	Infected with breast cancer

States Data

State	Measure	Value	Notes
S	prevalence	1-prevalence_c429
S	excess mortality rate	0
S	disabilty weights	0
I	prevalence	prevalence_c429
I	excess mortality rate	\(\frac{\text{deaths\_c429}}{\text{population} \times \text{prevalence\_c429}}\)
I	disability weights	\(\displaystyle{\sum_{s\in \text{sequelae\_c429}}} \scriptstyle{\text{disability\_weight}_s \,\times\, \text{prevalence}_s}\)	total disability weight over all sequelae with ids s_277, s_5486, s_5489, s_279, s_280, s_5492
ALL	cause specific mortality rate	\(\frac{\text{deaths\_c429}}{\text{population}}\)

Transition Data

Transition	Source	Sink	Value	Notes
i	S	I	\(\frac{\text{incidence\_rate\_c429}}{\text{1 - prevalence\_c429}}\)	Incidence rate in total population is divided by 1-prevalence_c429 to get incidence rate among the susceptible population.

Data Sources

Measure	Sources	Description	Notes
prevalence_c429	como	Prevalence of cause breast cancer
deaths_c429	codcorrect	Deaths from breast cancer
population	demography	Mid-year population for given country
incidence_rate_c429	como	Incidence rate for breast cancer
disability_weight_s{sid}	YLD appendix	Disability weights associated with each sequelae
prevalence_s{sid}	como	Prevalence of each sequelae

Validation Criteria

Todo

Describe tests for model validation.

References

[GBD-2017-YLD-Capstone-Appendix-1-Breast-Cancer]

Supplement to: GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 2018; 392: 1789–858 (pp. 310-317)