br Inclusion of criteria and subcriteria br We first
3.3.1. Inclusion of criteria and subcriteria
We first determined the goal of the decision making, which is selecting the best treatment for breast cancer, and according to this 4μ8C goal we selected the criteria and subcriteria that have an effect in the decision making process . We defined our inclusion criteria for this selection as general as possible to include various different breast cancer cases, and derived a comprehensive criteria based on our interviews with medical oncologists. We also cross-checked initially-defined criteria/subcriteria with the literature (e.g., medi-cal journals, books, and websites). Only those factors that influence the treatment strategy and are practiced in real life by the oncol-ogists are included in the AHP model and multi-criteria ranking algorithm.
We divide the treatment decision into two different steps. The first decision step includes four tumor-related criteria: the stage of breast cancer, breast cancer-related risk factors (cancerous tumor characteristics), biomarker breast cancer risk factors, and patient-
related risk factors. In addition to all those four criteria, the sec-ond step includes the criteria regarding financial, social, and logistic factors. All subcriteria and their levels for both decision steps are given in Table 3. Below we discuss the inclusion reasons of those criteria.
220.127.116.11. Stage of breast cancer. The stage of a cancer is one of the most important criteria in selecting treatment alternatives. It is also mentioned that the higher the stage, the higher the possibil-ity of chemotherapy recommended as a treatment regimen for the breast cancer patient .
In this study, we used an international staging system for can-cer, TNM . The TNM classification system describes the direct extent of the primary tumor, or degree of invasion, where the let-ter T followed by a number from 0 to 4 describes the size of the tumor and its spread to the skin and its lymphatics, the letter N followed by a number from 0 to 3 indicates the degree to which the cancer has spread to nearby lymph nodes, and the letter M fol-lowed by a 0 or 1 indicates whether or not the cancer has metas-tasized to distant organs in the body . For example, a small tumor that has not spread to lymph nodes or distant organs may be staged as (T1, N0, M0), while a stage IV cancer is written as
(Any T, Any N, M1) and describes the cancer as having spread to other organs of the body.
18.104.22.168. Breast cancer-related risk factors. Tumor size is one of the most important prognostic variables and is related to the breast cancer stage. Following a similar guideline with the M.D. Anderson Cancer Center [23,30], we classify the tumor size to be 2 cm or less, between 2 and 5 cm, and larger than 5 cm. This classification of tu-mor size is also studied in the literature (see, e.g., Jerez–Aragones´ et al ; Giordano et al. ). In addition to tumor size, crite-ria such as nodal status, tumor margin/location as well as tumor histology are declared to be critical factors that affect the cancer treatment according to the National Comprehensive Cancer Net-work breast cancer treatment guidelines .
22.214.171.124. Biomarker breast cancer risk factors. Biomarker breast can-cer related risk factors are also critical factors for determining breast cancer therapy. In clinical settings, biomarkers are the prog-nostic or predictive factors, which may sometimes lead to differ-ent therapies . Biomarker breast cancer risk factors include the ER/PR status and HER2 status, which determine if tumor contains or does not contain ER/PR and HER2 biomarker , Oncotype DX, a gene essay score of the tumor , and the grade of tumor, which determines how fast the tumor is growing .