Predicting Outcomes of Breast-Conserving Surgery in Breast Cancer Patients Using the Modified 5-Item Frailty Index

Predicting Outcomes of Breast-Conserving Surgery in Breast Cancer Patients Using the Modified 5-Item Frailty Index

Background: Breast cancer is the most common malignancy among women worldwide, with breast-conserving surgery (BCS) being a key treatment. The modified 5-item frailty index (mFI-5), a well-validated tool for assessing frailty, has shown predictive utility in other surgical contexts but remains under-explored in BCS.

Methods: Using the American College of Surgeons National Surgical Quality Improvement Program database (2008-2021), the investigators identified adult female breast cancer patients who underwent BCS. Frailty was assessed using the mFI-5, scored from 0 to 5, with higher scores indicating greater frailty. Multivariable logistic regression was employed to evaluate associations between mFI-5 scores and postoperative outcomes.

Main question: Can the mFI-5 predict adverse postoperative outcomes in breast-conserving surgery patients?

Inclusion Criteria

• Data from 14 annual datasets (2008-2021).
• Female breast cancer patients identified using diagnostic codes:
• ICD-9-CM 174: "Malignant neoplasm of female breast."
• ICD-9-CM 233.0: "Carcinoma in situ of breast."
• ICD-10-CM C50: "Malignant neoplasm of breast."
• ICD-10-CM D05: "Carcinoma in situ of breast."
• Focused on patients diagnosed with breast cancer.
• Further refinement:
• Only patients undergoing breast-conserving surgery (BCS).
• Identified by CPT code 19301: "Partial mastectomy without axillary lymphadenectomy."

Exclusion Criteria

• Missing essential anthropometric data (height and/or weight).
• Implausible BMI values (<7 kg/m² or >250 kg/m², assumed data entry errors).
• Miscoded or vague ICD or CPT entries.
• Concurrent invasive procedures other than BCS.
• Procedures performed by specialties other than general or plastic surgery.
• Male and non-binary patients or those with gender identity disorders (to focus on biologically female cohort).
• Non-elective (emergency) surgical cases.
• Patients with ASA physical status scores >4.
• Patients receiving anesthesia types other than general anesthesia.