risk_malignancy_index: Risk of Malignancy Index (RMI) for Ovarian Cancer

In cliot: Clinical Indices and Outcomes Tools

Risk of Malignancy Index (RMI) for Ovarian Cancer

Description

Calculates the Risk of Malignancy Index (RMI I) to stratify the risk of ovarian cancer in women with adnexal masses. The score combines serum CA-125 levels, ultrasound findings, and menopausal status. An RMI score greater than 200 suggests a higher risk of malignancy and typically warrants referral to a gynecological oncologist.

Usage

risk_malignancy_index(ca125_level, menopausal_status, multilocular_cyst,
                      solid_areas, bilateral_lesions, ascites,
                      intraabdominal_metastases)

Arguments

ca125_level	Numeric. Serum CA-125 level in U/mL.
menopausal_status	String. "pre" (1 point) or "post" (3 points). Post-menopausal is defined as >1 year of amenorrhea or age >50 in hysterectomized women.
multilocular_cyst	Numeric (0 or 1). Presence of a multilocular cystic lesion on ultrasound. (1 = Yes).
solid_areas	Numeric (0 or 1). Presence of solid areas within the mass on ultrasound. (1 = Yes).
bilateral_lesions	Numeric (0 or 1). Presence of bilateral lesions on ultrasound. (1 = Yes).
ascites	Numeric (0 or 1). Presence of ascites on ultrasound. (1 = Yes).
intraabdominal_metastases	Numeric (0 or 1). Presence of intra-abdominal metastases on ultrasound. (1 = Yes).

Details

The formula for RMI I is:

RMI = U \times M \times CA125

Where:

• U (Ultrasound Score): 0 if no features, 1 if 1 feature, 3 if 2-5 features.

• M (Menopausal Status): 1 if Pre-menopausal, 3 if Post-menopausal.

• CA125: Absolute value of serum CA-125.

Value

A list containing:

RMI_Score	The calculated Risk of Malignancy Index.
Risk_Category	Interpretation based on the threshold of 200 (High vs. Low).
Recommendation	Referral guidance.

References

Jacobs I, Oram D, Fairbanks J, et al. A risk of malignancy index incorporating CA 125, ultrasound and menopausal status for the accurate preoperative diagnosis of ovarian cancer. Br J Obstet Gynaecol. 1990;97(10):922-929. doi:10.1111/j.1471-0528.1990.tb02448.x

Examples

# Example 1: High Risk
# CA125 100, Post-menopausal (3), 2 US features (Solid, Ascites -> U=3)
# RMI = 3 * 3 * 100 = 900
risk_malignancy_index(100, "post", 0, 1, 0, 1, 0)

# Example 2: Low Risk
# CA125 25, Pre-menopausal (1), 1 US feature (Multilocular -> U=1)
# RMI = 1 * 1 * 25 = 25
risk_malignancy_index(25, "pre", 1, 0, 0, 0, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.