Ong C, Biswas A, Choolani M, Low JJ
Correspondence: A/Prof Jeffrey Low, firstname.lastname@example.org
Introduction The risk of malignancy index (RMI) is a scoring system used to triage benign from malignant ovarian masses. We compared the specificity and sensitivity of the four indices (RMI 1, RMI 2, RMI 3 and RMI 4) to discriminate a benign ovarian mass from a malignant one in a Southeast Asian population.
Methods This was a five-year retrospective study of women who were admitted for surgery due to ovarian masses. RMI scores were calculated based on standardised preoperative cancer antigen (CA)-125 levels, ultrasonography findings, menopausal status and tumour size based on ultrasonography. Postoperative histopathologic diagnosis was regarded as the definite outcome. Data were analysed using the Statistical Package for the Social Sciences, and Mann-Whitney U test was used to compare the individual RMI scores between the benign and malignant cases.
Results Out of the 480 patients reviewed, 228 women aged 10–65 years were included in the study. Of these, 17 (7.5%) had malignant disease and 211 (92.5%) had benign pathology. There was no statistical difference in the RMI 1, 2, 3 and 4 scores between the benign and malignant cases. Individual variables that were analysed showed significant differences in median CA-125 level and tumour size (p = 0.044 and p < 0.0005, respectively) between the benign and malignant cases.
Conclusion Our study shows that RMI is not a valuable triage tool for our Southeast Asian population. Further prospective validation, with regard to standardising results in different patient populations and centres, is required.
Keywords: CA125, ovarian cancer, risk of malignancy index, ultrasonography
Singapore Med J 2013; 54(3): 136-139; doi:10.11622/smedj.2013046
1. Trends in cancer incidence in Singapore 1968-2007. Singapore Cancer Registry Report Number 7. Singapore: National Registry of Diseases Office, 2010.
2. Singapore Cancer Registry interim report. Trends in cancer incidence in Singapore, 2004-2008. Singapore: National Registry of Diseases Office, 2010.
3. Junor EJ, Hole DJ, McNulty L, Mason M, Young J. Specialist gynaecologists and survival outcome in ovarian cancer: a Scottish national study of 1866 patients. Br J Obstet Gynaecol 1999; 106:1130-6.
4. 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; 97:922-9.
5. Tingulstad S, Hagen B, Skjeldestad FE, et al. Evaluation of a risk of malignancy index based on serum CA125, ultrasound findings and menopausal status in the pre-operative diagnosis of pelvic masses. Br J Obstet Gynaecol 1996; 103:826-31.
6. Tingulstad S, Hagen B, Skjeldestad FE, et al. The risk-of-malignancy index to evaluate potential ovarian cancers in local hospitals. Obstet Gynecol 1999; 93:448-52.
7. Morgante G, la Marca A, Ditto A, De Leo V. Comparison of two malignancy risk indices based on serum CA125, ultrasound score and menopausal status in the diagnosis of ovarian masses. Br J Obstet Gynaecol 1999; 106:524-7.
8. Yamamoto Y, Yamada R, Oguri H, Maeda N, Fukaya T. Comparison of four malignancy risk indices in the preoperative evaluation of patients with pelvic masses. Eur J Obstet Gynecol Reprod Biol 2009; 144:163-7.
9. Manjunath AP, Pratapkumar, Sujatha K, Vani R. Comparison of three risk of malignancy indices in evaluation of pelvic masses. Gynecol Oncol 2001; 81:225-9.
10. Davies AP, Jacobs I, Woolas R, Fish A, Oram D. The adnexal mass: benign or malignant? Evaluation of a risk of malignancy index. Br J Obstet Gynaecol 1993; 100:927-31.
11. Molina R, Escudero JM, Augé JM, et al. HE4 a novel tumour marker for ovarian cancer: comparison with CA 125 and ROMA algorithm in patient s with g ynaecological diseases. Tumour Biol 2011; 32:1087-95.
12. Moore RG, Jabre-Raughley M, Brown AK, et al. Comparison of a novel multiple marker assay vs the Risk of Malignancy Index for the prediction of epithelial ovarian cancer in patients with a pelvic mass. Am J Obstet Gynecol 2010; 203:228.e1-6.
13. Andersen MR, Goff BA, Lowe KA, et al. Use of a Symptom Index, CA125, and HE4 to predict ovarian cancer. Gynecol Oncol 2010; 116:378-83.