Factors predicting seroma formation after mastectomy for Chinese breast cancer patients.

BACKGROUND Seroma formation after mastectomy typically delays recovery and adds to morbidity. AIMS This retrospective review was undertaken to identify factors which predict development of seroma after mastectomy for breast cancer patients. SETTING AND DESIGN 119 consecutive patients intended for mastectomy for the treatment of primary breast cancer were included. Factors taken into consideration were epidemiological, peri-operative in nature and those related to wound drainage output. MATERIALS AND METHODS Total mastectomy was performed and axillary sampling was taken. All patients were reviewed within two weeks after leaving hospital, unless seroma formation was detected before discharge. The diagnosis of seroma was made clinically when a collection was detected beneath the skin flaps. STATISTICAL ANALYSIS USED Student's t test was used with continuous variables and the X2 test for categorical situations. Fisher's exact test was applied when small numbers were encountered. A two-tailed test of P< 0.05 was considered significant. Univariate analyses were performed. RESULTS The incidence of seroma formation was eight per cent. Five factors were identified to be significantly related to seroma formation: i) age over 45 years; ii) hypertension; iii) total drainage output exceeding 500 ml in the first three postoperative days; iv) drainage for more than eight days. Immediate breast reconstruction prevents the formation of seroma. CONCLUSION The presence of hypertension in a patient over 45 years should alert the surgeon to possible seroma formation, particularly when the post-operative drainage exceeded 500 ml in the first three days. Appropriate preventive measures should then be implemented.