Different annual recurrence pattern between lumpectomy and mastectomy: implication for breast cancer surveillance after breast-conserving surgery.

PURPOSE: To investigate the recurrence pattern and annual recurrence risk after breast-conserving surgery and compare them with those after mastectomy.
METHODS: This retrospective analysis included 6,135 consecutive unilateral breast cancer patients undergoing surgery in 1998-2008, with 847 lumpectomy patients and 5,288 mastectomy patients. Recurrence patterns were scrutinized and annual recurrence rates were calculated. Furthermore, a literature-based review including seven relevant studies was subsequently performed to confirm our single-institution data-based observations.
RESULTS: After lumpectomy, 50.9% of recurrences occurred within 3 years and 30.2% of recurrences were detected at 3-5 years; after mastectomy, 64.9% of recurrences occurred within 3 years and 20.4% occurred at 3-5 years. The major locoregional recurrence pattern after lumpectomy was ipsilateral breast tumor recurrence, which mainly (81.3%) occurred ≤5 years postsurgery but with a low incidence of 37.5% ≤3 years postsurgery. Annual recurrence curves indicated that the relapse peak after mastectomy emerged in the first 2 years; however, recurrence after lumpectomy increased annually with the highest peak near 5 years. By reviewing relevant studies, we confirmed our finding of different annual recurrence patterns for lumpectomy and mastectomy patients. The hazard ratio of dying for those recurring ≤5 years postlumpectomy relative to patients relapsing >5 years postlumpectomy was 4.62 (95% confidence interval, 1.05-20.28; p = .042).
CONCLUSIONS: Different recurrence patterns between mastectomy and lumpectomy patients imply that scheduling of surveillance visits should be more frequent during the 4-6 years after lumpectomy. Further prospective trials addressing the necessity of frequent and longer surveillance after lumpectomy are warranted.