Some breast cancer patients will develop a locoregional recurrence (recurrence in the breast, chest wall, or lymph nodes) after immediate breast reconstruction. The risk of locoregional recurrence depends in part on breast cancer subtype, lymph node status and tumor size. For example, it has been reported that those with triple negative (ER-/PR-/HER2-) disease treated with mastectomy are significantly less likely to be free of locoregional recurrence for a period of five years compared to women with hormone receptor positive/HER2- tumors.

Women with triple negative or HER2+ disease are more likely to relapse within the first two to three years if they do relapse than women with less aggressive breast cancer. In other words, there is an increased risk of relapse with a shorter time to relapse. Such women are also more likely to be candidates for radiation treatment after mastectomy than women with less aggressive disease. These are factors to take into account in making the decision as to whether to have immediate breast reconstruction after mastectomy or to delay or omit it. Now a new study has reported that women with triple negative disease and some women with HER2+ disease have significant rates of locoregional recurrence after mastectomy followed by immediate breast reconstruction.

Large study analyzed breast cancer relapse according to subtype

The study referenced at the beginning of this new article was designed to investigate the rate of locoregional recurrence after mastectomy with immediate reconstruction by breast cancer subtype. The study included 1,742 Italian women who underwent immediate breast reconstruction during the period 1997 to 2006. Participants were followed for a median of 74 months.

Each of the women were assigned to one of the following breast cancer subtypes:

  • Luminal A: estrogen receptor (ER) and/or progesterone receptor (PR) positive, HER2 negative, and low proliferation (Ki-67 < 14%)
  • Luminal B/HER2 negative: ER+ and/or PR+, HER2-, and high proliferation (Ki67 ≥ 14%)
  • Luminal B/HER2 positive: ER+ and/or PR+, HER2+, any Ki67
  • HER2positive/nonluminal: ER-, PR- and HER2+
  • Triple negative: ER-, PR- and HER2-.

Locoregional recurrence rates depend on subtype and other factors

The overall cumulative rate of locoregional recurrence was only 5.5%. However the five-year cumulative rate of locoregional recurrence varied considerably according to subtype:

  • Luminal A: 2.5%
  • Luminal B/HER2 negative: 5.0%
  • Luminal B/HER2 positive: 9.8%
  • HER2positive/nonluminal: 3.8%
  • Triple negative: 10.9%.
Note that women with HER2+ disease and at least one positive hormone receptor (ER+/PR+, ER+/PR- or ER-/PR+) had higher rates of locoregional recurrence than those with ER-/PR-/HER2+ disease.

Further analysis demonstrated that tumor size > 2 cm, body mass index (BMI) ≥ 25, triple negative subtype, and luminal B/HER2 positive subtype each were independently associated with heightened risk of locoregional recurrence. The authors conclude that these factors are independent prognostic factors for locoregional recurrence after immediate breast reconstruction.