Oncologic Outcomes No Worse With Newer Mastectomy Methods

For breast cancer patients receiving neoadjuvant chemotherapy (NACT), long-term oncologic outcomes for immediate breast reconstruction with nipple- or skin-sparing mastectomy were comparable to total mastectomy without reconstruction, a case-control study from Korea found.

In a propensity score-matched analysis involving nearly 650 patients, no significant differences were seen at a median 5.5 years follow-up between the immediate breast reconstruction group and the conventional mastectomy group for local recurrences (3.7% vs 3.4%), regional recurrences (7.1% vs 5.3%), and distant metastasis (17.3% vs 18.6%), BeomSeok Ko, MD, PhD, of the University of Ulsan College of Medicine in Seoul, and colleagues reported.

As described in JAMA Surgery, 5-year survival outcomes between the two groups, respectively, were largely similar:

• Recurrence-free survival: 95.6% vs 96.7% (HR 1.124, 95% CI 0.495-2.549, P=0.78)
• Disease-free survival: 76.5% vs 79.9% (HR 1.089, 95% CI 0.790-1.500, P=0.60)
• Distant metastasis-free survival: 82.5% vs 82.5% (HR 0.941, 95% CI 0.654-1.355, P=0.74)
• Overall survival: 92.0% vs 89.3% (HR 0.847, 95% CI 0.530-1.353, P=0.49)

“Our results suggest that the response to NACT should not be considered a contraindication to immediate breast reconstruction and, even in selected patients without response to NACT, immediate breast reconstruction can be a feasible option and should be discussed before surgical treatment,” the group wrote.

Due to improved cosmetic results and quality-of-life outcomes, immediate breast reconstruction with nipple- or skin-sparing techniques are increasingly being performed for women with breast cancer, Ko and colleagues explained. “However, evidence for the oncologic safety of this treatment approach is insufficient,” they wrote, and randomized trials are unrealistic given patient and physician preferences that factor into surgical decisions.

In an accompanying editorial, Rachel Greenup, MD, MPH, and colleagues from Duke University Medical Center in Durham, North Carolina, said the current study “provides reassurance that acceptable oncologic outcomes might be preserved in the setting of immediate breast reconstruction following NACT.”

“Thus, post-NACT surgical decisions should be made in the context of other patient and treatment characteristics that predispose women to perioperative complications and suboptimal outcomes (e.g., obesity, history of or potential for future radiotherapy, and smoking),” they wrote. “Socioeconomic factors and degree of perioperative support also are important in facilitating successful, integrated oncologic care and breast reconstruction.”

Ko’s group examined 1,266 breast cancer patients who received neoadjuvant chemotherapy before mastectomy from 2010 to 2016 at Asan Medical Center in Seoul, either with or without reconstruction. Patients who received nipple- or skin-sparing mastectomy followed by immediate breast reconstruction (n=526) tended to be younger, have earlier-stage disease, and were more likely to have hormone receptor (HR)-positive tumors compared to women who underwent conventional mastectomy (n=740). The propensity score-matched analysis included 323 patients for both groups.

Median patient age was 42 and 46 years, respectively, with most women having clinical T2 (56%) or T3 (40%) tumors, invasive ductal carcinoma (86-89%), and grade 1-2 tumors (71-72%). About half of the patients had HR-positive/HER2-negative tumors, while 21-22% had HR/HER2-positive disease, 14% had HR-negative/HER2-positive disease, and 12-14% had triple-negative disease. Most women responded to neoadjuvant chemotherapy, with partial responses in 47-49% and complete responses in 11-12%.

Despite matching, more patients in the conventional mastectomy group underwent axillary lymph node dissection compared to the reconstruction group (57.6% vs 46.1%; P=0.004).

In the immediate breast reconstruction group, 187 patients underwent nipple-sparing mastectomy. Recurrences involving the nipple-areola complex occurred in 2.1% of patients, while 4.8% and 7.0% had local or regional recurrences, respectively, and 16% developed distant metastases. The other 136 patients underwent skin-sparing mastectomy; here there were local and regional recurrences in 2.2% and 7.4%, while 19.1% developed distant metastases.