In our study, the 5-year overall survival rate of 46 breast cancer patients aged 85 years or older was 78.2%, suggesting that breast cancer surgery for extremely old patients is warranted. To our knowledge, this is the first report of the long-term survival of elderly patients aged 85 years or older.
Our study population included breast cancer patients with a wide range of TNM stages. Despite this wide range of stages, the 5-year overall survival rate was 78.2%, which is similar to the 5-year survival rate of patients with T2N0M0 breast cancer . Therefore, we believe that the 5-year survival rate of our study group was acceptable.
We believe that surgical treatment for elderly patients with breast cancer is extremely safe if their preoperative conditions are evaluated properly. In our series, there were no hospital deaths. Although some patients had wound infections, no severe postoperative complications were recorded. Results from other single-institute studies concerning postoperative mortality are favorable [7, 9], and a large cohort study based on a national database also showed an acceptable rate of postoperative mortality .
The evaluation of surgical safety is essential in elderly breast cancer patients, and the level of safety depends on the balance between surgical invasiveness and the patient’s tolerance. Surgical treatment for breast cancer is less invasive than other general surgeries and thus is safely performed in many patients. On the other hand, tolerability depends on co-morbidity [11, 12], frailty  and physical activity statuses , and these three factors are closely associated with one another .
Considering the low tolerance of elderly patients, some essential treatment procedures including axillary surgery, radiation treatment, and adjuvant chemotherapy were avoided [6, 8]. Several small studies investigated avoiding axillary dissection in clinically node-negative patients with small breast cancers and reported that the absence of axillary dissection does not affect overall survival [15–17]. However, 5.8–9% of patients experienced axillary recurrence. We believe that concomitant axillary surgery is preferable for two reasons. One, axillary surgery is not very invasive, and sentinel lymph node biopsy is appropriate in clinically node-negative cases . The second reason is that comorbid diseases may weaken the general condition of elderly patients during the interval between the initial surgery and potential axillary recurrence. This interval is reported to range from 7 to 157 months ; longer intervals can reduce the opportunity for a second surgery.
Radiation therapy after partial mastectomy tends to be avoided in elderly patients with breast cancer , because they are required to visit the hospital every day for several weeks. Although radiation therapy after a partial mastectomy does not seem to affect overall survival , no radiation elevates the risk of local recurrence [20–22]. Although mastectomy is related to a higher risk of postoperative hemorrhage than is partial mastectomy , mastectomy is preferred for patients who want to avoid radiation therapy.
Adjuvant chemotherapy improves the survival outcome of patients with early breast cancer; however, maintenance of the relative dose intensity is difficult in elderly patients [24–27]. Furthermore, treatment-related mortality increases with age . We believe that adjuvant chemotherapy is not appropriate for patients aged 85 years or older.
Our study has some limitations. This was a retrospective study of breast cancer patients who underwent surgical treatment, thus introducing selection bias. However, because such patients must have a good enough general condition to tolerate surgery, we believe that this bias does not alter our conclusion.