Mastectomy is the most commonly used salvage treatment for an in-breast tumor recurrence (IBTR) after lumpectomy and breast radiotherapy (RT)  A few reports concerning IBTR have included small numbers of patients treated with repeat breast conservation therapy using either lumpectomy alone, lumpectomy and brachytherapy, or lumpectomy and repeat low-dose external beam RT. Since 1985, I have been offering repeat high-dose partial breast RT after excision of an IBTR to women who have refused mastectomy or are considered suitable candidates for repeat lumpectomy with repeat high-dose partial breast RT. Goal was to determine whether excision of an in-breast tumor recurrence (IBTR) plus 5000 cGy in 25 fractions to the new operative area is both tolerated and effective as treatment for an IBTR after previous lumpectomy and whole breast irradiation

Discussion

Overall, the cosmetic result was good in most patients. It is likely that a breast in which 2 lumpectomies are performed will have subsequent distortion of the breast contour, especially if the lumpectomies are in the inferior portion of the breast. Also, after 2 lumpectomies, the breast is likely to be smaller than the opposite breast. Thus, the main outcome in terms of cosmesis in this series was the result of the surgery for the initial cancer and the IBTR. As noted above, 3 patients had even undergone 2 prior lumpectomies before developing an IBTR that was treated with a repeat course of RT. No rib fractures, pulmonary problems, or second malignancies attributable to the repeat course of RT occurred. Some patients did develop fibrosis in the re-irradiated area, and some, telangiectasia. Thus, even though portions of the breast received at least 10,000 cGy, RT was well tolerated, and only 1 patient did not complete the repeat course of RT (for nonmedical reasons).

Fisher reported that an IBTR, especially within a few years of lumpectomy, is indicative of a poor prognosis, with this group of patients having a 3-fold higher likelihood of developing distant metastases. Several other authors have reported a poorer prognosis after IBTR that develops sooner, rather than later, after conservative breast therapy However, other reports showed no relationship between the interval to IBTR and subsequent survival In the present series, to date, all distant metastases after IBTR appeared by 38 months. Seventeen women, including 3 with a second IBTR and 1 with recurrence in the axilla, were followed for >5 years after completion of the repeat course of RT without developing distant metastases. Eliminating the 2 patients with suspicious bone scans at IBTR, 6 additional patients developed distant metastases after repeat RT for IBTR. The interval to the IBTR after the first course of RT varied from 18 to 103 months, with 3 each having intervals <60 and >60 months. Similarly, for the 8 patients who developed a second IBTR after repeat RT, the intervals to the first IBTR ranged from 18 to 189 months, with 4 each having intervals <60 and >60 months. Thus, in the present series, the interval from breast RT to the first IBTR did not seem to have an impact on the outcome after IBTR, although the number of patients was small.

Because the number of women in this series with initially involved axillary nodes was small, it is difficult to determine whether an association between nodal involvement and a subsequent second IBTR after reirradiation exists. However, initial nodal involvement seemed to be associated with an increased risk of subsequent distant metastases (3 of 5 vs. 3 of 32).

Local recurrence on the chest wall after mastectomy has a worse outcome than an IBTR after breast conservation therapy. Previous reports from this institution reported a 5-year overall survival rate of about 46–49% after RT for postmastectomy chest wall recurrence, similar to reports from other institutions The 5-year survival rate after mastectomy for IBTR ranges from 55% to 86% . The 5-year overall and disease-free survival rates after repeat RT in the present series (77.9% and 68.5%, respectively) compare favorably with the results of mastectomy for IBTR.

Other than mastectomy, several approaches for the treatment of an IBTR have been tried in small numbers of patients. Kurtz reported on 50 patients treated with repeat wide local excision for IBTR. Seven patients also received 2000–3000 cGy with electrons and 4 received 5000 cGy using interstitial implants. However, 4 of the 11 patients who received RT developed a second IBTR similar to the rate of subsequent recurrence in patients treated by wide excision alone.

The occurrence of a second IBTR involving a different site in the breast after reirradiation in 5 of 8 patients indicates a likely geographic miss with the use of partial breast RT. However, 30 patients (76.9%) had an intact breast free of recurrence at last follow-up or at death after reirradiation. Fowble  in an analysis of mastectomy specimens in 31 patients in whom the diagnosis of IBTR was obtained by an excisional biopsy, found no residual tumor in 13 and residual tumor involving one quadrant in 9 additional patients. However, 9 patients (29%) had residual tumor involving two or more quadrants. I am concerned that a repeat course of high-dose RT to the entire breast would lead to a poor cosmetic result in most patients. Thus, reirradiation of the operative quadrant seems to be a reasonable compromise.

Three of 8 patients with a subsequent IBTR were still free of disease 29–130 months after reirradiation, and another was alive and well after mastectomy for a second IBTR and additional surgery and RT for recurrence on the chest wall. Four other women with a second IBTR developed concomitant distant metastases within 4 months of retreatment and thus would likely not have survived disease free had their first IBTR been treated with mastectomy. Thus, although mastectomy for the first IBTR after conservative therapy may have prevented some of the subsequent local recurrences, it is unlikely that mastectomy would have improved the overall survival in this series.

The small number of patients and patient preferences would probably preclude a prospective randomized clinical trial evaluating different local treatments (mastectomy vs. breast conservation) for an IBTR. Similarly, it would probably be difficult to do a clinical trial evaluating various systemic therapies for an IBTR in the absence of distant metastases. However, there are reports indicating a benefit for hormonal therapy in addition to RT to treat locoregional recurrence after mastectomy. In the present series, the use of systemic therapy for IBTR depended on the previous history of adjuvant therapy plus physician and patient preferences.

A repeat course of high-dose RT to the operative quadrant after excision of an IBTR appears to be a reasonable treatment for at least some women who wish to avoid mastectomy. Obviously, longer follow-up with more patients is necessary to confirm the suitability of repeat high-dose RT as treatment for an IBTR and to determine the optimal patients for such treatment.